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/* $Id: s_aatritemp.h,v 1.1 2003-02-28 11:49:40 pj Exp $ */
/*
* Mesa 3-D graphics library
* Version: 4.1
*
* 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.
*/
/*
* Antialiased Triangle Rasterizer Template
*
* This file is #include'd to generate custom AA triangle rasterizers.
* NOTE: this code hasn't been optimized yet. That'll come after it
* works correctly.
*
* The following macros may be defined to indicate what auxillary information
* must be copmuted across the triangle:
* DO_Z - if defined, compute Z values
* DO_RGBA - if defined, compute RGBA values
* DO_INDEX - if defined, compute color index values
* DO_SPEC - if defined, compute specular RGB values
* DO_TEX - if defined, compute unit 0 STRQ texcoords
* DO_MULTITEX - if defined, compute all unit's STRQ texcoords
*/
/*void triangle( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint pv )*/
{
const GLfloat *p0 = v0->win;
const GLfloat *p1 = v1->win;
const GLfloat *p2 = v2->win;
const SWvertex *vMin, *vMid, *vMax;
GLint iyMin, iyMax;
GLfloat yMin, yMax;
GLboolean ltor;
GLfloat majDx, majDy; /* major (i.e. long) edge dx and dy */
struct sw_span span;
#ifdef DO_Z
GLfloat zPlane[4];
#endif
#ifdef DO_FOG
GLfloat fogPlane[4];
#else
GLfloat *fog = NULL;
#endif
#ifdef DO_RGBA
GLfloat rPlane[4], gPlane[4], bPlane[4], aPlane[4];
#endif
#ifdef DO_INDEX
GLfloat iPlane[4];
#endif
#ifdef DO_SPEC
GLfloat srPlane[4], sgPlane[4], sbPlane[4];
#endif
#ifdef DO_TEX
GLfloat sPlane[4], tPlane[4], uPlane[4], vPlane[4];
GLfloat texWidth, texHeight;
#elif defined(DO_MULTITEX)
GLfloat sPlane[MAX_TEXTURE_UNITS][4]; /* texture S */
GLfloat tPlane[MAX_TEXTURE_UNITS][4]; /* texture T */
GLfloat uPlane[MAX_TEXTURE_UNITS][4]; /* texture R */
GLfloat vPlane[MAX_TEXTURE_UNITS][4]; /* texture Q */
GLfloat texWidth[MAX_TEXTURE_UNITS], texHeight[MAX_TEXTURE_UNITS];
#endif
GLfloat bf = SWRAST_CONTEXT(ctx)->_backface_sign;
INIT_SPAN(span, GL_POLYGON, 0, 0, SPAN_COVERAGE);
/* determine bottom to top order of vertices */
{
GLfloat y0 = v0->win[1];
GLfloat y1 = v1->win[1];
GLfloat y2 = v2->win[1];
if (y0 <= y1) {
if (y1 <= y2) {
vMin = v0; vMid = v1; vMax = v2; /* y0<=y1<=y2 */
}
else if (y2 <= y0) {
vMin = v2; vMid = v0; vMax = v1; /* y2<=y0<=y1 */
}
else {
vMin = v0; vMid = v2; vMax = v1; bf = -bf; /* y0<=y2<=y1 */
}
}
else {
if (y0 <= y2) {
vMin = v1; vMid = v0; vMax = v2; bf = -bf; /* y1<=y0<=y2 */
}
else if (y2 <= y1) {
vMin = v2; vMid = v1; vMax = v0; bf = -bf; /* y2<=y1<=y0 */
}
else {
vMin = v1; vMid = v2; vMax = v0; /* y1<=y2<=y0 */
}
}
}
majDx = vMax->win[0] - vMin->win[0];
majDy = vMax->win[1] - vMin->win[1];
{
const GLfloat botDx = vMid->win[0] - vMin->win[0];
const GLfloat botDy = vMid->win[1] - vMin->win[1];
const GLfloat area = majDx * botDy - botDx * majDy;
ltor = (GLboolean) (area < 0.0F);
/* Do backface culling */
if (area * bf < 0 || area == 0 || IS_INF_OR_NAN(area))
return;
}
#ifndef DO_OCCLUSION_TEST
ctx->OcclusionResult = GL_TRUE;
#endif
/* Plane equation setup:
* We evaluate plane equations at window (x,y) coordinates in order
* to compute color, Z, fog, texcoords, etc. This isn't terribly
* efficient but it's easy and reliable.
