fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2025-12-25 00:00:11 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

fixed RGB over/underflow bug for tiny triangles (bug 128969)

Browse source
This commit is contained in:
Brian Paul 2001-02-12 17:02:00 +00:00
parent 15bf1cd129
commit 3c84ab90f2
1 changed files with 36 additions and 43 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

79
src/mesa/swrast/s_tritemp.h
View file

@ -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);