ref: c05151aa1b7ac81866cf937c973e7038035dfe53
dir: /ref_gl/gl_warp.c/
/*
Copyright (C) 1997-2001 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 "gl_local.h"
extern model_t *loadmodel;
char skyname[MAX_QPATH];
float skyrotate;
vec3_t skyaxis;
image_t *sky_images[6];
msurface_t *warpface;
#define SUBDIVIDE_SIZE 64
//#define SUBDIVIDE_SIZE 1024
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;
vec3_t total;
float total_s, total_t;
if (numverts > 60)
ri.Sys_Error (ERR_DROP, "numverts = %i", numverts);
BoundPoly (numverts, verts, mins, maxs);
for (i=0 ; i<3 ; i++)
{
m = (mins[i] + maxs[i]) * 0.5;
m = SUBDIVIDE_SIZE * floor (m/SUBDIVIDE_SIZE + 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;
}
// add a point in the center to help keep warp valid
poly = Hunk_Alloc (sizeof(glpoly_t) + ((numverts-4)+2) * VERTEXSIZE*sizeof(float));
poly->next = warpface->polys;
warpface->polys = poly;
poly->numverts = numverts+2;
VectorClear (total);
total_s = 0;
total_t = 0;
for (i=0 ; i<numverts ; i++, verts+= 3)
{
VectorCopy (verts, poly->verts[i+1]);
s = DotProduct (verts, warpface->texinfo->vecs[0]);
t = DotProduct (verts, warpface->texinfo->vecs[1]);
total_s += s;
total_t += t;
VectorAdd (total, verts, total);
poly->verts[i+1][3] = s;
poly->verts[i+1][4] = t;
}
VectorScale (total, (1.0/numverts), poly->verts[0]);
poly->verts[0][3] = total_s/numverts;
poly->verts[0][4] = total_t/numverts;
// copy first vertex to last
memcpy (poly->verts[i+1], poly->verts[1], sizeof(poly->verts[0]));
}
/*
================
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;
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 r_turbsin[] =
{
#include "warpsin.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, *bp;
float *v;
int i;
float s, t, os, ot;
float scroll;
float rdt = r_newrefdef.time;
if (fa->texinfo->flags & SURF_FLOWING)
scroll = -64 * ( (r_newrefdef.time*0.5) - (int)(r_newrefdef.time*0.5) );
else
scroll = 0;
for (bp=fa->polys ; bp ; bp=bp->next)
{
p = bp;
qglBegin (GL_TRIANGLE_FAN);
for (i=0,v=p->verts[0] ; i<p->numverts ; i++, v+=VERTEXSIZE)
{
os = v[3];
ot = v[4];
#if !id386
s = os + r_turbsin[(int)((ot*0.125+r_newrefdef.time) * TURBSCALE) & 255];
#else
s = os + r_turbsin[Q_ftol( ((ot*0.125+rdt) * TURBSCALE) ) & 255];
#endif
s += scroll;
s *= (1.0/64);
#if !id386
t = ot + r_turbsin[(int)((os*0.125+rdt) * TURBSCALE) & 255];
#else
t = ot + r_turbsin[Q_ftol( ((os*0.125+rdt) * TURBSCALE) ) & 255];
#endif
t *= (1.0/64);
qglTexCoord2f (s, t);
qglVertex3fv (v);
}
qglEnd ();
}
}
//===================================================================
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];
float sky_min, sky_max;
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);
qglVertex3fv (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];
if (dv < 0.001)
continue; // don't divide by zero
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 ON_EPSILON 0.1 // point on plane side epsilon
#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)
ri.Sys_Error (ERR_DROP, "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_AddSkySurface
=================
*/
void R_AddSkySurface (msurface_t *fa)
{
int i;
vec3_t verts[MAX_CLIP_VERTS];
glpoly_t *p;
// calculate vertex values for sky box
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*2300;
b[1] = t*2300;
b[2] = 2300;
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];
}
// avoid bilerp seam
s = (s+1)*0.5;
t = (t+1)*0.5;
if (s < sky_min)
s = sky_min;
else if (s > sky_max)
s = sky_max;
if (t < sky_min)
t = sky_min;
else if (t > sky_max)
t = sky_max;
t = 1.0 - t;
qglTexCoord2f (s, t);
qglVertex3fv (v);
}
/*
==============
R_DrawSkyBox
==============
*/
int skytexorder[6] = {0,2,1,3,4,5};
void R_DrawSkyBox (void)
{
int i;
#if 0
qglEnable (GL_BLEND);
GL_TexEnv( GL_MODULATE );
qglColor4f (1,1,1,0.5);
qglDisable (GL_DEPTH_TEST);
#endif
if (skyrotate)
{ // check for no sky at all
for (i=0 ; i<6 ; i++)
if (skymins[0][i] < skymaxs[0][i]
&& skymins[1][i] < skymaxs[1][i])
break;
if (i == 6)
return; // nothing visible
}
qglPushMatrix ();
qglTranslatef (r_origin[0], r_origin[1], r_origin[2]);
qglRotatef (r_newrefdef.time * skyrotate, skyaxis[0], skyaxis[1], skyaxis[2]);
for (i=0 ; i<6 ; i++)
{
if (skyrotate)
{ // hack, forces full sky to draw when rotating
skymins[0][i] = -1;
skymins[1][i] = -1;
skymaxs[0][i] = 1;
skymaxs[1][i] = 1;
}
if (skymins[0][i] >= skymaxs[0][i]
|| skymins[1][i] >= skymaxs[1][i])
continue;
GL_Bind (sky_images[skytexorder[i]]->texnum);
qglBegin (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);
qglEnd ();
}
qglPopMatrix ();
#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
}
/*
============
R_SetSky
============
*/
// 3dstudio environment map names
char *suf[6] = {"rt", "bk", "lf", "ft", "up", "dn"};
void R_SetSky (char *name, float rotate, vec3_t axis)
{
int i;
char pathname[MAX_QPATH];
strncpy (skyname, name, sizeof(skyname)-1);
skyrotate = rotate;
VectorCopy (axis, skyaxis);
for (i=0 ; i<6 ; i++)
{
// chop down rotating skies for less memory
if (gl_skymip->value || skyrotate)
gl_picmip->value++;
if ( qglColorTableEXT && gl_ext_palettedtexture->value )
Com_sprintf (pathname, sizeof(pathname), "env/%s%s.pcx", skyname, suf[i]);
else
Com_sprintf (pathname, sizeof(pathname), "env/%s%s.tga", skyname, suf[i]);
sky_images[i] = GL_FindImage (pathname, it_sky);
if (!sky_images[i])
sky_images[i] = r_notexture;
if (gl_skymip->value || skyrotate)
{ // take less memory
gl_picmip->value--;
sky_min = 1.0/256;
sky_max = 255.0/256;
}
else
{
sky_min = 1.0/512;
sky_max = 511.0/512;
}
}
}