*/
#ifdef DO_Z
compute_plane(p0, p1, p2, p0[2], p1[2], p2[2], zPlane);
span.arrayMask |= SPAN_Z;
#endif
#ifdef DO_FOG
compute_plane(p0, p1, p2, v0->fog, v1->fog, v2->fog, fogPlane);
span.arrayMask |= SPAN_FOG;
#endif
#ifdef DO_RGBA
if (ctx->Light.ShadeModel == GL_SMOOTH) {
compute_plane(p0, p1, p2, v0->color[0], v1->color[0], v2->color[0], rPlane);
compute_plane(p0, p1, p2, v0->color[1], v1->color[1], v2->color[1], gPlane);
compute_plane(p0, p1, p2, v0->color[2], v1->color[2], v2->color[2], bPlane);
compute_plane(p0, p1, p2, v0->color[3], v1->color[3], v2->color[3], aPlane);
}
else {
constant_plane(v2->color[RCOMP], rPlane);
constant_plane(v2->color[GCOMP], gPlane);
constant_plane(v2->color[BCOMP], bPlane);
constant_plane(v2->color[ACOMP], aPlane);
}
span.arrayMask |= SPAN_RGBA;
#endif
#ifdef DO_INDEX
if (ctx->Light.ShadeModel == GL_SMOOTH) {
compute_plane(p0, p1, p2, (GLfloat) v0->index,
(GLfloat) v1->index, (GLfloat) v2->index, iPlane);
}
else {
constant_plane((GLfloat) v2->index, iPlane);
}
span.arrayMask |= SPAN_INDEX;
#endif
#ifdef DO_SPEC
if (ctx->Light.ShadeModel == GL_SMOOTH) {
compute_plane(p0, p1, p2, v0->specular[0], v1->specular[0], v2->specular[0],srPlane);
compute_plane(p0, p1, p2, v0->specular[1], v1->specular[1], v2->specular[1],sgPlane);
compute_plane(p0, p1, p2, v0->specular[2], v1->specular[2], v2->specular[2],sbPlane);
}
else {
constant_plane(v2->specular[RCOMP], srPlane);
constant_plane(v2->specular[GCOMP], sgPlane);
constant_plane(v2->specular[BCOMP], sbPlane);
}
span.arrayMask |= SPAN_SPEC;
#endif
#ifdef DO_TEX
{
const struct gl_texture_object *obj = ctx->Texture.Unit[0]._Current;
const struct gl_texture_image *texImage = obj->Image[obj->BaseLevel];
const GLfloat invW0 = v0->win[3];
const GLfloat invW1 = v1->win[3];
const GLfloat invW2 = v2->win[3];
const GLfloat s0 = v0->texcoord[0][0] * invW0;
const GLfloat s1 = v1->texcoord[0][0] * invW1;
const GLfloat s2 = v2->texcoord[0][0] * invW2;
const GLfloat t0 = v0->texcoord[0][1] * invW0;
const GLfloat t1 = v1->texcoord[0][1] * invW1;
const GLfloat t2 = v2->texcoord[0][1] * invW2;
const GLfloat r0 = v0->texcoord[0][2] * invW0;
const GLfloat r1 = v1->texcoord[0][2] * invW1;
const GLfloat r2 = v2->texcoord[0][2] * invW2;
const GLfloat q0 = v0->texcoord[0][3] * invW0;
const GLfloat q1 = v1->texcoord[0][3] * invW1;
const GLfloat q2 = v2->texcoord[0][3] * invW2;
compute_plane(p0, p1, p2, s0, s1, s2, sPlane);
compute_plane(p0, p1, p2, t0, t1, t2, tPlane);
compute_plane(p0, p1, p2, r0, r1, r2, uPlane);
compute_plane(p0, p1, p2, q0, q1, q2, vPlane);
texWidth = (GLfloat) texImage->Width;
texHeight = (GLfloat) texImage->Height;
}
span.arrayMask |= (SPAN_TEXTURE | SPAN_LAMBDA);
#elif defined(DO_MULTITEX)
{
GLuint u;
for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
if (ctx->Texture.Unit[u]._ReallyEnabled) {
const struct gl_texture_object *obj = ctx->Texture.Unit[u]._Current;
const struct gl_texture_image *texImage = obj->Image[obj->BaseLevel];
const GLfloat invW0 = v0->win[3];
