/* * Mesa 3-D graphics library * Version: 6.1 * * Copyright (C) 1999-2004 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. */ /* * Triangle Rasterizer Template * * This file is #include'd to generate custom triangle rasterizers. * * The following macros may be defined to indicate what auxillary information * must be interplated across the triangle: * INTERP_Z - if defined, interpolate vertex Z values * INTERP_W - if defined, interpolate vertex W values * INTERP_FOG - if defined, interpolate fog values * INTERP_RGB - if defined, interpolate RGB values * INTERP_ALPHA - if defined, interpolate Alpha values (req's INTERP_RGB) * INTERP_SPEC - if defined, interpolate specular RGB values * INTERP_INDEX - if defined, interpolate color index values * INTERP_INT_TEX - if defined, interpolate integer ST texcoords * (fast, simple 2-D texture mapping) * INTERP_TEX - if defined, interpolate set 0 float STRQ texcoords * NOTE: OpenGL STRQ = Mesa STUV (R was taken for red) * INTERP_MULTITEX - if defined, interpolate N units of STRQ texcoords * * When one can directly address pixels in the color buffer the following * macros can be defined and used to compute pixel addresses during * rasterization (see pRow): * 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 per triangle: * SETUP_CODE - code which is to be executed once per triangle * CLEANUP_CODE - code to execute at end of triangle * * The following macro MUST be defined: * RENDER_SPAN(span) - code to write a span of pixels. * * This code was designed for the origin to be in the lower-left corner. * * Inspired by triangle rasterizer code written by Allen Akin. Thanks Allen! * * * Some notes on rasterization accuracy: * * This code uses fixed point arithmetic (the GLfixed type) to iterate * over the triangle edges and interpolate ancillary data (such as Z, * color, secondary color, etc). The number of fractional bits in * GLfixed and the value of SUB_PIXEL_BITS has a direct bearing on the * accuracy of rasterization. * * If SUB_PIXEL_BITS=4 then we'll snap the vertices to the nearest * 1/16 of a pixel. If we're walking up a long, nearly vertical edge * (dx=1/16, dy=1024) we'll need 4 + 10 = 14 fractional bits in * GLfixed to walk the edge without error. If the maximum viewport * height is 4K pixels, then we'll need 4 + 12 = 16 fractional bits. * * Historically, Mesa has used 11 fractional bits in GLfixed, snaps * vertices to 1/16 pixel and allowed a maximum viewport height of 2K * pixels. 11 fractional bits is actually insufficient for accurately * rasterizing some triangles. More recently, the maximum viewport * height was increased to 4K pixels. Thus, Mesa should be using 16 * fractional bits in GLfixed. Unfortunately, there may be some issues * with setting FIXED_FRAC_BITS=16, such as multiplication overflow. * This will have to be examined in some detail... * * For now, if you find rasterization errors, particularly with tall, * sliver triangles, try increasing FIXED_FRAC_BITS and/or decreasing * SUB_PIXEL_BITS. */ /* * ColorTemp is used for intermediate color values. */ #if CHAN_TYPE == GL_FLOAT #define ColorTemp GLfloat #else #define ColorTemp GLint /* same as GLfixed */ #endif /* * Walk triangle edges with GLfixed or GLdouble */ #if TRIANGLE_WALK_DOUBLE #define GLinterp GLdouble #define InterpToInt(X) ((GLint) (X)) #define INTERP_ONE 1.0 #else #define GLinterp GLfixed #define InterpToInt(X) FixedToInt(X) #define INTERP_ONE FIXED_ONE #endif /* * Either loop over all texture units, or just use unit zero. */ #ifdef INTERP_MULTITEX #define TEX_UNIT_LOOP(CODE) \ { \ GLuint u; \ for (u = 0; u < ctx->Const.MaxTextureUnits; u++) { \ if (ctx->Texture._EnabledCoordUnits & (1 << u)) { \ CODE \ } \ } \ } #define INTERP_TEX #elif defined(INTERP_TEX) #define TEX_UNIT_LOOP(CODE) \ { \ const GLuint u = 0; \ CODE \ } #endif static void NAME(GLcontext *ctx, const SWvertex *v0, const SWvertex *v1, const SWvertex *v2 ) { typedef struct { const SWvertex *v0, *v1; /* Y(v0) < Y(v1) */ #if TRIANGLE_WALK_DOUBLE GLdouble dx; /* X(v1) - X(v0) */ GLdouble dy; /* Y(v1) - Y(v0) */ GLdouble dxdy; /* dx/dy */ GLdouble adjy; /* adjust from v[0]->fy to fsy, scaled */ GLdouble fsx; /* first sample point x coord */ GLdouble fsy; GLdouble fx0; /*X of lower endpoint */ #else GLfloat dx; /* X(v1) - X(v0) */ GLfloat dy; /* Y(v1) - Y(v0) */ GLfloat dxdy; /* dx/dy */ GLfixed fdxdy; /* dx/dy in fixed-point */ GLfloat adjy; /* adjust from v[0]->fy to fsy, scaled */ GLfixed fsx; /* first sample point x coord */ GLfixed fsy; GLfixed fx0; /* fixed pt X of lower endpoint */ #endif GLint lines; /* number of lines to be sampled on this edge */ } EdgeT; #ifdef INTERP_Z const GLint depthBits = ctx->Visual.depthBits; const GLint fixedToDepthShift = depthBits <= 16 ? FIXED_SHIFT : 0; const GLfloat maxDepth = ctx->DepthMaxF; #define