WebSVN - shark - Rev 57 - /shark/trunk/ports/mesa/src/swrast/s

/* $Id: s_texture.c,v 1.1 2003-02-28 11:49:43 pj Exp $ */

/*
* Mesa 3-D graphics library
* Version: 5.0
*
* Copyright (C) 1999-2002 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#include "glheader.h"
#include "context.h"
#include "colormac.h"
#include "macros.h"
#include "mmath.h"
#include "imports.h"
#include "texformat.h"
#include "teximage.h"

#include "s_context.h"
#include "s_texture.h"

/*
* These values are used in the fixed-point arithmetic used
* for linear filtering.
*/
#define WEIGHT_SCALE 65536.0F
#define WEIGHT_SHIFT 16

/*
* Used to compute texel locations for linear sampling.
* Input:
* wrapMode = GL_REPEAT, GL_CLAMP, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_BORDER_ARB
* S = texcoord in [0,1]
* SIZE = width (or height or depth) of texture
* Output:
* U = texcoord in [0, width]
* I0, I1 = two nearest texel indexes
*/
#define COMPUTE_LINEAR_TEXEL_LOCATIONS(wrapMode, S, U, SIZE, I0, I1) \
{ \
if (wrapMode == GL_REPEAT) { \
U = S * SIZE - 0.5F; \
I0 = IFLOOR(U) & (SIZE - 1); \
I1 = (I0 + 1) & (SIZE - 1); \
} \
else if (wrapMode == GL_CLAMP_TO_EDGE) { \
if (S <= 0.0F) \
U = 0.0F; \
else if (S >= 1.0F) \
U = (GLfloat) SIZE; \
else \
U = S * SIZE; \
U -= 0.5F; \
I0 = IFLOOR(U); \
I1 = I0 + 1; \
if (I0 < 0) \
I0 = 0; \
if (I1 >= (GLint) SIZE) \
I1 = SIZE - 1; \
} \
else if (wrapMode == GL_CLAMP_TO_BORDER_ARB) { \
const GLfloat min = -1.0F / (2.0F * SIZE); \
const GLfloat max = 1.0F - min; \
if (S <= min) \
U = min * SIZE; \
else if (S >= max) \
U = max * SIZE; \
else \
U = S * SIZE; \
U -= 0.5F; \
I0 = IFLOOR(U); \
I1 = I0 + 1; \
} \
else if (wrapMode == GL_MIRRORED_REPEAT_ARB) { \
const GLint flr = IFLOOR(S); \
if (flr & 1) \
U = 1.0F - (S - (GLfloat) flr); /* flr is odd */ \
else \
U = S - (GLfloat) flr; /* flr is even */ \
U = (U * SIZE) - 0.5F; \
I0 = IFLOOR(U); \
I1 = I0 + 1; \
if (I0 < 0) \
I0 = 0; \
if (I1 >= (GLint) SIZE) \
I1 = SIZE - 1; \
} \
else if (wrapMode == GL_MIRROR_CLAMP_ATI) { \
U = (GLfloat) fabs(S); \
if (U >= 1.0F) \
U = (GLfloat) SIZE; \
else \
U *= SIZE; \
U -= 0.5F; \
I0 = IFLOOR(U); \
I1 = I0 + 1; \
} \
else if (wrapMode == GL_MIRROR_CLAMP_TO_EDGE_ATI) { \
U = (GLfloat) fabs(S); \
if (U >= 1.0F) \
U = (GLfloat) SIZE; \
else \
U *= SIZE; \
U -= 0.5F; \
I0 = IFLOOR(U); \
I1 = I0 + 1; \
if (I0 < 0) \
I0 = 0; \
if (I1 >= (GLint) SIZE) \
I1 = SIZE - 1; \
} \
else { \
ASSERT(wrapMode == GL_CLAMP); \
if (S <= 0.0F) \
U = 0.0F; \
else if (S >= 1.0F) \
U = (GLfloat) SIZE; \
else \
U = S * SIZE; \
U -= 0.5F; \
I0 = IFLOOR(U); \
I1 = I0 + 1; \
} \
}

/*
* Used to compute texel location for nearest sampling.
*/
#define COMPUTE_NEAREST_TEXEL_LOCATION(wrapMode, S, SIZE, I) \
{ \
if (wrapMode == GL_REPEAT) { \
/* s limited to [0,1) */ \
/* i limited to [0,size-1] */ \
I = IFLOOR(S * SIZE); \
I &= (SIZE - 1); \
} \
else if (wrapMode == GL_CLAMP_TO_EDGE) { \
/* s limited to [min,max] */ \
/* i limited to [0, size-1] */ \
const GLfloat min = 1.0F / (2.0F * SIZE); \
const GLfloat max = 1.0F - min; \
if (S < min) \
I = 0; \
else if (S > max) \
I = SIZE - 1; \
else \
I = IFLOOR(S * SIZE); \
} \
else if (wrapMode == GL_CLAMP_TO_BORDER_ARB) { \
/* s limited to [min,max] */ \
/* i limited to [-1, size] */ \
const GLfloat min = -1.0F / (2.0F * SIZE); \
const GLfloat max = 1.0F - min; \
if (S <= min) \
I = -1; \
else if (S >= max) \
I = SIZE; \
else \
I = IFLOOR(S * SIZE); \
} \
else if (wrapMode == GL_MIRRORED_REPEAT_ARB) { \
const GLfloat min = 1.0F / (2.0F * SIZE); \
const GLfloat max = 1.0F - min; \
const GLint flr = IFLOOR(S); \
GLfloat u; \
if (flr & 1) \
u = 1.0F - (S - (GLfloat) flr); /* flr is odd */ \
else \
u = S - (GLfloat) flr; /* flr is even */ \
if (u < min) \
I = 0; \
else if (u > max) \
I = SIZE - 1; \
else \
I = IFLOOR(u * SIZE); \
} \
else if (wrapMode == GL_MIRROR_CLAMP_ATI) { \
/* s limited to [0,1] */ \
/* i limited to [0,size-1] */ \
const GLfloat u = (GLfloat) fabs(S); \
if (u <= 0.0F) \
I = 0; \
else if (u >= 1.0F) \
I = SIZE - 1; \
else \
I = IFLOOR(u * SIZE); \
} \
else if (wrapMode == GL_MIRROR_CLAMP_TO_EDGE_ATI) { \
/* s limited to [min,max] */ \
/* i limited to [0, size-1] */ \
const GLfloat min = 1.0F / (2.0F * SIZE); \
const GLfloat max = 1.0F - min; \
const GLfloat u = (GLfloat) fabs(S); \
if (u < min) \
I = 0; \
else if (u > max) \
I = SIZE - 1; \
else \
I = IFLOOR(u * SIZE); \
} \
else { \
ASSERT(wrapMode == GL_CLAMP); \
/* s limited to [0,1] */ \
/* i limited to [0,size-1] */ \
if (S <= 0.0F) \
I = 0; \
else if (S >= 1.0F) \
I = SIZE - 1; \
else \
I = IFLOOR(S * SIZE); \
} \
}

#define COMPUTE_LINEAR_REPEAT_TEXEL_LOCATION(S, U, SIZE, I0, I1) \
{ \
U = S * SIZE - 0.5F; \
I0 = IFLOOR(U) & (SIZE - 1); \
I1 = (I0 + 1) & (SIZE - 1); \
}

/*
* Compute linear mipmap levels for given lambda.
*/
#define COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda, level) \
{ \
if (lambda < 0.0F) \
level = tObj->BaseLevel; \
else if (lambda > tObj->_MaxLambda) \
level = (GLint) (tObj->BaseLevel + tObj->_MaxLambda); \
else \
level = (GLint) (tObj->BaseLevel + lambda); \
}

/*
* Compute nearest mipmap level for given lambda.
*/
#define COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda, level) \
{ \
GLfloat l; \
if (lambda <= 0.5F) \
l = 0.0F; \
else if (lambda > tObj->_MaxLambda + 0.4999F) \
l = tObj->_MaxLambda + 0.4999F; \
else \
l = lambda; \
level = (GLint) (tObj->BaseLevel + l + 0.5F); \
if (level > tObj->_MaxLevel) \
level = tObj->_MaxLevel; \
}

/*
* Note, the FRAC macro has to work perfectly. Otherwise you'll sometimes
* see 1-pixel bands of improperly weighted linear-sampled texels. The
* tests/texwrap.c demo is a good test.
* Also note, FRAC(x) doesn't truly return the fractional part of x for x < 0.
* Instead, if x < 0 then FRAC(x) = 1 - true_frac(x).
*/
#define FRAC(f) ((f) - IFLOOR(f))

/*
* Bitflags for texture border color sampling.
*/
#define I0BIT 1
#define I1BIT 2
#define J0BIT 4
#define J1BIT 8
#define K0BIT 16
#define K1BIT 32

/*
* Get texture palette entry.
*/
static void
palette_sample(const GLcontext *ctx,
const struct gl_texture_object *tObj,
GLint index, GLchan rgba[4] )
{
const GLchan *palette;
GLenum format;

if (ctx->Texture.SharedPalette) {
ASSERT(!ctx->Texture.Palette.FloatTable);
palette = (const GLchan *) ctx->Texture.Palette.Table;
format = ctx->Texture.Palette.Format;
}
else {
ASSERT(!tObj->Palette.FloatTable);
palette = (const GLchan *) tObj->Palette.Table;
format = tObj->Palette.Format;
}

switch (format) {
case GL_ALPHA:
rgba[ACOMP] = palette[index];
return;
case GL_LUMINANCE:
case GL_INTENSITY:
rgba[RCOMP] = palette[index];
return;
case GL_LUMINANCE_ALPHA:
rgba[RCOMP] = palette[(index << 1) + 0];
rgba[ACOMP] = palette[(index << 1) + 1];
return;
case GL_RGB:
rgba[RCOMP] = palette[index * 3 + 0];
rgba[GCOMP] = palette[index * 3 + 1];
rgba[BCOMP] = palette[index * 3 + 2];
return;
case GL_RGBA:
rgba[RCOMP] = palette[(index << 2) + 0];
rgba[GCOMP] = palette[(index << 2) + 1];
rgba[BCOMP] = palette[(index << 2) + 2];
rgba[ACOMP] = palette[(index << 2) + 3];
return;
default:
_mesa_problem(ctx, "Bad palette format in palette_sample");
}
}

/*
* The lambda[] array values are always monotonic. Either the whole span
* will be minified, magnified, or split between the two. This function
* determines the subranges in [0, n-1] that are to be minified or magnified.
*/
static INLINE void
compute_min_mag_ranges( GLfloat minMagThresh, GLuint n, const GLfloat lambda[],
GLuint *minStart, GLuint *minEnd,
GLuint *magStart, GLuint *magEnd )
{
ASSERT(lambda != NULL);
#if 0
/* Verify that lambda[] is monotonous.
* We can't really use this because the inaccuracy in the LOG2 function
* causes this test to fail, yet the resulting texturing is correct.
*/
if (n > 1) {
GLuint i;
printf("lambda delta = %g\n", lambda[0] - lambda[n-1]);
if (lambda[0] >= lambda[n-1]) { /* decreasing */
for (i = 0; i < n - 1; i++) {
ASSERT((GLint) (lambda[i] * 10) >= (GLint) (lambda[i+1] * 10));
}
}
else { /* increasing */
for (i = 0; i < n - 1; i++) {
ASSERT((GLint) (lambda[i] * 10) <= (GLint) (lambda[i+1] * 10));
}
}
}
#endif /* DEBUG */

/* since lambda is monotonous-array use this check first */
if (lambda[0] <= minMagThresh && lambda[n-1] <= minMagThresh) {
/* magnification for whole span */
*magStart = 0;
*magEnd = n;
*minStart = *minEnd = 0;
}
else if (lambda[0] > minMagThresh && lambda[n-1] > minMagThresh) {
/* minification for whole span */
*minStart = 0;
*minEnd = n;
*magStart = *magEnd = 0;
}
else {
/* a mix of minification and magnification */
GLuint i;
if (lambda[0] > minMagThresh) {
/* start with minification */
for (i = 1; i < n; i++) {
if (lambda[i] <= minMagThresh)
break;
}
*minStart = 0;
*minEnd = i;
*magStart = i;
*magEnd = n;
}
else {
/* start with magnification */
for (i = 1; i < n; i++) {
if (lambda[i] > minMagThresh)
break;
}
*magStart = 0;
*magEnd = i;
*minStart = i;
*minEnd = n;
}
}

#if 0
/* Verify the min/mag Start/End values
* We don't use this either (see above)
*/
{
GLint i;
for (i = 0; i < n; i++) {
if (lambda[i] > minMagThresh) {
/* minification */
ASSERT(i >= *minStart);
ASSERT(i < *minEnd);
}
else {
/* magnification */
ASSERT(i >= *magStart);
ASSERT(i < *magEnd);
}
}
}
#endif
}

/**********************************************************************/
/* 1-D Texture Sampling Functions */
/**********************************************************************/

/*
* Return the texture sample for coordinate (s) using GL_NEAREST filter.
*/
static void
sample_1d_nearest(GLcontext *ctx,
const struct gl_texture_object *tObj,
const struct gl_texture_image *img,
const GLfloat texcoord[4], GLchan rgba[4])
{
const GLint width = img->Width2; /* without border, power of two */
GLint i;

COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapS, texcoord[0], width, i);

/* skip over the border, if any */
i += img->Border;

if (i < 0 || i >= (GLint) img->Width) {
/* Need this test for GL_CLAMP_TO_BORDER_ARB mode */
COPY_CHAN4(rgba, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i, 0, 0, (GLvoid *) rgba);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, rgba[0], rgba);
}
}
}

/*
* Return the texture sample for coordinate (s) using GL_LINEAR filter.
*/
static void
sample_1d_linear(GLcontext *ctx,
const struct gl_texture_object *tObj,
const struct gl_texture_image *img,
const GLfloat texcoord[4], GLchan rgba[4])
{
const GLint width = img->Width2;
GLint i0, i1;
GLfloat u;
GLuint useBorderColor;

COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapS, texcoord[0], u, width, i0, i1);

useBorderColor = 0;
if (img->Border) {
i0 += img->Border;
i1 += img->Border;
}
else {
if (i0 < 0 || i0 >= width) useBorderColor |= I0BIT;
if (i1 < 0 || i1 >= width) useBorderColor |= I1BIT;
}

{
const GLfloat a = FRAC(u);

#if CHAN_TYPE == GL_FLOAT || CHAN_TYPE == GL_UNSIGNED_SHORT
const GLfloat w0 = (1.0F-a);
const GLfloat w1 = a ;
#else /* CHAN_BITS == 8 */
/* compute sample weights in fixed point in [0,WEIGHT_SCALE] */
const GLint w0 = IROUND_POS((1.0F - a) * WEIGHT_SCALE);
const GLint w1 = IROUND_POS( a * WEIGHT_SCALE);
#endif
GLchan t0[4], t1[4]; /* texels */

if (useBorderColor & I0BIT) {
COPY_CHAN4(t0, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i0, 0, 0, (GLvoid *) t0);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t0[0], t0);
}
}
if (useBorderColor & I1BIT) {
COPY_CHAN4(t1, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i1, 0, 0, (GLvoid *) t1);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t1[0], t1);
}
}

