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/* $Id: s_linetemp.h,v 1.1 2003-02-28 11:49:42 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.
*/
/*
* Line Rasterizer Template
*
* This file is #include'd to generate custom line rasterizers.
*
* The following macros may be defined to indicate what auxillary information
* must be interplated along the line:
* INTERP_Z - if defined, interpolate Z values
* INTERP_FOG - if defined, interpolate FOG values
* INTERP_RGB - if defined, interpolate RGB values
* INTERP_SPEC - if defined, interpolate specular RGB values
* INTERP_ALPHA - if defined, interpolate Alpha values
* INTERP_INDEX - if defined, interpolate color index values
* INTERP_TEX - if defined, interpolate unit 0 texcoords
* INTERP_MULTITEX - if defined, interpolate multi-texcoords
*
* When one can directly address pixels in the color buffer the following
* macros can be defined and used to directly compute pixel addresses during
* rasterization (see pixelPtr):
* PIXEL_TYPE - the datatype of a pixel (GLubyte, GLushort, GLuint)
* BYTES_PER_ROW - number of bytes per row in the color buffer
* PIXEL_ADDRESS(X,Y) - returns the address of pixel at (X,Y) where
* Y==0 at bottom of screen and increases upward.
*
* Similarly, for direct depth buffer access, this type is used for depth
* buffer addressing:
* DEPTH_TYPE - either GLushort or GLuint
*
* Optionally, one may provide one-time setup code
* SETUP_CODE - code which is to be executed once per line
*
* To actually "plot" each pixel the PLOT macro must be defined...
* PLOT(X,Y) - code to plot a pixel. Example:
* if (Z < *zPtr) {
* *zPtr = Z;
* color = pack_rgb( FixedToInt(r0), FixedToInt(g0),
* FixedToInt(b0) );
* put_pixel( X, Y, color );
* }
*
* This code was designed for the origin to be in the lower-left corner.
*
*/
/*void line( GLcontext *ctx, const SWvertex *vert0, const SWvertex *vert1 )*/
{
GLint x0 = (GLint) vert0->win[0];
GLint x1 = (GLint) vert1->win[0];
GLint y0 = (GLint) vert0->win[1];
GLint y1 = (GLint) vert1->win[1];
GLint dx, dy;
#ifdef INTERP_XY
GLint xstep, ystep;
#endif
#ifdef INTERP_Z
GLint z0, z1, dz;
const GLint depthBits = ctx->Visual.depthBits;
const GLint fixedToDepthShift = depthBits <= 16 ? FIXED_SHIFT : 0;
# define FixedToDepth(F) ((F) >> fixedToDepthShift)
# ifdef DEPTH_TYPE
GLint zPtrXstep, zPtrYstep;
DEPTH_TYPE *zPtr;
# endif
#endif
#ifdef INTERP_FOG
GLfloat fog0 = vert0->fog;
GLfloat dfog = vert1->fog - fog0;
#endif
#ifdef INTERP_RGB
GLfixed r0 = ChanToFixed(vert0->color[0]);
GLfixed dr = ChanToFixed(vert1->color[0]) - r0;
GLfixed g0 = ChanToFixed(vert0->color[1]);
GLfixed dg = ChanToFixed(vert1->color[1]) - g0;
GLfixed b0 = ChanToFixed(vert0->color[2]);
GLfixed db = ChanToFixed(vert1->color[2]) - b0;
#endif
#ifdef INTERP_SPEC
GLfixed sr0 = ChanToFixed(vert0->specular[0]);
