And after a while, access violations would happen. Often took 15 minutes. I'm sure they eventually happen during normal use and WinQuake just crashes.
#1 is C code only
#2 can happen in both C code and asm.
#1 This is for the C code (if you are using asm, this doesn't apply):
Code: Select all
/*
================
D_PolysetDrawFinalVerts
================
*/
void D_PolysetDrawFinalVerts (finalvert_t *fv, int numverts)
{
int i, z;
short *zbuf;
for (i=0 ; i<numverts ; i++, fv++)
{
// valid triangle coordinates for filling can include the bottom and
// right clip edges, due to the fill rule; these shouldn't be drawn
if ((fv->v[0] < r_refdef.vrectright) &&
(fv->v[1] < r_refdef.vrectbottom) )
{
#if 1 // Baker - in very rare occassions, these may have negative values and can result in a memory access violation
if (fv->v[0] >=0 && fv->v[1] >=0)
{
#endif
z = fv->v[5]>>16;
zbuf = zspantable[fv->v[1]] + fv->v[0];
if (z >= *zbuf)
{
int pix;
*zbuf = z;
pix = skintable[fv->v[3]>>16][fv->v[2]>>16];
pix = ((byte *)acolormap)[pix + (fv->v[4] & 0xFF00) ];
d_viewbuffer[d_scantable[fv->v[1]] + fv->v[0]] = pix;
}
#if 1 // Baker
}
#endif
}
}
}
#2 This one can happen using asm or C
[code]/*
================
D_RasterizeAliasPolySmooth
================
*/
void D_RasterizeAliasPolySmooth (void)
{
int initialleftheight, initialrightheight;
int *plefttop, *prighttop, *pleftbottom, *prightbottom;
int working_lstepx, originalcount;
plefttop = pedgetable->pleftedgevert0;
prighttop = pedgetable->prightedgevert0;
pleftbottom = pedgetable->pleftedgevert1;
prightbottom = pedgetable->prightedgevert1;
initialleftheight = pleftbottom[1] - plefttop[1];
initialrightheight = prightbottom[1] - prighttop[1];
//
// set the s, t, and light gradients, which are consistent across the triangle
// because being a triangle, things are affine
//
D_PolysetCalcGradients (r_affinetridesc.skinwidth);
//
// rasterize the polygon
//
//
// scan out the top (and possibly only) part of the left edge
//
d_pedgespanpackage = a_spans;
ystart = plefttop[1];
d_aspancount = plefttop[0] - prighttop[0];
d_ptex = (byte *)r_affinetridesc.pskin + (plefttop[2] >> 16) +
(plefttop[3] >> 16) * r_affinetridesc.skinwidth;
#if id386
d_sfrac = (plefttop[2] & 0xFFFF) << 16;
d_tfrac = (plefttop[3] & 0xFFFF) << 16;
#else
d_sfrac = plefttop[2] & 0xFFFF;
d_tfrac = plefttop[3] & 0xFFFF;
#endif
d_light = plefttop[4];
d_zi = plefttop[5];
d_pdest = (byte *)d_viewbuffer +
ystart * screenwidth + plefttop[0];
d_pz = d_pzbuffer + ystart * d_zwidth + plefttop[0];
if (initialleftheight == 1)
{
d_pedgespanpackage->pdest = d_pdest;
d_pedgespanpackage->pz = d_pz;
d_pedgespanpackage->count = d_aspancount;
d_pedgespanpackage->ptex = d_ptex;
d_pedgespanpackage->sfrac = d_sfrac;
d_pedgespanpackage->tfrac = d_tfrac;
// FIXME: need to clamp l, s, t, at both ends?
d_pedgespanpackage->light = d_light;
d_pedgespanpackage->zi = d_zi;
d_pedgespanpackage++;
}
else
{
D_PolysetSetUpForLineScan(plefttop[0], plefttop[1],
pleftbottom[0], pleftbottom[1]);
#if id386
d_pzbasestep = (d_zwidth + ubasestep) << 1;
d_pzextrastep = d_pzbasestep + 2;
#else
d_pzbasestep = d_zwidth + ubasestep;
d_pzextrastep = d_pzbasestep + 1;
#endif
d_pdestbasestep = screenwidth + ubasestep;
d_pdestextrastep = d_pdestbasestep + 1;
// TODO: can reuse partial expressions here
// for negative steps in x along left edge, bias toward overflow rather than
// underflow (sort of turning the floor () we did in the gradient calcs into
// ceil (), but plus a little bit)
if (ubasestep < 0)
working_lstepx = r_lstepx - 1;
else
working_lstepx = r_lstepx;
d_countextrastep = ubasestep + 1;
d_ptexbasestep = ((r_sstepy + r_sstepx * ubasestep) >> 16) +
((r_tstepy + r_tstepx * ubasestep) >> 16) *
r_affinetridesc.skinwidth;
#if id386
d_sfracbasestep = (r_sstepy + r_sstepx * ubasestep) << 16;
d_tfracbasestep = (r_tstepy + r_tstepx * ubasestep) << 16;
#else
d_sfracbasestep = (r_sstepy + r_sstepx * ubasestep) & 0xFFFF;
d_tfracbasestep = (r_tstepy + r_tstepx * ubasestep) & 0xFFFF;
#endif
d_lightbasestep = r_lstepy + working_lstepx * ubasestep;
d_zibasestep = r_zistepy + r_zistepx * ubasestep;
d_ptexextrastep = ((r_sstepy + r_sstepx * d_countextrastep) >> 16) +
((r_tstepy + r_tstepx * d_countextrastep) >> 16) *
