quakeforge-old/uquake/gl_warp.c
Jeff Teunissen c3f5581b0a Created new subdir: uquake. Pick your favorite U word for the meaning --
Unchained, Ultimate, Ultra, Up Yours, Underworld, Underground, Unified,
Unity, etc. You know the drill.

This takes care of the "standalone" problem with the wrong name, and the
recent snafu with multiple developers working on the same files
simultaneously...expect me (and probably others) to start locking dirs when
updates are taking place.

And yes, this update is really as large as it looks. Software only at the
moment, but I will have the makefile updated to build the GL builds as
well.
1999-12-26 13:51:52 +00:00

1092 lines
20 KiB
C

/*
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.
*/
// gl_warp.c -- sky and water polygons
#include "quakedef.h"
extern model_t *loadmodel;
int skytexturenum;
int solidskytexture;
int alphaskytexture;
float speedscale; // for top sky and bottom sky
msurface_t *warpface;
extern cvar_t gl_subdivide_size;
void BoundPoly (int numverts, float *verts, vec3_t mins, vec3_t maxs)
{
int i, j;
float *v;
mins[0] = mins[1] = mins[2] = 9999;
maxs[0] = maxs[1] = maxs[2] = -9999;
v = verts;
for (i=0 ; i<numverts ; i++)
for (j=0 ; j<3 ; j++, v++)
{
if (*v < mins[j])
mins[j] = *v;
if (*v > maxs[j])
maxs[j] = *v;
}
}
void SubdividePolygon (int numverts, float *verts)
{
int i, j, k;
vec3_t mins, maxs;
float m;
float *v;
vec3_t front[64], back[64];
int f, b;
float dist[64];
float frac;
glpoly_t *poly;
float s, t;
if (numverts > 60)
Sys_Error ("numverts = %i", numverts);
BoundPoly (numverts, verts, mins, maxs);
for (i=0 ; i<3 ; i++)
{
m = (mins[i] + maxs[i]) * 0.5;
m = gl_subdivide_size.value * floor (m/gl_subdivide_size.value + 0.5);
if (maxs[i] - m < 8)
continue;
if (m - mins[i] < 8)
continue;
// cut it
v = verts + i;
for (j=0 ; j<numverts ; j++, v+= 3)
dist[j] = *v - m;
// wrap cases
dist[j] = dist[0];
v-=i;
VectorCopy (verts, v);
f = b = 0;
v = verts;
for (j=0 ; j<numverts ; j++, v+= 3)
{
if (dist[j] >= 0)
{
VectorCopy (v, front[f]);
f++;
}
if (dist[j] <= 0)
{
VectorCopy (v, back[b]);
b++;
}
if (dist[j] == 0 || dist[j+1] == 0)
continue;
if ( (dist[j] > 0) != (dist[j+1] > 0) )
{
// clip point
frac = dist[j] / (dist[j] - dist[j+1]);
for (k=0 ; k<3 ; k++)
front[f][k] = back[b][k] = v[k] + frac*(v[3+k] - v[k]);
f++;
b++;
}
}
SubdividePolygon (f, front[0]);
SubdividePolygon (b, back[0]);
return;
}
poly = Hunk_Alloc (sizeof(glpoly_t) + (numverts-4) * VERTEXSIZE*sizeof(float));
poly->next = warpface->polys;
warpface->polys = poly;
poly->numverts = numverts;
for (i=0 ; i<numverts ; i++, verts+= 3)
{
VectorCopy (verts, poly->verts[i]);
s = DotProduct (verts, warpface->texinfo->vecs[0]);
t = DotProduct (verts, warpface->texinfo->vecs[1]);
poly->verts[i][3] = s;
poly->verts[i][4] = t;
}
}
/*
================
GL_SubdivideSurface
Breaks a polygon up along axial 64 unit
boundaries so that turbulent and sky warps
can be done reasonably.