GLfixed dsr = ChanToFixed(vert1->specular[0]) - sr0;
GLfixed sg0 = ChanToFixed(vert0->specular[1]);
GLfixed dsg = ChanToFixed(vert1->specular[1]) - sg0;
GLfixed sb0 = ChanToFixed(vert0->specular[2]);
GLfixed dsb = ChanToFixed(vert1->specular[2]) - sb0;
#endif
#ifdef INTERP_ALPHA
GLfixed a0 = ChanToFixed(vert0->color[3]);
GLfixed da = ChanToFixed(vert1->color[3]) - a0;
#endif
#ifdef INTERP_INDEX
GLint i0 = vert0->index << 8;
GLint di = (GLint) (vert1->index << 8) - i0;
#endif
#ifdef INTERP_TEX
const GLfloat invw0 = vert0->win[3];
const GLfloat invw1 = vert1->win[3];
GLfloat tex[4];
GLfloat dtex[4];
GLfloat fragTexcoord[4];
#endif
#ifdef INTERP_MULTITEX
const GLfloat invw0 = vert0->win[3];
const GLfloat invw1 = vert1->win[3];
GLfloat tex[MAX_TEXTURE_UNITS][4];
GLfloat dtex[MAX_TEXTURE_UNITS][4];
GLfloat fragTexcoord[MAX_TEXTURE_UNITS][4];
#endif
#ifdef PIXEL_ADDRESS
PIXEL_TYPE *pixelPtr;
GLint pixelXstep, pixelYstep;
#endif
#ifdef INTERP_TEX
{
tex[0] = invw0 * vert0->texcoord[0][0];
dtex[0] = invw1 * vert1->texcoord[0][0] - tex[0];
tex[1] = invw0 * vert0->texcoord[0][1];
dtex[1] = invw1 * vert1->texcoord[0][1] - tex[1];
tex[2] = invw0 * vert0->texcoord[0][2];
dtex[2] = invw1 * vert1->texcoord[0][2] - tex[2];
tex[3] = invw0 * vert0->texcoord[0][3];
dtex[3] = invw1 * vert1->texcoord[0][3] - tex[3];
}
#endif
#ifdef INTERP_MULTITEX
{
GLuint u;
for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
if (ctx->Texture.Unit[u]._ReallyEnabled) {
tex[u][0] = invw0 * vert0->texcoord[u][0];
dtex[u][0] = invw1 * vert1->texcoord[u][0] - tex[u][0];
tex[u][1] = invw0 * vert0->texcoord[u][1];
dtex[u][1] = invw1 * vert1->texcoord[u][1] - tex[u][1];
tex[u][2] = invw0 * vert0->texcoord[u][2];
dtex[u][2] = invw1 * vert1->texcoord[u][2] - tex[u][2];
tex[u][3] = invw0 * vert0->texcoord[u][3];
dtex[u][3] = invw1 * vert1->texcoord[u][3] - tex[u][3];
}
}
}
#endif
/* Cull primitives with malformed coordinates.
*/
{
float tmp = vert0->win[0] + vert0->win[1] + vert1->win[0] + vert1->win[1];
if (IS_INF_OR_NAN(tmp))
return;
}
/*
printf("%s():\n", __FUNCTION__);
printf(" (%f, %f, %f) -> (%f, %f, %f)\n",
vert0->win[0], vert0->win[1], vert0->win[2],
vert1->win[0], vert1->win[1], vert1->win[2]);
printf(" (%d, %d, %d) -> (%d, %d, %d)\n",
vert0->color[0], vert0->color[1], vert0->color[2],
vert1->color[0], vert1->color[1], vert1->color[2]);
printf(" (%d, %d, %d) -> (%d, %d, %d)\n",
vert0->specular[0], vert0->specular[1], vert0->specular[2],
vert1->specular[0], vert1->specular[1], vert1->specular[2]);
*/
/*
* Despite being clipped to the view volume, the line's window coordinates
* may just lie outside the window bounds. That is, if the legal window
* coordinates are [0,W-1][0,H-1], it's possible for x==W and/or y==H.
* This quick and dirty code nudges the endpoints inside the window if
* necessary.
