diff options
| -rw-r--r-- | src/mesa/swrast/s_tritemp.h | 79 |
1 files changed, 36 insertions, 43 deletions
diff --git a/src/mesa/swrast/s_tritemp.h b/src/mesa/swrast/s_tritemp.h index a622abee9b..32c0f107e3 100644 --- a/src/mesa/swrast/s_tritemp.h +++ b/src/mesa/swrast/s_tritemp.h @@ -1,4 +1,4 @@ -/* $Id: s_tritemp.h,v 1.9 2001/02/06 21:42:49 brianp Exp $ */ +/* $Id: s_tritemp.h,v 1.10 2001/02/12 17:02:00 brianp Exp $ */ /* * Mesa 3-D graphics library @@ -99,6 +99,7 @@ GLfloat oneOverArea; const SWvertex *vMin, *vMid, *vMax; /* Y(vMin)<=Y(vMid)<=Y(vMax) */ float bf = SWRAST_CONTEXT(ctx)->_backface_sign; + GLboolean tiny; /* find the order of the 3 vertices along the Y axis */ { @@ -155,10 +156,14 @@ return; /* check for very tiny triangle */ - if (area * area < (0.05F * 0.05F)) /* square to ensure positive value */ + if (area * area < (0.05F * 0.05F)) { /* square to ensure positive value */ oneOverArea = 1.0F / 0.05F; /* a close-enough value */ - else + tiny = GL_TRUE; + } + else { oneOverArea = 1.0F / area; + tiny = GL_FALSE; + } } #ifndef DO_OCCLUSION_TEST @@ -328,32 +333,31 @@ } #endif #ifdef INTERP_RGB - { + if (tiny) { + /* This is kind of a hack to eliminate RGB color over/underflow + * problems when rendering very tiny triangles. We're not doing + * anything with alpha or specular color at this time. + */ + drdx = drdy = 0.0; fdrdx = 0; + dgdx = dgdy = 0.0; fdgdx = 0; + dbdx = dbdy = 0.0; fdbdx = 0; + } + else { GLfloat eMaj_dr, eBot_dr; - eMaj_dr = (GLint) vMax->color[0] - - (GLint) vMin->color[0]; - eBot_dr = (GLint) vMid->color[0] - - (GLint) vMin->color[0]; + GLfloat eMaj_dg, eBot_dg; + GLfloat eMaj_db, eBot_db; + eMaj_dr = (GLint) vMax->color[0] - (GLint) vMin->color[0]; + eBot_dr = (GLint) vMid->color[0] - (GLint) vMin->color[0]; drdx = oneOverArea * (eMaj_dr * eBot.dy - eMaj.dy * eBot_dr); fdrdx = SignedFloatToFixed(drdx); drdy = oneOverArea * (eMaj.dx * eBot_dr - eMaj_dr * eBot.dx); - } - { - GLfloat eMaj_dg, eBot_dg; - eMaj_dg = (GLint) vMax->color[1] - - (GLint) vMin->color[1]; - eBot_dg = (GLint) vMid->color[1] - - (GLint) vMin->color[1]; + eMaj_dg = (GLint) vMax->color[1] - (GLint) vMin->color[1]; + eBot_dg = (GLint) vMid->color[1] - (GLint) vMin->color[1]; dgdx = oneOverArea * (eMaj_dg * eBot.dy - eMaj.dy * eBot_dg); fdgdx = SignedFloatToFixed(dgdx); dgdy = oneOverArea * (eMaj.dx * eBot_dg - eMaj_dg * eBot.dx); - } - { - GLfloat eMaj_db, eBot_db; - eMaj_db = (GLint) vMax->color[2] - - (GLint) vMin->color[2]; - eBot_db = (GLint) vMid->color[2] - - (GLint) vMin->color[2]; + eMaj_db = (GLint) vMax->color[2] - (GLint) vMin->color[2]; + eBot_db = (GLint) vMid->color[2] - (GLint) vMin->color[2]; dbdx = oneOverArea * (eMaj_db * eBot.dy - eMaj.dy * eBot_db); fdbdx = SignedFloatToFixed(dbdx); dbdy = oneOverArea * (eMaj.dx * eBot_db - eMaj_db * eBot.dx); @@ -362,30 +366,24 @@ #ifdef INTERP_SPEC { GLfloat eMaj_dsr, eBot_dsr; - eMaj_dsr = (GLint) vMax->specular[0] - - (GLint) vMin->specular[0]; - eBot_dsr = (GLint) vMid->specular[0] - - (GLint) vMin->specular[0]; + eMaj_dsr = (GLint) vMax->specular[0] - (GLint) vMin->specular[0]; + eBot_dsr = (GLint) vMid->specular[0] - (GLint) vMin->specular[0]; dsrdx = oneOverArea * (eMaj_dsr * eBot.dy - eMaj.dy * eBot_dsr); fdsrdx = SignedFloatToFixed(dsrdx); dsrdy = oneOverArea * (eMaj.dx * eBot_dsr - eMaj_dsr * eBot.dx); } { GLfloat eMaj_dsg, eBot_dsg; - eMaj_dsg = (GLint) vMax->specular[1] - - (GLint) vMin->specular[1]; - eBot_dsg = (GLint) vMid->specular[1] - - (GLint) vMin->specular[1]; + eMaj_dsg = (GLint) vMax->specular[1] - (GLint) vMin->specular[1]; + eBot_dsg = (GLint) vMid->specular[1] - (GLint) vMin->specular[1]; dsgdx = oneOverArea * (eMaj_dsg * eBot.dy - eMaj.dy * eBot_dsg); fdsgdx = SignedFloatToFixed(dsgdx); dsgdy = oneOverArea * (eMaj.dx * eBot_dsg - eMaj_dsg * eBot.dx); } { GLfloat eMaj_dsb, eBot_dsb; - eMaj_dsb = (GLint) vMax->specular[2] - - (GLint) vMin->specular[2]; - eBot_dsb = (GLint) vMid->specular[2] - - (GLint) vMin->specular[2]; + eMaj_dsb = (GLint) vMax->specular[2] - (GLint) vMin->specular[2]; + eBot_dsb = (GLint) vMid->specular[2] - (GLint) vMin->specular[2]; dsbdx = oneOverArea * (eMaj_dsb * eBot.dy - eMaj.dy * eBot_dsb); fdsbdx = SignedFloatToFixed(dsbdx); dsbdy = oneOverArea * (eMaj.dx * eBot_dsb - eMaj_dsb * eBot.dx); @@ -394,10 +392,8 @@ #ifdef INTERP_ALPHA { GLfloat eMaj_da, eBot_da; - eMaj_da = (GLint) vMax->color[3] - - (GLint) vMin->color[3]; - eBot_da = (GLint) vMid->color[3] - - (GLint) vMin->color[3]; + eMaj_da = (GLint) vMax->color[3] - (GLint) vMin->color[3]; + eBot_da = (GLint) vMid->color[3] - (GLint) vMin->color[3]; dadx = oneOverArea * (eMaj_da * eBot.dy - eMaj.dy * eBot_da); fdadx = SignedFloatToFixed(dadx); dady = oneOverArea * (eMaj.dx * eBot_da - eMaj_da * eBot.dx); @@ -406,10 +402,8 @@ #ifdef INTERP_INDEX { GLfloat eMaj_di, eBot_di; - eMaj_di = (GLint) vMax->index - - (GLint) vMin->index; - eBot_di = (GLint) vMid->index - - (GLint) vMin->index; + eMaj_di = (GLint) vMax->index - (GLint) vMin->index; + eBot_di = (GLint) vMid->index - (GLint) vMin->index; didx = oneOverArea * (eMaj_di * eBot.dy - eMaj.dy * eBot_di); fdidx = SignedFloatToFixed(didx); didy = oneOverArea * (eMaj.dx * eBot_di - eMaj_di * eBot.dx); @@ -459,7 +453,6 @@ dudx = oneOverArea * (eMaj_du * eBot.dy - eMaj.dy * eBot_du); dudy = oneOverArea * (eMaj.dx * eBot_du - eMaj_du * eBot.dx); - eMaj_dv = vMax->texcoord[0][3] * wMax - vMin->texcoord[0][3] * wMin; eBot_dv = vMid->texcoord[0][3] * wMid - vMin->texcoord[0][3] * wMin; dvdx = oneOverArea * (eMaj_dv * eBot.dy - eMaj.dy * eBot_dv); |