const GLfloat invW1 = v1->win[3];
const GLfloat invW2 = v2->win[3];
const GLfloat s0 = v0->texcoord[u][0] * invW0;
const GLfloat s1 = v1->texcoord[u][0] * invW1;
const GLfloat s2 = v2->texcoord[u][0] * invW2;
const GLfloat t0 = v0->texcoord[u][1] * invW0;
const GLfloat t1 = v1->texcoord[u][1] * invW1;
const GLfloat t2 = v2->texcoord[u][1] * invW2;
const GLfloat r0 = v0->texcoord[u][2] * invW0;
const GLfloat r1 = v1->texcoord[u][2] * invW1;
const GLfloat r2 = v2->texcoord[u][2] * invW2;
const GLfloat q0 = v0->texcoord[u][3] * invW0;
const GLfloat q1 = v1->texcoord[u][3] * invW1;
const GLfloat q2 = v2->texcoord[u][3] * invW2;
compute_plane(p0, p1, p2, s0, s1, s2, sPlane[u]);
compute_plane(p0, p1, p2, t0, t1, t2, tPlane[u]);
compute_plane(p0, p1, p2, r0, r1, r2, uPlane[u]);
compute_plane(p0, p1, p2, q0, q1, q2, vPlane[u]);
texWidth[u] = (GLfloat) texImage->Width;
texHeight[u] = (GLfloat) texImage->Height;
}
}
}
span.arrayMask |= (SPAN_TEXTURE | SPAN_LAMBDA);
#endif
/* Begin bottom-to-top scan over the triangle.
* The long edge will either be on the left or right side of the
* triangle. We always scan from the long edge toward the shorter
* edges, stopping when we find that coverage = 0. If the long edge
* is on the left we scan left-to-right. Else, we scan right-to-left.
*/
yMin = vMin->win[1];
yMax = vMax->win[1];
iyMin = (GLint) yMin;
iyMax = (GLint) yMax + 1;
if (ltor) {
/* scan left to right */
const GLfloat *pMin = vMin->win;
const GLfloat *pMid = vMid->win;
const GLfloat *pMax = vMax->win;
const GLfloat dxdy = majDx / majDy;
const GLfloat xAdj = dxdy < 0.0F ? -dxdy : 0.0F;
GLfloat x = pMin[0] - (yMin - iyMin) * dxdy;
GLint iy;
for (iy = iyMin; iy < iyMax; iy++, x += dxdy) {
GLint ix, startX = (GLint) (x - xAdj);
GLuint count;
GLfloat coverage = 0.0F;
/* skip over fragments with zero coverage */
while (startX < MAX_WIDTH) {
coverage = compute_coveragef(pMin, pMid, pMax, startX, iy);
if (coverage > 0.0F)
break;
startX++;
}
/* enter interior of triangle */
ix = startX;
count = 0;
while (coverage > 0.0F) {
/* (cx,cy) = center of fragment */
const GLfloat cx = ix + 0.5F, cy = iy + 0.5F;
struct span_arrays *array = span.array;
#ifdef DO_INDEX
array->coverage[count] = (GLfloat) compute_coveragei(pMin, pMid, pMax, ix, iy);
#else
array->coverage[count] = coverage;
#endif
#ifdef DO_Z
array->z[count] = (GLdepth) solve_plane(cx, cy, zPlane);
#endif
#ifdef DO_FOG
array->fog[count] = solve_plane(cx, cy, fogPlane);
#endif
#ifdef DO_RGBA
array->rgba[count][RCOMP] = solve_plane_chan(cx, cy, rPlane);
array->rgba[count][GCOMP] = solve_plane_chan(cx, cy, gPlane);
array->rgba[count][BCOMP] = solve_plane_chan(cx, cy, bPlane);
array->rgba[count][ACOMP] = solve_plane_chan(cx, cy, aPlane);
#endif
#ifdef DO_INDEX
array->index[count] = (GLint) solve_plane(cx, cy, iPlane);
#endif
#ifdef DO_SPEC
array->spec[count][RCOMP] = solve_plane_chan(cx, cy, srPlane);
array->spec[count][GCOMP] = solve_plane_chan(cx, cy, sgPlane);
array->spec[count][BCOMP] = solve_plane_chan(cx, cy, sbPlane);
