mirror of
https://git.code.sf.net/p/quake/quakeforge
synced 2024-11-27 22:52:21 +00:00
134 lines
3.2 KiB
C
134 lines
3.2 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
|
|
|
|
$Id$
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include "config.h"
|
|
#endif
|
|
|
|
#include "d_local.h"
|
|
#include "r_local.h"
|
|
#include "render.h"
|
|
|
|
#define SKY_SPAN_SHIFT 5
|
|
#define SKY_SPAN_MAX (1 << SKY_SPAN_SHIFT)
|
|
|
|
|
|
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 - ((int) vid.width >> 1)) / temp;
|
|
wv = 8192.0 * (float) (((int) 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 = skytime * 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
|
|
D_DrawSkyScans8 (espan_t *pspan)
|
|
{
|
|
int count, spancount, u, v;
|
|
unsigned char *pdest;
|
|
fixed16_t s, t, snext, tnext, sstep, tstep;
|
|
int spancountminus1;
|
|
|
|
sstep = 0; // keep compiler happy
|
|
tstep = 0; // ditto
|
|
|
|
do {
|
|
pdest = (unsigned char *) ((byte *) d_viewbuffer +
|
|
(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++ = 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);
|
|
}
|