kolibrios-fun/contrib/other/sdlquake-1.0.9/r_sky.c

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/*
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.
*/
// r_sky.c
#include "quakedef.h"
#include "r_local.h"
#include "d_local.h"
int iskyspeed = 8;
int iskyspeed2 = 2;
float skyspeed, skyspeed2;
float skytime;
byte *r_skysource;
int r_skymade;
int r_skydirect; // not used?
// TODO: clean up these routines
byte bottomsky[128*131];
byte bottommask[128*131];
byte newsky[128*256]; // newsky and topsky both pack in here, 128 bytes
// of newsky on the left of each scan, 128 bytes
// of topsky on the right, because the low-level
// drawers need 256-byte scan widths
/*
=============
R_InitSky
A sky texture is 256*128, with the right side being a masked overlay
==============
*/
void R_InitSky (texture_t *mt)
{
int i, j;
byte *src;
src = (byte *)mt + mt->offsets[0];
for (i=0 ; i<128 ; i++)
{
for (j=0 ; j<128 ; j++)
{
newsky[(i*256) + j + 128] = src[i*256 + j + 128];
}
}
for (i=0 ; i<128 ; i++)
{
for (j=0 ; j<131 ; j++)
{
if (src[i*256 + (j & 0x7F)])
{
bottomsky[(i*131) + j] = src[i*256 + (j & 0x7F)];
bottommask[(i*131) + j] = 0;
}
else
{
bottomsky[(i*131) + j] = 0;
bottommask[(i*131) + j] = 0xff;
}
}
}
r_skysource = newsky;
}
/*
=================
R_MakeSky
=================
*/
void R_MakeSky (void)
{
int x, y;
int ofs, baseofs;
int xshift, yshift;
unsigned *pnewsky;
static int xlast = -1, ylast = -1;
xshift = skytime*skyspeed;
yshift = skytime*skyspeed;
if ((xshift == xlast) && (yshift == ylast))
return;
xlast = xshift;
ylast = yshift;
pnewsky = (unsigned *)&newsky[0];
for (y=0 ; y<SKYSIZE ; y++)
{
baseofs = ((y+yshift) & SKYMASK) * 131;
// FIXME: clean this up
#if UNALIGNED_OK
for (x=0 ; x<SKYSIZE ; x += 4)
{
ofs = baseofs + ((x+xshift) & SKYMASK);
// PORT: unaligned dword access to bottommask and bottomsky
*pnewsky = (*(pnewsky + (128 / sizeof (unsigned))) &
*(unsigned *)&bottommask[ofs]) |
*(unsigned *)&bottomsky[ofs];
pnewsky++;
}
#else
for (x=0 ; x<SKYSIZE ; x++)
{
ofs = baseofs + ((x+xshift) & SKYMASK);
*(byte *)pnewsky = (*((byte *)pnewsky + 128) &
*(byte *)&bottommask[ofs]) |
*(byte *)&bottomsky[ofs];
pnewsky = (unsigned *)((byte *)pnewsky + 1);
}
#endif
pnewsky += 128 / sizeof (unsigned);
}
r_skymade = 1;
}
/*
=================
R_GenSkyTile
=================
*/
void R_GenSkyTile (void *pdest)
{
int x, y;
int ofs, baseofs;
int xshift, yshift;
unsigned *pnewsky;
unsigned *pd;
xshift = skytime*skyspeed;
yshift = skytime*skyspeed;
pnewsky = (unsigned *)&newsky[0];
pd = (unsigned *)pdest;
for (y=0 ; y<SKYSIZE ; y++)
{
baseofs = ((y+yshift) & SKYMASK) * 131;
// FIXME: clean this up
#if UNALIGNED_OK
for (x=0 ; x<SKYSIZE ; x += 4)
{
ofs = baseofs + ((x+xshift) & SKYMASK);
// PORT: unaligned dword access to bottommask and bottomsky
*pd = (*(pnewsky + (128 / sizeof (unsigned))) &
*(unsigned *)&bottommask[ofs]) |
*(unsigned *)&bottomsky[ofs];
pnewsky++;
pd++;
}
#else
for (x=0 ; x<SKYSIZE ; x++)
{
ofs = baseofs + ((x+xshift) & SKYMASK);
*(byte *)pd = (*((byte *)pnewsky + 128) &
*(byte *)&bottommask[ofs]) |
*(byte *)&bottomsky[ofs];
pnewsky = (unsigned *)((byte *)pnewsky + 1);
pd = (unsigned *)((byte *)pd + 1);
}
#endif
pnewsky += 128 / sizeof (unsigned);
}
}
/*
=================
R_GenSkyTile16
=================
*/
void R_GenSkyTile16 (void *pdest)
{
int x, y;
int ofs, baseofs;
int xshift, yshift;
byte *pnewsky;
unsigned short *pd;
xshift = skytime * skyspeed;
yshift = skytime * skyspeed;
pnewsky = (byte *)&newsky[0];
pd = (unsigned short *)pdest;
for (y=0 ; y<SKYSIZE ; y++)
{
baseofs = ((y+yshift) & SKYMASK) * 131;
// FIXME: clean this up
// FIXME: do faster unaligned version?
for (x=0 ; x<SKYSIZE ; x++)
{
ofs = baseofs + ((x+xshift) & SKYMASK);
*pd = d_8to16table[(*(pnewsky + 128) &
*(byte *)&bottommask[ofs]) |
*(byte *)&bottomsky[ofs]];
pnewsky++;
pd++;
}
pnewsky += TILE_SIZE;
}
}
/*
=============
R_SetSkyFrame
==============
*/
void R_SetSkyFrame (void)
{
int g, s1, s2;
float temp;
skyspeed = iskyspeed;
skyspeed2 = iskyspeed2;
g = GreatestCommonDivisor (iskyspeed, iskyspeed2);
s1 = iskyspeed / g;
s2 = iskyspeed2 / g;
temp = SKYSIZE * s1 * s2;
skytime = cl.time - ((int)(cl.time / temp) * temp);
r_skymade = 0;
}