#endif
#ifdef DO_TEX
{
const GLfloat invQ = solve_plane_recip(cx, cy, vPlane);
array->texcoords[0][count][0] = solve_plane(cx, cy, sPlane) * invQ;
array->texcoords[0][count][1] = solve_plane(cx, cy, tPlane) * invQ;
array->texcoords[0][count][2] = solve_plane(cx, cy, uPlane) * invQ;
array->lambda[0][count] = compute_lambda(sPlane, tPlane, vPlane,
cx, cy, invQ,
texWidth, texHeight);
}
#elif defined(DO_MULTITEX)
{
GLuint unit;
for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
if (ctx->Texture.Unit[unit]._ReallyEnabled) {
GLfloat invQ = solve_plane_recip(cx, cy, vPlane[unit]);
array->texcoords[unit][count][0] = solve_plane(cx, cy, sPlane[unit]) * invQ;
array->texcoords[unit][count][1] = solve_plane(cx, cy, tPlane[unit]) * invQ;
array->texcoords[unit][count][2] = solve_plane(cx, cy, uPlane[unit]) * invQ;
array->lambda[unit][count] = compute_lambda(sPlane[unit],
tPlane[unit], vPlane[unit], cx, cy, invQ,
texWidth[unit], texHeight[unit]);
}
}
}
#endif
ix++;
count++;
coverage = compute_coveragef(pMin, pMid, pMax, ix, iy);
}
if (ix <= startX)
continue;
span.x = startX;
span.y = iy;
span.end = (GLuint) ix - (GLuint) startX;
ASSERT(span.interpMask == 0);
#if defined(DO_MULTITEX) || defined(DO_TEX)
_mesa_write_texture_span(ctx, &span);
#elif defined(DO_RGBA)
_mesa_write_rgba_span(ctx, &span);
#elif defined(DO_INDEX)
_mesa_write_index_span(ctx, &span);
#endif
}
}
else {
/* scan right to left */
const GLfloat *pMin = vMin->win;
const GLfloat *pMid = vMid->win;
const GLfloat *pMax = vMax->win;
const GLfloat dxdy = majDx / majDy;
const GLfloat xAdj = dxdy > 0 ? dxdy : 0.0F;
GLfloat x = pMin[0] - (yMin - iyMin) * dxdy;
GLint iy;
for (iy = iyMin; iy < iyMax; iy++, x += dxdy) {
GLint ix, left, startX = (GLint) (x + xAdj);
GLuint count, n;
GLfloat coverage = 0.0F;
/* make sure we're not past the window edge */
if (startX >= ctx->DrawBuffer->_Xmax) {
startX = ctx->DrawBuffer->_Xmax - 1;
}
/* skip fragments with zero coverage */
while (startX >= 0) {
coverage = compute_coveragef(pMin, pMax, pMid, startX, iy);
if (coverage > 0.0F)
break;
startX--;
}
/* enter interior of triangle */
ix = startX;
count = 0;
while (coverage > 0.0F) {
/* (cx,cy) = center of fragment */
const GLfloat cx = ix + 0.5F, cy = iy + 0.5F;
struct span_arrays *array = span.array;
#ifdef DO_INDEX
array->coverage[ix] = (GLfloat) compute_coveragei(pMin, pMax, pMid, ix, iy);
#else
array->coverage[ix] = coverage;
#endif
#ifdef DO_Z
array->z[ix] = (GLdepth) solve_plane(cx, cy, zPlane);
#endif
#ifdef DO_FOG
array->fog[ix] = solve_plane(cx, cy, fogPlane);
#endif
#ifdef DO_RGBA
array->rgba[ix][RCOMP] = solve_plane_chan(cx, cy, rPlane);
array->rgba[ix][GCOMP] = solve_plane_chan(cx, cy, gPlane);
array->rgba[ix][BCOMP] = solve_plane_chan(cx, cy, bPlane);
array->rgba[ix][ACOMP] = solve_plane_chan(cx, cy, aPlane);
#endif
#ifdef DO_INDEX
array->index[ix] = (GLint) solve_plane(cx, cy, iPlane);
#endif
#ifdef DO_SPEC
array->spec[ix][RCOMP] = solve_plane_chan(cx, cy, srPlane);
array->spec[ix][GCOMP] = solve_plane_chan(cx, cy, sgPlane);