================
*/
void GL_SubdivideSurface (msurface_t *fa)
{
vec3_t verts[64];
int numverts;
int i;
int lindex;
float *vec;
texture_t *t;
warpface = fa;
//
// convert edges back to a normal polygon
//
numverts = 0;
for (i=0 ; i<fa->numedges ; i++)
{
lindex = loadmodel->surfedges[fa->firstedge + i];
if (lindex > 0)
vec = loadmodel->vertexes[loadmodel->edges[lindex].v[0]].position;
else
vec = loadmodel->vertexes[loadmodel->edges[-lindex].v[1]].position;
VectorCopy (vec, verts[numverts]);
numverts++;
}
SubdividePolygon (numverts, verts[0]);
}
//=========================================================
// speed up sin calculations - Ed
float turbsin[] =
{
#include "gl_warp_sin.h"
};
#define TURBSCALE (256.0 / (2 * M_PI))
/*
=============
EmitWaterPolys
Does a water warp on the pre-fragmented glpoly_t chain
=============
*/
void EmitWaterPolys (msurface_t *fa)
{
glpoly_t *p;
float *v;
int i;
float s, t, os, ot;
for (p=fa->polys ; p ; p=p->next)
{
glBegin (GL_POLYGON);
for (i=0,v=p->verts[0] ; i<p->numverts ; i++, v+=VERTEXSIZE)
{
os = v[3];
ot = v[4];
s = os + turbsin[(int)((ot*0.125+realtime) * TURBSCALE) & 255];
s *= (1.0/64);
t = ot + turbsin[(int)((os*0.125+realtime) * TURBSCALE) & 255];
t *= (1.0/64);
glTexCoord2f (s, t);
glVertex3fv (v);
}
glEnd ();
}
}
/*
=============
EmitSkyPolys
=============
*/
void EmitSkyPolys (msurface_t *fa)
{
glpoly_t *p;
float *v;
int i;
float s, t;
vec3_t dir;
float length;
for (p=fa->polys ; p ; p=p->next)
{
glBegin (GL_POLYGON);
for (i=0,v=p->verts[0] ; i<p->numverts ; i++, v+=VERTEXSIZE)
{
VectorSubtract (v, r_origin, dir);
dir[2] *= 3; // flatten the sphere
length = dir[0]*dir[0] + dir[1]*dir[1] + dir[2]*dir[2];
length = sqrt (length);
length = 6*63/length;
dir[0] *= length;
dir[1] *= length;
s = (speedscale + dir[0]) * (1.0/128);
t = (speedscale + dir[1]) * (1.0/128);
glTexCoord2f (s, t);
glVertex3fv (v);
}
glEnd ();
}
}
/*
===============
EmitBothSkyLayers
Does a sky warp on the pre-fragmented glpoly_t chain
This will be called for brushmodels, the world
will have them chained together.
===============
*/
void EmitBothSkyLayers (msurface_t *fa)
{
int i;
int lindex;
float *vec;
GL_DisableMultitexture();
GL_Bind (solidskytexture);
speedscale = realtime*8;
speedscale -= (int)speedscale & ~127 ;
EmitSkyPolys (fa);
glEnable (GL_BLEND);
GL_Bind (alphaskytexture);
speedscale = realtime*16;
speedscale -= (int)speedscale & ~127 ;
EmitSkyPolys (fa);
glDisable (GL_BLEND);
}
#ifndef QUAKE2
/*
=================
R_DrawSkyChain
=================
*/
void R_DrawSkyChain (msurface_t *s)
{
msurface_t *fa;
GL_DisableMultitexture();
// used when gl_texsort is on
GL_Bind(solidskytexture);
speedscale = realtime*8;
speedscale -= (int)speedscale & ~127 ;
for (fa=s ; fa ; fa=fa->texturechain)
EmitSkyPolys (fa);
glEnable (GL_BLEND);
GL_Bind (alphaskytexture);
speedscale = realtime*16;
speedscale -= (int)speedscale & ~127 ;
for (fa=s ; fa ; fa=fa->texturechain)
EmitSkyPolys (fa);
glDisable (GL_BLEND);
}
#endif
/*
=================================================================
Quake 2 environment sky
=================================================================
*/
#ifdef QUAKE2
