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|
/*
* Mesa 3-D graphics library
* Version: 3.3
*
* Copyright (C) 1999-2000 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_STUV0 - if defined, compute unit 0 STRQ texcoords
* DO_STUV1 - if defined, compute unit 1 STRQ texcoords
*/
/*void triangle( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint pv )*/
{
const struct vertex_buffer *VB = ctx->VB;
const GLfloat *p0 = VB->Win.data[v0];
const GLfloat *p1 = VB->Win.data[v1];
const GLfloat *p2 = VB->Win.data[v2];
GLint vMin, vMid, vMax;
GLint iyMin, iyMax;
GLfloat yMin, yMax;
GLboolean ltor;
GLfloat majDx, majDy;
#ifdef DO_Z
GLfloat zPlane[4]; /* Z (depth) */
GLdepth z[MAX_WIDTH];
#endif
#ifdef DO_RGBA
GLfloat rPlane[4], gPlane[4], bPlane[4], aPlane[4]; /* color */
GLubyte rgba[MAX_WIDTH][4];
#endif
#ifdef DO_INDEX
GLfloat iPlane[4]; /* color index */
GLuint index[MAX_WIDTH];
#endif
#ifdef DO_SPEC
GLfloat srPlane[4], sgPlane[4], sbPlane[4]; /* spec color */
GLubyte spec[MAX_WIDTH][4];
#endif
#ifdef DO_STUV0
GLfloat s0Plane[4], t0Plane[4], u0Plane[4], v0Plane[4]; /* texture 0 */
GLfloat width0, height0;
GLfloat s[MAX_TEXTURE_UNITS][MAX_WIDTH];
GLfloat t[MAX_TEXTURE_UNITS][MAX_WIDTH];
GLfloat u[MAX_TEXTURE_UNITS][MAX_WIDTH];
GLfloat lambda[MAX_TEXTURE_UNITS][MAX_WIDTH];
#endif
#ifdef DO_STUV1
GLfloat s1Plane[4], t1Plane[4], u1Plane[4], v1Plane[4]; /* texture 1 */
GLfloat width1, height1;
#endif
GLfloat bf = ctx->backface_sign;
/* determine bottom to top order of vertices */
{
GLfloat y0 = VB->Win.data[v0][1];
GLfloat y1 = VB->Win.data[v1][1];
GLfloat y2 = VB->Win.data[v2][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 = VB->Win.data[vMax][0] - VB->Win.data[vMin][0];
majDy = VB->Win.data[vMax][1] - VB->Win.data[vMin][1];
{
const GLfloat botDx = VB->Win.data[vMid][0] - VB->Win.data[vMin][0];
const GLfloat botDy = VB->Win.data[vMid][1] - VB->Win.data[vMin][1];
const GLfloat area = majDx * botDy - botDx * majDy;
ltor = (GLboolean) (area < 0.0F);
/* Do backface culling */
if (area * bf < 0 || area * area < .0025)
return;
}
#ifndef DO_OCCLUSION_TEST
ctx->OcclusionResult = GL_TRUE;
#endif
/* plane setup */
#ifdef DO_Z
compute_plane(p0, p1, p2, p0[2], p1[2], p2[2], zPlane);
#endif
#ifdef DO_RGBA
if (ctx->Light.ShadeModel == GL_SMOOTH) {
GLubyte (*rgba)[4] = VB->ColorPtr->data;
compute_plane(p0, p1, p2, rgba[v0][0], rgba[v1][0], rgba[v2][0], rPlane);
compute_plane(p0, p1, p2, rgba[v0][1], rgba[v1][1], rgba[v2][1], gPlane);
compute_plane(p0, p1, p2, rgba[v0][2], rgba[v1][2], rgba[v2][2], bPlane);