FixedToDepth(F) ((F) >> fixedToDepthShift) #endif EdgeT eMaj, eTop, eBot; GLfloat oneOverArea; const SWvertex *vMin, *vMid, *vMax; /* Y(vMin)<=Y(vMid)<=Y(vMax) */ GLfloat bf = SWRAST_CONTEXT(ctx)->_BackfaceSign; #if !TRIANGLE_WALK_DOUBLE const GLint snapMask = ~((FIXED_ONE / (1 << SUB_PIXEL_BITS)) - 1); /* for x/y coord snapping */ #endif GLinterp vMin_fx, vMin_fy, vMid_fx, vMid_fy, vMax_fx, vMax_fy; struct sw_span span; INIT_SPAN(span, GL_POLYGON, 0, 0, 0); #ifdef INTERP_Z (void) fixedToDepthShift; #endif /* printf("%s()\n", __FUNCTION__); printf(" %g, %g, %g\n", v0->win[0], v0->win[1], v0->win[2]); printf(" %g, %g, %g\n", v1->win[0], v1->win[1], v1->win[2]); printf(" %g, %g, %g\n", v2->win[0], v2->win[1], v2->win[2]); */ /* ASSERT(v0->win[2] >= 0.0); ASSERT(v1->win[2] >= 0.0); ASSERT(v2->win[2] >= 0.0); */ /* Compute fixed point x,y coords w/ half-pixel offsets and snapping. * And find the order of the 3 vertices along the Y axis. */ { #if TRIANGLE_WALK_DOUBLE const GLdouble fy0 = v0->win[1] - 0.5; const GLdouble fy1 = v1->win[1] - 0.5; const GLdouble fy2 = v2->win[1] - 0.5; #else const GLfixed fy0 = FloatToFixed(v0->win[1] - 0.5F) & snapMask; const GLfixed fy1 = FloatToFixed(v1->win[1] - 0.5F) & snapMask; const GLfixed fy2 = FloatToFixed(v2->win[1] - 0.5F) & snapMask; #endif if (fy0 <= fy1) { if (fy1 <= fy2) { /* y0 <= y1 <= y2 */ vMin = v0; vMid = v1; vMax = v2; vMin_fy = fy0; vMid_fy = fy1; vMax_fy = fy2; } else if (fy2 <= fy0) { /* y2 <= y0 <= y1 */ vMin = v2; vMid = v0; vMax = v1; vMin_fy = fy2; vMid_fy = fy0; vMax_fy = fy1; } else { /* y0 <= y2 <= y1 */ vMin = v0; vMid = v2; vMax = v1; vMin_fy = fy0; vMid_fy = fy2; vMax_fy = fy1; bf = -bf; } } else { if (fy0 <= fy2) { /* y1 <= y0 <= y2 */ vMin = v1; vMid = v0; vMax = v2; vMin_fy = fy1; vMid_fy = fy0; vMax_fy = fy2; bf = -bf; } else if (fy2 <= fy1) { /* y2 <= y1 <= y0 */ vMin = v2; vMid = v1; vMax = v0; vMin_fy = fy2; vMid_fy = fy1; vMax_fy = fy0; bf = -bf; } else { /* y1 <= y2 <= y0 */ vMin = v1; vMid = v2; vMax = v0; vMin_fy = fy1; vMid_fy = fy2; vMax_fy = fy0; } } /* fixed point X coords */ #if TRIANGLE_WALK_DOUBLE vMin_fx = vMin->win[0] + 0.5; vMid_fx = vMid->win[0] + 0.5; vMax_fx = vMax->win[0] + 0.5; #else vMin_fx = FloatToFixed(vMin->win[0] + 0.5F) & snapMask; vMid_fx = FloatToFixed(vMid->win[0] + 0.5F) & snapMask; vMax_fx = FloatToFixed(vMax->win[0] + 0.5F) & snapMask; #endif } /* vertex/edge relationship */ eMaj.v0 = vMin; eMaj.v1 = vMax; /*TODO: .v1's not needed */ eTop.v0 = vMid; eTop.v1 = vMax; eBot.v0 = vMin; eBot.v1 = vMid; /* compute deltas for each edge: vertex[upper] - vertex[lower] */ #if TRIANGLE_WALK_DOUBLE eMaj.dx = vMax_fx - vMin_fx; eMaj.dy = vMax_fy - vMin_fy; eTop.dx = vMax_fx - vMid_fx; eTop.dy = vMax_fy - vMid_fy; eBot.dx = vMid_fx - vMin_fx; eBot.dy = vMid_fy - vMin_fy; #else eMaj.dx = FixedToFloat(vMax_fx - vMin_fx); eMaj.dy = FixedToFloat(vMax_fy - vMin_fy); eTop.dx = FixedToFloat(vMax_fx - vMid_fx); eTop.dy = FixedToFloat(vMax_fy - vMid_fy); eBot.dx = FixedToFloat(vMid_fx - vMin_fx); eBot.dy = FixedToFloat(vMid_fy - vMin_fy); #endif /* compute area, oneOverArea and perform backface culling */ { #if TRIANGLE_WALK_DOUBLE const GLdouble area = eMaj.dx * eBot.dy - eBot.dx * eMaj.dy; #else const GLfloat area = eMaj.dx * eBot.dy - eBot.dx * eMaj.dy; #endif /* Do backface culling */ if (area * bf < 0.0) return; if (IS_INF_OR_NAN(area) || area == 0.0F) return; oneOverArea = 1.0F / area; } span.facing = ctx->_Facing; /* for 2-sided stencil test */ /* Edge setup. For a triangle strip these could be reused... */ { #if TRIANGLE_WALK_DOUBLE eMaj.fsy = CEILF(vMin_fy); eMaj.lines = (GLint) CEILF(vMax_fy - eMaj.fsy); #else eMaj.fsy = FixedCeil(vMin_fy); eMaj.lines = FixedToInt(FixedCeil(vMax_fy - eMaj.fsy)); #endif if (eMaj.lines > 0) { eMaj.dxdy = eMaj.dx / eMaj.dy; #if TRIANGLE_WALK_DOUBLE eMaj.adjy = (eMaj.fsy - vMin_fy) * FIXED_SCALE; /* SCALED! */ eMaj.fx0 = vMin_fx; eMaj.fsx = eMaj.fx0 + (eMaj.adjy * eMaj.dxdy) / (GLdouble) FIXED_SCALE; #else eMaj.fdxdy = SignedFloatToFixed(eMaj.dxdy); eMaj.adjy = (GLfloat) (eMaj.fsy - vMin_fy); /* SCALED! */ eMaj.fx0 = vMin_fx; eMaj.fsx = eMaj.fx0 + (GLfixed) (eMaj.adjy * eMaj.dxdy); #endif } else { return; /*CULLED*/ } #if TRIANGLE_WALK_DOUBLE eTop.fsy = CEILF(vMid_fy); eTop.lines = (GLint) CEILF(vMax_fy - eTop.fsy); #else eTop.fsy = FixedCeil(vMid_fy); eTop.lines = FixedToInt(FixedCeil(vMax_fy - eTop.fsy)); #endif if (eTop.lines > 0) { eTop.dxdy = eTop.dx / eTop.dy; #if TRIANGLE_WALK_DOUBLE eTop.adjy = (eTop.fsy - vMid_fy) * FIXED_SCALE; /* SCALED! */ eTop.fx0 = vMid_fx; eTop.fsx = eTop.fx0 + (eTop.adjy * eTop.dxdy) / (GLdouble) FIXED_SCALE; #else eTop.fdxdy = SignedFloatToFixed(eTop.dxdy); eTop.adjy = (GLfloat) (eTop.fsy - vMid_fy); /* SCALED! */ eTop.fx0 = vMid_fx; eTop.fsx = eTop.fx0 + (GLfixed) (eTop.adjy * eTop.dxdy); #endif } #if