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-rw-r--r--source/gl_sky.c402
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diff --git a/source/gl_sky.c b/source/gl_sky.c
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+++ b/source/gl_sky.c
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+/*
+Copyright (C) 2003-2006 Andrey Nazarov
+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.
+
+*/
+
+#include "gl_local.h"
+
+static char skyname[MAX_QPATH];
+static float skyrotate;
+static vec3_t skyaxis;
+static image_t *sky_images[6];
+
+static vec3_t skyclip[6] = {
+ {1,1,0},
+ {1,-1,0},
+ {0,-1,1},
+ {0,1,1},
+ {1,0,1},
+ {-1,0,1}
+};
+
+// 1 = s, 2 = t, 3 = 2048
+static 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
+};
+
+// s = [0]/[2], t = [1]/[2]
+static int vec_to_st[6][3] = {
+ {-2,3,1},
+ {2,3,-1},
+
+ {1,3,2},
+ {-1,3,-2},
+
+ {-2,-1,3},
+ {-2,1,-3}
+};
+
+static float skymins[2][6], skymaxs[2][6];
+static float sky_min, sky_max;
+
+static void DrawSkyPolygon (int nump, vec3_t vecs)
+{
+ int i,j;
+ vec3_t v, av;
+ float s, t, dv;
+ int axis;
+ float *vp;
+
+ // 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
+
+#define SIDE_FRONT 0
+#define SIDE_BACK 1
+#define SIDE_ON 2
+
+static 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)
+ Com_Error( ERR_DROP, "ClipSkyPolygon: MAX_CLIP_VERTS");
+ if (stage == 6)
+ { // fully clipped, so draw it
+ DrawSkyPolygon (nump, vecs);
+ return;
+ }
+
+ front = back = qfalse;
+ norm = skyclip[stage];
+ for (i=0, v = vecs ; i<nump ; i++, v+=3)
+ {
+ d = DotProduct (v, norm);
+ if (d > ON_EPSILON)
+ {
+ front = qtrue;
+ sides[i] = SIDE_FRONT;
+ }
+ else if (d < -ON_EPSILON)
+ {
+ back = qtrue;
+ 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( bspSurface_t *fa ) {
+ int i;
+ vec3_t verts[MAX_CLIP_VERTS];
+ bspPoly_t *p;
+ vec_t *vert;
+
+ // calculate vertex values for sky box
+ for (p=fa->polys ; p ; p=p->next)
+ {
+ vert = p->vertices;
+ for (i=0 ; i<p->numVerts ; i++)
+ {
+ VectorSubtract (vert, modelViewOrigin, verts[i]);
+ vert += VERTEX_SIZE;
+ }
+ 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;
+ }
+}
+
+
+static void MakeSkyVec (float s, float t, int axis)
+{
+ vec3_t v, b;
+ int j, k;
+
+ b[0] = s*4800;//2300;
+ b[1] = t*4800;//2300;
+ b[2] = 4800;//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
+==============
+*/
+void R_DrawSkyBox( void ) {
+ int i;
+ static int skytexorder[6] = {0,2,1,3,4,5};
+
+ 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 (modelViewOrigin[0], modelViewOrigin[1], modelViewOrigin[2]);
+ qglRotatef (glr.fd.time * skyrotate,
+ skyaxis[0], skyaxis[1], skyaxis[2]);
+ qglColor3f( 1, 1, 1 );
+ GL_Bits( GLS_DEFAULT );
+
+ 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_BindTexture (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 ();
+}
+
+
+/*
+============
+R_SetSky
+============
+*/
+void R_SetSky( const char *name, float rotate, vec3_t axis ) {
+ int i;
+ char pathname[MAX_QPATH];
+ // 3dstudio environment map names
+ static char *suf[6] = {"rt", "bk", "lf", "ft", "up", "dn"};
+
+ Q_strncpyz( skyname, name, sizeof( skyname ) );
+ skyrotate = rotate;
+ VectorCopy (axis, skyaxis);
+
+ for (i=0 ; i<6 ; i++)
+ {
+ Com_sprintf (pathname, sizeof(pathname), "env/%s%s.tga",
+ skyname, suf[i]);
+
+ sky_images[i] = R_FindImage (pathname, it_sky);
+ if (!sky_images[i])
+ sky_images[i] = r_notexture;
+
+ /*if (gl_skymip->integer || skyrotate)
+ { // take less memory
+ sky_min = 1.0/256;
+ sky_max = 255.0/256;
+ }
+ else*/
+ {
+ sky_min = 1.0/512;
+ sky_max = 511.0/512;
+ }
+ }
+
+}
+
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