quakeforge/libs/video/renderer/sw32/d_sky.c
Bill Currie a05210d864 [video] Get 16 and 32 bit sw32 mostly working in x11
Lighting on alias models seems to be borked, and skies are borked in
both sw renderers (seems to be nothing to do with this commit, though).
2021-07-11 00:09:41 +09:00

284 lines
6.5 KiB
C

/*
d_sky.c
(description)
Copyright (C) 1996-1997 Id Software, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to:
Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#define NH_DEFINE
#include "namehack.h"
#include "QF/render.h"
#include "QF/sys.h"
#include "d_local.h"
#include "r_internal.h"
#include "vid_sw.h"
#define SKY_SPAN_SHIFT 5
#define SKY_SPAN_MAX (1 << SKY_SPAN_SHIFT)
static void
D_Sky_uv_To_st (int u, int v, fixed16_t *s, fixed16_t *t)
{
float wu, wv, temp;
vec3_t end;
if (r_refdef.vrect.width >= r_refdef.vrect.height)
temp = (float) r_refdef.vrect.width;
else
temp = (float) r_refdef.vrect.height;
wu = 8192.0 * (float) (u - (vid.width >> 1)) / temp;
wv = 8192.0 * (float) ((vid.height >> 1) - v) / temp;
end[0] = 4096 * vpn[0] + wu * vright[0] + wv * vup[0];
end[1] = 4096 * vpn[1] + wu * vright[1] + wv * vup[1];
end[2] = 4096 * vpn[2] + wu * vright[2] + wv * vup[2];
end[2] *= 3;
VectorNormalize (end);
temp = sw32_r_skytime * sw32_r_skyspeed; // TODO: add D_SetupFrame & set this there
*s = (int) ((temp + 6 * (SKYSIZE / 2 - 1) * end[0]) * 0x10000);
*t = (int) ((temp + 6 * (SKYSIZE / 2 - 1) * end[1]) * 0x10000);
}
void
sw32_D_DrawSkyScans (espan_t *pspan)
{
switch(sw32_ctx->pixbytes) {
case 1:
{
int count, spancount, u, v;
byte *pdest;
fixed16_t s, t, snext, tnext, sstep, tstep;
int spancountminus1;
sstep = 0; // keep compiler happy
tstep = 0; // ditto
snext = 0; // ditto
tnext = 0; // ditto
do {
pdest = (byte *) sw32_d_viewbuffer + sw32_screenwidth * pspan->v + pspan->u;
count = pspan->count;
// calculate the initial s & t
u = pspan->u;
v = pspan->v;
D_Sky_uv_To_st (u, v, &s, &t);
do {
if (count >= SKY_SPAN_MAX)
spancount = SKY_SPAN_MAX;
else
spancount = count;
count -= spancount;
if (count) {
u += spancount;
// calculate s and t at far end of span,
// calculate s and t steps across span by shifting
D_Sky_uv_To_st (u, v, &snext, &tnext);
sstep = (snext - s) >> SKY_SPAN_SHIFT;
tstep = (tnext - t) >> SKY_SPAN_SHIFT;
} else {
// calculate s and t at last pixel in span,
// calculate s and t steps across span by division
spancountminus1 = (float) (spancount - 1);
if (spancountminus1 > 0) {
u += spancountminus1;
D_Sky_uv_To_st (u, v, &snext, &tnext);
sstep = (snext - s) / spancountminus1;
tstep = (tnext - t) / spancountminus1;
}
}
do {
*pdest++ = ((byte *) sw32_r_skysource)
[((t & R_SKY_TMASK) >> 8) + ((s & R_SKY_SMASK) >> 16)];
s += sstep;
t += tstep;
} while (--spancount > 0);
s = snext;
t = tnext;
} while (count > 0);
} while ((pspan = pspan->pnext) != NULL);
}
break;
case 2:
{
int count, spancount, u, v;
short *pdest;
fixed16_t s, t, snext, tnext, sstep, tstep;
int spancountminus1;
sstep = 0; // keep compiler happy
tstep = 0; // ditto
snext = 0; // ditto
tnext = 0; // ditto
do {
pdest = (short *) sw32_d_viewbuffer + sw32_screenwidth * pspan->v + pspan->u;
count = pspan->count;
// calculate the initial s & t
u = pspan->u;
v = pspan->v;
D_Sky_uv_To_st (u, v, &s, &t);
do {
if (count >= SKY_SPAN_MAX)
spancount = SKY_SPAN_MAX;
else
spancount = count;
count -= spancount;
if (count) {
u += spancount;
// calculate s and t at far end of span,
// calculate s and t steps across span by shifting
D_Sky_uv_To_st (u, v, &snext, &tnext);
sstep = (snext - s) >> SKY_SPAN_SHIFT;
tstep = (tnext - t) >> SKY_SPAN_SHIFT;
} else {
// calculate s and t at last pixel in span,
// calculate s and t steps across span by division
spancountminus1 = (float) (spancount - 1);
if (spancountminus1 > 0) {
u += spancountminus1;
D_Sky_uv_To_st (u, v, &snext, &tnext);
sstep = (snext - s) / spancountminus1;
tstep = (tnext - t) / spancountminus1;
}
}
do {
*pdest++ = ((short *) sw32_r_skysource)
[((t & R_SKY_TMASK) >> 8) + ((s & R_SKY_SMASK) >> 16)];
s += sstep;
t += tstep;
} while (--spancount > 0);
s = snext;
t = tnext;
} while (count > 0);
} while ((pspan = pspan->pnext) != NULL);
}
break;
case 4:
{
int count, spancount, u, v;
int *pdest;
fixed16_t s, t, snext, tnext, sstep, tstep;
int spancountminus1;
sstep = 0; // keep compiler happy
tstep = 0; // ditto
snext = 0; // ditto
tnext = 0; // ditto
do {
pdest = (int *) sw32_d_viewbuffer + sw32_screenwidth * pspan->v + pspan->u;
count = pspan->count;
// calculate the initial s & t
u = pspan->u;
v = pspan->v;
D_Sky_uv_To_st (u, v, &s, &t);
do {
if (count >= SKY_SPAN_MAX)
spancount = SKY_SPAN_MAX;
else
spancount = count;
count -= spancount;
if (count) {
u += spancount;
// calculate s and t at far end of span,
// calculate s and t steps across span by shifting
D_Sky_uv_To_st (u, v, &snext, &tnext);
sstep = (snext - s) >> SKY_SPAN_SHIFT;
tstep = (tnext - t) >> SKY_SPAN_SHIFT;
} else {
// calculate s and t at last pixel in span,
// calculate s and t steps across span by division
spancountminus1 = (float) (spancount - 1);
if (spancountminus1 > 0) {
u += spancountminus1;
D_Sky_uv_To_st (u, v, &snext, &tnext);
sstep = (snext - s) / spancountminus1;
tstep = (tnext - t) / spancountminus1;
}
}
do {
*pdest++ = ((int *) sw32_r_skysource)
[((t & R_SKY_TMASK) >> 8) + ((s & R_SKY_SMASK) >> 16)];
s += sstep;
t += tstep;
} while (--spancount > 0);
s = snext;
t = tnext;
} while (count > 0);
} while ((pspan = pspan->pnext) != NULL);
}
break;
default:
Sys_Error("D_DrawSkyScans: unsupported r_pixbytes %i", sw32_ctx->pixbytes);
}
}