#if CHAN_TYPE == GL_FLOAT
rgba[0] = w0 * t0[0] + w1 * t1[0];
rgba[1] = w0 * t0[1] + w1 * t1[1];
rgba[2] = w0 * t0[2] + w1 * t1[2];
rgba[3] = w0 * t0[3] + w1 * t1[3];
#elif CHAN_TYPE == GL_UNSIGNED_SHORT
rgba[0] = (GLchan) (w0 * t0[0] + w1 * t1[0] + 0.5);
rgba[1] = (GLchan) (w0 * t0[1] + w1 * t1[1] + 0.5);
rgba[2] = (GLchan) (w0 * t0[2] + w1 * t1[2] + 0.5);
rgba[3] = (GLchan) (w0 * t0[3] + w1 * t1[3] + 0.5);
#else /* CHAN_BITS == 8 */
rgba[0] = (GLchan) ((w0 * t0[0] + w1 * t1[0]) >> WEIGHT_SHIFT);
rgba[1] = (GLchan) ((w0 * t0[1] + w1 * t1[1]) >> WEIGHT_SHIFT);
rgba[2] = (GLchan) ((w0 * t0[2] + w1 * t1[2]) >> WEIGHT_SHIFT);
rgba[3] = (GLchan) ((w0 * t0[3] + w1 * t1[3]) >> WEIGHT_SHIFT);
#endif

}
}

static void
sample_1d_nearest_mipmap_nearest(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
GLint level;
COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
sample_1d_nearest(ctx, tObj, tObj->Image[level], texcoord[i], rgba[i]);
}
}

static void
sample_1d_linear_mipmap_nearest(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
GLint level;
COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
sample_1d_linear(ctx, tObj, tObj->Image[level], texcoord[i], rgba[i]);
}
}

/*
* This is really just needed in order to prevent warnings with some compilers.
*/
#if CHAN_TYPE == GL_FLOAT
#define CHAN_CAST
#else
#define CHAN_CAST (GLchan) (GLint)
#endif

static void
sample_1d_nearest_mipmap_linear(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
GLint level;
COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
if (level >= tObj->_MaxLevel) {
sample_1d_nearest(ctx, tObj, tObj->Image[tObj->_MaxLevel],
texcoord[i], rgba[i]);
}
else {
GLchan t0[4], t1[4];
const GLfloat f = FRAC(lambda[i]);
sample_1d_nearest(ctx, tObj, tObj->Image[level ], texcoord[i], t0);
sample_1d_nearest(ctx, tObj, tObj->Image[level+1], texcoord[i], t1);
rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
}
}
}

static void
sample_1d_linear_mipmap_linear(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
GLint level;
COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
if (level >= tObj->_MaxLevel) {
sample_1d_linear(ctx, tObj, tObj->Image[tObj->_MaxLevel],
texcoord[i], rgba[i]);
}
else {
GLchan t0[4], t1[4];
const GLfloat f = FRAC(lambda[i]);
sample_1d_linear(ctx, tObj, tObj->Image[level ], texcoord[i], t0);
sample_1d_linear(ctx, tObj, tObj->Image[level+1], texcoord[i], t1);
rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
}
}
}

static void
sample_nearest_1d( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4], const GLfloat lambda[],
GLchan rgba[][4] )
{
GLuint i;
struct gl_texture_image *image = tObj->Image[tObj->BaseLevel];
(void) lambda;
for (i=0;i<n;i++) {
sample_1d_nearest(ctx, tObj, image, texcoords[i], rgba[i]);
}
}

static void
sample_linear_1d( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4], const GLfloat lambda[],
GLchan rgba[][4] )
{
GLuint i;
struct gl_texture_image *image = tObj->Image[tObj->BaseLevel];
(void) lambda;
for (i=0;i<n;i++) {
sample_1d_linear(ctx, tObj, image, texcoords[i], rgba[i]);
}
}

/*
* Given an (s) texture coordinate and lambda (level of detail) value,
* return a texture sample.
*
*/
static void
sample_lambda_1d( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4],
const GLfloat lambda[], GLchan rgba[][4] )
{
GLuint minStart, minEnd; /* texels with minification */
GLuint magStart, magEnd; /* texels with magnification */
GLuint i;

ASSERT(lambda != NULL);
compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
n, lambda, &minStart, &minEnd, &magStart, &magEnd);

if (minStart < minEnd) {
/* do the minified texels */
const GLuint m = minEnd - minStart;
switch (tObj->MinFilter) {
case GL_NEAREST:
for (i = minStart; i < minEnd; i++)
sample_1d_nearest(ctx, tObj, tObj->Image[tObj->BaseLevel],
texcoords[i], rgba[i]);
break;
case GL_LINEAR:
for (i = minStart; i < minEnd; i++)
sample_1d_linear(ctx, tObj, tObj->Image[tObj->BaseLevel],
texcoords[i], rgba[i]);
break;
case GL_NEAREST_MIPMAP_NEAREST:
sample_1d_nearest_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_LINEAR_MIPMAP_NEAREST:
sample_1d_linear_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_NEAREST_MIPMAP_LINEAR:
sample_1d_nearest_mipmap_linear(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_LINEAR_MIPMAP_LINEAR:
sample_1d_linear_mipmap_linear(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
default:
_mesa_problem(ctx, "Bad min filter in sample_1d_texture");
return;
}
}

if (magStart < magEnd) {
/* do the magnified texels */
switch (tObj->MagFilter) {
case GL_NEAREST:
for (i = magStart; i < magEnd; i++)
sample_1d_nearest(ctx, tObj, tObj->Image[tObj->BaseLevel],
texcoords[i], rgba[i]);
break;
case GL_LINEAR:
for (i = magStart; i < magEnd; i++)
sample_1d_linear(ctx, tObj, tObj->Image[tObj->BaseLevel],
texcoords[i], rgba[i]);
break;
default:
_mesa_problem(ctx, "Bad mag filter in sample_1d_texture");
return;
}
}
}

/**********************************************************************/
/* 2-D Texture Sampling Functions */
/**********************************************************************/

/*
* Return the texture sample for coordinate (s,t) using GL_NEAREST filter.
*/
static INLINE void
sample_2d_nearest(GLcontext *ctx,
const struct gl_texture_object *tObj,
const struct gl_texture_image *img,
const GLfloat texcoord[4],
GLchan rgba[])
{
const GLint width = img->Width2; /* without border, power of two */
const GLint height = img->Height2; /* without border, power of two */
GLint i, j;

COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapS, texcoord[0], width, i);
COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapT, texcoord[1], height, j);

/* skip over the border, if any */
i += img->Border;
j += img->Border;

if (i < 0 || i >= (GLint) img->Width || j < 0 || j >= (GLint) img->Height) {
/* Need this test for GL_CLAMP_TO_BORDER_ARB mode */
COPY_CHAN4(rgba, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i, j, 0, (GLvoid *) rgba);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, rgba[0], rgba);
}
}
}

/*
* Return the texture sample for coordinate (s,t) using GL_LINEAR filter.
* New sampling code contributed by Lynn Quam <quam@ai.sri.com>.
*/
static INLINE void
sample_2d_linear(GLcontext *ctx,
const struct gl_texture_object *tObj,
const struct gl_texture_image *img,
const GLfloat texcoord[4],
GLchan rgba[])
{
const GLint width = img->Width2;
const GLint height = img->Height2;
GLint i0, j0, i1, j1;
GLuint useBorderColor;
GLfloat u, v;

COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapS, texcoord[0], u, width, i0, i1);
COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapT, texcoord[1], v, height, j0, j1);

useBorderColor = 0;
if (img->Border) {
i0 += img->Border;
i1 += img->Border;
j0 += img->Border;
j1 += img->Border;
}
else {
if (i0 < 0 || i0 >= width) useBorderColor |= I0BIT;
if (i1 < 0 || i1 >= width) useBorderColor |= I1BIT;
if (j0 < 0 || j0 >= height) useBorderColor |= J0BIT;
if (j1 < 0 || j1 >= height) useBorderColor |= J1BIT;
}

{
const GLfloat a = FRAC(u);
const GLfloat b = FRAC(v);

#if CHAN_TYPE == GL_FLOAT || CHAN_TYPE == GL_UNSIGNED_SHORT
const GLfloat w00 = (1.0F-a) * (1.0F-b);
const GLfloat w10 = a * (1.0F-b);
const GLfloat w01 = (1.0F-a) * b ;
const GLfloat w11 = a * b ;
#else /* CHAN_BITS == 8 */
/* compute sample weights in fixed point in [0,WEIGHT_SCALE] */
const GLint w00 = IROUND_POS((1.0F-a) * (1.0F-b) * WEIGHT_SCALE);
const GLint w10 = IROUND_POS( a * (1.0F-b) * WEIGHT_SCALE);
const GLint w01 = IROUND_POS((1.0F-a) * b * WEIGHT_SCALE);
const GLint w11 = IROUND_POS( a * b * WEIGHT_SCALE);
#endif
GLchan t00[4];
GLchan t10[4];
GLchan t01[4];
GLchan t11[4];

if (useBorderColor & (I0BIT | J0BIT)) {
COPY_CHAN4(t00, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i0, j0, 0, (GLvoid *) t00);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t00[0], t00);
}
}
if (useBorderColor & (I1BIT | J0BIT)) {
COPY_CHAN4(t10, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i1, j0, 0, (GLvoid *) t10);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t10[0], t10);
}
}
if (useBorderColor & (I0BIT | J1BIT)) {
COPY_CHAN4(t01, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i0, j1, 0, (GLvoid *) t01);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t01[0], t01);
}
}
if (useBorderColor & (I1BIT | J1BIT)) {
COPY_CHAN4(t11, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i1, j1, 0, (GLvoid *) t11);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t11[0], t11);
}
}
#if CHAN_TYPE == GL_FLOAT
rgba[0] = w00 * t00[0] + w10 * t10[0] + w01 * t01[0] + w11 * t11[0];
rgba[1] = w00 * t00[1] + w10 * t10[1] + w01 * t01[1] + w11 * t11[1];
rgba[2] = w00 * t00[2] + w10 * t10[2] + w01 * t01[2] + w11 * t11[2];
rgba[3] = w00 * t00[3] + w10 * t10[3] + w01 * t01[3] + w11 * t11[3];
#elif CHAN_TYPE == GL_UNSIGNED_SHORT
rgba[0] = (GLchan) (w00 * t00[0] + w10 * t10[0] +
w01 * t01[0] + w11 * t11[0] + 0.5);
rgba[1] = (GLchan) (w00 * t00[1] + w10 * t10[1] +
w01 * t01[1] + w11 * t11[1] + 0.5);
rgba[2] = (GLchan) (w00 * t00[2] + w10 * t10[2] +
w01 * t01[2] + w11 * t11[2] + 0.5);
rgba[3] = (GLchan) (w00 * t00[3] + w10 * t10[3] +
w01 * t01[3] + w11 * t11[3] + 0.5);
#else /* CHAN_BITS == 8 */
rgba[0] = (GLchan) ((w00 * t00[0] + w10 * t10[0] +
w01 * t01[0] + w11 * t11[0]) >> WEIGHT_SHIFT);
rgba[1] = (GLchan) ((w00 * t00[1] + w10 * t10[1] +
w01 * t01[1] + w11 * t11[1]) >> WEIGHT_SHIFT);
rgba[2] = (GLchan) ((w00 * t00[2] + w10 * t10[2] +
w01 * t01[2] + w11 * t11[2]) >> WEIGHT_SHIFT);
rgba[3] = (GLchan) ((w00 * t00[3] + w10 * t10[3] +
w01 * t01[3] + w11 * t11[3]) >> WEIGHT_SHIFT);
#endif

}

}

/*
* As above, but we know WRAP_S == REPEAT and WRAP_T == REPEAT
* and we're not using a paletted texture.
*/
static INLINE void
sample_2d_linear_repeat(GLcontext *ctx,
const struct gl_texture_object *tObj,
const struct gl_texture_image *img,
const GLfloat texcoord[4],
GLchan rgba[])
{
const GLint width = img->Width2;
const GLint height = img->Height2;
GLint i0, j0, i1, j1;
GLfloat u, v;

ASSERT(tObj->WrapS == GL_REPEAT);
ASSERT(tObj->WrapT == GL_REPEAT);
ASSERT(img->Border == 0);
ASSERT(img->Format != GL_COLOR_INDEX);

COMPUTE_LINEAR_REPEAT_TEXEL_LOCATION(texcoord[0], u, width, i0, i1);
COMPUTE_LINEAR_REPEAT_TEXEL_LOCATION(texcoord[1], v, height, j0, j1);

{
const GLfloat a = FRAC(u);
const GLfloat b = FRAC(v);

#if CHAN_TYPE == GL_FLOAT || CHAN_TYPE == GL_UNSIGNED_SHORT
const GLfloat w00 = (1.0F-a) * (1.0F-b);
const GLfloat w10 = a * (1.0F-b);
const GLfloat w01 = (1.0F-a) * b ;
const GLfloat w11 = a * b ;
#else /* CHAN_BITS == 8 */
/* compute sample weights in fixed point in [0,WEIGHT_SCALE] */
const GLint w00 = IROUND_POS((1.0F-a) * (1.0F-b) * WEIGHT_SCALE);
const GLint w10 = IROUND_POS( a * (1.0F-b) * WEIGHT_SCALE);
const GLint w01 = IROUND_POS((1.0F-a) * b * WEIGHT_SCALE);
const GLint w11 = IROUND_POS( a * b * WEIGHT_SCALE);
#endif
GLchan t00[4];
GLchan t10[4];
GLchan t01[4];
GLchan t11[4];

(*img->FetchTexel)(img, i0, j0, 0, (GLvoid *) t00);
(*img->FetchTexel)(img, i1, j0, 0, (GLvoid *) t10);
(*img->FetchTexel)(img, i0, j1, 0, (GLvoid *) t01);
(*img->FetchTexel)(img, i1, j1, 0, (GLvoid *) t11);