*/
#ifdef CLIP_HACK
{
GLint w = ctx->DrawBuffer->Width;
GLint h = ctx->DrawBuffer->Height;
if ((x0==w) | (x1==w)) {
if ((x0==w) & (x1==w))
return;
x0 -= x0==w;
x1 -= x1==w;
}
if ((y0==h) | (y1==h)) {
if ((y0==h) & (y1==h))
return;
y0 -= y0==h;
y1 -= y1==h;
}
}
#endif
dx = x1 - x0;
dy = y1 - y0;
if (dx==0 && dy==0) {
return;
}
/*
* Setup
*/
#ifdef SETUP_CODE
SETUP_CODE
#endif
#ifdef INTERP_Z
# ifdef DEPTH_TYPE
zPtr = (DEPTH_TYPE *) _mesa_zbuffer_address(ctx, x0, y0);
# endif
if (depthBits <= 16) {
z0 = FloatToFixed(vert0->win[2]) + FIXED_HALF;
z1 = FloatToFixed(vert1->win[2]) + FIXED_HALF;
}
else {
z0 = (int) vert0->win[2];
z1 = (int) vert1->win[2];
}
#endif
#ifdef PIXEL_ADDRESS
pixelPtr = (PIXEL_TYPE *) PIXEL_ADDRESS(x0,y0);
#endif
if (dx<0) {
dx = -dx; /* make positive */
#ifdef INTERP_XY
xstep = -1;
#endif
#if defined(INTERP_Z) && defined(DEPTH_TYPE)
zPtrXstep = -((GLint)sizeof(DEPTH_TYPE));
#endif
#ifdef PIXEL_ADDRESS
pixelXstep = -((GLint)sizeof(PIXEL_TYPE));
#endif
}
else {
#ifdef INTERP_XY
xstep = 1;
#endif
#if defined(INTERP_Z) && defined(DEPTH_TYPE)
zPtrXstep = ((GLint)sizeof(DEPTH_TYPE));
#endif
#ifdef PIXEL_ADDRESS
pixelXstep = ((GLint)sizeof(PIXEL_TYPE));
#endif
}
if (dy<0) {
dy = -dy; /* make positive */
#ifdef INTERP_XY
ystep = -1;
#endif
#if defined(INTERP_Z) && defined(DEPTH_TYPE)
zPtrYstep = -((GLint) (ctx->DrawBuffer->Width * sizeof(DEPTH_TYPE)));
#endif
#ifdef PIXEL_ADDRESS
pixelYstep = BYTES_PER_ROW;
#endif
}
else {
#ifdef INTERP_XY
ystep = 1;
#endif
#if defined(INTERP_Z) && defined(DEPTH_TYPE)
zPtrYstep = (GLint) (ctx->DrawBuffer->Width * sizeof(DEPTH_TYPE));
#endif
#ifdef PIXEL_ADDRESS
pixelYstep = -(BYTES_PER_ROW);
#endif
}
/*
* Draw
*/
if (dx>dy) {
/*** X-major line ***/
GLint i;
GLint errorInc = dy+dy;
GLint error = errorInc-dx;
GLint errorDec = error-dx;
#ifdef SET_XMAJOR
xMajor = GL_TRUE;
#endif
#ifdef INTERP_Z
dz = (z1-z0) / dx;
#endif
#ifdef INTERP_FOG
dfog /= dx;
#endif
#ifdef INTERP_RGB
dr /= dx; /* convert from whole line delta to per-pixel delta */
dg /= dx;
db /= dx;
#endif
#ifdef INTERP_SPEC
dsr /= dx; /* convert from whole line delta to per-pixel delta */
dsg /= dx;
dsb /= dx;
#endif
#ifdef INTERP_ALPHA
da /= dx;
#endif
#ifdef INTERP_INDEX
di /= dx;
#endif
#ifdef INTERP_TEX
{
const GLfloat invDx = 1.0F / (GLfloat) dx;
dtex[0] *= invDx;
dtex[1] *= invDx;
dtex[2] *= invDx;
dtex[3] *= invDx;
}
#endif
#ifdef INTERP_MULTITEX
{
const GLfloat invDx = 1.0F / (GLfloat) dx;
GLuint u;
for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