TRIANGLE_WALK_DOUBLE eBot.fsy = CEILF(vMin_fy); eBot.lines = (GLint) CEILF(vMid_fy - eBot.fsy); #else eBot.fsy = FixedCeil(vMin_fy); eBot.lines = FixedToInt(FixedCeil(vMid_fy - eBot.fsy)); #endif if (eBot.lines > 0) { eBot.dxdy = eBot.dx / eBot.dy; #if TRIANGLE_WALK_DOUBLE eBot.adjy = (eBot.fsy - vMin_fy) * FIXED_SCALE; /* SCALED! */ eBot.fx0 = vMin_fx; eBot.fsx = eBot.fx0 + (eBot.adjy * eBot.dxdy) / (GLdouble) FIXED_SCALE; #else eBot.fdxdy = SignedFloatToFixed(eBot.dxdy); eBot.adjy = (GLfloat) (eBot.fsy - vMin_fy); /* SCALED! */ eBot.fx0 = vMin_fx; eBot.fsx = eBot.fx0 + (GLfixed) (eBot.adjy * eBot.dxdy); #endif } } /* * Conceptually, we view a triangle as two subtriangles * separated by a perfectly horizontal line. The edge that is * intersected by this line is one with maximal absolute dy; we * call it a ``major'' edge. The other two edges are the * ``top'' edge (for the upper subtriangle) and the ``bottom'' * edge (for the lower subtriangle). If either of these two * edges is horizontal or very close to horizontal, the * corresponding subtriangle might cover zero sample points; * we take care to handle such cases, for performance as well * as correctness. * * By stepping rasterization parameters along the major edge, * we can avoid recomputing them at the discontinuity where * the top and bottom edges meet. However, this forces us to * be able to scan both left-to-right and right-to-left. * Also, we must determine whether the major edge is at the * left or right side of the triangle. We do this by * computing the magnitude of the cross-product of the major * and top edges. Since this magnitude depends on the sine of * the angle between the two edges, its sign tells us whether * we turn to the left or to the right when travelling along * the major edge to the top edge, and from this we infer * whether the major edge is on the left or the right. * * Serendipitously, this cross-product magnitude is also a * value we need to compute the iteration parameter * derivatives for the triangle, and it can be used to perform * backface culling because its sign tells us whether the * triangle is clockwise or counterclockwise. In this code we * refer to it as ``area'' because it's also proportional to * the pixel area of the triangle. */ { GLint scan_from_left_to_right; /* true if scanning left-to-right */ #ifdef INTERP_INDEX GLfloat didx, didy; #endif /* * Execute user-supplied setup code */ #ifdef SETUP_CODE SETUP_CODE #endif scan_from_left_to_right = (oneOverArea < 0.0F); /* compute d?/dx and d?/dy derivatives */ #ifdef INTERP_Z span.interpMask |= SPAN_Z; { GLfloat eMaj_dz = vMax->win[2] - vMin->win[2]; GLfloat eBot_dz = vMid->win[2] - vMin->win[2]; span.dzdx = oneOverArea * (eMaj_dz * eBot.dy - eMaj.dy * eBot_dz); if (span.dzdx > maxDepth || span.dzdx < -maxDepth) { /* probably a sliver triangle */ span.dzdx = 0.0; span.dzdy = 0.0; } else { span.dzdy = oneOverArea * (eMaj.dx * eBot_dz - eMaj_dz * eBot.dx); } if (depthBits <= 16) span.zStep = SignedFloatToFixed(span.dzdx); else span.zStep = (GLint) span.dzdx; } #endif #ifdef INTERP_W span.interpMask |= SPAN_W; { const GLfloat eMaj_dw = vMax->win[3] - vMin->win[3]; const GLfloat eBot_dw = vMid->win[3] - vMin->win[3]; span.dwdx = oneOverArea * (eMaj_dw * eBot.dy - eMaj.dy * eBot_dw); span.dwdy = oneOverArea * (eMaj.dx * eBot_dw - eMaj_dw * eBot.dx); } #endif #ifdef INTERP_FOG span.interpMask |= SPAN_FOG; { # ifdef INTERP_W const GLfloat wMax = vMax->win[3], wMin = vMin->win[3], wMid = vMid->win[3]; const GLfloat eMaj_dfog = vMax->fog * wMax - vMin->fog * wMin; const GLfloat eBot_dfog = vMid->fog * wMid - vMin->fog * wMin; # else const GLfloat eMaj_dfog = vMax->fog - vMin->fog; const GLfloat eBot_dfog = vMid->fog - vMin->fog; # endif span.dfogdx = oneOverArea * (eMaj_dfog * eBot.dy - eMaj.dy * eBot_dfog); span.dfogdy = oneOverArea * (eMaj.dx * eBot_dfog - eMaj_dfog * eBot.dx); span.fogStep = span.dfogdx; } #endif #ifdef INTERP_RGB span.interpMask |= SPAN_RGBA; if (ctx->Light.ShadeModel == GL_SMOOTH) { GLfloat eMaj_dr = (GLfloat) ((ColorTemp) vMax->color[RCOMP] - vMin->color[RCOMP]); GLfloat eBot_dr = (GLfloat) ((ColorTemp) vMid->color[RCOMP] - vMin->color[RCOMP]); GLfloat eMaj_dg = (GLfloat) ((ColorTemp) vMax->color[GCOMP] - vMin->color[GCOMP]); GLfloat eBot_dg = (GLfloat) ((ColorTemp) vMid->color[GCOMP] - vMin->color[GCOMP]); GLfloat eMaj_db = (GLfloat) ((ColorTemp) vMax->color[BCOMP] - vMin->color[BCOMP]); GLfloat eBot_db = (GLfloat) ((ColorTemp) vMid->color[BCOMP] - vMin->color[BCOMP]); # ifdef INTERP_ALPHA GLfloat eMaj_da = (GLfloat) ((ColorTemp) vMax->color[ACOMP] - vMin->color[ACOMP]); GLfloat eBot_da = (GLfloat) ((ColorTemp) vMid->color[ACOMP] - vMin->color[ACOMP]); # endif span.drdx = oneOverArea * (eMaj_dr * eBot.dy - eMaj.dy * eBot_dr); span.drdy = oneOverArea * (eMaj.dx * eBot_dr - eMaj_dr * eBot.dx); span.dgdx = oneOverArea * (eMaj_dg * eBot.dy - eMaj.dy * eBot_dg); span.dgdy = oneOverArea * (eMaj.dx * eBot_dg - eMaj_dg * eBot.dx); span.dbdx = oneOverArea * (eMaj_db * eBot.dy - eMaj.dy * eBot_db); span.dbdy = oneOverArea * (eMaj.dx * eBot_db - eMaj_db * eBot.dx); # if CHAN_TYPE == GL_FLOAT span.redStep = span.drdx; span.greenStep = span.dgdx; span.blueStep = span.dbdx; # else span.redStep = SignedFloatToFixed(span.drdx); span.greenStep = SignedFloatToFixed(span.dgdx); span.blueStep = SignedFloatToFixed(span.dbdx); # endif /* GL_FLOAT */ # ifdef INTERP_ALPHA span.dadx = oneOverArea * (eMaj_da * eBot.dy - eMaj.dy * eBot_da); span.dady = oneOverArea * (eMaj.dx * eBot_da - eMaj_da * eBot.dx); # if CHAN_TYPE == GL_FLOAT span.alphaStep = span.dadx; # else span.alphaStep = SignedFloatToFixed(span.dadx); # endif /* GL_FLOAT */ # endif /* INTERP_ALPHA */ } else { ASSERT (ctx->Light.ShadeModel == GL_FLAT); span.interpMask |= SPAN_FLAT; span.drdx = span.drdy = 0.0F; span.dgdx = span.dgdy = 0.0F; span.dbdx = span.dbdy = 0.0F; # if CHAN_TYPE == GL_FLOAT span.redStep = 0.0F; span.greenStep = 0.0F; span.blueStep = 0.0F; # else span.redStep = 0; span.greenStep = 0; span.blueStep = 0; # endif /* GL_FLOAT */ # ifdef INTERP_ALPHA span.dadx = span.dady = 0.0F; # if CHAN_TYPE == GL_FLOAT span.alphaStep = 0.0F; # else span.alphaStep = 0; # endif /* GL_FLOAT */ # endif } #endif /* INTERP_RGB */ #ifdef INTERP_SPEC span.interpMask |= SPAN_SPEC; if (ctx->Light.ShadeModel == GL_SMOOTH) { GLfloat eMaj_dsr = (GLfloat) ((ColorTemp) vMax->specular[RCOMP] - vMin->specular[RCOMP]); GLfloat eBot_dsr = (GLfloat) ((ColorTemp) vMid->specular[RCOMP] - vMin->specular[RCOMP]); GLfloat eMaj_dsg = (GLfloat) ((ColorTemp) vMax->specular[GCOMP] - vMin->specular[GCOMP]); GLfloat eBot_dsg = (GLfloat) ((ColorTemp) vMid->specular[GCOMP] - vMin->specular[GCOMP]); GLfloat eMaj_dsb = (GLfloat) ((ColorTemp) vMax->specular[BCOMP] - vMin->specular[BCOMP]); GLfloat eBot_dsb = (GLfloat) ((ColorTemp) vMid->specular[BCOMP] - vMin->specular[BCOMP]); span.dsrdx = oneOverArea * (eMaj_dsr * eBot.dy - eMaj.dy * eBot_dsr); span.dsrdy = oneOverArea * (eMaj.dx * eBot_dsr - eMaj_dsr * eBot.dx); span.dsgdx = oneOverArea * (eMaj_dsg * eBot.dy - eMaj.dy * eBot_dsg); span.dsgdy = oneOverArea * (eMaj.dx * eBot_dsg - eMaj_dsg * eBot.dx); span.dsbdx = oneOverArea * (eMaj_dsb * eBot.dy - eMaj.dy * eBot_dsb); span.dsbdy = oneOverArea * (eMaj.dx * eBot_dsb - eMaj_dsb * eBot.dx); # if CHAN_TYPE == GL_FLOAT span.specRedStep = span.dsrdx; span.specGreenStep = span.dsgdx; span.specBlueStep = span.dsbdx; # else span.specRedStep = SignedFloatToFixed(span.dsrdx); span.specGreenStep = SignedFloatToFixed(span.dsgdx); span.specBlueStep = SignedFloatToFixed(span.dsbdx); # endif } else { span.dsrdx = span.dsrdy = 0.0F; span.dsgdx = span.dsgdy = 0.0F; span.dsbdx = span.dsbdy = 0.0F; # if CHAN_TYPE == GL_FLOAT span.specRedStep = 0.0F; span.specGreenStep = 0.0F; span.specBlueStep = 0.0F; # else span.specRedStep = 0; span.specGreenStep = 0; span.specBlueStep = 0; # endif } #endif /* INTERP_SPEC */ #ifdef INTERP_INDEX span.interpMask |= SPAN_INDEX; if (ctx->Light.ShadeModel == GL_SMOOTH) { GLfloat eMaj_di = vMax->index - vMin->index; GLfloat eBot_di = vMid->index - vMin->index; didx = oneOverArea * (eMaj_di * eBot.dy - eMaj.dy * eBot_di); didy = oneOverArea * (eMaj.dx * eBot_di - eMaj_di * eBot.dx); span.indexStep = SignedFloatToFixed(didx); } else { span.interpMask |= SPAN_FLAT; didx = didy = 0.0F; span.indexStep = 0; } #endif #ifdef INTERP_INT_TEX span.interpMask |= SPAN_INT_TEXTURE; { GLfloat eMaj_ds = (vMax->texcoord[0][0] - vMin->texcoord[0][0]) * S_SCALE; GLfloat eBot_ds = (vMid->texcoord[0][0] - vMin->texcoord[0][0]) * S_SCALE; GLfloat eMaj_dt = (vMax->texcoord[0][1] - vMin->texcoord[0][1]) * T_SCALE; GLfloat eBot_dt = (vMid->texcoord[0][1] - vMin->texcoord[0][1]) * T_SCALE; span.texStepX[0][0] = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds); span.texStepY[0][0] = oneOverArea * (eMaj.dx * eBot_ds - eMaj_ds * eBot.dx); span.texStepX[0][1] = oneOverArea * (eMaj_dt * eBot.dy - eMaj.dy * eBot_dt); span.texStepY[0][1] = oneOverArea * (eMaj.dx * eBot_dt - eMaj_dt * eBot.dx); span.intTexStep[0] = SignedFloatToFixed(span.texStepX[0][0]); span.intTexStep[1] = SignedFloatToFixed(span.texStepX[0][1]); } #endif #ifdef INTERP_TEX span.interpMask |= SPAN_TEXTURE; { /* win[3] is 1/W */ const GLfloat wMax = vMax->win[3], wMin = vMin->win[3], wMid = vMid->win[3]; TEX_UNIT_LOOP( GLfloat eMaj_ds = vMax->texcoord[u][0] * wMax - vMin->texcoord[u][0] * wMin; GLfloat eBot_ds = vMid->texcoord[u][0] * wMid - vMin->texcoord[u][0] * wMin; GLfloat eMaj_dt = vMax->texcoord[u][1] * wMax - vMin->texcoord[u][1] * wMin; GLfloat eBot_dt = vMid->texcoord[u][1] * wMid - vMin->texcoord[u][1] * wMin; GLfloat eMaj_du = vMax->texcoord[u][2] * wMax - vMin->texcoord[u][2] * wMin; GLfloat eBot_du = vMid->texcoord[u][2] * wMid - vMin->texcoord[u][2] * wMin; GLfloat eMaj_dv = vMax->texcoord[u][3] * wMax - vMin->texcoord[u][3] * wMin; GLfloat eBot_dv = vMid->texcoord[u][3] * wMid - vMin->texcoord[u][3] * wMin; span.texStepX[u][0] = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds); span.texStepY[u][0] = oneOverArea * (eMaj.dx * eBot_ds - eMaj_ds * eBot.dx); span.texStepX[u][1] = oneOverArea * (eMaj_dt * eBot.dy - eMaj.dy * eBot_dt); span.texStepY[u][1] = oneOverArea * (eMaj.dx * eBot_dt - eMaj_dt * eBot.dx); span.texStepX[u][2] = oneOverArea * (eMaj_du * eBot.dy - eMaj.dy * eBot_du); span.texStepY[u][2] = oneOverArea * (eMaj.dx * eBot_du - eMaj_du * eBot.dx); span.texStepX[u][3] = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv); span.texStepY[u][3] = oneOverArea * (eMaj.dx * eBot_dv - eMaj_dv * eBot.dx); ) } #endif /* * We always sample at pixel centers. However, we avoid * explicit half-pixel offsets in this code by incorporating * the proper offset in each of x and y during the * transformation to window coordinates. * * We also apply the usual rasterization rules to prevent * cracks and overlaps. A pixel is considered inside a * subtriangle if it meets all of four conditions: it is on or * to the right of the left edge, strictly to the left of the * right edge, on or below the top edge, and strictly above * the bottom edge. (Some edges may be degenerate.) * * The following discussion assumes left-to-right scanning * (that is, the major edge is on the left); the right-to-left * case is a straightforward variation. * * We start by finding the half-integral y coordinate that is * at or below the top of the triangle. This gives us the * first scan line that could possibly contain pixels that are * inside the triangle. * * Next we creep down the major edge until we reach that y, * and compute the corresponding x coordinate on the edge. * Then we find the half-integral x that lies on or just * inside the edge. This is the first pixel that might lie in * the interior of the triangle. (We won't know for sure * until we check the other edges.) * * As we rasterize the triangle, we'll step down the major * edge. For each step in y, we'll move an integer number * of steps in x. There are two possible x step sizes, which * we'll call the ``inner'' step (guaranteed to land on the * edge or inside it) and the ``outer'' step (guaranteed to * land on the edge or outside it). The inner and outer steps * differ by one. During rasterization we maintain an error * term that indicates our distance from the true edge, and * select either the inner step or the outer step, whichever * gets us to the first pixel that falls inside the triangle. * * All parameters (z, red, etc.) as well as the buffer * addresses for color and z have inner and outer step values, * so that we can increment them appropriately. This method * eliminates the need to adjust parameters by creeping a * sub-pixel amount into the triangle at each scanline. */ { GLint subTriangle; GLinterp fxLeftEdge = 0, fxRightEdge = 0; GLinterp fdxLeftEdge = 0, fdxRightEdge = 0; GLinterp fError = 0, fdError = 0; #ifdef PIXEL_ADDRESS PIXEL_TYPE *pRow = NULL; GLint dPRowOuter = 0, dPRowInner; /* offset in bytes */ #endif #ifdef INTERP_Z # ifdef DEPTH_TYPE DEPTH_TYPE *zRow = NULL; GLint dZRowOuter = 0, dZRowInner; /* offset in bytes */ # endif GLfixed zLeft = 0, fdzOuter = 0, fdzInner; #endif #ifdef INTERP_W GLfloat wLeft = 0, dwOuter = 0, dwInner; #endif #ifdef INTERP_FOG GLfloat fogLeft = 0, dfogOuter = 0, dfogInner; #endif #ifdef INTERP_RGB ColorTemp rLeft = 0, fdrOuter = 0, fdrInner; ColorTemp gLeft = 0, fdgOuter = 0, fdgInner; ColorTemp bLeft = 0, fdbOuter = 0, fdbInner; #endif #ifdef INTERP_ALPHA ColorTemp aLeft = 0, fdaOuter = 0, fdaInner; #endif #ifdef INTERP_SPEC ColorTemp srLeft=0, dsrOuter=0, dsrInner; ColorTemp sgLeft=0, dsgOuter=0, dsgInner; ColorTemp sbLeft=0, dsbOuter=0, dsbInner; #endif #ifdef INTERP_INDEX GLfixed iLeft=0, diOuter=0, diInner; #endif #ifdef INTERP_INT_TEX GLfixed sLeft=0, dsOuter=0, dsInner; GLfixed tLeft=0, dtOuter=0, dtInner; #endif #ifdef INTERP_TEX GLfloat sLeft[MAX_TEXTURE_COORD_UNITS]; GLfloat tLeft[MAX_TEXTURE_COORD_UNITS]; GLfloat uLeft[MAX_TEXTURE_COORD_UNITS]; GLfloat vLeft[MAX_TEXTURE_COORD_UNITS]; GLfloat dsOuter[MAX_TEXTURE_COORD_UNITS], dsInner[MAX_TEXTURE_COORD_UNITS]; GLfloat dtOuter[MAX_TEXTURE_COORD_UNITS], dtInner[MAX_TEXTURE_COORD_UNITS]; GLfloat duOuter[MAX_TEXTURE_COORD_UNITS], duInner[MAX_TEXTURE_COORD_UNITS]; GLfloat dvOuter[MAX_TEXTURE_COORD_UNITS], dvInner[MAX_TEXTURE_COORD_UNITS]; #endif for (subTriangle=0; subTriangle<=1; subTriangle++) { EdgeT *eLeft, *eRight; int setupLeft, setupRight; int lines; if (subTriangle==0) { /* bottom half */ if (scan_from_left_to_right) { eLeft = &eMaj; eRight = &eBot; lines = eRight->lines; setupLeft = 1; setupRight = 1; } else { eLeft = &eBot; eRight = &eMaj; lines = eLeft->lines; setupLeft = 1; setupRight = 1; } } else { /* top half */ if (scan_from_left_to_right) { eLeft = &eMaj; eRight = &eTop; lines = eRight->lines; setupLeft = 0; setupRight = 1; } else { eLeft = &eTop; eRight = &eMaj; lines = eLeft->lines; setupLeft = 1; setupRight = 0; } if (lines == 0) return; } if (setupLeft && eLeft->lines > 0) { const SWvertex *vLower = eLeft->v0; #if TRIANGLE_WALK_DOUBLE const GLdouble fsy = eLeft->fsy; const GLdouble fsx = eLeft->fsx; const GLdouble fx = CEILF(fsx); const GLdouble adjx = (fx - eLeft->fx0) * FIXED_SCALE; /* SCALED! */ #else const GLfixed fsy = eLeft->fsy; const GLfixed fsx = eLeft->fsx; /* no fractional part */ const GLfixed fx = FixedCeil(fsx); /* no fractional part */ const GLfixed adjx = (GLinterp) (fx - eLeft->fx0); /* SCALED! */ #endif const GLinterp adjy = eLeft->adjy; /* SCALED! */ GLint idxOuter; #if TRIANGLE_WALK_DOUBLE GLdouble dxOuter; fError = fx - fsx - 1.0; fxLeftEdge = fsx; fdxLeftEdge = eLeft->dxdy; dxOuter = FLOORF(fdxLeftEdge); fdError = dxOuter - fdxLeftEdge + 1.0; idxOuter = (GLint) dxOuter; span.y = (GLint) fsy; #else GLfloat dxOuter; GLfixed fdxOuter; fError = fx - fsx - FIXED_ONE; fxLeftEdge = fsx - FIXED_EPSILON; fdxLeftEdge = eLeft->fdxdy; fdxOuter = FixedFloor(fdxLeftEdge - FIXED_EPSILON); fdError = fdxOuter - fdxLeftEdge + FIXED_ONE; idxOuter = FixedToInt(fdxOuter); dxOuter = (GLfloat) idxOuter; span.y = FixedToInt(fsy); #endif /* silence warnings on some compilers */ (void) dxOuter; (void) adjx; (void) adjy; (void) vLower; #ifdef PIXEL_ADDRESS { pRow = (PIXEL_TYPE *) PIXEL_ADDRESS(InterpToInt(fxLeftEdge), span.y); dPRowOuter = -((int)BYTES_PER_ROW) + idxOuter * sizeof(PIXEL_TYPE); /* negative because Y=0 at bottom and increases upward */ } #endif /* * Now we need the set of parameter (z, color, etc.) values at * the point (fx, fsy). This gives us properly-sampled parameter * values that we can step from pixel to pixel. Furthermore, * although we might have intermediate results that overflow * the normal parameter range when we step temporarily outside * the triangle, we shouldn't overflow or underflow for any * pixel that's actually inside the triangle. */ #ifdef INTERP_Z { GLfloat z0 = vLower->win[2]; if (depthBits <= 16) { /* interpolate fixed-pt values */ GLfloat tmp = (z0 * FIXED_SCALE + span.dzdx * adjx + span.dzdy * adjy) + FIXED_HALF; if (tmp < MAX_GLUINT / 2) zLeft = (GLfixed) tmp; else zLeft = MAX_GLUINT / 2; fdzOuter = SignedFloatToFixed(span.dzdy + dxOuter * span.dzdx); } else { /* interpolate depth values exactly */ zLeft = (GLint) (z0 + span.dzdx * FixedToFloat(adjx) + span.dzdy * FixedToFloat(adjy)); fdzOuter = (GLint) (span.dzdy + dxOuter * span.dzdx); } # ifdef DEPTH_TYPE zRow = (DEPTH_TYPE *) _swrast_zbuffer_address(ctx, InterpToInt(fxLeftEdge), span.y); dZRowOuter = (ctx->DrawBuffer->Width + idxOuter) * sizeof(DEPTH_TYPE); # endif } #endif #ifdef INTERP_W wLeft = vLower->win[3] + (span.dwdx * adjx + span.dwdy * adjy) * (1.0F/FIXED_SCALE); dwOuter = span.dwdy + dxOuter * span.dwdx; #endif #ifdef INTERP_FOG # ifdef INTERP_W fogLeft = vLower->fog * vLower->win[3] + (span.dfogdx * adjx + span.dfogdy * adjy) * (1.0F/FIXED_SCALE); # else fogLeft = vLower->fog + (span.dfogdx * adjx + span.dfogdy * adjy) * (1.0F/FIXED_SCALE); # endif dfogOuter = span.dfogdy + dxOuter * span.dfogdx; #endif #ifdef INTERP_RGB if (ctx->Light.ShadeModel == GL_SMOOTH) { # if CHAN_TYPE == GL_FLOAT rLeft = vLower->color[RCOMP] + (span.drdx * adjx + span.drdy * adjy) * (1.0F / FIXED_SCALE); gLeft = vLower->color[GCOMP] + (span.dgdx * adjx + span.dgdy * adjy) * (1.0F / FIXED_SCALE); bLeft = vLower->color[BCOMP] + (span.dbdx * adjx + span.dbdy * adjy) * (1.0F / FIXED_SCALE); fdrOuter = span.drdy + dxOuter * span.drdx; fdgOuter = span.dgdy + dxOuter * span.dgdx; fdbOuter = span.dbdy + dxOuter * span.dbdx; # else rLeft = (GLint)(ChanToFixed(vLower->color[RCOMP]) + span.drdx * adjx + span.drdy * adjy) + FIXED_HALF; gLeft = (GLint)(ChanToFixed(vLower->color[GCOMP]) + span.dgdx * adjx + span.dgdy * adjy) + FIXED_HALF; bLeft = (GLint)(ChanToFixed(vLower->color[BCOMP]) + span.dbdx * adjx + span.dbdy * adjy) + FIXED_HALF; fdrOuter = SignedFloatToFixed(span.drdy + dxOuter * span.drdx); fdgOuter = SignedFloatToFixed(span.dgdy + dxOuter * span.dgdx); fdbOuter = SignedFloatToFixed(span.dbdy + dxOuter * span.dbdx); # endif # ifdef INTERP_ALPHA # if CHAN_TYPE == GL_FLOAT aLeft = vLower->color[ACOMP] + (span.dadx * adjx + span.dady * adjy) * (1.0F / FIXED_SCALE); fdaOuter = span.dady + dxOuter * span.dadx; # else aLeft = (GLint)(ChanToFixed(vLower->color[ACOMP]) + span.dadx * adjx + span.dady * adjy) + FIXED_HALF; fdaOuter = SignedFloatToFixed(span.dady + dxOuter * span.dadx); # endif # endif } else { ASSERT (ctx->Light.ShadeModel == GL_FLAT); # if CHAN_TYPE == GL_FLOAT rLeft = v2->color[RCOMP]; gLeft = v2->color[GCOMP]; bLeft = v2->color[BCOMP]; fdrOuter = fdgOuter = fdbOuter = 0.0F; # else rLeft = ChanToFixed(v2->color[RCOMP]); gLeft = ChanToFixed(v2->color[GCOMP]); bLeft = ChanToFixed(v2->color[BCOMP]); fdrOuter = fdgOuter = fdbOuter = 0; # endif # ifdef INTERP_ALPHA # if CHAN_TYPE == GL_FLOAT aLeft = v2->color[ACOMP]; fdaOuter = 0.0F; # else aLeft = ChanToFixed(v2->color[ACOMP]); fdaOuter = 0; # endif # endif } #endif #ifdef INTERP_SPEC if (ctx->Light.ShadeModel == GL_SMOOTH) { # if CHAN_TYPE == GL_FLOAT srLeft = vLower->specular[RCOMP] + (span.dsrdx * adjx + span.dsrdy * adjy) * (1.0F / FIXED_SCALE); sgLeft = vLower->specular[GCOMP] + (span.dsgdx * adjx + span.dsgdy * adjy) * (1.0F / FIXED_SCALE); sbLeft = vLower->specular[BCOMP] + (span.dsbdx * adjx + span.dsbdy * adjy) * (1.0F / FIXED_SCALE); dsrOuter = span.dsrdy + dxOuter * span.dsrdx; dsgOuter = span.dsgdy + dxOuter * span.dsgdx; dsbOuter = span.dsbdy + dxOuter * span.dsbdx; # else srLeft = (GLfixed) (ChanToFixed(vLower->specular[RCOMP]) + span.dsrdx * adjx + span.dsrdy * adjy) + FIXED_HALF; sgLeft = (GLfixed) (ChanToFixed(vLower->specular[GCOMP]) + span.dsgdx * adjx + span.dsgdy * adjy) + FIXED_HALF; sbLeft = (GLfixed) (ChanToFixed(vLower->specular[BCOMP]) + span.dsbdx * adjx + span.dsbdy * adjy) + FIXED_HALF; dsrOuter = SignedFloatToFixed(span.dsrdy + dxOuter * span.dsrdx); dsgOuter = SignedFloatToFixed(span.dsgdy + dxOuter * span.dsgdx); dsbOuter = SignedFloatToFixed(span.dsbdy + dxOuter * span.dsbdx); # endif } else { #if CHAN_TYPE == GL_FLOAT srLeft = v2->specular[RCOMP]; sgLeft = v2->specular[GCOMP]; sbLeft = v2->specular[BCOMP]; dsrOuter = dsgOuter = dsbOuter = 0.0F; # else srLeft = ChanToFixed(v2->specular[RCOMP]); sgLeft = ChanToFixed(v2->specular[GCOMP]); sbLeft = ChanToFixed(v2->specular[BCOMP]); dsrOuter = dsgOuter = dsbOuter = 0; # endif } #endif #ifdef INTERP_INDEX if (ctx->Light.ShadeModel == GL_SMOOTH) { iLeft = (GLfixed)(vLower->index * FIXED_SCALE + didx * adjx + didy * adjy) + FIXED_HALF; diOuter = SignedFloatToFixed(didy + dxOuter * didx); } else { iLeft = FloatToFixed(v2->index); diOuter = 0; } #endif #ifdef INTERP_INT_TEX { GLfloat s0, t0; s0 = vLower->texcoord[0][0] * S_SCALE; sLeft = (GLfixed)(s0 * FIXED_SCALE + span.texStepX[0][0] * adjx + span.texStepY[0][0] * adjy) + FIXED_HALF; dsOuter = SignedFloatToFixed(span.texStepY[0][0] + dxOuter * span.texStepX[0][0]); t0 = vLower->texcoord[0][1] * T_SCALE; tLeft = (GLfixed)(t0 * FIXED_SCALE + span.texStepX[0][1] * adjx + span.texStepY[0][1] * adjy) + FIXED_HALF; dtOuter = SignedFloatToFixed(span.texStepY[0][1] + dxOuter * span.texStepX[0][1]); } #endif #ifdef INTERP_TEX TEX_UNIT_LOOP( const GLfloat invW = vLower->win[3]; const GLfloat s0 = vLower->texcoord[u][0] * invW; const GLfloat t0 = vLower->texcoord[u][1] * invW; const GLfloat u0 = vLower->texcoord[u][2] * invW; const GLfloat v0 = vLower->texcoord[u][3] * invW; sLeft[u] = s0 + (span.texStepX[u][0] * adjx + span.texStepY[u][0] * adjy) * (1.0F/FIXED_SCALE); tLeft[u] = t0 + (span.texStepX[u][1] * adjx + span.texStepY[u][1] * adjy) * (1.0F/FIXED_SCALE); uLeft[u] = u0 + (span.texStepX[u][2] * adjx + span.texStepY[u][2] * adjy) * (1.0F/FIXED_SCALE); vLeft[u] = v0 + (span.texStepX[u][3] * adjx + span.texStepY[u][3] * adjy) * (1.0F/FIXED_SCALE); dsOuter[u] = span.texStepY[u][0] + dxOuter * span.texStepX[u][0]; dtOuter[u] = span.texStepY[u][1] + dxOuter * span.texStepX[u][1]; duOuter[u] = span.texStepY[u][2] + dxOuter * span.texStepX[u][2]; dvOuter[u] = span.texStepY[u][3] + dxOuter * span.texStepX[u][3]; ) #endif } /*if setupLeft*/ if (setupRight && eRight->lines>0) { #if TRIANGLE_WALK_DOUBLE fxRightEdge = eRight->fsx; fdxRightEdge = eRight->dxdy; #else fxRightEdge = eRight->fsx - FIXED_EPSILON; fdxRightEdge = eRight->fdxdy; #endif } if (lines==0) { continue; } /* Rasterize setup */ #ifdef PIXEL_ADDRESS dPRowInner = dPRowOuter + sizeof(PIXEL_TYPE); #endif #ifdef INTERP_Z # ifdef DEPTH_TYPE dZRowInner = dZRowOuter + sizeof(DEPTH_TYPE); # endif fdzInner = fdzOuter + span.zStep; #endif #ifdef INTERP_W dwInner = dwOuter + span.dwdx; #endif #ifdef INTERP_FOG dfogInner = dfogOuter + span.dfogdx; #endif #ifdef INTERP_RGB fdrInner = fdrOuter + span.redStep; fdgInner = fdgOuter + span.greenStep; fdbInner = fdbOuter + span.blueStep; #endif #ifdef INTERP_ALPHA fdaInner = fdaOuter + span.alphaStep; #endif #ifdef INTERP_SPEC dsrInner = dsrOuter + span.specRedStep; dsgInner = dsgOuter + span.specGreenStep; dsbInner = dsbOuter + span.specBlueStep; #endif #ifdef INTERP_INDEX diInner = diOuter + span.indexStep; #endif #ifdef INTERP_INT_TEX dsInner = dsOuter + span.intTexStep[0]; dtInner = dtOuter + span.intTexStep[1]; #endif #ifdef INTERP_TEX