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Optimized R_DrawTiltedSpan_8

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chi.miru 2015-04-29 02:36:18 -04:00
parent ae935a0955
commit c4306b624d
1 changed files with 77 additions and 2 deletions
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79
src/r_draw8.c
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@ -551,8 +551,8 @@ void R_DrawTiltedSpan_8(void)
source = ds_source;
colormap = ds_colormap;
// The "perfect" reference version of this routine. Pretty slow.
// Use it only to see how things are supposed to look.
#if 0 // The "perfect" reference version of this routine. Pretty slow.
// Use it only to see how things are supposed to look.
i = 0;
do
{
@ -566,6 +566,81 @@ void R_DrawTiltedSpan_8(void)
vz += ds_sv.x;
} while (--width >= 0);
}
#else
#define SPANSIZE 16
#define INVSPAN 0.0625f
double startz = 1.f/iz;
double startu = uz*startz;
double startv = vz*startz;
double izstep, uzstep, vzstep;
izstep = ds_sz.x * SPANSIZE;
uzstep = ds_su.x * SPANSIZE;
vzstep = ds_sv.x * SPANSIZE;
//x1 = 0;
width++;
while (width >= SPANSIZE)
{
iz += izstep;
uz += uzstep;
vz += vzstep;
double endz = 1.f/iz;
double endu = uz*endz;
double endv = vz*endz;
UINT32 stepu = (INT64)((endu - startu) * INVSPAN);
UINT32 stepv = (INT64)((endv - startv) * INVSPAN);
u = (INT64)(startu) + viewx;
v = (INT64)(startv) + viewy;
for (i = SPANSIZE-1; i >= 0; i--)
{
*dest = colormap[source[((v >> nflatyshift) & nflatmask) | (u >> nflatxshift)]];
dest++;
u += stepu;
v += stepv;
}
startu = endu;
startv = endv;
width -= SPANSIZE;
}
if (width > 0)
{
if (width == 1)
{
u = (INT64)(startu);
v = (INT64)(startv);
*dest = colormap[source[((v >> nflatyshift) & nflatmask) | (u >> nflatxshift)]];
}
else
{
double left = width;
iz += ds_sz.x * left;
uz += ds_su.x * left;
vz += ds_sv.x * left;
double endz = 1.f/iz;
double endu = uz*endz;
double endv = vz*endz;
left = 1.f/left;
UINT32 stepu = (INT64)((endu - startu) * left);
UINT32 stepv = (INT64)((endv - startv) * left);
u = (INT64)(startu) + viewx;
v = (INT64)(startv) + viewy;
for (; width != 0; width--)
{
*dest = colormap[source[((v >> nflatyshift) & nflatmask) | (u >> nflatxshift)]];
dest++;
u += stepu;
v += stepv;
}
}
}
#endif
}
#endif // ESLOPE
/** \brief The R_DrawSplat_8 function