if (ctx->Texture.Unit[u]._ReallyEnabled) {
dtex[u][0] *= invDx;
dtex[u][1] *= invDx;
dtex[u][2] *= invDx;
dtex[u][3] *= invDx;
}
}
}
#endif
for (i=0;i<dx;i++) {
#ifdef INTERP_Z
GLdepth Z = FixedToDepth(z0);
#endif
#ifdef INTERP_INDEX
GLint I = i0 >> 8;
#endif
#ifdef INTERP_TEX
{
const GLfloat invQ = tex[3] ? (1.0F / tex[3]) : 1.0F;
fragTexcoord[0] = tex[0] * invQ;
fragTexcoord[1] = tex[1] * invQ;
fragTexcoord[2] = tex[2] * invQ;
fragTexcoord[3] = tex[3];
}
#endif
#ifdef INTERP_MULTITEX
{
GLuint u;
for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
if (ctx->Texture.Unit[u]._ReallyEnabled) {
const GLfloat invQ = 1.0F / tex[u][3];
fragTexcoord[u][0] = tex[u][0] * invQ;
fragTexcoord[u][1] = tex[u][1] * invQ;
fragTexcoord[u][2] = tex[u][2] * invQ;
fragTexcoord[u][3] = tex[u][3];
}
}
}
#endif
PLOT( x0, y0 );
#ifdef INTERP_XY
x0 += xstep;
#endif
#ifdef INTERP_Z
# ifdef DEPTH_TYPE
zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrXstep);
# endif
z0 += dz;
#endif
#ifdef INTERP_FOG
fog0 += dfog;
#endif
#ifdef INTERP_RGB
r0 += dr;
g0 += dg;
b0 += db;
#endif
#ifdef INTERP_SPEC
sr0 += dsr;
sg0 += dsg;
sb0 += dsb;
#endif
#ifdef INTERP_ALPHA
a0 += da;
#endif
#ifdef INTERP_INDEX
i0 += di;
#endif
#ifdef INTERP_TEX
tex[0] += dtex[0];
tex[1] += dtex[1];
tex[2] += dtex[2];
tex[3] += dtex[3];
#endif
#ifdef INTERP_MULTITEX
{
GLuint u;
for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
if (ctx->Texture.Unit[u]._ReallyEnabled) {
tex[u][0] += dtex[u][0];
tex[u][1] += dtex[u][1];
tex[u][2] += dtex[u][2];
tex[u][3] += dtex[u][3];
}
}
}
#endif
#ifdef PIXEL_ADDRESS
pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelXstep);
#endif
if (error<0) {
error += errorInc;
}
else {
error += errorDec;
#ifdef INTERP_XY
y0 += ystep;
#endif
#if defined(INTERP_Z) && defined(DEPTH_TYPE)
zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrYstep);
#endif
#ifdef PIXEL_ADDRESS
pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelYstep);
#endif
}
}
}
else {
/*** Y-major line ***/
GLint i;
GLint errorInc = dx+dx;
GLint error = errorInc-dy;
GLint errorDec = error-dy;
#ifdef INTERP_Z
dz = (z1-z0) / dy;
#endif
#ifdef INTERP_FOG
dfog /= dy;
#endif
#ifdef INTERP_RGB
dr /= dy; /* convert from whole line delta to per-pixel delta */
dg /= dy;
db /= dy;
#endif
#ifdef INTERP_SPEC
dsr /= dy; /* convert from whole line delta to per-pixel delta */
dsg /= dy;
dsb /= dy;
#endif
#ifdef INTERP_ALPHA
da /= dy;
#endif
#ifdef INTERP_INDEX
di /= dy;
#endif
#ifdef INTERP_TEX
{
const GLfloat invDy = 1.0F / (GLfloat) dy;