array->spec[ix][BCOMP] = solve_plane_chan(cx, cy, sbPlane);
#endif
#ifdef DO_TEX
{
const GLfloat invQ = solve_plane_recip(cx, cy, vPlane);
array->texcoords[0][ix][0] = solve_plane(cx, cy, sPlane) * invQ;
array->texcoords[0][ix][1] = solve_plane(cx, cy, tPlane) * invQ;
array->texcoords[0][ix][2] = solve_plane(cx, cy, uPlane) * invQ;
array->lambda[0][ix] = compute_lambda(sPlane, tPlane, vPlane,
cx, cy, invQ, texWidth, texHeight);
}
#elif defined(DO_MULTITEX)
{
GLuint unit;
for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
if (ctx->Texture.Unit[unit]._ReallyEnabled) {
GLfloat invQ = solve_plane_recip(cx, cy, vPlane[unit]);
array->texcoords[unit][ix][0] = solve_plane(cx, cy, sPlane[unit]) * invQ;
array->texcoords[unit][ix][1] = solve_plane(cx, cy, tPlane[unit]) * invQ;
array->texcoords[unit][ix][2] = solve_plane(cx, cy, uPlane[unit]) * invQ;
array->lambda[unit][ix] = compute_lambda(sPlane[unit],
tPlane[unit],
vPlane[unit],
cx, cy, invQ,
texWidth[unit],
texHeight[unit]);
}
}
}
#endif
ix--;
count++;
coverage = compute_coveragef(pMin, pMax, pMid, ix, iy);
}
if (startX <= ix)
continue;
n = (GLuint) startX - (GLuint) ix;
left = ix + 1;
/* shift all values to the left */
/* XXX this is temporary */
{
struct span_arrays *array = span.array;
GLint j;
for (j = 0; j < (GLint) n; j++) {
#ifdef DO_RGBA
COPY_4V(array->rgba[j], array->rgba[j + left]);
#endif
#ifdef DO_SPEC
COPY_4V(array->spec[j], array->spec[j + left]);
#endif
#ifdef DO_INDEX
array->index[j] = array->index[j + left];
#endif
#ifdef DO_Z
array->z[j] = array->z[j + left];
#endif
#ifdef DO_FOG
array->fog[j] = array->fog[j + left];
#endif
#ifdef DO_TEX
COPY_4V(array->texcoords[0][j], array->texcoords[0][j + left]);
#endif
#if defined(DO_MULTITEX) || defined(DO_TEX)
array->lambda[0][j] = array->lambda[0][j + left];
#endif
array->coverage[j] = array->coverage[j + left];
}
}
#ifdef DO_MULTITEX
/* shift texcoords */
{
struct span_arrays *array = span.array;
GLuint unit;
for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
if (ctx->Texture.Unit[unit]._ReallyEnabled) {
GLint j;
for (j = 0; j < (GLint) n; j++) {
array->texcoords[unit][j][0] = array->texcoords[unit][j + left][0];
array->texcoords[unit][j][1] = array->texcoords[unit][j + left][1];
array->texcoords[unit][j][2] = array->texcoords[unit][j + left][2];
array->lambda[unit][j] = array->lambda[unit][j + left];
}
}
}
}
#endif
span.x = left;
span.y = iy;
span.end = n;
ASSERT(span.interpMask == 0);
#if defined(DO_MULTITEX) || defined(DO_TEX)
_mesa_write_texture_span(ctx, &span);
#elif defined(DO_RGBA)
_mesa_write_rgba_span(ctx, &span);
#elif defined(DO_INDEX)
_mesa_write_index_span(ctx, &span);
#endif
}
}
}
#ifdef DO_Z
#undef DO_Z
#endif
#ifdef DO_FOG
#undef DO_FOG
#endif
#ifdef DO_RGBA
#undef DO_RGBA
#endif
#ifdef DO_INDEX
#undef DO_INDEX
#endif
#ifdef DO_SPEC
#undef DO_SPEC
#endif
#ifdef DO_TEX
#undef DO_TEX
#endif
#ifdef DO_MULTITEX
#undef DO_MULTITEX
#endif
#ifdef DO_OCCLUSION_TEST
#undef DO_OCCLUSION_TEST
#endif