compute_plane(p0, p1, p2, rgba[v0][3], rgba[v1][3], rgba[v2][3], aPlane);
}
else {
constant_plane(VB->ColorPtr->data[pv][RCOMP], rPlane);
constant_plane(VB->ColorPtr->data[pv][GCOMP], gPlane);
constant_plane(VB->ColorPtr->data[pv][BCOMP], bPlane);
constant_plane(VB->ColorPtr->data[pv][ACOMP], aPlane);
}
#endif
#ifdef DO_INDEX
if (ctx->Light.ShadeModel == GL_SMOOTH) {
compute_plane(p0, p1, p2, VB->IndexPtr->data[v0],
VB->IndexPtr->data[v1], VB->IndexPtr->data[v2], iPlane);
}
else {
constant_plane(VB->IndexPtr->data[pv], iPlane);
}
#endif
#ifdef DO_SPEC
{
GLubyte (*spec)[4] = VB->Specular;
compute_plane(p0, p1, p2, spec[v0][0], spec[v1][0], spec[v2][0],srPlane);
compute_plane(p0, p1, p2, spec[v0][1], spec[v1][1], spec[v2][1],sgPlane);
compute_plane(p0, p1, p2, spec[v0][2], spec[v1][2], spec[v2][2],sbPlane);
}
#endif
#ifdef DO_STUV0
{
const struct gl_texture_object *obj = ctx->Texture.Unit[0].Current;
const struct gl_texture_image *texImage = obj->Image[obj->BaseLevel];
const GLint tSize = 3;
const GLfloat invW0 = VB->Win.data[v0][3];
const GLfloat invW1 = VB->Win.data[v1][3];
const GLfloat invW2 = VB->Win.data[v2][3];
GLfloat (*texCoord)[4] = VB->TexCoordPtr[0]->data;
const GLfloat s0 = texCoord[v0][0] * invW0;
const GLfloat s1 = texCoord[v1][0] * invW1;
const GLfloat s2 = texCoord[v2][0] * invW2;
const GLfloat t0 = (tSize > 1) ? texCoord[v0][1] * invW0 : 0.0F;
const GLfloat t1 = (tSize > 1) ? texCoord[v1][1] * invW1 : 0.0F;
const GLfloat t2 = (tSize > 1) ? texCoord[v2][1] * invW2 : 0.0F;
const GLfloat r0 = (tSize > 2) ? texCoord[v0][2] * invW0 : 0.0F;
const GLfloat r1 = (tSize > 2) ? texCoord[v1][2] * invW1 : 0.0F;
const GLfloat r2 = (tSize > 2) ? texCoord[v2][2] * invW2 : 0.0F;
const GLfloat q0 = (tSize > 3) ? texCoord[v0][3] * invW0 : invW0;
const GLfloat q1 = (tSize > 3) ? texCoord[v1][3] * invW1 : invW1;
const GLfloat q2 = (tSize > 3) ? texCoord[v2][3] * invW2 : invW2;
compute_plane(p0, p1, p2, s0, s1, s2, s0Plane);
compute_plane(p0, p1, p2, t0, t1, t2, t0Plane);
compute_plane(p0, p1, p2, r0, r1, r2, u0Plane);
compute_plane(p0, p1, p2, q0, q1, q2, v0Plane);
width0 = (GLfloat) texImage->Width;
height0 = (GLfloat) texImage->Height;
}
#endif
#ifdef DO_STUV1
{
const struct gl_texture_object *obj = ctx->Texture.Unit[1].Current;
const struct gl_texture_image *texImage = obj->Image[obj->BaseLevel];
const GLint tSize = VB->TexCoordPtr[1]->size;
const GLfloat invW0 = VB->Win.data[v0][3];
const GLfloat invW1 = VB->Win.data[v1][3];
const GLfloat invW2 = VB->Win.data[v2][3];
GLfloat (*texCoord)[4] = VB->TexCoordPtr[1]->data;