#define SKY_TEX 2000
/*
=================================================================
PCX Loading
=================================================================
*/
typedef struct
{
char manufacturer;
char version;
char encoding;
char bits_per_pixel;
unsigned short xmin,ymin,xmax,ymax;
unsigned short hres,vres;
unsigned char palette[48];
char reserved;
char color_planes;
unsigned short bytes_per_line;
unsigned short palette_type;
char filler[58];
unsigned data; // unbounded
} pcx_t;
byte *pcx_rgb;
/*
============
LoadPCX
============
*/
void LoadPCX (FILE *f)
{
pcx_t *pcx, pcxbuf;
byte palette[768];
byte *pix;
int x, y;
int dataByte, runLength;
int count;
//
// parse the PCX file
//
fread (&pcxbuf, 1, sizeof(pcxbuf), f);
pcx = &pcxbuf;
if (pcx->manufacturer != 0x0a
|| pcx->version != 5
|| pcx->encoding != 1
|| pcx->bits_per_pixel != 8
|| pcx->xmax >= 320
|| pcx->ymax >= 256)
{
Con_Printf ("Bad pcx file\n");
return;
}
// seek to palette
fseek (f, -768, SEEK_END);
fread (palette, 1, 768, f);
fseek (f, sizeof(pcxbuf) - 4, SEEK_SET);
count = (pcx->xmax+1) * (pcx->ymax+1);
pcx_rgb = malloc( count * 4);
for (y=0 ; y<=pcx->ymax ; y++)
{
pix = pcx_rgb + 4*y*(pcx->xmax+1);
for (x=0 ; x<=pcx->ymax ; )
{
dataByte = fgetc(f);
if((dataByte & 0xC0) == 0xC0)
{
runLength = dataByte & 0x3F;
dataByte = fgetc(f);
}
else
runLength = 1;
while(runLength-- > 0)
{
pix[0] = palette[dataByte*3];
pix[1] = palette[dataByte*3+1];
pix[2] = palette[dataByte*3+2];
pix[3] = 255;
pix += 4;
x++;
}
}
}
}
/*
=========================================================
TARGA LOADING
=========================================================
*/
typedef struct _TargaHeader {
unsigned char id_length, colormap_type, image_type;
unsigned short colormap_index, colormap_length;
unsigned char colormap_size;
unsigned short x_origin, y_origin, width, height;
unsigned char pixel_size, attributes;
} TargaHeader;
TargaHeader targa_header;
byte *targa_rgba;
int fgetLittleShort (FILE *f)
{
byte b1, b2;
b1 = fgetc(f);
b2 = fgetc(f);
return (short)(b1 + b2*256);
}
int fgetLittleLong (FILE *f)
{
byte b1, b2, b3, b4;
b1 = fgetc(f);
b2 = fgetc(f);
b3 = fgetc(f);
b4 = fgetc(f);
return b1 + (b2<<8) + (b3<<16) + (b4<<24);
}
/*
=============
LoadTGA
=============
*/
void LoadTGA (FILE *fin)
{
int columns, rows, numPixels;
byte *pixbuf;
int row, column;
targa_header.id_length = fgetc(fin);
targa_header.colormap_type = fgetc(fin);
targa_header.image_type = fgetc(fin);
targa_header.colormap_index = fgetLittleShort(fin);
targa_header.colormap_length = fgetLittleShort(fin);
targa_header.colormap_size = fgetc(fin);
targa_header.x_origin = fgetLittleShort(fin);
targa_header.y_origin = fgetLittleShort(fin);
targa_header.width = fgetLittleShort(fin);
targa_header.height = fgetLittleShort(fin);
targa_header.pixel_size = fgetc(fin);
targa_header.attributes = fgetc(fin);
if (targa_header.image_type!=2
&& targa_header.image_type!=10)
Sys_Error ("LoadTGA: Only type 2 and 10 targa RGB images supported\n");
if (targa_header.colormap_type !=0
|| (targa_header.pixel_size!=32 && targa_header.pixel_size!=24))
Sys_Error ("Texture_LoadTGA: Only 32 or 24 bit images supported (no colormaps)\n");