dtex[0] *= invDy;
dtex[1] *= invDy;
dtex[2] *= invDy;
dtex[3] *= invDy;
}
#endif
#ifdef INTERP_MULTITEX
{
const GLfloat invDy = 1.0F / (GLfloat) dy;
GLuint u;
for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
if (ctx->Texture.Unit[u]._ReallyEnabled) {
dtex[u][0] *= invDy;
dtex[u][1] *= invDy;
dtex[u][2] *= invDy;
dtex[u][3] *= invDy;
}
}
}
#endif
for (i=0;i<dy;i++) {
#ifdef INTERP_Z
GLdepth Z = FixedToDepth(z0);
#endif
#ifdef INTERP_INDEX
GLint I = i0 >> 8;
#endif
#ifdef INTERP_TEX
{
const GLfloat invQ = tex[3] ? (1.0F / tex[3]) : 1.0F;
fragTexcoord[0] = tex[0] * invQ;
fragTexcoord[1] = tex[1] * invQ;
fragTexcoord[2] = tex[2] * invQ;
fragTexcoord[3] = tex[3];
}
#endif
#ifdef INTERP_MULTITEX
{
GLuint u;
for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
if (ctx->Texture.Unit[u]._ReallyEnabled) {
const GLfloat invQ = 1.0F / tex[u][3];
fragTexcoord[u][0] = tex[u][0] * invQ;
fragTexcoord[u][1] = tex[u][1] * invQ;
fragTexcoord[u][2] = tex[u][2] * invQ;
fragTexcoord[u][3] = tex[u][3];
}
}
}
#endif
PLOT( x0, y0 );
#ifdef INTERP_XY
y0 += ystep;
#endif
#ifdef INTERP_Z
# ifdef DEPTH_TYPE
zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrYstep);
# endif
z0 += dz;
#endif
#ifdef INTERP_FOG
fog0 += dfog;
#endif
#ifdef INTERP_RGB
r0 += dr;
g0 += dg;
b0 += db;
#endif
#ifdef INTERP_SPEC
sr0 += dsr;
sg0 += dsg;
sb0 += dsb;
#endif
#ifdef INTERP_ALPHA
a0 += da;
#endif
#ifdef INTERP_INDEX
i0 += di;
#endif
#ifdef INTERP_TEX
tex[0] += dtex[0];
tex[1] += dtex[1];
tex[2] += dtex[2];
tex[3] += dtex[3];
#endif
#ifdef INTERP_MULTITEX
{
GLuint u;
for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
if (ctx->Texture.Unit[u]._ReallyEnabled) {
tex[u][0] += dtex[u][0];
tex[u][1] += dtex[u][1];
tex[u][2] += dtex[u][2];
tex[u][3] += dtex[u][3];
}
}
}
#endif
#ifdef PIXEL_ADDRESS
pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelYstep);
#endif
if (error<0) {
error += errorInc;
}
else {
error += errorDec;
#ifdef INTERP_XY
x0 += xstep;
#endif
#if defined(INTERP_Z) && defined(DEPTH_TYPE)
zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrXstep);
#endif
#ifdef PIXEL_ADDRESS
pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelXstep);
#endif
}
}
}
}
#undef INTERP_XY
#undef INTERP_Z
#undef INTERP_FOG
#undef INTERP_RGB
#undef INTERP_SPEC
#undef INTERP_ALPHA
#undef INTERP_TEX
#undef INTERP_MULTITEX
#undef INTERP_INDEX
#undef PIXEL_ADDRESS
#undef PIXEL_TYPE
#undef DEPTH_TYPE
#undef BYTES_PER_ROW
#undef SETUP_CODE
#undef PLOT
#undef CLIP_HACK
#undef FixedToDepth
#undef SET_XMAJOR