ref: b64d816a6b39760ca8df9434d7277bf8babe55b3
dir: /d_scan.c/
#include "quakedef.h"
static unsigned char *r_turb_pbase, *r_turb_pdest;
static fixed16_t r_turb_s, r_turb_t, r_turb_sstep, r_turb_tstep;
static int *r_turb_turb;
static int r_turb_spancount;
static uzint *r_turb_z;
/*
=============
D_WarpScreen
// this performs a slight compression of the screen at the same time as
// the sine warp, to keep the edges from wrapping
=============
*/
void D_WarpScreen (void)
{
int w, h;
int u,v;
byte *dest;
int *turb;
int *col;
byte **row;
float wratio, hratio;
static byte *rowptr[MAXHEIGHT+(AMP2*2)];
static int column[MAXWIDTH+(AMP2*2)];
w = r_refdef.vrect.width;
h = r_refdef.vrect.height;
wratio = w / (float)scr_vrect.width;
hratio = h / (float)scr_vrect.height;
for(v = 0; v < scr_vrect.height+AMP2*2; v++)
rowptr[v] = d_viewbuffer + (r_refdef.vrect.y * screenwidth) + (screenwidth * (int)((float)v * hratio * h / (h + AMP2 * 2)));
for(u = 0; u < scr_vrect.width+AMP2*2; u++)
column[u] = r_refdef.vrect.x + (int)((float)u * wratio * w / (w + AMP2 * 2));
turb = intsintable + ((int)(cl.time*SPEED)&(CYCLE-1));
dest = vid.buffer + scr_vrect.y * vid.rowbytes + scr_vrect.x;
for(v = 0; v < scr_vrect.height; v++, dest += vid.rowbytes){
col = &column[turb[v]];
row = &rowptr[v];
for(u = 0; u < scr_vrect.width; u += 4){
dest[u+0] = row[turb[u+0]][col[u+0]];
dest[u+1] = row[turb[u+1]][col[u+1]];
dest[u+2] = row[turb[u+2]][col[u+2]];
dest[u+3] = row[turb[u+3]][col[u+3]];
}
}
}
/*
=============
D_DrawTurbulent8Span
=============
*/
void D_DrawTurbulent8Span (int izi, byte alpha)
{
int sturb, tturb;
do{
sturb = ((r_turb_s + r_turb_turb[(r_turb_t>>16)&(CYCLE-1)])>>16)&63;
tturb = ((r_turb_t + r_turb_turb[(r_turb_s>>16)&(CYCLE-1)])>>16)&63;
if(*r_turb_z <= (izi >> 16) || (r_drawflags & DRAW_BLEND) == 0)
*r_turb_pdest = blendalpha(*(r_turb_pbase + (tturb<<6) + sturb), *r_turb_pdest, alpha);
r_turb_s += r_turb_sstep;
r_turb_t += r_turb_tstep;
r_turb_pdest++;
r_turb_z++;
}while(--r_turb_spancount > 0);
}
void
Turbulent8(espan_t *pspan, byte alpha)
{
int count;
fixed16_t snext, tnext;
double sdivz, tdivz, zi, z, du, dv, spancountminus1;
double sdivz16stepu, tdivz16stepu, zi16stepu;
r_turb_turb = sintable + ((int)(cl.time*SPEED)&(CYCLE-1));
r_turb_sstep = 0; // keep compiler happy
r_turb_tstep = 0; // ditto
r_turb_pbase = (byte*)cacheblock;
sdivz16stepu = d_sdivzstepu * 16;
tdivz16stepu = d_tdivzstepu * 16;
zi16stepu = d_zistepu * 16;
do{
r_turb_pdest = (byte *)d_viewbuffer + screenwidth*pspan->v + pspan->u;
r_turb_z = d_pzbuffer + d_zwidth*pspan->v + pspan->u;
count = pspan->count;
// calculate the initial s/z, t/z, 1/z, s, and t and clamp
du = pspan->u;
dv = pspan->v;
sdivz = d_sdivzorigin + dv*d_sdivzstepv + du*d_sdivzstepu;
tdivz = d_tdivzorigin + dv*d_tdivzstepv + du*d_tdivzstepu;
zi = d_ziorigin + dv*d_zistepv + du*d_zistepu;
z = (float)0x10000 / zi; // prescale to 16.16 fixed-point
r_turb_s = (int)(sdivz * z) + sadjust;
r_turb_s = clamp(r_turb_s, 0, bbextents);
r_turb_t = (int)(tdivz * z) + tadjust;