columns = targa_header.width;
rows = targa_header.height;
numPixels = columns * rows;
targa_rgba = malloc (numPixels*4);
if (targa_header.id_length != 0)
fseek(fin, targa_header.id_length, SEEK_CUR); // skip TARGA image comment
if (targa_header.image_type==2) { // Uncompressed, RGB images
for(row=rows-1; row>=0; row--) {
pixbuf = targa_rgba + row*columns*4;
for(column=0; column<columns; column++) {
unsigned char red,green,blue,alphabyte;
switch (targa_header.pixel_size) {
case 24:
blue = getc(fin);
green = getc(fin);
red = getc(fin);
*pixbuf++ = red;
*pixbuf++ = green;
*pixbuf++ = blue;
*pixbuf++ = 255;
break;
case 32:
blue = getc(fin);
green = getc(fin);
red = getc(fin);
alphabyte = getc(fin);
*pixbuf++ = red;
*pixbuf++ = green;
*pixbuf++ = blue;
*pixbuf++ = alphabyte;
break;
}
}
}
}
else if (targa_header.image_type==10) { // Runlength encoded RGB images
unsigned char red,green,blue,alphabyte,packetHeader,packetSize,j;
for(row=rows-1; row>=0; row--) {
pixbuf = targa_rgba + row*columns*4;
for(column=0; column<columns; ) {
packetHeader=getc(fin);
packetSize = 1 + (packetHeader & 0x7f);
if (packetHeader & 0x80) { // run-length packet
switch (targa_header.pixel_size) {
case 24:
blue = getc(fin);
green = getc(fin);
red = getc(fin);
alphabyte = 255;
break;
case 32:
blue = getc(fin);
green = getc(fin);
red = getc(fin);
alphabyte = getc(fin);
break;
}
for(j=0;j<packetSize;j++) {
*pixbuf++=red;
*pixbuf++=green;
*pixbuf++=blue;
*pixbuf++=alphabyte;
column++;
if (column==columns) { // run spans across rows
column=0;
if (row>0)
row--;
else
goto breakOut;
pixbuf = targa_rgba + row*columns*4;
}
}
}
else { // non run-length packet
for(j=0;j<packetSize;j++) {
switch (targa_header.pixel_size) {
case 24:
blue = getc(fin);
green = getc(fin);
red = getc(fin);
*pixbuf++ = red;
*pixbuf++ = green;
*pixbuf++ = blue;
*pixbuf++ = 255;
break;
case 32:
blue = getc(fin);
green = getc(fin);
red = getc(fin);
alphabyte = getc(fin);
*pixbuf++ = red;
*pixbuf++ = green;
*pixbuf++ = blue;
*pixbuf++ = alphabyte;
break;
}
column++;
if (column==columns) { // pixel packet run spans across rows
column=0;
if (row>0)
row--;
else
goto breakOut;
pixbuf = targa_rgba + row*columns*4;
}
}
}
}
breakOut:;
}
}
fclose(fin);
}
/*
==================
R_LoadSkys
==================
*/
char *suf[6] = {"rt", "bk", "lf", "ft", "up", "dn"};
void R_LoadSkys (void)
{
int i;
FILE *f;
char name[64];
for (i=0 ; i<6 ; i++)
{
GL_Bind (SKY_TEX + i);
sprintf (name, "gfx/env/bkgtst%s.tga", suf[i]);
COM_FOpenFile (name, &f);
if (!f)
{
Con_Printf ("Couldn't load %s\n", name);
continue;
}
LoadTGA (f);
// LoadPCX (f);
glTexImage2D (GL_TEXTURE_2D, 0, gl_solid_format, 256, 256, 0, GL_RGBA, GL_UNSIGNED_BYTE, targa_rgba);
// glTexImage2D (GL_TEXTURE_2D, 0, gl_solid_format, 256, 256, 0, GL_RGBA, GL_UNSIGNED_BYTE, pcx_rgb);
free (targa_rgba);
// free (pcx_rgb);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
}
}
vec3_t skyclip[6] = {
{1,1,0},
{1,-1,0},
{0,-1,1},
{0,1,1},
{1,0,1},
{-1,0,1}
};
int c_sky;
// 1 = s, 2 = t, 3 = 2048
int st_to_vec[6][3] =
{
{3,-1,2},
{-3,1,2},
{1,3,2},
{-1,-3,2},
{-2,-1,3}, // 0 degrees yaw, look straight up
