/* * Mesa 3-D graphics library * Version: 7.0.3 * * Copyright (C) 1999-2007 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_ATTRIBS - if defined, compute texcoords, varying, etc. */ /*void triangle( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint pv )*/ { const SWcontext *swrast = SWRAST_CONTEXT(ctx); 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 */ SWspan 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 #if defined(DO_ATTRIBS) GLfloat sPlane[FRAG_ATTRIB_MAX][4]; /* texture S */ GLfloat tPlane[FRAG_ATTRIB_MAX][4]; /* texture T */ GLfloat uPlane[FRAG_ATTRIB_MAX][4]; /* texture R */ GLfloat vPlane[FRAG_ATTRIB_MAX][4]; /* texture Q */ #endif GLfloat bf = SWRAST_CONTEXT(ctx)->_BackfaceCullSign; (void) swrast; 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]; /* front/back-face determination and cullling */ { 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; /* Do backface culling */ if (area * bf < 0 || area == 0 || IS_INF_OR_NAN(area)) return; ltor = (GLboolean) (area < 0.0F); span.facing = area * swrast->_BackfaceSign > 0.0F; } /* 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->attrib[FRAG_ATTRIB_FOGC][0], v1->attrib[FRAG_ATTRIB_FOGC][0], v2->attrib[FRAG_ATTRIB_FOGC][0], fogPlane); span.arrayMask |= SPAN_FOG; #endif #ifdef DO_RGBA if (ctx->Light.ShadeModel == GL_SMOOTH) { compute_plane(p0, p1, p2, v0->color[RCOMP], v1->color[RCOMP], v2->color[RCOMP], rPlane); compute_plane(p0, p1, p2, v0->color[GCOMP], v1->color[GCOMP], v2->color[GCOMP], gPlane); compute_plane(p0, p1, p2, v0->color[BCOMP], v1->color[BCOMP], v2->color[BCOMP], bPlane); compute_plane(p0, p1, p2, v0->color[ACOMP], v1->color[ACOMP], v2->color[ACOMP], 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, v1->index, v2->index, iPlane); } else { constant_plane(v2->index, iPlane); } span.arrayMask |= SPAN_INDEX; #endif #ifdef DO_SPEC if (ctx->Light.ShadeModel == GL_SMOOTH) { compute_plane(p0, p1, p2, v0->specular[RCOMP], v1->specular[RCOMP], v2->specular[RCOMP], srPlane); compute_plane(p0, p1, p2, v0->specular[GCOMP], v1->specular[GCOMP], v2->specular[GCOMP], sgPlane); compute_plane(p0, p1, p2, v0->specular[BCOMP], v1->specular[BCOMP], v2->specular[BCOMP], 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 #if defined(DO_ATTRIBS) { const GLfloat invW0 = v0->win[3]; const GLfloat invW1 = v1->win[3]; const GLfloat invW2 = v2->win[3]; ATTRIB_LOOP_BEGIN const GLfloat s0 = v0->attrib[attr][0] * invW0; const GLfloat s1 = v1->attrib[attr][0] * invW1; const GLfloat s2 = v2->attrib[attr][0] * invW2; const GLfloat t0 = v0->attrib[attr][1] * invW0; const GLfloat t1 = v1->attrib[attr][1] * invW1; const GLfloat t2 = v2->attrib[attr][1] * invW2; const GLfloat r0 = v0->attrib[attr][2] * invW0; const GLfloat r1 = v1->attrib[attr][2] * invW1; const GLfloat r2 = v2->attrib[attr][2] * invW2; const GLfloat q0 = v0->attrib[attr][3] * invW0; const GLfloat q1 = v1->attrib[attr][3] * invW1; const GLfloat q2 = v2->attrib[attr][3] * invW2; compute_plane(p0, p1, p2, s0, s1, s2, sPlane[attr]); compute_plane(p0, p1, p2, t0, t1, t2, tPlane[attr]); compute_plane(p0, p1, p2, r0, r1, r2, uPlane[attr]); compute_plane(p0, p1, p2, q0, q1, q2, vPlane[attr]); ATTRIB_LOOP_END } span.arrayMask |= (SPAN_TEXTURE | SPAN_LAMBDA | SPAN_VARYING); #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; SWspanarrays *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] = (GLuint) solve_plane(cx, cy, zPlane); #endif #ifdef DO_FOG array->attribs[FRAG_ATTRIB_FOGC][count][0] = 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 #if defined(DO_ATTRIBS) ATTRIB_LOOP_BEGIN GLfloat invQ = solve_plane_recip(cx, cy, vPlane[attr]); array->attribs[attr][count][0] = solve_plane(cx, cy, sPlane[attr]) * invQ; array->attribs[attr][count][1] = solve_plane(cx, cy, tPlane[attr]) * invQ; array->attribs[attr][count][2] = solve_plane(cx, cy, uPlane[attr]) * invQ; if (attr >= FRAG_ATTRIB_TEX0 && attr < FRAG_ATTRIB_VAR0) { const GLuint unit = attr - FRAG_ATTRIB_TEX0; array->lambda[unit][count] = compute_lambda(ctx, sPlane[attr], tPlane[attr], vPlane[attr], cx, cy, invQ, unit); } ATTRIB_LOOP_END #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_RGBA) _swrast_write_rgba_span(ctx, &span); #else _swrast_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; SWspanarrays *array = span.array; ASSERT(ix >= 0); #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] = (GLuint) solve_plane(cx, cy, zPlane); #endif #ifdef DO_FOG array->attribs[FRAG_ATTRIB_FOGC][ix][0] = 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 #if defined(DO_ATTRIBS) ATTRIB_LOOP_BEGIN GLfloat invQ = solve_plane_recip(cx, cy, vPlane[attr]); array->attribs[attr][ix][0] = solve_plane(cx, cy, sPlane[attr]) * invQ; array->attribs[attr][ix][1] = solve_plane(cx, cy, tPlane[attr]) * invQ; array->attribs[attr][ix][2] = solve_plane(cx, cy, uPlane[attr]) * invQ; if (attr >= FRAG_ATTRIB_TEX0 && attr < FRAG_ATTRIB_VAR0) { const GLuint unit = attr - FRAG_ATTRIB_TEX0; array->lambda[unit][ix] = compute_lambda(ctx, sPlane[attr], tPlane[attr], vPlane[attr], cx, cy, invQ, unit); } ATTRIB_LOOP_END #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 */ { SWspanarrays *array = span.array; GLint j; for (j = 0; j < (GLint) n; j++) { #ifdef DO_RGBA COPY_CHAN4(array->rgba[j], array->rgba[j + left]); #endif #ifdef DO_SPEC COPY_CHAN4(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->attribs[FRAG_ATTRIB_FOGC][j][0] = array->attribs[FRAG_ATTRIB_FOGC][j + left][0]; #endif #if defined(DO_ATTRIBS) array->lambda[0][j] = array->lambda[0][j + left]; #endif array->coverage[j] = array->coverage[j + left]; } } #ifdef DO_ATTRIBS /* shift texcoords, varying */ { SWspanarrays *array = span.array; ATTRIB_LOOP_BEGIN GLint j; for (j = 0; j < (GLint) n; j++) { array->attribs[attr][j][0] = array->attribs[attr][j + left][0]; array->attribs[attr][j][1] = array->attribs[attr][j + left][1]; array->attribs[attr][j][2] = array->attribs[attr][j + left][2]; /*array->lambda[unit][j] = array->lambda[unit][j + left];*/ } ATTRIB_LOOP_END } #endif span.x = left; span.y = iy; span.end = n; ASSERT(span.interpMask == 0); #if defined(DO_RGBA) _swrast_write_rgba_span(ctx, &span); #else _swrast_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_ATTRIBS #undef DO_ATTRIBS #endif #ifdef DO_OCCLUSION_TEST #undef DO_OCCLUSION_TEST #endif