#if CHAN_TYPE == GL_FLOAT
rgba[0] = w00 * t00[0] + w10 * t10[0] + w01 * t01[0] + w11 * t11[0];
rgba[1] = w00 * t00[1] + w10 * t10[1] + w01 * t01[1] + w11 * t11[1];
rgba[2] = w00 * t00[2] + w10 * t10[2] + w01 * t01[2] + w11 * t11[2];
rgba[3] = w00 * t00[3] + w10 * t10[3] + w01 * t01[3] + w11 * t11[3];
#elif CHAN_TYPE == GL_UNSIGNED_SHORT
rgba[0] = (GLchan) (w00 * t00[0] + w10 * t10[0] +
w01 * t01[0] + w11 * t11[0] + 0.5);
rgba[1] = (GLchan) (w00 * t00[1] + w10 * t10[1] +
w01 * t01[1] + w11 * t11[1] + 0.5);
rgba[2] = (GLchan) (w00 * t00[2] + w10 * t10[2] +
w01 * t01[2] + w11 * t11[2] + 0.5);
rgba[3] = (GLchan) (w00 * t00[3] + w10 * t10[3] +
w01 * t01[3] + w11 * t11[3] + 0.5);
#else /* CHAN_BITS == 8 */
rgba[0] = (GLchan) ((w00 * t00[0] + w10 * t10[0] +
w01 * t01[0] + w11 * t11[0]) >> WEIGHT_SHIFT);
rgba[1] = (GLchan) ((w00 * t00[1] + w10 * t10[1] +
w01 * t01[1] + w11 * t11[1]) >> WEIGHT_SHIFT);
rgba[2] = (GLchan) ((w00 * t00[2] + w10 * t10[2] +
w01 * t01[2] + w11 * t11[2]) >> WEIGHT_SHIFT);
rgba[3] = (GLchan) ((w00 * t00[3] + w10 * t10[3] +
w01 * t01[3] + w11 * t11[3]) >> WEIGHT_SHIFT);
#endif

}

}

static void
sample_2d_nearest_mipmap_nearest(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
for (i = 0; i < n; i++) {
GLint level;
COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
sample_2d_nearest(ctx, tObj, tObj->Image[level], texcoord[i], rgba[i]);
}
}

static void
sample_2d_linear_mipmap_nearest(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
GLint level;
COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
sample_2d_linear(ctx, tObj, tObj->Image[level], texcoord[i], rgba[i]);
}
}

static void
sample_2d_nearest_mipmap_linear(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
GLint level;
COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
if (level >= tObj->_MaxLevel) {
sample_2d_nearest(ctx, tObj, tObj->Image[tObj->_MaxLevel],
texcoord[i], rgba[i]);
}
else {
GLchan t0[4], t1[4]; /* texels */
const GLfloat f = FRAC(lambda[i]);
sample_2d_nearest(ctx, tObj, tObj->Image[level ], texcoord[i], t0);
sample_2d_nearest(ctx, tObj, tObj->Image[level+1], texcoord[i], t1);
rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
}
}
}

/* Trilinear filtering */
static void
sample_2d_linear_mipmap_linear( GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4] )
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
GLint level;
COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
if (level >= tObj->_MaxLevel) {
sample_2d_linear(ctx, tObj, tObj->Image[tObj->_MaxLevel],
texcoord[i], rgba[i]);
}
else {
GLchan t0[4], t1[4]; /* texels */
const GLfloat f = FRAC(lambda[i]);
sample_2d_linear(ctx, tObj, tObj->Image[level ], texcoord[i], t0);
sample_2d_linear(ctx, tObj, tObj->Image[level+1], texcoord[i], t1);
rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
}
}
}

static void
sample_2d_linear_mipmap_linear_repeat( GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4] )
{
GLuint i;
ASSERT(lambda != NULL);
ASSERT(tObj->WrapS == GL_REPEAT);
ASSERT(tObj->WrapT == GL_REPEAT);
for (i = 0; i < n; i++) {
GLint level;
COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
if (level >= tObj->_MaxLevel) {
sample_2d_linear_repeat(ctx, tObj, tObj->Image[tObj->_MaxLevel],
texcoord[i], rgba[i]);
}
else {
GLchan t0[4], t1[4]; /* texels */
const GLfloat f = FRAC(lambda[i]);
sample_2d_linear_repeat(ctx, tObj, tObj->Image[level ], texcoord[i], t0);
sample_2d_linear_repeat(ctx, tObj, tObj->Image[level+1], texcoord[i], t1);
rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
}
}
}

static void
sample_nearest_2d( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4],
const GLfloat lambda[], GLchan rgba[][4] )
{
GLuint i;
struct gl_texture_image *image = tObj->Image[tObj->BaseLevel];
(void) lambda;
for (i=0;i<n;i++) {
sample_2d_nearest(ctx, tObj, image, texcoords[i], rgba[i]);
}
}

static void
sample_linear_2d( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4],
const GLfloat lambda[], GLchan rgba[][4] )
{
GLuint i;
struct gl_texture_image *image = tObj->Image[tObj->BaseLevel];
(void) lambda;
for (i=0;i<n;i++) {
sample_2d_linear(ctx, tObj, image, texcoords[i], rgba[i]);
}
}

/*
* Optimized 2-D texture sampling:
* S and T wrap mode == GL_REPEAT
* GL_NEAREST min/mag filter
* No border,
* RowStride == Width,
* Format = GL_RGB
*/
static void
opt_sample_rgb_2d( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoords[][4],
const GLfloat lambda[], GLchan rgba[][4] )
{
const struct gl_texture_image *img = tObj->Image[tObj->BaseLevel];
const GLfloat width = (GLfloat) img->Width;
const GLfloat height = (GLfloat) img->Height;
const GLint colMask = img->Width - 1;
const GLint rowMask = img->Height - 1;
const GLint shift = img->WidthLog2;
GLuint k;
(void) lambda;
ASSERT(tObj->WrapS==GL_REPEAT);
ASSERT(tObj->WrapT==GL_REPEAT);
ASSERT(img->Border==0);
ASSERT(img->Format==GL_RGB);

for (k=0; k<n; k++) {
GLint i = IFLOOR(texcoords[k][0] * width) & colMask;
GLint j = IFLOOR(texcoords[k][1] * height) & rowMask;
GLint pos = (j << shift) | i;
GLchan *texel = ((GLchan *) img->Data) + 3*pos;
rgba[k][RCOMP] = texel[0];
rgba[k][GCOMP] = texel[1];
rgba[k][BCOMP] = texel[2];
}
}

/*
* Optimized 2-D texture sampling:
* S and T wrap mode == GL_REPEAT
* GL_NEAREST min/mag filter
* No border
* RowStride == Width,
* Format = GL_RGBA
*/
static void
opt_sample_rgba_2d( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoords[][4],
const GLfloat lambda[], GLchan rgba[][4] )
{
const struct gl_texture_image *img = tObj->Image[tObj->BaseLevel];
const GLfloat width = (GLfloat) img->Width;
const GLfloat height = (GLfloat) img->Height;
const GLint colMask = img->Width - 1;
const GLint rowMask = img->Height - 1;
const GLint shift = img->WidthLog2;
GLuint i;
(void) lambda;
ASSERT(tObj->WrapS==GL_REPEAT);
ASSERT(tObj->WrapT==GL_REPEAT);
ASSERT(img->Border==0);
ASSERT(img->Format==GL_RGBA);

for (i = 0; i < n; i++) {
const GLint col = IFLOOR(texcoords[i][0] * width) & colMask;
const GLint row = IFLOOR(texcoords[i][1] * height) & rowMask;
const GLint pos = (row << shift) | col;
const GLchan *texel = ((GLchan *) img->Data) + (pos << 2); /* pos*4 */
COPY_CHAN4(rgba[i], texel);
}
}

/*
* Given an array of texture coordinate and lambda (level of detail)
* values, return an array of texture sample.
*/
static void
sample_lambda_2d( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoords[][4],
const GLfloat lambda[], GLchan rgba[][4] )
{
const struct gl_texture_image *tImg = tObj->Image[tObj->BaseLevel];
GLuint minStart, minEnd; /* texels with minification */
GLuint magStart, magEnd; /* texels with magnification */

const GLboolean repeatNoBorder = (tObj->WrapS == GL_REPEAT)
&& (tObj->WrapT == GL_REPEAT)
&& (tImg->Border == 0 && (tImg->Width == tImg->RowStride))
&& (tImg->Format != GL_COLOR_INDEX);

ASSERT(lambda != NULL);
compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
n, lambda, &minStart, &minEnd, &magStart, &magEnd);

if (minStart < minEnd) {
/* do the minified texels */
const GLuint m = minEnd - minStart;
switch (tObj->MinFilter) {
case GL_NEAREST:
if (repeatNoBorder) {
switch (tImg->Format) {
case GL_RGB:
opt_sample_rgb_2d(ctx, texUnit, tObj, m, texcoords + minStart,
NULL, rgba + minStart);
break;
case GL_RGBA:
opt_sample_rgba_2d(ctx, texUnit, tObj, m, texcoords + minStart,
NULL, rgba + minStart);
break;
default:
sample_nearest_2d(ctx, texUnit, tObj, m, texcoords + minStart,
NULL, rgba + minStart );
}
}
else {
sample_nearest_2d(ctx, texUnit, tObj, m, texcoords + minStart,
NULL, rgba + minStart);
}
break;
case GL_LINEAR:
sample_linear_2d(ctx, texUnit, tObj, m, texcoords + minStart,
NULL, rgba + minStart);
break;
case GL_NEAREST_MIPMAP_NEAREST:
sample_2d_nearest_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_LINEAR_MIPMAP_NEAREST:
sample_2d_linear_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_NEAREST_MIPMAP_LINEAR:
sample_2d_nearest_mipmap_linear(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_LINEAR_MIPMAP_LINEAR:
if (repeatNoBorder)
sample_2d_linear_mipmap_linear_repeat(ctx, tObj, m,
texcoords + minStart, lambda + minStart, rgba + minStart);
else
sample_2d_linear_mipmap_linear(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
default:
_mesa_problem(ctx, "Bad min filter in sample_2d_texture");
return;
}
}

if (magStart < magEnd) {
/* do the magnified texels */
const GLuint m = magEnd - magStart;

switch (tObj->MagFilter) {
case GL_NEAREST:
if (repeatNoBorder) {
switch (tImg->Format) {
case GL_RGB:
opt_sample_rgb_2d(ctx, texUnit, tObj, m, texcoords + magStart,
NULL, rgba + magStart);
break;
case GL_RGBA:
opt_sample_rgba_2d(ctx, texUnit, tObj, m, texcoords + magStart,
NULL, rgba + magStart);
break;
default:
sample_nearest_2d(ctx, texUnit, tObj, m, texcoords + magStart,
NULL, rgba + magStart );
}
}
else {
sample_nearest_2d(ctx, texUnit, tObj, m, texcoords + magStart,
NULL, rgba + magStart);
}
break;
case GL_LINEAR:
sample_linear_2d(ctx, texUnit, tObj, m, texcoords + magStart,
NULL, rgba + magStart);
break;
default:
_mesa_problem(ctx, "Bad mag filter in sample_lambda_2d");
}
}
}

/**********************************************************************/
/* 3-D Texture Sampling Functions */
/**********************************************************************/

/*
* Return the texture sample for coordinate (s,t,r) using GL_NEAREST filter.
*/
static void
sample_3d_nearest(GLcontext *ctx,
const struct gl_texture_object *tObj,
const struct gl_texture_image *img,
const GLfloat texcoord[4],
GLchan rgba[4])
{
const GLint width = img->Width2; /* without border, power of two */
const GLint height = img->Height2; /* without border, power of two */
const GLint depth = img->Depth2; /* without border, power of two */
GLint i, j, k;

COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapS, texcoord[0], width, i);
COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapT, texcoord[1], height, j);
COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapR, texcoord[2], depth, k);

if (i < 0 || i >= (GLint) img->Width ||
j < 0 || j >= (GLint) img->Height ||
k < 0 || k >= (GLint) img->Depth) {
/* Need this test for GL_CLAMP_TO_BORDER_ARB mode */
COPY_CHAN4(rgba, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i, j, k, (GLvoid *) rgba);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, rgba[0], rgba);
}
}
}

/*
* Return the texture sample for coordinate (s,t,r) using GL_LINEAR filter.
*/
static void
sample_3d_linear(GLcontext *ctx,
const struct gl_texture_object *tObj,
const struct gl_texture_image *img,
const GLfloat texcoord[4],
GLchan rgba[4])
{
const GLint width = img->Width2;
const GLint height = img->Height2;
const GLint depth = img->Depth2;
GLint i0, j0, k0, i1, j1, k1;
GLuint useBorderColor;
GLfloat u, v, w;

COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapS, texcoord[0], u, width, i0, i1);
COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapT, texcoord[1], v, height, j0, j1);
COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapR, texcoord[2], w, depth, k0, k1);

useBorderColor = 0;
if (img->Border) {
i0 += img->Border;
i1 += img->Border;
j0 += img->Border;
j1 += img->Border;
k0 += img->Border;
k1 += img->Border;
}
else {
/* check if sampling texture border color */
if (i0 < 0 || i0 >= width) useBorderColor |= I0BIT;
if (i1 < 0 || i1 >= width) useBorderColor |= I1BIT;
if (j0 < 0 || j0 >= height) useBorderColor |= J0BIT;
if (j1 < 0 || j1 >= height) useBorderColor |= J1BIT;
if (k0 < 0 || k0 >= depth) useBorderColor |= K0BIT;
if (k1 < 0 || k1 >= depth) useBorderColor |= K1BIT;
}

{
const GLfloat a = FRAC(u);
const GLfloat b = FRAC(v);
const GLfloat c = FRAC(w);

#if CHAN_TYPE == GL_FLOAT || CHAN_TYPE == GL_UNSIGNED_SHORT
/* compute sample weights in fixed point in [0,WEIGHT_SCALE] */
GLfloat w000 = (1.0F-a) * (1.0F-b) * (1.0F-c);
GLfloat w100 = a * (1.0F-b) * (1.0F-c);
GLfloat w010 = (1.0F-a) * b * (1.0F-c);
GLfloat w110 = a * b * (1.0F-c);
GLfloat w001 = (1.0F-a) * (1.0F-b) * c ;
GLfloat w101 = a * (1.0F-b) * c ;
GLfloat w011 = (1.0F-a) * b * c ;
GLfloat w111 = a * b * c ;
#else /* CHAN_BITS == 8 */
/* compute sample weights in fixed point in [0,WEIGHT_SCALE] */
GLint w000 = IROUND_POS((1.0F-a) * (1.0F-b) * (1.0F-c) * WEIGHT_SCALE);
GLint w100 = IROUND_POS( a * (1.0F-b) * (1.0F-c) * WEIGHT_SCALE);
GLint w010 = IROUND_POS((1.0F-a) * b * (1.0F-c) * WEIGHT_SCALE);
GLint w110 = IROUND_POS( a * b * (1.0F-c) * WEIGHT_SCALE);
GLint w001 = IROUND_POS((1.0F-a) * (1.0F-b) * c * WEIGHT_SCALE);
GLint w101 = IROUND_POS( a * (1.0F-b) * c * WEIGHT_SCALE);
GLint w011 = IROUND_POS((1.0F-a) * b * c * WEIGHT_SCALE);
GLint w111 = IROUND_POS( a * b * c * WEIGHT_SCALE);
#endif