{2,-1,-3} // look straight down
// {-1,2,3},
// {1,2,-3}
};
// s = [0]/[2], t = [1]/[2]
int vec_to_st[6][3] =
{
{-2,3,1},
{2,3,-1},
{1,3,2},
{-1,3,-2},
{-2,-1,3},
{-2,1,-3}
// {-1,2,3},
// {1,2,-3}
};
float skymins[2][6], skymaxs[2][6];
void DrawSkyPolygon (int nump, vec3_t vecs)
{
int i,j;
vec3_t v, av;
float s, t, dv;
int axis;
float *vp;
c_sky++;
#if 0
glBegin (GL_POLYGON);
for (i=0 ; i<nump ; i++, vecs+=3)
{
VectorAdd(vecs, r_origin, v);
glVertex3fv (v);
}
glEnd();
return;
#endif
// decide which face it maps to
VectorCopy (vec3_origin, v);
for (i=0, vp=vecs ; i<nump ; i++, vp+=3)
{
VectorAdd (vp, v, v);
}
av[0] = fabs(v[0]);
av[1] = fabs(v[1]);
av[2] = fabs(v[2]);
if (av[0] > av[1] && av[0] > av[2])
{
if (v[0] < 0)
axis = 1;
else
axis = 0;
}
else if (av[1] > av[2] && av[1] > av[0])
{
if (v[1] < 0)
axis = 3;
else
axis = 2;
}
else
{
if (v[2] < 0)
axis = 5;
else
axis = 4;
}
// project new texture coords
for (i=0 ; i<nump ; i++, vecs+=3)
{
j = vec_to_st[axis][2];
if (j > 0)
dv = vecs[j - 1];
else
dv = -vecs[-j - 1];
j = vec_to_st[axis][0];
if (j < 0)
s = -vecs[-j -1] / dv;
else
s = vecs[j-1] / dv;
j = vec_to_st[axis][1];
if (j < 0)
t = -vecs[-j -1] / dv;
else
t = vecs[j-1] / dv;
if (s < skymins[0][axis])
skymins[0][axis] = s;
if (t < skymins[1][axis])
skymins[1][axis] = t;
if (s > skymaxs[0][axis])
skymaxs[0][axis] = s;
if (t > skymaxs[1][axis])
skymaxs[1][axis] = t;
}
}
#define MAX_CLIP_VERTS 64
void ClipSkyPolygon (int nump, vec3_t vecs, int stage)
{
float *norm;
float *v;
qboolean front, back;
float d, e;
float dists[MAX_CLIP_VERTS];
int sides[MAX_CLIP_VERTS];
vec3_t newv[2][MAX_CLIP_VERTS];
int newc[2];
int i, j;
if (nump > MAX_CLIP_VERTS-2)
Sys_Error ("ClipSkyPolygon: MAX_CLIP_VERTS");
if (stage == 6)
{ // fully clipped, so draw it
DrawSkyPolygon (nump, vecs);
return;
}
front = back = false;
norm = skyclip[stage];
for (i=0, v = vecs ; i<nump ; i++, v+=3)
{
d = DotProduct (v, norm);
if (d > ON_EPSILON)
{
front = true;
sides[i] = SIDE_FRONT;
}
else if (d < ON_EPSILON)
{
back = true;
sides[i] = SIDE_BACK;
}
else
sides[i] = SIDE_ON;
dists[i] = d;
}
if (!front || !back)
{ // not clipped
ClipSkyPolygon (nump, vecs, stage+1);
return;
}
// clip it
sides[i] = sides[0];
dists[i] = dists[0];
VectorCopy (vecs, (vecs+(i*3)) );
newc[0] = newc[1] = 0;
for (i=0, v = vecs ; i<nump ; i++, v+=3)
{
switch (sides[i])
{
case SIDE_FRONT:
VectorCopy (v, newv[0][newc[0]]);
newc[0]++;
break;
case SIDE_BACK:
VectorCopy (v, newv[1][newc[1]]);
newc[1]++;
break;
case SIDE_ON:
VectorCopy (v, newv[0][newc[0]]);
newc[0]++;
VectorCopy (v, newv[1][newc[1]]);
newc[1]++;
break;
}
if (sides[i] == SIDE_ON || sides[i+1] == SIDE_ON || sides[i+1] == sides[i])
continue;
d = dists[i] / (dists[i] - dists[i+1]);
for (j=0 ; j<3 ; j++)
{
e = v[j] + d*(v[j+3] - v[j]);
newv[0][newc[0]][j] = e;
newv[1][newc[1]][j] = e;
}
newc[0]++;
newc[1]++;
}
// continue
ClipSkyPolygon (newc[0], newv[0][0], stage+1);
ClipSkyPolygon (newc[1], newv[1][0], stage+1);
}
/*
=================
R_DrawSkyChain
=================
*/
void R_DrawSkyChain (msurface_t *s)
{
msurface_t *fa;
int i;
vec3_t verts[MAX_CLIP_VERTS];
glpoly_t *p;
c_sky = 0;
GL_Bind(solidskytexture);
