/* | |
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 the Free Software | |
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
*/ | |
// d_sky.c | |
#include "quakedef.h" | |
#include "r_local.h" | |
#include "d_local.h" | |
#define SKY_SPAN_SHIFT 5 | |
#define SKY_SPAN_MAX (1 << SKY_SPAN_SHIFT) | |
/* | |
================= | |
D_Sky_uv_To_st | |
================= | |
*/ | |
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); | |
} | |
/* | |
================= | |
D_DrawSkyScans8 | |
================= | |
*/ | |
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); | |
} | |