GLchan t000[4], t010[4], t001[4], t011[4];
GLchan t100[4], t110[4], t101[4], t111[4];

if (useBorderColor & (I0BIT | J0BIT | K0BIT)) {
COPY_CHAN4(t000, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i0, j0, k0, (GLvoid *) t000);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t000[0], t000);
}
}
if (useBorderColor & (I1BIT | J0BIT | K0BIT)) {
COPY_CHAN4(t100, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i1, j0, k0, (GLvoid *) t100);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t100[0], t100);
}
}
if (useBorderColor & (I0BIT | J1BIT | K0BIT)) {
COPY_CHAN4(t010, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i0, j1, k0, (GLvoid *) t010);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t010[0], t010);
}
}
if (useBorderColor & (I1BIT | J1BIT | K0BIT)) {
COPY_CHAN4(t110, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i1, j1, k0, (GLvoid *) t110);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t110[0], t110);
}
}

if (useBorderColor & (I0BIT | J0BIT | K1BIT)) {
COPY_CHAN4(t001, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i0, j0, k1, (GLvoid *) t001);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t001[0], t001);
}
}
if (useBorderColor & (I1BIT | J0BIT | K1BIT)) {
COPY_CHAN4(t101, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i1, j0, k1, (GLvoid *) t101);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t101[0], t101);
}
}
if (useBorderColor & (I0BIT | J1BIT | K1BIT)) {
COPY_CHAN4(t011, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i0, j1, k1, (GLvoid *) t011);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t011[0], t011);
}
}
if (useBorderColor & (I1BIT | J1BIT | K1BIT)) {
COPY_CHAN4(t111, tObj->_BorderChan);
}
else {
(*img->FetchTexel)(img, i1, j1, k1, (GLvoid *) t111);
if (img->Format == GL_COLOR_INDEX) {
palette_sample(ctx, tObj, t111[0], t111);
}
}

#if CHAN_TYPE == GL_FLOAT
rgba[0] = w000*t000[0] + w010*t010[0] + w001*t001[0] + w011*t011[0] +
w100*t100[0] + w110*t110[0] + w101*t101[0] + w111*t111[0];
rgba[1] = w000*t000[1] + w010*t010[1] + w001*t001[1] + w011*t011[1] +
w100*t100[1] + w110*t110[1] + w101*t101[1] + w111*t111[1];
rgba[2] = w000*t000[2] + w010*t010[2] + w001*t001[2] + w011*t011[2] +
w100*t100[2] + w110*t110[2] + w101*t101[2] + w111*t111[2];
rgba[3] = w000*t000[3] + w010*t010[3] + w001*t001[3] + w011*t011[3] +
w100*t100[3] + w110*t110[3] + w101*t101[3] + w111*t111[3];
#elif CHAN_TYPE == GL_UNSIGNED_SHORT
rgba[0] = (GLchan) (w000*t000[0] + w010*t010[0] +
w001*t001[0] + w011*t011[0] +
w100*t100[0] + w110*t110[0] +
w101*t101[0] + w111*t111[0] + 0.5);
rgba[1] = (GLchan) (w000*t000[1] + w010*t010[1] +
w001*t001[1] + w011*t011[1] +
w100*t100[1] + w110*t110[1] +
w101*t101[1] + w111*t111[1] + 0.5);
rgba[2] = (GLchan) (w000*t000[2] + w010*t010[2] +
w001*t001[2] + w011*t011[2] +
w100*t100[2] + w110*t110[2] +
w101*t101[2] + w111*t111[2] + 0.5);
rgba[3] = (GLchan) (w000*t000[3] + w010*t010[3] +
w001*t001[3] + w011*t011[3] +
w100*t100[3] + w110*t110[3] +
w101*t101[3] + w111*t111[3] + 0.5);
#else /* CHAN_BITS == 8 */
rgba[0] = (GLchan) (
(w000*t000[0] + w010*t010[0] + w001*t001[0] + w011*t011[0] +
w100*t100[0] + w110*t110[0] + w101*t101[0] + w111*t111[0] )
>> WEIGHT_SHIFT);
rgba[1] = (GLchan) (
(w000*t000[1] + w010*t010[1] + w001*t001[1] + w011*t011[1] +
w100*t100[1] + w110*t110[1] + w101*t101[1] + w111*t111[1] )
>> WEIGHT_SHIFT);
rgba[2] = (GLchan) (
(w000*t000[2] + w010*t010[2] + w001*t001[2] + w011*t011[2] +
w100*t100[2] + w110*t110[2] + w101*t101[2] + w111*t111[2] )
>> WEIGHT_SHIFT);
rgba[3] = (GLchan) (
(w000*t000[3] + w010*t010[3] + w001*t001[3] + w011*t011[3] +
w100*t100[3] + w110*t110[3] + w101*t101[3] + w111*t111[3] )
>> WEIGHT_SHIFT);
#endif

}
}

static void
sample_3d_nearest_mipmap_nearest(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4] )
{
GLuint i;
for (i = 0; i < n; i++) {
GLint level;
COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
sample_3d_nearest(ctx, tObj, tObj->Image[level], texcoord[i], rgba[i]);
}
}

static void
sample_3d_linear_mipmap_nearest(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
GLint level;
COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
sample_3d_linear(ctx, tObj, tObj->Image[level], texcoord[i], rgba[i]);
}
}

static void
sample_3d_nearest_mipmap_linear(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
GLint level;
COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
if (level >= tObj->_MaxLevel) {
sample_3d_nearest(ctx, tObj, tObj->Image[tObj->_MaxLevel],
texcoord[i], rgba[i]);
}
else {
GLchan t0[4], t1[4]; /* texels */
const GLfloat f = FRAC(lambda[i]);
sample_3d_nearest(ctx, tObj, tObj->Image[level ], texcoord[i], t0);
sample_3d_nearest(ctx, tObj, tObj->Image[level+1], texcoord[i], t1);
rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
}
}
}

static void
sample_3d_linear_mipmap_linear(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
GLint level;
COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
if (level >= tObj->_MaxLevel) {
sample_3d_linear(ctx, tObj, tObj->Image[tObj->_MaxLevel],
texcoord[i], rgba[i]);
}
else {
GLchan t0[4], t1[4]; /* texels */
const GLfloat f = FRAC(lambda[i]);
sample_3d_linear(ctx, tObj, tObj->Image[level ], texcoord[i], t0);
sample_3d_linear(ctx, tObj, tObj->Image[level+1], texcoord[i], t1);
rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
}
}
}

static void
sample_nearest_3d(GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4], const GLfloat lambda[],
GLchan rgba[][4])
{
GLuint i;
struct gl_texture_image *image = tObj->Image[tObj->BaseLevel];
(void) lambda;
for (i=0;i<n;i++) {
sample_3d_nearest(ctx, tObj, image, texcoords[i], rgba[i]);
}
}

static void
sample_linear_3d( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4],
const GLfloat lambda[], GLchan rgba[][4] )
{
GLuint i;
struct gl_texture_image *image = tObj->Image[tObj->BaseLevel];
(void) lambda;
for (i=0;i<n;i++) {
sample_3d_linear(ctx, tObj, image, texcoords[i], rgba[i]);
}
}

/*
* Given an (s,t,r) texture coordinate and lambda (level of detail) value,
* return a texture sample.
*/
static void
sample_lambda_3d( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4], const GLfloat lambda[],
GLchan rgba[][4] )
{
GLuint minStart, minEnd; /* texels with minification */
GLuint magStart, magEnd; /* texels with magnification */
GLuint i;

ASSERT(lambda != NULL);
compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
n, lambda, &minStart, &minEnd, &magStart, &magEnd);

if (minStart < minEnd) {
/* do the minified texels */
GLuint m = minEnd - minStart;
switch (tObj->MinFilter) {
case GL_NEAREST:
for (i = minStart; i < minEnd; i++)
sample_3d_nearest(ctx, tObj, tObj->Image[tObj->BaseLevel],
texcoords[i], rgba[i]);
break;
case GL_LINEAR:
for (i = minStart; i < minEnd; i++)
sample_3d_linear(ctx, tObj, tObj->Image[tObj->BaseLevel],
texcoords[i], rgba[i]);
break;
case GL_NEAREST_MIPMAP_NEAREST:
sample_3d_nearest_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_LINEAR_MIPMAP_NEAREST:
sample_3d_linear_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_NEAREST_MIPMAP_LINEAR:
sample_3d_nearest_mipmap_linear(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_LINEAR_MIPMAP_LINEAR:
sample_3d_linear_mipmap_linear(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
default:
_mesa_problem(ctx, "Bad min filter in sample_3d_texture");
return;
}
}

if (magStart < magEnd) {
/* do the magnified texels */
switch (tObj->MagFilter) {
case GL_NEAREST:
for (i = magStart; i < magEnd; i++)
sample_3d_nearest(ctx, tObj, tObj->Image[tObj->BaseLevel],
texcoords[i], rgba[i]);
break;
case GL_LINEAR:
for (i = magStart; i < magEnd; i++)
sample_3d_linear(ctx, tObj, tObj->Image[tObj->BaseLevel],
texcoords[i], rgba[i]);
break;
default:
_mesa_problem(ctx, "Bad mag filter in sample_3d_texture");
return;
}
}
}

/**********************************************************************/
/* Texture Cube Map Sampling Functions */
/**********************************************************************/

/*
* Choose one of six sides of a texture cube map given the texture
* coord (rx,ry,rz). Return pointer to corresponding array of texture
* images.
*/
static const struct gl_texture_image **
choose_cube_face(const struct gl_texture_object *texObj,
const GLfloat texcoord[4], GLfloat newCoord[4])
{
/*
major axis
direction target sc tc ma
---------- ------------------------------- --- --- ---
+rx TEXTURE_CUBE_MAP_POSITIVE_X_EXT -rz -ry rx
-rx TEXTURE_CUBE_MAP_NEGATIVE_X_EXT +rz -ry rx
+ry TEXTURE_CUBE_MAP_POSITIVE_Y_EXT +rx +rz ry
-ry TEXTURE_CUBE_MAP_NEGATIVE_Y_EXT +rx -rz ry
+rz TEXTURE_CUBE_MAP_POSITIVE_Z_EXT +rx -ry rz
-rz TEXTURE_CUBE_MAP_NEGATIVE_Z_EXT -rx -ry rz
*/
const GLfloat rx = texcoord[0];
const GLfloat ry = texcoord[1];
const GLfloat rz = texcoord[2];
const struct gl_texture_image **imgArray;
const GLfloat arx = ABSF(rx), ary = ABSF(ry), arz = ABSF(rz);
GLfloat sc, tc, ma;

if (arx > ary && arx > arz) {
if (rx >= 0.0F) {
imgArray = (const struct gl_texture_image **) texObj->Image;
sc = -rz;
tc = -ry;
ma = arx;
}
else {
imgArray = (const struct gl_texture_image **) texObj->NegX;
sc = rz;
tc = -ry;
ma = arx;
}
}
else if (ary > arx && ary > arz) {
if (ry >= 0.0F) {
imgArray = (const struct gl_texture_image **) texObj->PosY;
sc = rx;
tc = rz;
ma = ary;
}
else {
imgArray = (const struct gl_texture_image **) texObj->NegY;
sc = rx;
tc = -rz;
ma = ary;
}
}
else {
if (rz > 0.0F) {
imgArray = (const struct gl_texture_image **) texObj->PosZ;
sc = rx;
tc = -ry;
ma = arz;
}
else {
imgArray = (const struct gl_texture_image **) texObj->NegZ;
sc = -rx;
tc = -ry;
ma = arz;
}
}

newCoord[0] = ( sc / ma + 1.0F ) * 0.5F;
newCoord[1] = ( tc / ma + 1.0F ) * 0.5F;
return imgArray;
}

static void
sample_nearest_cube(GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4], const GLfloat lambda[],
GLchan rgba[][4])
{
GLuint i;
(void) lambda;
for (i = 0; i < n; i++) {
const struct gl_texture_image **images;
GLfloat newCoord[4];
images = choose_cube_face(tObj, texcoords[i], newCoord);
sample_2d_nearest(ctx, tObj, images[tObj->BaseLevel],
newCoord, rgba[i]);
}
}

static void
sample_linear_cube(GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
(void) lambda;
for (i = 0; i < n; i++) {
const struct gl_texture_image **images;
GLfloat newCoord[4];
images = choose_cube_face(tObj, texcoords[i], newCoord);
sample_2d_linear(ctx, tObj, images[tObj->BaseLevel],
newCoord, rgba[i]);
}
}

static void
sample_cube_nearest_mipmap_nearest(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
const struct gl_texture_image **images;
GLfloat newCoord[4];
GLint level;
COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
images = choose_cube_face(tObj, texcoord[i], newCoord);
sample_2d_nearest(ctx, tObj, images[level], newCoord, rgba[i]);
}
}

static void
sample_cube_linear_mipmap_nearest(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
const struct gl_texture_image **images;
GLfloat newCoord[4];
GLint level;
COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
images = choose_cube_face(tObj, texcoord[i], newCoord);
sample_2d_linear(ctx, tObj, images[level], newCoord, rgba[i]);
}
}

static void
sample_cube_nearest_mipmap_linear(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
const struct gl_texture_image **images;
GLfloat newCoord[4];
GLint level;
COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
images = choose_cube_face(tObj, texcoord[i], newCoord);
if (level >= tObj->_MaxLevel) {
sample_2d_nearest(ctx, tObj, images[tObj->_MaxLevel],
newCoord, rgba[i]);
}
else {
GLchan t0[4], t1[4]; /* texels */
const GLfloat f = FRAC(lambda[i]);
sample_2d_nearest(ctx, tObj, images[level ], newCoord, t0);
sample_2d_nearest(ctx, tObj, images[level+1], newCoord, t1);
rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
}
}
}

static void
sample_cube_linear_mipmap_linear(GLcontext *ctx,
const struct gl_texture_object *tObj,
GLuint n, GLfloat texcoord[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
GLuint i;
ASSERT(lambda != NULL);
for (i = 0; i < n; i++) {
const struct gl_texture_image **images;
GLfloat newCoord[4];
GLint level;
COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
images = choose_cube_face(tObj, texcoord[i], newCoord);
if (level >= tObj->_MaxLevel) {
sample_2d_linear(ctx, tObj, images[tObj->_MaxLevel],
newCoord, rgba[i]);
}
else {
GLchan t0[4], t1[4];
const GLfloat f = FRAC(lambda[i]);
sample_2d_linear(ctx, tObj, images[level ], newCoord, t0);
sample_2d_linear(ctx, tObj, images[level+1], newCoord, t1);
rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
}
}
}

static void
sample_lambda_cube( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4], const GLfloat lambda[],
GLchan rgba[][4])
{
GLuint minStart, minEnd; /* texels with minification */
GLuint magStart, magEnd; /* texels with magnification */