const GLfloat s0 = texCoord[v0][0] * invW0;
const GLfloat s1 = texCoord[v1][0] * invW1;
const GLfloat s2 = texCoord[v2][0] * invW2;
const GLfloat t0 = (tSize > 1) ? texCoord[v0][1] * invW0 : 0.0F;
const GLfloat t1 = (tSize > 1) ? texCoord[v1][1] * invW1 : 0.0F;
const GLfloat t2 = (tSize > 1) ? texCoord[v2][1] * invW2 : 0.0F;
const GLfloat r0 = (tSize > 2) ? texCoord[v0][2] * invW0 : 0.0F;
const GLfloat r1 = (tSize > 2) ? texCoord[v1][2] * invW1 : 0.0F;
const GLfloat r2 = (tSize > 2) ? texCoord[v2][2] * invW2 : 0.0F;
const GLfloat q0 = (tSize > 3) ? texCoord[v0][3] * invW0 : invW0;
const GLfloat q1 = (tSize > 3) ? texCoord[v1][3] * invW1 : invW1;
const GLfloat q2 = (tSize > 3) ? texCoord[v2][3] * invW2 : invW2;
compute_plane(p0, p1, p2, s0, s1, s2, s1Plane);
compute_plane(p0, p1, p2, t0, t1, t2, t1Plane);
compute_plane(p0, p1, p2, r0, r1, r2, u1Plane);
compute_plane(p0, p1, p2, q0, q1, q2, v1Plane);
width1 = (GLfloat) texImage->Width;
height1 = (GLfloat) texImage->Height;
}
#endif
yMin = VB->Win.data[vMin][1];
yMax = VB->Win.data[vMax][1];
iyMin = (int) yMin;
iyMax = (int) yMax + 1;
if (ltor) {
/* scan left to right */
const float *pMin = VB->Win.data[vMin];
const float *pMid = VB->Win.data[vMid];
const float *pMax = VB->Win.data[vMax];
const float dxdy = majDx / majDy;
const float xAdj = dxdy < 0.0F ? -dxdy : 0.0F;
float x = VB->Win.data[vMin][0] - (yMin - iyMin) * dxdy;
int iy;
for (iy = iyMin; iy < iyMax; iy++, x += dxdy) {
GLint ix, startX = (GLint) (x - xAdj);
GLuint count, n;
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) {
#ifdef DO_Z
z[count] = (GLdepth) solve_plane(ix, iy, zPlane);
#endif
#ifdef DO_RGBA
rgba[count][RCOMP] = solve_plane_0_255(ix, iy, rPlane);
rgba[count][GCOMP] = solve_plane_0_255(ix, iy, gPlane);
rgba[count][BCOMP] = solve_plane_0_255(ix, iy, bPlane);
rgba[count][ACOMP] = (GLubyte) (solve_plane_0_255(ix, iy, aPlane) * coverage);
#endif
#ifdef DO_INDEX
{
GLint frac = compute_coveragei(pMin, pMid, pMax, ix, iy);
GLint indx = (GLint) solve_plane(ix, iy, iPlane);
index[count] = (indx & ~0xf) | frac;
}
#endif
#ifdef DO_SPEC
spec[count][RCOMP] = solve_plane_0_255(ix, iy, srPlane);
spec[count][GCOMP] = solve_plane_0_255(ix, iy, sgPlane);
spec[count][BCOMP] = solve_plane_0_255(ix, iy, sbPlane);
#endif
#ifdef DO_STUV0
{
GLfloat invQ = solve_plane_recip(ix, iy, v0Plane);
s[0][count] = solve_plane(ix, iy, s0Plane) * invQ;
t[0][count] = solve_plane(ix, iy, t0Plane) * invQ;
u[0][count] = solve_plane(ix, iy, u0Plane) * invQ;
lambda[0][count] = compute_lambda(s0Plane, t0Plane, invQ,