r_turb_t = clamp(r_turb_t, 0, bbextentt);
do{
// calculate s and t at the far end of the span
r_turb_spancount = min(count, 16);
count -= r_turb_spancount;
if(count){
// calculate s/z, t/z, zi->fixed s and t at far end of span,
// calculate s and t steps across span by shifting
sdivz += sdivz16stepu;
tdivz += tdivz16stepu;
zi += zi16stepu;
z = (float)0x10000 / zi; // prescale to 16.16 fixed-point
snext = (int)(sdivz * z) + sadjust;
// prevent round-off error on <0 steps from causing overstepping & running off the edge of the texture
snext = clamp(snext, 16, bbextents);
tnext = (int)(tdivz * z) + tadjust;
tnext = clamp(tnext, 16, bbextentt); // guard against round-off error on <0 steps
r_turb_sstep = (snext - r_turb_s) >> 4;
r_turb_tstep = (tnext - r_turb_t) >> 4;
}else{
// calculate s/z, t/z, zi->fixed s and t at last pixel in span (so
// can't step off polygon), clamp, calculate s and t steps across
// span by division, biasing steps low so we don't run off the
// texture
spancountminus1 = (float)(r_turb_spancount - 1);
sdivz += d_sdivzstepu * spancountminus1;
tdivz += d_tdivzstepu * spancountminus1;
zi += d_zistepu * spancountminus1;
z = (float)0x10000 / zi; // prescale to 16.16 fixed-point
snext = (int)(sdivz * z) + sadjust;
// prevent round-off error on <0 steps from causing overstepping & running off the edge of the texture
snext = clamp(snext, 16, bbextents);
tnext = (int)(tdivz * z) + tadjust;
tnext = clamp(tnext, 16, bbextentt); // guard against round-off error on <0 steps
if(r_turb_spancount > 1){
r_turb_sstep = (snext - r_turb_s) / (r_turb_spancount - 1);
r_turb_tstep = (tnext - r_turb_t) / (r_turb_spancount - 1);
}
}
r_turb_s = r_turb_s & ((CYCLE<<16)-1);
r_turb_t = r_turb_t & ((CYCLE<<16)-1);
D_DrawTurbulent8Span((int)(zi * 0x8000 * 0x10000), alpha);
r_turb_s = snext;
r_turb_t = tnext;
}while(count > 0);
}while((pspan = pspan->pnext) != nil);
}
void
D_DrawSpans16(espan_t *pspan, int forceblend, byte alpha) //qbism- up it from 8 to 16
{
int count, spancount, izistep;
byte *pbase, *pdest;
uzint *pz;
fixed16_t s, t, snext, tnext, sstep, tstep;
double sdivz, tdivz, zi, z, du, dv, spancountminus1;
double sdivzstepu, tdivzstepu, zistepu;
sstep = 0; // keep compiler happy
tstep = 0; // ditto
pbase = (byte*)cacheblock;
sdivzstepu = d_sdivzstepu * 16;
tdivzstepu = d_tdivzstepu * 16;
zistepu = d_zistepu * 16;
izistep = (int)(d_zistepu * 0x8000 * 0x10000);
do{
pdest = (byte *)d_viewbuffer + screenwidth*pspan->v + pspan->u;
pz = d_pzbuffer + d_zwidth*pspan->v + pspan->u;
count = pspan->count;
// calculate the initial s/z, t/z, 1/z, s, and t and clamp
du = pspan->u;
dv = pspan->v;
sdivz = d_sdivzorigin + dv*d_sdivzstepv + du*d_sdivzstepu;
tdivz = d_tdivzorigin + dv*d_tdivzstepv + du*d_tdivzstepu;
zi = d_ziorigin + dv*d_zistepv + du*d_zistepu;
z = (float)0x10000 / zi; // prescale to 16.16 fixed-point
s = (int)(sdivz * z) + sadjust;
s = clamp(s, 0, bbextents);
t = (int)(tdivz * z) + tadjust;
t = clamp(t, 0, bbextentt);
do{
// calculate s and t at the far end of the span