ASSERT(lambda != NULL);
compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
n, lambda, &minStart, &minEnd, &magStart, &magEnd);

if (minStart < minEnd) {
/* do the minified texels */
const GLuint m = minEnd - minStart;
switch (tObj->MinFilter) {
case GL_NEAREST:
sample_nearest_cube(ctx, texUnit, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_LINEAR:
sample_linear_cube(ctx, texUnit, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_NEAREST_MIPMAP_NEAREST:
sample_cube_nearest_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_LINEAR_MIPMAP_NEAREST:
sample_cube_linear_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_NEAREST_MIPMAP_LINEAR:
sample_cube_nearest_mipmap_linear(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
case GL_LINEAR_MIPMAP_LINEAR:
sample_cube_linear_mipmap_linear(ctx, tObj, m, texcoords + minStart,
lambda + minStart, rgba + minStart);
break;
default:
_mesa_problem(ctx, "Bad min filter in sample_lambda_cube");
}
}

if (magStart < magEnd) {
/* do the magnified texels */
const GLuint m = magEnd - magStart;
switch (tObj->MagFilter) {
case GL_NEAREST:
sample_nearest_cube(ctx, texUnit, tObj, m, texcoords + magStart,
lambda + magStart, rgba + magStart);
break;
case GL_LINEAR:
sample_linear_cube(ctx, texUnit, tObj, m, texcoords + magStart,
lambda + magStart, rgba + magStart);
break;
default:
_mesa_problem(ctx, "Bad mag filter in sample_lambda_cube");
}
}
}

/**********************************************************************/
/* Texture Rectangle Sampling Functions */
/**********************************************************************/

static void
sample_nearest_rect(GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4], const GLfloat lambda[],
GLchan rgba[][4])
{
const struct gl_texture_image *img = tObj->Image[0];
const GLfloat width = (GLfloat) img->Width;
const GLfloat height = (GLfloat) img->Height;
const GLint width_minus_1 = img->Width - 1;
const GLint height_minus_1 = img->Height - 1;
GLuint i;

(void) texUnit;
(void) lambda;

ASSERT(tObj->WrapS == GL_CLAMP ||
tObj->WrapS == GL_CLAMP_TO_EDGE ||
tObj->WrapS == GL_CLAMP_TO_BORDER_ARB);
ASSERT(tObj->WrapT == GL_CLAMP ||
tObj->WrapT == GL_CLAMP_TO_EDGE ||
tObj->WrapT == GL_CLAMP_TO_BORDER_ARB);
ASSERT(img->Format != GL_COLOR_INDEX);

/* XXX move Wrap mode tests outside of loops for common cases */
for (i = 0; i < n; i++) {
GLint row, col;
/* NOTE: we DO NOT use [0, 1] texture coordinates! */
if (tObj->WrapS == GL_CLAMP) {
col = IFLOOR( CLAMP(texcoords[i][0], 0.0F, width) );
}
else if (tObj->WrapS == GL_CLAMP_TO_EDGE) {
col = IFLOOR( CLAMP(texcoords[i][0], 0.5F, width - 0.5F) );
}
else {
col = IFLOOR( CLAMP(texcoords[i][0], -0.5F, width + 0.5F) );
}
if (tObj->WrapT == GL_CLAMP) {
row = IFLOOR( CLAMP(texcoords[i][1], 0.0F, height) );
}
else if (tObj->WrapT == GL_CLAMP_TO_EDGE) {
row = IFLOOR( CLAMP(texcoords[i][1], 0.5F, height - 0.5F) );
}
else {
row = IFLOOR( CLAMP(texcoords[i][1], -0.5F, height + 0.5F) );
}

col = CLAMP(col, 0, width_minus_1);
row = CLAMP(row, 0, height_minus_1);

(*img->FetchTexel)(img, col, row, 0, (GLvoid *) rgba[i]);
}
}

static void
sample_linear_rect(GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4],
const GLfloat lambda[], GLchan rgba[][4])
{
const struct gl_texture_image *img = tObj->Image[0];
const GLfloat width = (GLfloat) img->Width;
const GLfloat height = (GLfloat) img->Height;
const GLint width_minus_1 = img->Width - 1;
const GLint height_minus_1 = img->Height - 1;
GLuint i;

(void) texUnit;
(void) lambda;

ASSERT(tObj->WrapS == GL_CLAMP ||
tObj->WrapS == GL_CLAMP_TO_EDGE ||
tObj->WrapS == GL_CLAMP_TO_BORDER_ARB);
ASSERT(tObj->WrapT == GL_CLAMP ||
tObj->WrapT == GL_CLAMP_TO_EDGE ||
tObj->WrapT == GL_CLAMP_TO_BORDER_ARB);
ASSERT(img->Format != GL_COLOR_INDEX);

/* XXX lots of opportunity for optimization in this loop */
for (i = 0; i < n; i++) {
GLfloat frow, fcol;
GLint row0, col0, row1, col1;
GLchan t00[4], t01[4], t10[4], t11[4];
GLfloat a, b, w00, w01, w10, w11;

/* NOTE: we DO NOT use [0, 1] texture coordinates! */
if (tObj->WrapS == GL_CLAMP) {
fcol = CLAMP(texcoords[i][0], 0.0F, width);
}
else if (tObj->WrapS == GL_CLAMP_TO_EDGE) {
fcol = CLAMP(texcoords[i][0], 0.5F, width - 0.5F);
}
else {
fcol = CLAMP(texcoords[i][0], -0.5F, width + 0.5F);
}
if (tObj->WrapT == GL_CLAMP) {
frow = CLAMP(texcoords[i][1], 0.0F, height);
}
else if (tObj->WrapT == GL_CLAMP_TO_EDGE) {
frow = CLAMP(texcoords[i][1], 0.5F, height - 0.5F);
}
else {
frow = CLAMP(texcoords[i][1], -0.5F, height + 0.5F);
}

/* compute integer rows/columns */
col0 = IFLOOR(fcol);
col1 = col0 + 1;
col0 = CLAMP(col0, 0, width_minus_1);
col1 = CLAMP(col1, 0, width_minus_1);
row0 = IFLOOR(frow);
row1 = row0 + 1;
row0 = CLAMP(row0, 0, height_minus_1);
row1 = CLAMP(row1, 0, height_minus_1);

/* get four texel samples */
(*img->FetchTexel)(img, col0, row0, 0, (GLvoid *) t00);
(*img->FetchTexel)(img, col1, row0, 0, (GLvoid *) t10);
(*img->FetchTexel)(img, col0, row1, 0, (GLvoid *) t01);
(*img->FetchTexel)(img, col1, row1, 0, (GLvoid *) t11);

/* compute sample weights */
a = FRAC(fcol);
b = FRAC(frow);
w00 = (1.0F-a) * (1.0F-b);
w10 = a * (1.0F-b);
w01 = (1.0F-a) * b ;
w11 = a * b ;

/* compute weighted average of samples */
rgba[i][0] =
(GLchan) (w00 * t00[0] + w10 * t10[0] + w01 * t01[0] + w11 * t11[0]);
rgba[i][1] =
(GLchan) (w00 * t00[1] + w10 * t10[1] + w01 * t01[1] + w11 * t11[1]);
rgba[i][2] =
(GLchan) (w00 * t00[2] + w10 * t10[2] + w01 * t01[2] + w11 * t11[2]);
rgba[i][3] =
(GLchan) (w00 * t00[3] + w10 * t10[3] + w01 * t01[3] + w11 * t11[3]);
}
}

static void
sample_lambda_rect( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4], const GLfloat lambda[],
GLchan rgba[][4])
{
GLuint minStart, minEnd, magStart, magEnd;

/* We only need lambda to decide between minification and magnification.
* There is no mipmapping with rectangular textures.
*/
compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
n, lambda, &minStart, &minEnd, &magStart, &magEnd);

if (minStart < minEnd) {
if (tObj->MinFilter == GL_NEAREST) {
sample_nearest_rect( ctx, texUnit, tObj, minEnd - minStart,
texcoords + minStart, NULL, rgba + minStart);
}
else {
sample_linear_rect( ctx, texUnit, tObj, minEnd - minStart,
texcoords + minStart, NULL, rgba + minStart);
}
}
if (magStart < magEnd) {
if (tObj->MagFilter == GL_NEAREST) {
sample_nearest_rect( ctx, texUnit, tObj, magEnd - magStart,
texcoords + magStart, NULL, rgba + magStart);
}
else {
sample_linear_rect( ctx, texUnit, tObj, magEnd - magStart,
texcoords + magStart, NULL, rgba + magStart);
}
}
}

/*
* Sample a shadow/depth texture.
*/
static void
sample_depth_texture( GLcontext *ctx, GLuint unit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4], const GLfloat lambda[],
GLchan texel[][4] )
{
const GLint baseLevel = tObj->BaseLevel;
const struct gl_texture_image *texImage = tObj->Image[baseLevel];
const GLuint width = texImage->Width;
const GLuint height = texImage->Height;
GLchan ambient;
GLenum function;
GLchan result;

(void) unit;

ASSERT(tObj->Image[tObj->BaseLevel]->Format == GL_DEPTH_COMPONENT);
ASSERT(tObj->Target == GL_TEXTURE_1D ||
tObj->Target == GL_TEXTURE_2D ||
tObj->Target == GL_TEXTURE_RECTANGLE_NV);

UNCLAMPED_FLOAT_TO_CHAN(ambient, tObj->ShadowAmbient);

/* XXXX if tObj->MinFilter != tObj->MagFilter, we're ignoring lambda */

/* XXX this could be precomputed and saved in the texture object */
if (tObj->CompareFlag) {
/* GL_SGIX_shadow */
if (tObj->CompareOperator == GL_TEXTURE_LEQUAL_R_SGIX) {
function = GL_LEQUAL;
}
else {
ASSERT(tObj->CompareOperator == GL_TEXTURE_GEQUAL_R_SGIX);
function = GL_GEQUAL;
}
}
else if (tObj->CompareMode == GL_COMPARE_R_TO_TEXTURE_ARB) {
/* GL_ARB_shadow */
function = tObj->CompareFunc;
}
else {
function = GL_NONE; /* pass depth through as grayscale */
}

if (tObj->MagFilter == GL_NEAREST) {
GLuint i;
for (i = 0; i < n; i++) {
GLfloat depthSample;
GLint col, row;
/* XXX fix for texture rectangle! */
COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapS, texcoords[i][0], width, col);
COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapT, texcoords[i][1], height, row);
depthSample = *((const GLfloat *) texImage->Data + row * width + col);

switch (function) {
case GL_LEQUAL:
result = (texcoords[i][2] <= depthSample) ? CHAN_MAX : ambient;
break;
case GL_GEQUAL:
result = (texcoords[i][2] >= depthSample) ? CHAN_MAX : ambient;
break;
case GL_LESS:
result = (texcoords[i][2] < depthSample) ? CHAN_MAX : ambient;
break;
case GL_GREATER:
result = (texcoords[i][2] > depthSample) ? CHAN_MAX : ambient;
break;
case GL_EQUAL:
result = (texcoords[i][2] == depthSample) ? CHAN_MAX : ambient;
break;
case GL_NOTEQUAL:
result = (texcoords[i][2] != depthSample) ? CHAN_MAX : ambient;
break;
case GL_ALWAYS:
result = CHAN_MAX;
break;
case GL_NEVER:
result = ambient;
break;
case GL_NONE:
CLAMPED_FLOAT_TO_CHAN(result, depthSample);
break;
default:
_mesa_problem(ctx, "Bad compare func in sample_depth_texture");
return;
}

switch (tObj->DepthMode) {
case GL_LUMINANCE:
texel[i][RCOMP] = result;
texel[i][GCOMP] = result;
texel[i][BCOMP] = result;
texel[i][ACOMP] = CHAN_MAX;
break;
case GL_INTENSITY:
texel[i][RCOMP] = result;
texel[i][GCOMP] = result;
texel[i][BCOMP] = result;
texel[i][ACOMP] = result;
break;
case GL_ALPHA:
texel[i][RCOMP] = 0;
texel[i][GCOMP] = 0;
texel[i][BCOMP] = 0;
texel[i][ACOMP] = result;
break;
default:
_mesa_problem(ctx, "Bad depth texture mode");
}
}
}
else {
GLuint i;
ASSERT(tObj->MagFilter == GL_LINEAR);
for (i = 0; i < n; i++) {
GLfloat depth00, depth01, depth10, depth11;
GLint i0, i1, j0, j1;
GLfloat u, v;
GLuint useBorderTexel;

/* XXX fix for texture rectangle! */
COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapS, texcoords[i][0], u, width, i0, i1);
COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapT, texcoords[i][1], v, height,j0, j1);

useBorderTexel = 0;
if (texImage->Border) {
i0 += texImage->Border;
i1 += texImage->Border;
j0 += texImage->Border;
j1 += texImage->Border;
}
else {
if (i0 < 0 || i0 >= (GLint) width) useBorderTexel |= I0BIT;
if (i1 < 0 || i1 >= (GLint) width) useBorderTexel |= I1BIT;
if (j0 < 0 || j0 >= (GLint) height) useBorderTexel |= J0BIT;
if (j1 < 0 || j1 >= (GLint) height) useBorderTexel |= J1BIT;
}