// calculate vertex values for sky box
for (fa=s ; fa ; fa=fa->texturechain)
{
for (p=fa->polys ; p ; p=p->next)
{
for (i=0 ; i<p->numverts ; i++)
{
VectorSubtract (p->verts[i], r_origin, verts[i]);
}
ClipSkyPolygon (p->numverts, verts[0], 0);
}
}
}
/*
==============
R_ClearSkyBox
==============
*/
void R_ClearSkyBox (void)
{
int i;
for (i=0 ; i<6 ; i++)
{
skymins[0][i] = skymins[1][i] = 9999;
skymaxs[0][i] = skymaxs[1][i] = -9999;
}
}
void MakeSkyVec (float s, float t, int axis)
{
vec3_t v, b;
int j, k;
b[0] = s*2048;
b[1] = t*2048;
b[2] = 2048;
for (j=0 ; j<3 ; j++)
{
k = st_to_vec[axis][j];
if (k < 0)
v[j] = -b[-k - 1];
else
v[j] = b[k - 1];
v[j] += r_origin[j];
}
// avoid bilerp seam
s = (s+1)*0.5;
t = (t+1)*0.5;
if (s < 1.0/512)
s = 1.0/512;
else if (s > 511.0/512)
s = 511.0/512;
if (t < 1.0/512)
t = 1.0/512;
else if (t > 511.0/512)
t = 511.0/512;
t = 1.0 - t;
glTexCoord2f (s, t);
glVertex3fv (v);
}
/*
==============
R_DrawSkyBox
==============
*/
int skytexorder[6] = {0,2,1,3,4,5};
void R_DrawSkyBox (void)
{
int i, j, k;
vec3_t v;
float s, t;
#if 0
glEnable (GL_BLEND);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glColor4f (1,1,1,0.5);
glDisable (GL_DEPTH_TEST);
#endif
for (i=0 ; i<6 ; i++)
{
if (skymins[0][i] >= skymaxs[0][i]
|| skymins[1][i] >= skymaxs[1][i])
continue;
GL_Bind (SKY_TEX+skytexorder[i]);
#if 0
skymins[0][i] = -1;
skymins[1][i] = -1;
skymaxs[0][i] = 1;
skymaxs[1][i] = 1;
#endif
glBegin (GL_QUADS);
MakeSkyVec (skymins[0][i], skymins[1][i], i);
MakeSkyVec (skymins[0][i], skymaxs[1][i], i);
MakeSkyVec (skymaxs[0][i], skymaxs[1][i], i);
MakeSkyVec (skymaxs[0][i], skymins[1][i], i);
glEnd ();
}
#if 0
glDisable (GL_BLEND);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glColor4f (1,1,1,0.5);
glEnable (GL_DEPTH_TEST);
#endif
}
#endif
//===============================================================
/*
=============
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, p;
byte *src;
unsigned trans[128*128];
unsigned transpix;
int r, g, b;
unsigned *rgba;
extern int skytexturenum;
src = (byte *)mt + mt->offsets[0];
// make an average value for the back to avoid
// a fringe on the top level
r = g = b = 0;
for (i=0 ; i<128 ; i++)
for (j=0 ; j<128 ; j++)
{
p = src[i*256 + j + 128];
rgba = &d_8to24table[p];
trans[(i*128) + j] = *rgba;
r += ((byte *)rgba)[0];
g += ((byte *)rgba)[1];
b += ((byte *)rgba)[2];
}
((byte *)&transpix)[0] = r/(128*128);
((byte *)&transpix)[1] = g/(128*128);
((byte *)&transpix)[2] = b/(128*128);
((byte *)&transpix)[3] = 0;
if (!solidskytexture)
solidskytexture = texture_extension_number++;
GL_Bind (solidskytexture );
glTexImage2D (GL_TEXTURE_2D, 0, gl_solid_format, 128, 128, 0, GL_RGBA, GL_UNSIGNED_BYTE, trans);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
for (i=0 ; i<128 ; i++)
for (j=0 ; j<128 ; j++)
{
p = src[i*256 + j];
if (p == 0)
trans[(i*128) + j] = transpix;
else
trans[(i*128) + j] = d_8to24table[p];
}
if (!alphaskytexture)
alphaskytexture = texture_extension_number++;
GL_Bind(alphaskytexture);
glTexImage2D (GL_TEXTURE_2D, 0, gl_alpha_format, 128, 128, 0, GL_RGBA, GL_UNSIGNED_BYTE, trans);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
}