r_affinetridesc.skinwidth;
#if id386
d_sfracextrastep = (r_sstepy + r_sstepx*d_countextrastep) << 16;
d_tfracextrastep = (r_tstepy + r_tstepx*d_countextrastep) << 16;
#else
d_sfracextrastep = (r_sstepy + r_sstepx*d_countextrastep) & 0xFFFF;
d_tfracextrastep = (r_tstepy + r_tstepx*d_countextrastep) & 0xFFFF;
#endif
d_lightextrastep = d_lightbasestep + working_lstepx;
d_ziextrastep = d_zibasestep + r_zistepx;
D_PolysetScanLeftEdge (initialleftheight);
}
//
// scan out the bottom part of the left edge, if it exists
//
if (pedgetable->numleftedges == 2)
{
int height;
plefttop = pleftbottom;
pleftbottom = pedgetable->pleftedgevert2;
height = pleftbottom[1] - plefttop[1];
// TODO: make this a function; modularize this function in general
ystart = plefttop[1];
d_aspancount = plefttop[0] - prighttop[0];
d_ptex = (byte *)r_affinetridesc.pskin + (plefttop[2] >> 16) +
(plefttop[3] >> 16) * r_affinetridesc.skinwidth;
d_sfrac = 0;
d_tfrac = 0;
d_light = plefttop[4];
d_zi = plefttop[5];
d_pdest = (byte *)d_viewbuffer + ystart * screenwidth + plefttop[0];
d_pz = d_pzbuffer + ystart * d_zwidth + plefttop[0];
if (height == 1)
{
d_pedgespanpackage->pdest = d_pdest;
d_pedgespanpackage->pz = d_pz;
d_pedgespanpackage->count = d_aspancount;
d_pedgespanpackage->ptex = d_ptex;
d_pedgespanpackage->sfrac = d_sfrac;
d_pedgespanpackage->tfrac = d_tfrac;
// FIXME: need to clamp l, s, t, at both ends?
d_pedgespanpackage->light = d_light;
d_pedgespanpackage->zi = d_zi;
d_pedgespanpackage++;
}
else
{
D_PolysetSetUpForLineScan(plefttop[0], plefttop[1],
pleftbottom[0], pleftbottom[1]);
d_pdestbasestep = screenwidth + ubasestep;
d_pdestextrastep = d_pdestbasestep + 1;
#if id386
d_pzbasestep = (d_zwidth + ubasestep) << 1;
d_pzextrastep = d_pzbasestep + 2;
#else
d_pzbasestep = d_zwidth + ubasestep;
d_pzextrastep = d_pzbasestep + 1;
#endif
if (ubasestep < 0)
working_lstepx = r_lstepx - 1;
else
working_lstepx = r_lstepx;
d_countextrastep = ubasestep + 1;
d_ptexbasestep = ((r_sstepy + r_sstepx * ubasestep) >> 16) +
((r_tstepy + r_tstepx * ubasestep) >> 16) *
r_affinetridesc.skinwidth;
#if id386
d_sfracbasestep = (r_sstepy + r_sstepx * ubasestep) << 16;
d_tfracbasestep = (r_tstepy + r_tstepx * ubasestep) << 16;
#else
d_sfracbasestep = (r_sstepy + r_sstepx * ubasestep) & 0xFFFF;
d_tfracbasestep = (r_tstepy + r_tstepx * ubasestep) & 0xFFFF;
#endif
d_lightbasestep = r_lstepy + working_lstepx * ubasestep;
d_zibasestep = r_zistepy + r_zistepx * ubasestep;
d_ptexextrastep = ((r_sstepy + r_sstepx * d_countextrastep) >> 16) +
((r_tstepy + r_tstepx * d_countextrastep) >> 16) *
r_affinetridesc.skinwidth;
#if id386
d_sfracextrastep = ((r_sstepy+r_sstepx*d_countextrastep) & 0xFFFF)<<16;
d_tfracextrastep = ((r_tstepy+r_tstepx*d_countextrastep) & 0xFFFF)<<16;
#else
d_sfracextrastep = (r_sstepy+r_sstepx*d_countextrastep) & 0xFFFF;
d_tfracextrastep = (r_tstepy+r_tstepx*d_countextrastep) & 0xFFFF;
#endif
d_lightextrastep = d_lightbasestep + working_lstepx;
d_ziextrastep = d_zibasestep + r_zistepx;
D_PolysetScanLeftEdge (height);
}
}
// scan out the top (and possibly only) part of the right edge, updating the
// count field
d_pedgespanpackage = a_spans;
D_PolysetSetUpForLineScan(prighttop[0], prighttop[1],
prightbottom[0], prightbottom[1]);
d_aspancount = 0;
d_countextrastep = ubasestep + 1;
originalcount = a_spans[initialrightheight].count;
a_spans[initialrightheight].count = -999999; // mark end of the spanpackages
D_PolysetDrawSpans8 (a_spans);
// scan out the bottom part of the right edge, if it exists
if (pedgetable->numrightedges == 2)
{
int height;
spanpackage_t *pstart;
pstart = a_spans + initialrightheight;
pstart->count = originalcount;
#if 1 // Baker: In very rare situations, the count can be zero which will result in a memory access violation
if (pstart->count) // Baker
{
#endif
d_aspancount = prightbottom[0] - prighttop[0];
prighttop = prightbottom;
prightbottom = pedgetable->prightedgevert2;
height = prightbottom[1] - prighttop[1];
D_PolysetSetUpForLineScan(prighttop[0], prighttop[1],
prightbottom[0], prightbottom[1]);
d_countextrastep = ubasestep + 1;
a_spans[initialrightheight + height].count = -999999;
// mark end of the spanpackages
D_PolysetDrawSpans8 (pstart);
#if 1 // Baker
}
#endif
}
}