/* get four depth samples from the texture */
if (useBorderTexel & (I0BIT | J0BIT)) {
depth00 = 1.0;
}
else {
depth00 = *((const GLfloat *) texImage->Data + j0 * width + i0);
}
if (useBorderTexel & (I1BIT | J0BIT)) {
depth10 = 1.0;
}
else {
depth10 = *((const GLfloat *) texImage->Data + j0 * width + i1);
}
if (useBorderTexel & (I0BIT | J1BIT)) {
depth01 = 1.0;
}
else {
depth01 = *((const GLfloat *) texImage->Data + j1 * width + i0);
}
if (useBorderTexel & (I1BIT | J1BIT)) {
depth11 = 1.0;
}
else {
depth11 = *((const GLfloat *) texImage->Data + j1 * width + i1);
}

if (0) {
/* compute a single weighted depth sample and do one comparison */
const GLfloat a = FRAC(u + 1.0F);
const GLfloat b = FRAC(v + 1.0F);
const GLfloat w00 = (1.0F - a) * (1.0F - b);
const GLfloat w10 = ( a) * (1.0F - b);
const GLfloat w01 = (1.0F - a) * ( b);
const GLfloat w11 = ( a) * ( b);
const GLfloat depthSample = w00 * depth00 + w10 * depth10
+ w01 * depth01 + w11 * depth11;
if ((depthSample <= texcoords[i][2] && function == GL_LEQUAL) ||
(depthSample >= texcoords[i][2] && function == GL_GEQUAL)) {
result = ambient;
}
else {
result = CHAN_MAX;
}
}
else {
/* Do four depth/R comparisons and compute a weighted result.
* If this touches on somebody's I.P., I'll remove this code
* upon request.
*/
const GLfloat d = (CHAN_MAXF - (GLfloat) ambient) * 0.25F;
GLfloat luminance = CHAN_MAXF;

switch (function) {
case GL_LEQUAL:
if (depth00 <= texcoords[i][2]) luminance -= d;
if (depth01 <= texcoords[i][2]) luminance -= d;
if (depth10 <= texcoords[i][2]) luminance -= d;
if (depth11 <= texcoords[i][2]) luminance -= d;
result = (GLchan) luminance;
break;
case GL_GEQUAL:
if (depth00 >= texcoords[i][2]) luminance -= d;
if (depth01 >= texcoords[i][2]) luminance -= d;
if (depth10 >= texcoords[i][2]) luminance -= d;
if (depth11 >= texcoords[i][2]) luminance -= d;
result = (GLchan) luminance;
break;
case GL_LESS:
if (depth00 < texcoords[i][2]) luminance -= d;
if (depth01 < texcoords[i][2]) luminance -= d;
if (depth10 < texcoords[i][2]) luminance -= d;
if (depth11 < texcoords[i][2]) luminance -= d;
result = (GLchan) luminance;
break;
case GL_GREATER:
if (depth00 > texcoords[i][2]) luminance -= d;
if (depth01 > texcoords[i][2]) luminance -= d;
if (depth10 > texcoords[i][2]) luminance -= d;
if (depth11 > texcoords[i][2]) luminance -= d;
result = (GLchan) luminance;
break;
case GL_EQUAL:
if (depth00 == texcoords[i][2]) luminance -= d;
if (depth01 == texcoords[i][2]) luminance -= d;
if (depth10 == texcoords[i][2]) luminance -= d;
if (depth11 == texcoords[i][2]) luminance -= d;
result = (GLchan) luminance;
break;
case GL_NOTEQUAL:
if (depth00 != texcoords[i][2]) luminance -= d;
if (depth01 != texcoords[i][2]) luminance -= d;
if (depth10 != texcoords[i][2]) luminance -= d;
if (depth11 != texcoords[i][2]) luminance -= d;
result = (GLchan) luminance;
break;
case GL_ALWAYS:
result = 0;
break;
case GL_NEVER:
result = CHAN_MAX;
break;
case GL_NONE:
/* ordinary bilinear filtering */
{
const GLfloat a = FRAC(u + 1.0F);
const GLfloat b = FRAC(v + 1.0F);
const GLfloat w00 = (1.0F - a) * (1.0F - b);
const GLfloat w10 = ( a) * (1.0F - b);
const GLfloat w01 = (1.0F - a) * ( b);
const GLfloat w11 = ( a) * ( b);
const GLfloat depthSample = w00 * depth00 + w10 * depth10
+ w01 * depth01 + w11 * depth11;
CLAMPED_FLOAT_TO_CHAN(result, depthSample);
}
break;
default:
_mesa_problem(ctx, "Bad compare func in sample_depth_texture");
return;
}
}

switch (tObj->DepthMode) {
case GL_LUMINANCE:
texel[i][RCOMP] = result;
texel[i][GCOMP] = result;
texel[i][BCOMP] = result;
texel[i][ACOMP] = CHAN_MAX;
break;
case GL_INTENSITY:
texel[i][RCOMP] = result;
texel[i][GCOMP] = result;
texel[i][BCOMP] = result;
texel[i][ACOMP] = result;
break;
case GL_ALPHA:
texel[i][RCOMP] = 0;
texel[i][GCOMP] = 0;
texel[i][BCOMP] = 0;
texel[i][ACOMP] = result;
break;
default:
_mesa_problem(ctx, "Bad depth texture mode");
}
} /* for */
} /* if filter */
}

#if 0
/*
* Experimental depth texture sampling function.
*/
static void
sample_depth_texture2(const GLcontext *ctx,
const struct gl_texture_unit *texUnit,
GLuint n, GLfloat texcoords[][4],
GLchan texel[][4])
{
const struct gl_texture_object *texObj = texUnit->_Current;
const GLint baseLevel = texObj->BaseLevel;
const struct gl_texture_image *texImage = texObj->Image[baseLevel];
const GLuint width = texImage->Width;
const GLuint height = texImage->Height;
GLchan ambient;
GLboolean lequal, gequal;

if (texObj->Target != GL_TEXTURE_2D) {
_mesa_problem(ctx, "only 2-D depth textures supported at this time");
return;
}

if (texObj->MinFilter != texObj->MagFilter) {
_mesa_problem(ctx, "mipmapped depth textures not supported at this time");
return;
}

/* XXX the GL_SGIX_shadow extension spec doesn't say what to do if
* GL_TEXTURE_COMPARE_SGIX == GL_TRUE but the current texture object
* isn't a depth texture.
*/
if (texImage->Format != GL_DEPTH_COMPONENT) {
_mesa_problem(ctx,"GL_TEXTURE_COMPARE_SGIX enabled with non-depth texture");
return;
}

UNCLAMPED_FLOAT_TO_CHAN(ambient, tObj->ShadowAmbient);

if (texObj->CompareOperator == GL_TEXTURE_LEQUAL_R_SGIX) {
lequal = GL_TRUE;
gequal = GL_FALSE;
}
else {
lequal = GL_FALSE;
gequal = GL_TRUE;
}

{
GLuint i;
for (i = 0; i < n; i++) {
const GLint K = 3;
GLint col, row, ii, jj, imin, imax, jmin, jmax, samples, count;
GLfloat w;
GLchan lum;
COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapS, texcoords[i][0],
width, col);
COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapT, texcoords[i][1],
height, row);

imin = col - K;
imax = col + K;
jmin = row - K;
jmax = row + K;

if (imin < 0) imin = 0;
if (imax >= width) imax = width - 1;
if (jmin < 0) jmin = 0;
if (jmax >= height) jmax = height - 1;

samples = (imax - imin + 1) * (jmax - jmin + 1);
count = 0;
for (jj = jmin; jj <= jmax; jj++) {
for (ii = imin; ii <= imax; ii++) {
GLfloat depthSample = *((const GLfloat *) texImage->Data
+ jj * width + ii);
if ((depthSample <= r[i] && lequal) ||
(depthSample >= r[i] && gequal)) {
count++;
}
}
}

w = (GLfloat) count / (GLfloat) samples;
w = CHAN_MAXF - w * (CHAN_MAXF - (GLfloat) ambient);
lum = (GLint) w;

texel[i][RCOMP] = lum;
texel[i][GCOMP] = lum;
texel[i][BCOMP] = lum;
texel[i][ACOMP] = CHAN_MAX;
}
}
}
#endif

/**
* We use this function when a texture object is in an "incomplete" state.
*/
static void
null_sample_func( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *tObj, GLuint n,
GLfloat texcoords[][4], const GLfloat lambda[],
GLchan rgba[][4])
{
}

/**
* Setup the texture sampling function for this texture object.
*/
void
_swrast_choose_texture_sample_func( GLcontext *ctx, GLuint texUnit,
const struct gl_texture_object *t )
{
SWcontext *swrast = SWRAST_CONTEXT(ctx);

if (!t->Complete) {
swrast->TextureSample[texUnit] = null_sample_func;
}
else {
const GLboolean needLambda = (GLboolean) (t->MinFilter != t->MagFilter);
const GLenum format = t->Image[t->BaseLevel]->Format;

if (needLambda) {
/* Compute min/mag filter threshold */
if (t->MagFilter == GL_LINEAR
&& (t->MinFilter == GL_NEAREST_MIPMAP_NEAREST ||
t->MinFilter == GL_NEAREST_MIPMAP_LINEAR)) {
swrast->_MinMagThresh[texUnit] = 0.5F;
}
else {
swrast->_MinMagThresh[texUnit] = 0.0F;
}
}

switch (t->Target) {
case GL_TEXTURE_1D:
if (format == GL_DEPTH_COMPONENT) {
swrast->TextureSample[texUnit] = sample_depth_texture;
}
else if (needLambda) {
swrast->TextureSample[texUnit] = sample_lambda_1d;
}
else if (t->MinFilter == GL_LINEAR) {
swrast->TextureSample[texUnit] = sample_linear_1d;
}
else {
ASSERT(t->MinFilter == GL_NEAREST);
swrast->TextureSample[texUnit] = sample_nearest_1d;
}
break;
case GL_TEXTURE_2D:
if (format == GL_DEPTH_COMPONENT) {
swrast->TextureSample[texUnit] = sample_depth_texture;
}
else if (needLambda) {
swrast->TextureSample[texUnit] = sample_lambda_2d;
}
else if (t->MinFilter == GL_LINEAR) {
swrast->TextureSample[texUnit] = sample_linear_2d;
}
else {
GLint baseLevel = t->BaseLevel;
ASSERT(t->MinFilter == GL_NEAREST);
if (t->WrapS == GL_REPEAT &&
t->WrapT == GL_REPEAT &&
t->Image[baseLevel]->Border == 0 &&
t->Image[baseLevel]->TexFormat->MesaFormat == MESA_FORMAT_RGB) {
swrast->TextureSample[texUnit] = opt_sample_rgb_2d;
}
else if (t->WrapS == GL_REPEAT &&
t->WrapT == GL_REPEAT &&
t->Image[baseLevel]->Border == 0 &&
t->Image[baseLevel]->TexFormat->MesaFormat == MESA_FORMAT_RGBA) {
swrast->TextureSample[texUnit] = opt_sample_rgba_2d;
}
else
swrast->TextureSample[texUnit] = sample_nearest_2d;
}
break;
case GL_TEXTURE_3D:
if (needLambda) {
swrast->TextureSample[texUnit] = sample_lambda_3d;
}
else if (t->MinFilter == GL_LINEAR) {
swrast->TextureSample[texUnit] = sample_linear_3d;
}
else {
ASSERT(t->MinFilter == GL_NEAREST);
swrast->TextureSample[texUnit] = sample_nearest_3d;
}
break;
case GL_TEXTURE_CUBE_MAP_ARB:
if (needLambda) {
swrast->TextureSample[texUnit] = sample_lambda_cube;
}
else if (t->MinFilter == GL_LINEAR) {
swrast->TextureSample[texUnit] = sample_linear_cube;
}
else {
ASSERT(t->MinFilter == GL_NEAREST);
swrast->TextureSample[texUnit] = sample_nearest_cube;
}
break;
case GL_TEXTURE_RECTANGLE_NV:
if (needLambda) {
swrast->TextureSample[texUnit] = sample_lambda_rect;
}
else if (t->MinFilter == GL_LINEAR) {
swrast->TextureSample[texUnit] = sample_linear_rect;
}
else {
ASSERT(t->MinFilter == GL_NEAREST);
swrast->TextureSample[texUnit] = sample_nearest_rect;
}
break;
default:
_mesa_problem(ctx, "invalid target in _swrast_choose_texture_sample_func");
}
}
}

#define PROD(A,B) ( (GLuint)(A) * ((GLuint)(B)+1) )
#define S_PROD(A,B) ( (GLint)(A) * ((GLint)(B)+1) )

/**
* Do texture application for GL_ARB/EXT_texture_env_combine.
* Input:
* ctx - rendering context
* textureUnit - the texture unit to apply
* n - number of fragments to process (span width)
* primary_rgba - incoming fragment color array
* texelBuffer - pointer to texel colors for all texture units
* Input/Output:
* rgba - incoming colors, which get modified here
*/
static INLINE void
texture_combine( const GLcontext *ctx, GLuint unit, GLuint n,
CONST GLchan (*primary_rgba)[4],
CONST GLchan *texelBuffer,
GLchan (*rgba)[4] )
{
const struct gl_texture_unit *textureUnit = &(ctx->Texture.Unit[unit]);
const GLchan (*argRGB [3])[4];
const GLchan (*argA [3])[4];
const GLuint RGBshift = textureUnit->CombineScaleShiftRGB;
const GLuint Ashift = textureUnit->CombineScaleShiftA;
#if CHAN_TYPE == GL_FLOAT
const GLchan RGBmult = (GLfloat) (1 << RGBshift);
const GLchan Amult = (GLfloat) (1 << Ashift);
#else
const GLint half = (CHAN_MAX + 1) / 2;
#endif
GLuint i, j;

/* GLchan ccolor[3][4]; */
DEFMNARRAY(GLchan, ccolor, 3, 3 * MAX_WIDTH, 4); /* mac 32k limitation */
CHECKARRAY(ccolor, return); /* mac 32k limitation */

ASSERT(ctx->Extensions.EXT_texture_env_combine ||
ctx->Extensions.ARB_texture_env_combine);
ASSERT(SWRAST_CONTEXT(ctx)->_AnyTextureCombine);

/*
printf("modeRGB 0x%x modeA 0x%x srcRGB1 0x%x srcA1 0x%x srcRGB2 0x%x srcA2 0x%x\n",
textureUnit->CombineModeRGB,
textureUnit->CombineModeA,
textureUnit->CombineSourceRGB[0],
textureUnit->CombineSourceA[0],
textureUnit->CombineSourceRGB[1],
textureUnit->CombineSourceA[1]);
*/

/*
* Do operand setup for up to 3 operands. Loop over the terms.
*/
for (j = 0; j < 3; j++) {
const GLenum srcA = textureUnit->CombineSourceA[j];
const GLenum srcRGB = textureUnit->CombineSourceRGB[j];

switch (srcA) {
case GL_TEXTURE:
argA[j] = (const GLchan (*)[4])
(texelBuffer + unit * (n * 4 * sizeof(GLchan)));
break;
case GL_PRIMARY_COLOR_EXT:
argA[j] = primary_rgba;
break;
case GL_PREVIOUS_EXT:
argA[j] = (const GLchan (*)[4]) rgba;
break;
case GL_CONSTANT_EXT:
{
GLchan alpha, (*c)[4] = ccolor[j];
UNCLAMPED_FLOAT_TO_CHAN(alpha, textureUnit->EnvColor[3]);
for (i = 0; i < n; i++)
c[i][ACOMP] = alpha;
argA[j] = (const GLchan (*)[4]) ccolor[j];
}
break;
default:
/* ARB_texture_env_crossbar source */
{
const GLuint srcUnit = srcA - GL_TEXTURE0_ARB;
ASSERT(srcUnit < ctx->Const.MaxTextureUnits);
if (!ctx->Texture.Unit[srcUnit]._ReallyEnabled)
return;
argA[j] = (const GLchan (*)[4])
(texelBuffer + srcUnit * (n * 4 * sizeof(GLchan)));
}
}

switch (srcRGB) {
case GL_TEXTURE:
argRGB[j] = (const GLchan (*)[4])
(texelBuffer + unit * (n * 4 * sizeof(GLchan)));
break;
case GL_PRIMARY_COLOR_EXT:
argRGB[j] = primary_rgba;
break;
case GL_PREVIOUS_EXT:
argRGB[j] = (const GLchan (*)[4]) rgba;
break;
case GL_CONSTANT_EXT:
{
GLchan (*c)[4] = ccolor[j];
GLchan red, green, blue, alpha;
UNCLAMPED_FLOAT_TO_CHAN(red, textureUnit->EnvColor[0]);
UNCLAMPED_FLOAT_TO_CHAN(green, textureUnit->EnvColor[1]);
UNCLAMPED_FLOAT_TO_CHAN(blue, textureUnit->EnvColor[2]);
UNCLAMPED_FLOAT_TO_CHAN(alpha, textureUnit->EnvColor[3]);
for (i = 0; i < n; i++) {
c[i][RCOMP] = red;
c[i][GCOMP] = green;
c[i][BCOMP] = blue;
c[i][ACOMP] = alpha;
}
argRGB[j] = (const GLchan (*)[4]) ccolor[j];
}
break;
default:
/* ARB_texture_env_crossbar source */
{
const GLuint srcUnit = srcRGB - GL_TEXTURE0_ARB;
ASSERT(srcUnit < ctx->Const.MaxTextureUnits);
if (!ctx->Texture.Unit[srcUnit]._ReallyEnabled)
return;
argRGB[j] = (const GLchan (*)[4])
(texelBuffer + srcUnit * (n * 4 * sizeof(GLchan)));
}
}

if (textureUnit->CombineOperandRGB[j] != GL_SRC_COLOR) {
const GLchan (*src)[4] = argRGB[j];
GLchan (*dst)[4] = ccolor[j];