width0, height0);
}
#endif
#ifdef DO_STUV1
{
GLfloat invQ = solve_plane_recip(ix, iy, v1Plane);
s[1][count] = solve_plane(ix, iy, s1Plane) * invQ;
t[1][count] = solve_plane(ix, iy, t1Plane) * invQ;
u[1][count] = solve_plane(ix, iy, u1Plane) * invQ;
lambda[1][count] = compute_lambda(s1Plane, t1Plane, invQ,
width1, height1);
}
#endif
ix++;
count++;
coverage = compute_coveragef(pMin, pMid, pMax, ix, iy);
}
n = (GLuint) ix - (GLuint) startX;
#ifdef DO_STUV1
# ifdef DO_SPEC
gl_write_multitexture_span(ctx, 2, n, startX, iy, z,
(CONST GLfloat (*)[MAX_WIDTH]) s,
(CONST GLfloat (*)[MAX_WIDTH]) t,
(CONST GLfloat (*)[MAX_WIDTH]) u,
(GLfloat (*)[MAX_WIDTH]) lambda,
rgba, (CONST GLubyte (*)[4]) spec,
GL_POLYGON);
# else
gl_write_multitexture_span(ctx, 2, n, startX, iy, z,
(CONST GLfloat (*)[MAX_WIDTH]) s,
(CONST GLfloat (*)[MAX_WIDTH]) t,
(CONST GLfloat (*)[MAX_WIDTH]) u,
lambda, rgba, NULL, GL_POLYGON);
# endif
#elif defined(DO_STUV0)
# ifdef DO_SPEC
gl_write_texture_span(ctx, n, startX, iy, z,
s[0], t[0], u[0], lambda[0], rgba,
(CONST GLubyte (*)[4]) spec, GL_POLYGON);
# else
gl_write_texture_span(ctx, n, startX, iy, z,
s[0], t[0], u[0], lambda[0],
rgba, NULL, GL_POLYGON);
# endif
#elif defined(DO_RGBA)
gl_write_rgba_span(ctx, n, startX, iy, z, rgba, GL_POLYGON);
#elif defined(DO_INDEX)
gl_write_index_span(ctx, n, startX, iy, z, index, GL_POLYGON);
#endif
}
}
else {
/* scan right to left */
const GLfloat *pMin = VB->Win.data[vMin];
const GLfloat *pMid = VB->Win.data[vMid];
const GLfloat *pMax = VB->Win.data[vMax];
const GLfloat dxdy = majDx / majDy;
const GLfloat xAdj = dxdy > 0 ? dxdy : 0.0F;
GLfloat x = VB->Win.data[vMin][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;
/* skip fragments with zero coverage */
while (startX >= 0) {
coverage = compute_coveragef(pMin, pMax, pMid, startX, iy);
if (coverage > 0.0F)
break;
startX--;
}
if (startX > ctx->DrawBuffer->Xmax) {
startX = ctx->DrawBuffer->Xmax;
}
/* enter interior of triangle */
ix = startX;
count = 0;
while (coverage > 0.0F) {
#ifdef DO_Z
z[ix] = (GLdepth) solve_plane(ix, iy, zPlane);
#endif
#ifdef DO_RGBA
rgba[ix][RCOMP] = solve_plane_0_255(ix, iy, rPlane);
rgba[ix][GCOMP] = solve_plane_0_255(ix, iy, gPlane);
rgba[ix][BCOMP] = solve_plane_0_255(ix, iy, bPlane);
rgba[ix][ACOMP] = (GLubyte) (solve_plane_0_255(ix, iy, aPlane) * coverage);
#endif
#ifdef DO_INDEX
{
GLint frac = compute_coveragei(pMin, pMax, pMid, ix, iy);
GLint indx = (GLint) solve_plane(ix, iy, iPlane);
index[ix] = (indx & ~0xf) | frac;
}
#endif
#ifdef DO_SPEC
