/* * 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) { /* (cx,cy) = center of fragment */ GLfloat cx = ix + 0.5F, cy = iy + 0.5F; #ifdef DO_Z z[count] = (GLdepth) solve_plane(cx, cy, zPlane); #endif #ifdef DO_RGBA rgba[count][RCOMP] = solve_plane_0_255(cx, cy, rPlane); rgba[count][GCOMP] = solve_plane_0_255(cx, cy, gPlane); rgba[count][BCOMP] = solve_plane_0_255(cx, cy, bPlane); rgba[count][ACOMP] = (GLubyte) (solve_plane_0_255(cx, cy, aPlane) * coverage); #endif #ifdef DO_INDEX { GLint frac = compute_coveragei(pMin, pMid, pMax, ix, iy); GLint indx = (GLint) solve_plane(cx, cy, iPlane); index[count] = (indx & ~0xf) | frac; } #endif #ifdef DO_SPEC spec[count][RCOMP] = solve_plane_0_255(cx, cy, srPlane); spec[count][GCOMP] = solve_plane_0_255(cx, cy, sgPlane); spec[count][BCOMP] = solve_plane_0_255(cx, cy, sbPlane); #endif #ifdef DO_STUV0 { const GLfloat invQ = solve_plane_recip(cx, cy, v0Plane); s[0][count] = solve_plane(cx, cy, s0Plane) * invQ; t[0][count] = solve_plane(cx, cy, t0Plane) * invQ; u[0][count] = solve_plane(cx, cy, u0Plane) * invQ; lambda[0][count] = compute_lambda(s0Plane, t0Plane, invQ, width0, height0); } #endif #ifdef DO_STUV1 { const GLfloat invQ = solve_plane_recip(cx, cy, v1Plane); s[1][count] = solve_plane(cx, cy, s1Plane) * invQ; t[1][count] = solve_plane(cx, cy, t1Plane) * invQ; u[1][count] = solve_plane(cx, cy, 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) { /* (cx,cy) = center of fragment */ const GLfloat cx = ix + 0.5F, cy = iy + 0.5F; #ifdef DO_Z z[ix] = (GLdepth) solve_plane(cx, cy, zPlane); #endif #ifdef DO_RGBA rgba[ix][RCOMP] = solve_plane_0_255(cx, cy, rPlane); rgba[ix][GCOMP] = solve_plane_0_255(cx, cy, gPlane); rgba[ix][BCOMP] = solve_plane_0_255(cx, cy, bPlane); rgba[ix][ACOMP] = (GLubyte) (solve_plane_0_255(cx, cy, aPlane) * coverage); #endif #ifdef DO_INDEX { GLint frac = compute_coveragei(pMin, pMax, pMid, ix, iy); GLint indx = (GLint) solve_plane(cx, cy, iPlane); index[ix] = (indx & ~0xf) | frac; } #endif #ifdef DO_SPEC spec[ix][RCOMP] = solve_plane_0_255(cx, cy, srPlane); spec[ix][GCOMP] = solve_plane_0_255(cx, cy, sgPlane); spec[ix][BCOMP] = solve_plane_0_255(cx, cy, sbPlane); #endif #ifdef DO_STUV0 { const GLfloat invQ = solve_plane_recip(cx, cy, v0Plane); s[0][ix] = solve_plane(cx, cy, s0Plane) * invQ; t[0][ix] = solve_plane(cx, cy, t0Plane) * invQ; u[0][ix] = solve_plane(cx, cy, u0Plane) * invQ; lambda[0][ix] = compute_lambda(s0Plane, t0Plane, invQ, width0, height0); } #endif #ifdef DO_STUV1 { const GLfloat invQ = solve_plane_recip(cx, cy, v1Plane); s[1][ix] = solve_plane(cx, cy, s1Plane) * invQ; t[1][ix] = solve_plane(cx, cy, t1Plane) * invQ; u[1][ix] = solve_plane(cx, cy, 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