/* point to new arg[j] storage */
argRGB[j] = (const GLchan (*)[4]) ccolor[j];

if (textureUnit->CombineOperandRGB[j] == GL_ONE_MINUS_SRC_COLOR) {
for (i = 0; i < n; i++) {
dst[i][RCOMP] = CHAN_MAX - src[i][RCOMP];
dst[i][GCOMP] = CHAN_MAX - src[i][GCOMP];
dst[i][BCOMP] = CHAN_MAX - src[i][BCOMP];
}
}
else if (textureUnit->CombineOperandRGB[j] == GL_SRC_ALPHA) {
for (i = 0; i < n; i++) {
dst[i][RCOMP] = src[i][ACOMP];
dst[i][GCOMP] = src[i][ACOMP];
dst[i][BCOMP] = src[i][ACOMP];
}
}
else {
ASSERT(textureUnit->CombineOperandRGB[j] ==GL_ONE_MINUS_SRC_ALPHA);
for (i = 0; i < n; i++) {
dst[i][RCOMP] = CHAN_MAX - src[i][ACOMP];
dst[i][GCOMP] = CHAN_MAX - src[i][ACOMP];
dst[i][BCOMP] = CHAN_MAX - src[i][ACOMP];
}
}
}

if (textureUnit->CombineOperandA[j] == GL_ONE_MINUS_SRC_ALPHA) {
const GLchan (*src)[4] = argA[j];
GLchan (*dst)[4] = ccolor[j];
argA[j] = (const GLchan (*)[4]) ccolor[j];
for (i = 0; i < n; i++) {
dst[i][ACOMP] = CHAN_MAX - src[i][ACOMP];
}
}

if (textureUnit->CombineModeRGB == GL_REPLACE &&
textureUnit->CombineModeA == GL_REPLACE) {
break; /* done, we need only arg0 */
}

if (j == 1 &&
textureUnit->CombineModeRGB != GL_INTERPOLATE_EXT &&
textureUnit->CombineModeA != GL_INTERPOLATE_EXT) {
break; /* arg0 and arg1 are done. we don't need arg2. */
}
}

/*
* Do the texture combine.
*/
switch (textureUnit->CombineModeRGB) {
case GL_REPLACE:
{
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
if (RGBshift) {
for (i = 0; i < n; i++) {
#if CHAN_TYPE == GL_FLOAT
rgba[i][RCOMP] = arg0[i][RCOMP] * RGBmult;
rgba[i][GCOMP] = arg0[i][GCOMP] * RGBmult;
rgba[i][BCOMP] = arg0[i][BCOMP] * RGBmult;
#else
GLuint r = (GLuint) arg0[i][RCOMP] << RGBshift;
GLuint g = (GLuint) arg0[i][GCOMP] << RGBshift;
GLuint b = (GLuint) arg0[i][BCOMP] << RGBshift;
rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
#endif
}
}
else {
for (i = 0; i < n; i++) {
rgba[i][RCOMP] = arg0[i][RCOMP];
rgba[i][GCOMP] = arg0[i][GCOMP];
rgba[i][BCOMP] = arg0[i][BCOMP];
}
}
}
break;
case GL_MODULATE:
{
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
#if CHAN_TYPE != GL_FLOAT
const GLint shift = CHAN_BITS - RGBshift;
#endif
for (i = 0; i < n; i++) {
#if CHAN_TYPE == GL_FLOAT
rgba[i][RCOMP] = arg0[i][RCOMP] * arg1[i][RCOMP] * RGBmult;
rgba[i][GCOMP] = arg0[i][GCOMP] * arg1[i][GCOMP] * RGBmult;
rgba[i][BCOMP] = arg0[i][BCOMP] * arg1[i][BCOMP] * RGBmult;
#else
GLuint r = PROD(arg0[i][RCOMP], arg1[i][RCOMP]) >> shift;
GLuint g = PROD(arg0[i][GCOMP], arg1[i][GCOMP]) >> shift;
GLuint b = PROD(arg0[i][BCOMP], arg1[i][BCOMP]) >> shift;
rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
#endif
}
}
break;
case GL_ADD:
{
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
for (i = 0; i < n; i++) {
#if CHAN_TYPE == GL_FLOAT
rgba[i][RCOMP] = (arg0[i][RCOMP] + arg1[i][RCOMP]) * RGBmult;
rgba[i][GCOMP] = (arg0[i][GCOMP] + arg1[i][GCOMP]) * RGBmult;
rgba[i][BCOMP] = (arg0[i][BCOMP] + arg1[i][BCOMP]) * RGBmult;
#else
GLint r = ((GLint) arg0[i][RCOMP] + (GLint) arg1[i][RCOMP]) << RGBshift;
GLint g = ((GLint) arg0[i][GCOMP] + (GLint) arg1[i][GCOMP]) << RGBshift;
GLint b = ((GLint) arg0[i][BCOMP] + (GLint) arg1[i][BCOMP]) << RGBshift;
rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
#endif
}
}
break;
case GL_ADD_SIGNED_EXT:
{
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
for (i = 0; i < n; i++) {
#if CHAN_TYPE == GL_FLOAT
rgba[i][RCOMP] = (arg0[i][RCOMP] + arg1[i][RCOMP] - 0.5) * RGBmult;
rgba[i][GCOMP] = (arg0[i][GCOMP] + arg1[i][GCOMP] - 0.5) * RGBmult;
rgba[i][BCOMP] = (arg0[i][BCOMP] + arg1[i][BCOMP] - 0.5) * RGBmult;
#else
GLint r = (GLint) arg0[i][RCOMP] + (GLint) arg1[i][RCOMP] -half;
GLint g = (GLint) arg0[i][GCOMP] + (GLint) arg1[i][GCOMP] -half;
GLint b = (GLint) arg0[i][BCOMP] + (GLint) arg1[i][BCOMP] -half;
r = (r < 0) ? 0 : r << RGBshift;
g = (g < 0) ? 0 : g << RGBshift;
b = (b < 0) ? 0 : b << RGBshift;
rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
#endif
}
}
break;
case GL_INTERPOLATE_EXT:
{
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
#if CHAN_TYPE != GL_FLOAT
const GLint shift = CHAN_BITS - RGBshift;
#endif
for (i = 0; i < n; i++) {
#if CHAN_TYPE == GL_FLOAT
rgba[i][RCOMP] = (arg0[i][RCOMP] * arg2[i][RCOMP] +
arg1[i][RCOMP] * (CHAN_MAXF - arg2[i][RCOMP])) * RGBmult;
rgba[i][GCOMP] = (arg0[i][GCOMP] * arg2[i][GCOMP] +
arg1[i][GCOMP] * (CHAN_MAXF - arg2[i][GCOMP])) * RGBmult;
rgba[i][BCOMP] = (arg0[i][BCOMP] * arg2[i][BCOMP] +
arg1[i][BCOMP] * (CHAN_MAXF - arg2[i][BCOMP])) * RGBmult;
#else
GLuint r = (PROD(arg0[i][RCOMP], arg2[i][RCOMP])
+ PROD(arg1[i][RCOMP], CHAN_MAX - arg2[i][RCOMP]))
>> shift;
GLuint g = (PROD(arg0[i][GCOMP], arg2[i][GCOMP])
+ PROD(arg1[i][GCOMP], CHAN_MAX - arg2[i][GCOMP]))
>> shift;
GLuint b = (PROD(arg0[i][BCOMP], arg2[i][BCOMP])
+ PROD(arg1[i][BCOMP], CHAN_MAX - arg2[i][BCOMP]))
>> shift;
rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
#endif
}
}
break;
case GL_SUBTRACT_ARB:
{
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
for (i = 0; i < n; i++) {
#if CHAN_TYPE == GL_FLOAT
rgba[i][RCOMP] = (arg0[i][RCOMP] - arg1[i][RCOMP]) * RGBmult;
rgba[i][GCOMP] = (arg0[i][GCOMP] - arg1[i][GCOMP]) * RGBmult;
rgba[i][BCOMP] = (arg0[i][BCOMP] - arg1[i][BCOMP]) * RGBmult;
#else
GLint r = ((GLint) arg0[i][RCOMP] - (GLint) arg1[i][RCOMP]) << RGBshift;
GLint g = ((GLint) arg0[i][GCOMP] - (GLint) arg1[i][GCOMP]) << RGBshift;
GLint b = ((GLint) arg0[i][BCOMP] - (GLint) arg1[i][BCOMP]) << RGBshift;
rgba[i][RCOMP] = (GLchan) CLAMP(r, 0, CHAN_MAX);
rgba[i][GCOMP] = (GLchan) CLAMP(g, 0, CHAN_MAX);
rgba[i][BCOMP] = (GLchan) CLAMP(b, 0, CHAN_MAX);
#endif
}
}
break;
case GL_DOT3_RGB_EXT:
case GL_DOT3_RGBA_EXT:
{
/* Do not scale the result by 1 2 or 4 */
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
for (i = 0; i < n; i++) {
#if CHAN_TYPE == GL_FLOAT
GLchan dot = ((arg0[i][RCOMP]-0.5F) * (arg1[i][RCOMP]-0.5F) +
(arg0[i][GCOMP]-0.5F) * (arg1[i][GCOMP]-0.5F) +
(arg0[i][BCOMP]-0.5F) * (arg1[i][BCOMP]-0.5F))
* 4.0F;
dot = CLAMP(dot, 0.0F, CHAN_MAXF);
#else
GLint dot = (S_PROD((GLint)arg0[i][RCOMP] - half,
(GLint)arg1[i][RCOMP] - half) +
S_PROD((GLint)arg0[i][GCOMP] - half,
(GLint)arg1[i][GCOMP] - half) +
S_PROD((GLint)arg0[i][BCOMP] - half,
(GLint)arg1[i][BCOMP] - half)) >> 6;
dot = CLAMP(dot, 0, CHAN_MAX);
#endif
rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = (GLchan) dot;
}
}
break;
case GL_DOT3_RGB_ARB:
case GL_DOT3_RGBA_ARB:
{
/* DO scale the result by 1 2 or 4 */
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
for (i = 0; i < n; i++) {
#if CHAN_TYPE == GL_FLOAT
GLchan dot = ((arg0[i][RCOMP]-0.5F) * (arg1[i][RCOMP]-0.5F) +
(arg0[i][GCOMP]-0.5F) * (arg1[i][GCOMP]-0.5F) +
(arg0[i][BCOMP]-0.5F) * (arg1[i][BCOMP]-0.5F))
* 4.0F * RGBmult;
dot = CLAMP(dot, 0.0, CHAN_MAXF);
#else
GLint dot = (S_PROD((GLint)arg0[i][RCOMP] - half,
(GLint)arg1[i][RCOMP] - half) +
S_PROD((GLint)arg0[i][GCOMP] - half,
(GLint)arg1[i][GCOMP] - half) +
S_PROD((GLint)arg0[i][BCOMP] - half,
(GLint)arg1[i][BCOMP] - half)) >> 6;
dot <<= RGBshift;
dot = CLAMP(dot, 0, CHAN_MAX);
#endif
rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = (GLchan) dot;
}
}
break;
default:
_mesa_problem(ctx, "invalid combine mode");
}

switch (textureUnit->CombineModeA) {
case GL_REPLACE:
{
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
if (Ashift) {
for (i = 0; i < n; i++) {
#if CHAN_TYPE == GL_FLOAT
GLchan a = arg0[i][ACOMP] * Amult;
#else
GLuint a = (GLuint) arg0[i][ACOMP] << Ashift;
#endif
rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
}
}
else {
for (i = 0; i < n; i++) {
rgba[i][ACOMP] = arg0[i][ACOMP];
}
}
}
break;
case GL_MODULATE:
{
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
#if CHAN_TYPE != GL_FLOAT
const GLint shift = CHAN_BITS - Ashift;
#endif
for (i = 0; i < n; i++) {
#if CHAN_TYPE == GL_FLOAT
rgba[i][ACOMP] = arg0[i][ACOMP] * arg1[i][ACOMP] * Amult;
#else
GLuint a = (PROD(arg0[i][ACOMP], arg1[i][ACOMP]) >> shift);
rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
#endif
}
}
break;
case GL_ADD:
{
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
for (i = 0; i < n; i++) {
#if CHAN_TYPE == GL_FLOAT
rgba[i][ACOMP] = (arg0[i][ACOMP] + arg1[i][ACOMP]) * Amult;
#else
GLint a = ((GLint) arg0[i][ACOMP] + arg1[i][ACOMP]) << Ashift;
rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
#endif
}
}
break;
case GL_ADD_SIGNED_EXT:
{
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
for (i = 0; i < n; i++) {
#if CHAN_TYPE == GL_FLOAT
rgba[i][ACOMP] = (arg0[i][ACOMP] + arg1[i][ACOMP] - 0.5F) * Amult;
#else
GLint a = (GLint) arg0[i][ACOMP] + (GLint) arg1[i][ACOMP] -half;
a = (a < 0) ? 0 : a << Ashift;
rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
#endif
}
}
break;
case GL_INTERPOLATE_EXT:
{
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
#if CHAN_TYPE != GL_FLOAT
const GLint shift = CHAN_BITS - Ashift;
#endif
for (i=0; i<n; i++) {
#if CHAN_TYPE == GL_FLOAT
rgba[i][ACOMP] = (arg0[i][ACOMP] * arg2[i][ACOMP] +
arg1[i][ACOMP] * (CHAN_MAXF - arg2[i][ACOMP]))
* Amult;
#else
GLuint a = (PROD(arg0[i][ACOMP], arg2[i][ACOMP])
+ PROD(arg1[i][ACOMP], CHAN_MAX - arg2[i][ACOMP]))
>> shift;
rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
#endif
}
}
break;
case GL_SUBTRACT_ARB:
{
const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
for (i = 0; i < n; i++) {
#if CHAN_TYPE == GL_FLOAT
rgba[i][ACOMP] = (arg0[i][ACOMP] - arg1[i][ACOMP]) * Amult;
#else
GLint a = ((GLint) arg0[i][ACOMP] - (GLint) arg1[i][ACOMP]) << Ashift;
rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
#endif
}
}
break;

default:
_mesa_problem(ctx, "invalid combine mode");
}

/* Fix the alpha component for GL_DOT3_RGBA_EXT/ARB combining.
* This is kind of a kludge. It would have been better if the spec
* were written such that the GL_COMBINE_ALPHA value could be set to
* GL_DOT3.
*/
if (textureUnit->CombineModeRGB == GL_DOT3_RGBA_EXT ||
textureUnit->CombineModeRGB == GL_DOT3_RGBA_ARB) {
for (i = 0; i < n; i++) {
rgba[i][ACOMP] = rgba[i][RCOMP];
}
}
UNDEFARRAY(ccolor); /* mac 32k limitation */
}
#undef PROD