spec[ix][RCOMP] = solve_plane_0_255(ix, iy, srPlane);
spec[ix][GCOMP] = solve_plane_0_255(ix, iy, sgPlane);
spec[ix][BCOMP] = solve_plane_0_255(ix, iy, sbPlane);
#endif
#ifdef DO_STUV0
{
GLfloat invQ = solve_plane_recip(ix, iy, v0Plane);
s[0][ix] = solve_plane(ix, iy, s0Plane) * invQ;
t[0][ix] = solve_plane(ix, iy, t0Plane) * invQ;
u[0][ix] = solve_plane(ix, iy, u0Plane) * invQ;
lambda[0][ix] = compute_lambda(s0Plane, t0Plane, invQ,
width0, height0);
}
#endif
#ifdef DO_STUV1
{
GLfloat invQ = solve_plane_recip(ix, iy, v1Plane);
s[1][ix] = solve_plane(ix, iy, s1Plane) * invQ;
t[1][ix] = solve_plane(ix, iy, t1Plane) * invQ;
u[1][ix] = solve_plane(ix, iy, u1Plane) * invQ;
lambda[1][ix] = compute_lambda(s1Plane, t1Plane, invQ,
width1, height1);
}
#endif
ix--;
count++;
coverage = compute_coveragef(pMin, pMax, pMid, ix, iy);
}
n = (GLuint) startX - (GLuint) ix;
left = ix + 1;
#ifdef DO_STUV1
{
GLuint j;
for (j = 0; j < n; j++) {
s[0][j] = s[0][j + left];
t[0][j] = t[0][j + left];
u[0][j] = u[0][j + left];
s[1][j] = s[1][j + left];
t[1][j] = t[1][j + left];
u[1][j] = u[1][j + left];
lambda[0][j] = lambda[0][j + left];
lambda[1][j] = lambda[1][j + left];
}
}
# ifdef DO_SPEC
gl_write_multitexture_span(ctx, 2, n, left, iy, z + left,
(CONST GLfloat (*)[MAX_WIDTH]) s,
(CONST GLfloat (*)[MAX_WIDTH]) t,
(CONST GLfloat (*)[MAX_WIDTH]) u,
lambda, rgba + left,
(CONST GLubyte (*)[4]) (spec + left),
GL_POLYGON);
# else
gl_write_multitexture_span(ctx, 2, n, left, iy, z + left,
(CONST GLfloat (*)[MAX_WIDTH]) s,
(CONST GLfloat (*)[MAX_WIDTH]) t,
(CONST GLfloat (*)[MAX_WIDTH]) u,
lambda,
rgba + left, NULL, GL_POLYGON);
# endif
#elif defined(DO_STUV0)
# ifdef DO_SPEC
gl_write_texture_span(ctx, n, left, iy, z + left,
s[0] + left, t[0] + left, u[0] + left,
lambda[0] + left, rgba + left,
(CONST GLubyte (*)[4]) (spec + left),
GL_POLYGON);
# else
gl_write_texture_span(ctx, n, left, iy, z + left,
s[0] + left, t[0] + left,
u[0] + left, lambda[0] + left,
rgba + left, NULL, GL_POLYGON);
# endif
#elif defined(DO_RGBA)
gl_write_rgba_span(ctx, n, left, iy, z + left,
rgba + left, GL_POLYGON);
#elif defined(DO_INDEX)
gl_write_index_span(ctx, n, left, iy, z + left,
index + left, GL_POLYGON);
#endif
}
}
}
#ifdef DO_Z
#undef DO_Z
#endif
#ifdef DO_RGBA
#undef DO_RGBA
#endif
#ifdef DO_INDEX
#undef DO_INDEX
#endif
#ifdef DO_SPEC
#undef DO_SPEC
#endif
#ifdef DO_STUV0
#undef DO_STUV0
#endif
#ifdef DO_STUV1
#undef DO_STUV1
#endif
#ifdef DO_OCCLUSION_TEST
#undef DO_OCCLUSION_TEST
#endif
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