spancount = min(count, 16);
count -= spancount;
if(count){
// calculate s/z, t/z, zi->fixed s and t at far end of span,
// calculate s and t steps across span by shifting
sdivz += sdivzstepu;
tdivz += tdivzstepu;
zi += zistepu;
z = (float)0x10000 / zi; // prescale to 16.16 fixed-point
snext = (int)(sdivz * z) + sadjust;
// prevent round-off error on <0 steps from
// from causing overstepping & running off the
// edge of the texture
snext = clamp(snext, 16, bbextents);
tnext = (int)(tdivz * z) + tadjust;
// guard against round-off error on <0 steps
tnext = clamp(tnext, 16, bbextentt);
sstep = (snext - s) >> 4;
tstep = (tnext - t) >> 4;
}else{
// calculate s/z, t/z, zi->fixed s and t at last pixel in span (so
// can't step off polygon), clamp, calculate s and t steps across
// span by division, biasing steps low so we don't run off the
// texture
spancountminus1 = (float)(spancount - 1);
sdivz += d_sdivzstepu * spancountminus1;
tdivz += d_tdivzstepu * spancountminus1;
zi += d_zistepu * spancountminus1;
z = (float)0x10000 / zi; // prescale to 16.16 fixed-point
snext = (int)(sdivz * z) + sadjust;
// prevent round-off error on <0 steps from
// from causing overstepping & running off the
// edge of the texture
snext = clamp(snext, 16, bbextents);
tnext = (int)(tdivz * z) + tadjust;
// guard against round-off error on <0 steps
tnext = clamp(tnext, 16, bbextentt);
if(spancount > 1){
sstep = (snext - s) / (spancount - 1);
tstep = (tnext - t) / (spancount - 1);
}
}
if(spancount > 0){
void dospan(byte *, byte *, int, int, int, int, int, int);
void dospan_alpha(byte *, byte *, int, int, int, int, int, int, byte, uzint *, int,int);
if((r_drawflags & DRAW_BLEND) != 0 || forceblend)
dospan_alpha(pdest, pbase, s, t, sstep, tstep, spancount, cachewidth, alpha, pz, (int)(zi * 0x8000 * 0x10000), izistep);
else
dospan(pdest, pbase, s, t, sstep, tstep, spancount, cachewidth);
pdest += spancount;
pz += spancount;
}
s = snext;
t = tnext;
}while(count > 0);
}while((pspan = pspan->pnext) != nil);
}
void
D_DrawZSpans(espan_t *pspan)
{
int count, doublecount, izistep;
int izi;
uzint *pdest;
unsigned ltemp;
double zi;
float du, dv;
if((r_drawflags & DRAW_BLEND) != 0)
return;
// FIXME: check for clamping/range problems
// we count on FP exceptions being turned off to avoid range problems
izistep = (int)(d_zistepu * 0x8000 * 0x10000);
do{
pdest = d_pzbuffer + (d_zwidth * pspan->v) + pspan->u;
count = pspan->count;
// calculate the initial 1/z
du = (float)pspan->u;
dv = (float)pspan->v;
zi = d_ziorigin + dv*d_zistepv + du*d_zistepu;
// we count on FP exceptions being turned off to avoid range problems
izi = (int)(zi * 0x8000 * 0x10000);
if((uintptr)pdest & 0x02){
*pdest++ = (short)(izi >> 16);
izi += izistep;
count--;
}
if((doublecount = count >> 1) > 0){
do{
ltemp = izi >> 16;
izi += izistep;
ltemp |= izi & 0xFFFF0000;
izi += izistep;
*(int *)pdest = ltemp;
pdest += 2;
}while (--doublecount > 0);
}
if(count & 1)
*pdest = (short)(izi >> 16);
}while((pspan = pspan->pnext) != nil);
}