/**
* Implement NVIDIA's GL_NV_texture_env_combine4 extension when
* texUnit->EnvMode == GL_COMBINE4_NV.
*/
static INLINE void
texture_combine4( const GLcontext *ctx, GLuint unit, GLuint n,
CONST GLchan (*primary_rgba)[4],
CONST GLchan *texelBuffer,
GLchan (*rgba)[4] )
{
}

/**
* Apply a conventional OpenGL texture env mode (REPLACE, ADD, BLEND,
* MODULATE, or DECAL) to an array of fragments.
* Input: textureUnit - pointer to texture unit to apply
* format - base internal texture format
* n - number of fragments
* primary_rgba - primary colors (may alias rgba for single texture)
* texels - array of texel colors
* InOut: rgba - incoming fragment colors modified by texel colors
* according to the texture environment mode.
*/
static void
texture_apply( const GLcontext *ctx,
const struct gl_texture_unit *texUnit,
GLuint n,
CONST GLchan primary_rgba[][4], CONST GLchan texel[][4],
GLchan rgba[][4] )
{
GLint baseLevel;
GLuint i;
GLint Rc, Gc, Bc, Ac;
GLenum format;

ASSERT(texUnit);
ASSERT(texUnit->_Current);

baseLevel = texUnit->_Current->BaseLevel;
ASSERT(texUnit->_Current->Image[baseLevel]);

format = texUnit->_Current->Image[baseLevel]->Format;

if (format == GL_COLOR_INDEX || format == GL_DEPTH_COMPONENT
|| format == GL_YCBCR_MESA) {
format = GL_RGBA; /* a bit of a hack */
}

switch (texUnit->EnvMode) {
case GL_REPLACE:
switch (format) {
case GL_ALPHA:
for (i=0;i<n;i++) {
/* Cv = Cf */
/* Av = At */
rgba[i][ACOMP] = texel[i][ACOMP];
}
break;
case GL_LUMINANCE:
for (i=0;i<n;i++) {
/* Cv = Lt */
GLchan Lt = texel[i][RCOMP];
rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = Lt;
/* Av = Af */
}
break;
case GL_LUMINANCE_ALPHA:
for (i=0;i<n;i++) {
GLchan Lt = texel[i][RCOMP];
/* Cv = Lt */
rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = Lt;
/* Av = At */
rgba[i][ACOMP] = texel[i][ACOMP];
}
break;
case GL_INTENSITY:
for (i=0;i<n;i++) {
/* Cv = It */
GLchan It = texel[i][RCOMP];
rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = It;
/* Av = It */
rgba[i][ACOMP] = It;
}
break;
case GL_RGB:
for (i=0;i<n;i++) {
/* Cv = Ct */
rgba[i][RCOMP] = texel[i][RCOMP];
rgba[i][GCOMP] = texel[i][GCOMP];
rgba[i][BCOMP] = texel[i][BCOMP];
/* Av = Af */
}
break;
case GL_RGBA:
for (i=0;i<n;i++) {
/* Cv = Ct */
rgba[i][RCOMP] = texel[i][RCOMP];
rgba[i][GCOMP] = texel[i][GCOMP];
rgba[i][BCOMP] = texel[i][BCOMP];
/* Av = At */
rgba[i][ACOMP] = texel[i][ACOMP];
}
break;
default:
_mesa_problem(ctx, "Bad format (GL_REPLACE) in texture_apply");
return;
}
break;

case GL_MODULATE:
switch (format) {
case GL_ALPHA:
for (i=0;i<n;i++) {
/* Cv = Cf */
/* Av = AfAt */
rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
}
break;
case GL_LUMINANCE:
for (i=0;i<n;i++) {
/* Cv = LtCf */
GLchan Lt = texel[i][RCOMP];
rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], Lt );
rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], Lt );
rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], Lt );
/* Av = Af */
}
break;
case GL_LUMINANCE_ALPHA:
for (i=0;i<n;i++) {
/* Cv = CfLt */
GLchan Lt = texel[i][RCOMP];
rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], Lt );
rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], Lt );
rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], Lt );
/* Av = AfAt */
rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
}
break;
case GL_INTENSITY:
for (i=0;i<n;i++) {
/* Cv = CfIt */
GLchan It = texel[i][RCOMP];
rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], It );
rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], It );
rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], It );
/* Av = AfIt */
rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], It );
}
break;
case GL_RGB:
for (i=0;i<n;i++) {
/* Cv = CfCt */
rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], texel[i][RCOMP] );
rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], texel[i][GCOMP] );
rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], texel[i][BCOMP] );
/* Av = Af */
}
break;
case GL_RGBA:
for (i=0;i<n;i++) {
/* Cv = CfCt */
rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], texel[i][RCOMP] );
rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], texel[i][GCOMP] );
rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], texel[i][BCOMP] );
/* Av = AfAt */
rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
}
break;
default:
_mesa_problem(ctx, "Bad format (GL_MODULATE) in texture_apply");
return;
}
break;

case GL_DECAL:
switch (format) {
case GL_ALPHA:
case GL_LUMINANCE:
case GL_LUMINANCE_ALPHA:
case GL_INTENSITY:
/* undefined */
break;
case GL_RGB:
for (i=0;i<n;i++) {
/* Cv = Ct */
rgba[i][RCOMP] = texel[i][RCOMP];
rgba[i][GCOMP] = texel[i][GCOMP];
rgba[i][BCOMP] = texel[i][BCOMP];
/* Av = Af */
}
break;
case GL_RGBA:
for (i=0;i<n;i++) {
/* Cv = Cf(1-At) + CtAt */
GLint t = texel[i][ACOMP], s = CHAN_MAX - t;
rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(texel[i][RCOMP],t);
rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(texel[i][GCOMP],t);
rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(texel[i][BCOMP],t);
/* Av = Af */
}
break;
default:
_mesa_problem(ctx, "Bad format (GL_DECAL) in texture_apply");
return;
}
break;

case GL_BLEND:
Rc = (GLint) (texUnit->EnvColor[0] * CHAN_MAXF);
Gc = (GLint) (texUnit->EnvColor[1] * CHAN_MAXF);
Bc = (GLint) (texUnit->EnvColor[2] * CHAN_MAXF);
Ac = (GLint) (texUnit->EnvColor[3] * CHAN_MAXF);
switch (format) {
case GL_ALPHA:
for (i=0;i<n;i++) {
/* Cv = Cf */
/* Av = AfAt */
rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
}
break;
case GL_LUMINANCE:
for (i=0;i<n;i++) {
/* Cv = Cf(1-Lt) + CcLt */
GLchan Lt = texel[i][RCOMP], s = CHAN_MAX - Lt;
rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, Lt);
rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, Lt);
rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, Lt);
/* Av = Af */
}
break;
case GL_LUMINANCE_ALPHA:
for (i=0;i<n;i++) {
/* Cv = Cf(1-Lt) + CcLt */
GLchan Lt = texel[i][RCOMP], s = CHAN_MAX - Lt;
rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, Lt);
rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, Lt);
rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, Lt);
/* Av = AfAt */
rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP],texel[i][ACOMP]);
}
break;
case GL_INTENSITY:
for (i=0;i<n;i++) {
/* Cv = Cf(1-It) + CcLt */
GLchan It = texel[i][RCOMP], s = CHAN_MAX - It;
rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, It);
rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, It);
rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, It);
/* Av = Af(1-It) + Ac*It */
rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], s) + CHAN_PRODUCT(Ac, It);
}
break;
case GL_RGB:
for (i=0;i<n;i++) {
/* Cv = Cf(1-Ct) + CcCt */
rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], (CHAN_MAX-texel[i][RCOMP])) + CHAN_PRODUCT(Rc,texel[i][RCOMP]);
rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], (CHAN_MAX-texel[i][GCOMP])) + CHAN_PRODUCT(Gc,texel[i][GCOMP]);
rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], (CHAN_MAX-texel[i][BCOMP])) + CHAN_PRODUCT(Bc,texel[i][BCOMP]);
/* Av = Af */
}
break;
case GL_RGBA:
for (i=0;i<n;i++) {
/* Cv = Cf(1-Ct) + CcCt */
rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], (CHAN_MAX-texel[i][RCOMP])) + CHAN_PRODUCT(Rc,texel[i][RCOMP]);
rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], (CHAN_MAX-texel[i][GCOMP])) + CHAN_PRODUCT(Gc,texel[i][GCOMP]);
rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], (CHAN_MAX-texel[i][BCOMP])) + CHAN_PRODUCT(Bc,texel[i][BCOMP]);
/* Av = AfAt */
rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP],texel[i][ACOMP]);
}
break;
default:
_mesa_problem(ctx, "Bad format (GL_BLEND) in texture_apply");
return;
}
break;

/* XXX don't clamp results if GLchan is float??? */

case GL_ADD: /* GL_EXT_texture_add_env */
switch (format) {
case GL_ALPHA:
for (i=0;i<n;i++) {
/* Rv = Rf */
/* Gv = Gf */
/* Bv = Bf */
rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
}
break;
case GL_LUMINANCE:
for (i=0;i<n;i++) {
GLuint Lt = texel[i][RCOMP];
GLuint r = rgba[i][RCOMP] + Lt;
GLuint g = rgba[i][GCOMP] + Lt;
GLuint b = rgba[i][BCOMP] + Lt;
rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
/* Av = Af */
}
break;
case GL_LUMINANCE_ALPHA:
for (i=0;i<n;i++) {
GLuint Lt = texel[i][RCOMP];
GLuint r = rgba[i][RCOMP] + Lt;
GLuint g = rgba[i][GCOMP] + Lt;
GLuint b = rgba[i][BCOMP] + Lt;
rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
}
break;
case GL_INTENSITY:
for (i=0;i<n;i++) {
GLchan It = texel[i][RCOMP];
GLuint r = rgba[i][RCOMP] + It;
GLuint g = rgba[i][GCOMP] + It;
GLuint b = rgba[i][BCOMP] + It;
GLuint a = rgba[i][ACOMP] + It;
rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
rgba[i][ACOMP] = MIN2(a, CHAN_MAX);
}
break;
case GL_RGB:
for (i=0;i<n;i++) {
GLuint r = rgba[i][RCOMP] + texel[i][RCOMP];
GLuint g = rgba[i][GCOMP] + texel[i][GCOMP];
GLuint b = rgba[i][BCOMP] + texel[i][BCOMP];
rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
/* Av = Af */
}
break;
case GL_RGBA:
for (i=0;i<n;i++) {
GLuint r = rgba[i][RCOMP] + texel[i][RCOMP];
GLuint g = rgba[i][GCOMP] + texel[i][GCOMP];
GLuint b = rgba[i][BCOMP] + texel[i][BCOMP];
rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
}
break;
default:
_mesa_problem(ctx, "Bad format (GL_ADD) in texture_apply");
return;
}
break;

default:
_mesa_problem(ctx, "Bad env mode in texture_apply");
return;
}
}

/**
* Apply texture mapping to a span of fragments.
*/
void
_swrast_texture_span( GLcontext *ctx, struct sw_span *span )
{
SWcontext *swrast = SWRAST_CONTEXT(ctx);
GLchan primary_rgba[MAX_WIDTH][4];
GLuint unit;

ASSERT(span->end < MAX_WIDTH);
ASSERT(span->arrayMask & SPAN_TEXTURE);

/*
* Save copy of the incoming fragment colors (the GL_PRIMARY_COLOR)
*/
if (swrast->_AnyTextureCombine)
MEMCPY(primary_rgba, span->array->rgba, 4 * span->end * sizeof(GLchan));

/*
* Must do all texture sampling before combining in order to
* accomodate GL_ARB_texture_env_crossbar.
*/
for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
if (ctx->Texture.Unit[unit]._ReallyEnabled) {
const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
const struct gl_texture_object *curObj = texUnit->_Current;
GLfloat *lambda = span->array->lambda[unit];
GLchan (*texels)[4] = (GLchan (*)[4])
(swrast->TexelBuffer + unit * (span->end * 4 * sizeof(GLchan)));

/* adjust texture lod (lambda) */
if (span->arrayMask | SPAN_LAMBDA) {
if (texUnit->LodBias != 0.0F) {
/* apply LOD bias, but don't clamp yet */
GLuint i;
for (i = 0; i < span->end; i++) {
lambda[i] += texUnit->LodBias;
}
}

if (curObj->MinLod != -1000.0 || curObj->MaxLod != 1000.0) {
/* apply LOD clamping to lambda */
const GLfloat min = curObj->MinLod;
const GLfloat max = curObj->MaxLod;
GLuint i;
for (i = 0; i < span->end; i++) {
GLfloat l = lambda[i];
lambda[i] = CLAMP(l, min, max);
}
}
}

/* Sample the texture (span->end fragments) */
swrast->TextureSample[unit]( ctx, unit, texUnit->_Current,
span->end, span->array->texcoords[unit],
lambda, texels );
}
}

/*
* OK, now apply the texture (aka texture combine/blend).
* We modify the span->color.rgba values.
*/
for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
if (ctx->Texture.Unit[unit]._ReallyEnabled) {
const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
if (texUnit->EnvMode == GL_COMBINE_EXT) {
/* GL_ARB/EXT_texture_env_combine */
texture_combine( ctx, unit, span->end,
(CONST GLchan (*)[4]) primary_rgba,
swrast->TexelBuffer,
span->array->rgba );
}
else if (texUnit->EnvMode == GL_COMBINE4_NV) {
/* GL_NV_texture_env_combine4 */
texture_combine4( ctx, unit, span->end,
(CONST GLchan (*)[4]) primary_rgba,
swrast->TexelBuffer,
span->array->rgba );
}
else {
/* conventional texture blend */
const GLchan (*texels)[4] = (const GLchan (*)[4])
(swrast->TexelBuffer + unit *
(span->end * 4 * sizeof(GLchan)));
texture_apply( ctx, texUnit, span->end,
(CONST GLchan (*)[4]) primary_rgba, texels,
span->array->rgba );
}
}
}
}

Subversion Repositories shark

(root)/shark/trunk/ports/mesa/src/swrast/s_texture.c @ 59 - Rev 57