TEX_UNIT_LOOP( dsInner[u] = dsOuter[u] + span.texStepX[u][0]; dtInner[u] = dtOuter[u] + span.texStepX[u][1]; duInner[u] = duOuter[u] + span.texStepX[u][2]; dvInner[u] = dvOuter[u] + span.texStepX[u][3]; ) #endif while (lines > 0) { /* initialize the span interpolants to the leftmost value */ /* ff = fixed-pt fragment */ const GLint right = InterpToInt(fxRightEdge); span.x = InterpToInt(fxLeftEdge); if (right <= span.x) span.end = 0; else span.end = right - span.x; #ifdef INTERP_Z span.z = zLeft; #endif #ifdef INTERP_W span.w = wLeft; #endif #ifdef INTERP_FOG span.fog = fogLeft; #endif #ifdef INTERP_RGB span.red = rLeft; span.green = gLeft; span.blue = bLeft; #endif #ifdef INTERP_ALPHA span.alpha = aLeft; #endif #ifdef INTERP_SPEC span.specRed = srLeft; span.specGreen = sgLeft; span.specBlue = sbLeft; #endif #ifdef INTERP_INDEX span.index = iLeft; #endif #ifdef INTERP_INT_TEX span.intTex[0] = sLeft; span.intTex[1] = tLeft; #endif #ifdef INTERP_TEX TEX_UNIT_LOOP( span.tex[u][0] = sLeft[u]; span.tex[u][1] = tLeft[u]; span.tex[u][2] = uLeft[u]; span.tex[u][3] = vLeft[u]; ) #endif if (span.end > 1) { /* Under rare circumstances, we might have to fudge the * colors. XXX does this really happen anymore??? */ const GLint len = span.end - 1; (void) len; #ifdef INTERP_RGB { GLfixed ffrend = span.red + len * span.redStep; GLfixed ffgend = span.green + len * span.greenStep; GLfixed ffbend = span.blue + len * span.blueStep; if (ffrend < 0) { span.red -= ffrend; if (span.red < 0) span.red = 0; } if (ffgend < 0) { span.green -= ffgend; if (span.green < 0) span.green = 0; } if (ffbend < 0) { span.blue -= ffbend; if (span.blue < 0) span.blue = 0; } } #endif #ifdef INTERP_ALPHA { GLfixed ffaend = span.alpha + len * span.alphaStep; if (ffaend < 0) { span.alpha -= ffaend; if (span.alpha < 0) span.alpha = 0; } } #endif #ifdef INTERP_SPEC { GLfixed ffsrend = span.specRed + len * span.specRedStep; GLfixed ffsgend = span.specGreen + len * span.specGreenStep; GLfixed ffsbend = span.specBlue + len * span.specBlueStep; if (ffsrend < 0) { span.specRed -= ffsrend; if (span.specRed < 0) span.specRed = 0; } if (ffsgend < 0) { span.specGreen -= ffsgend; if (span.specGreen < 0) span.specGreen = 0; } if (ffsbend < 0) { span.specBlue -= ffsbend; if (span.specBlue < 0) span.specBlue = 0; } } #endif #ifdef INTERP_INDEX if (span.index < 0) span.index = 0; #endif } /* span.end > 1 */ /* This is where we actually generate fragments */ if (span.end > 0) { RENDER_SPAN( span ); } /* * Advance to the next scan line. Compute the * new edge coordinates, and adjust the * pixel-center x coordinate so that it stays * on or inside the major edge. */ span.y++; lines--; fxLeftEdge += fdxLeftEdge; fxRightEdge += fdxRightEdge; fError += fdError; if (fError >= 0) { fError -= INTERP_ONE; #ifdef PIXEL_ADDRESS pRow = (PIXEL_TYPE *) ((GLubyte *) pRow + dPRowOuter); #endif #ifdef INTERP_Z # ifdef DEPTH_TYPE zRow = (DEPTH_TYPE *) ((GLubyte *) zRow + dZRowOuter); # endif zLeft += fdzOuter; #endif #ifdef INTERP_W wLeft += dwOuter; #endif #ifdef INTERP_FOG fogLeft += dfogOuter; #endif #ifdef INTERP_RGB rLeft += fdrOuter; gLeft += fdgOuter; bLeft += fdbOuter; #endif #ifdef INTERP_ALPHA aLeft += fdaOuter; #endif #ifdef INTERP_SPEC srLeft += dsrOuter; sgLeft += dsgOuter; sbLeft += dsbOuter; #endif #ifdef INTERP_INDEX iLeft += diOuter; #endif #ifdef INTERP_INT_TEX sLeft += dsOuter; tLeft += dtOuter; #endif #ifdef INTERP_TEX TEX_UNIT_LOOP( sLeft[u] += dsOuter[u]; tLeft[u] += dtOuter[u]; uLeft[u] += duOuter[u]; vLeft[u] += dvOuter[u]; ) #endif } else { #ifdef PIXEL_ADDRESS pRow = (PIXEL_TYPE *) ((GLubyte *) pRow + dPRowInner); #endif #ifdef INTERP_Z # ifdef DEPTH_TYPE zRow = (DEPTH_TYPE *) ((GLubyte *) zRow + dZRowInner); # endif zLeft += fdzInner; #endif #ifdef INTERP_W wLeft += dwInner; #endif #ifdef INTERP_FOG fogLeft += dfogInner; #endif #ifdef INTERP_RGB rLeft += fdrInner; gLeft += fdgInner; bLeft += fdbInner; #endif #ifdef INTERP_ALPHA aLeft += fdaInner; #endif #ifdef INTERP_SPEC srLeft += dsrInner; sgLeft += dsgInner; sbLeft += dsbInner; #endif #ifdef INTERP_INDEX iLeft += diInner; #endif #ifdef INTERP_INT_TEX sLeft += dsInner; tLeft += dtInner; #endif #ifdef INTERP_TEX TEX_UNIT_LOOP( sLeft[u] += dsInner[u]; tLeft[u] += dtInner[u]; uLeft[u] += duInner[u]; vLeft[u] += dvInner[u]; ) #endif } } /*while lines>0*/ } /* for subTriangle */ } #ifdef CLEANUP_CODE CLEANUP_CODE #endif } } #undef SETUP_CODE #undef CLEANUP_CODE #undef RENDER_SPAN #undef PIXEL_TYPE #undef BYTES_PER_ROW #undef PIXEL_ADDRESS #undef INTERP_Z #undef INTERP_W #undef INTERP_FOG #undef INTERP_RGB #undef INTERP_ALPHA #undef INTERP_SPEC #undef INTERP_INDEX #undef INTERP_INT_TEX #undef INTERP_TEX #undef INTERP_MULTITEX #undef TEX_UNIT_LOOP #undef S_SCALE #undef T_SCALE #undef FixedToDepth #undef ColorTemp #undef GLinterp #undef InterpToInt #undef INTERP_ONE #undef NAME