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-rw-r--r--apps/plugins/sdl/progs/quake/r_light.c260
1 files changed, 260 insertions, 0 deletions
diff --git a/apps/plugins/sdl/progs/quake/r_light.c b/apps/plugins/sdl/progs/quake/r_light.c
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+++ b/apps/plugins/sdl/progs/quake/r_light.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_light.c
+
+#include "quakedef.h"
+#include "r_local.h"
+
+int r_dlightframecount;
+
+
+/*
+==================
+R_AnimateLight
+==================
+*/
+void R_AnimateLight (void)
+{
+ int i,j,k;
+
+//
+// light animations
+// 'm' is normal light, 'a' is no light, 'z' is double bright
+ i = (int)(cl.time*10);
+ for (j=0 ; j<MAX_LIGHTSTYLES ; j++)
+ {
+ if (!cl_lightstyle[j].length)
+ {
+ d_lightstylevalue[j] = 256;
+ continue;
+ }
+ k = i % cl_lightstyle[j].length;
+ k = cl_lightstyle[j].map[k] - 'a';
+ k = k*22;
+ d_lightstylevalue[j] = k;
+ }
+}
+
+
+/*
+=============================================================================
+
+DYNAMIC LIGHTS
+
+=============================================================================
+*/
+
+/*
+=============
+R_MarkLights
+=============
+*/
+void R_MarkLights (dlight_t *light, int bit, mnode_t *node)
+{
+ mplane_t *splitplane;
+ float dist;
+ msurface_t *surf;
+ int i;
+
+ if (node->contents < 0)
+ return;
+
+ splitplane = node->plane;
+ dist = DotProduct (light->origin, splitplane->normal) - splitplane->dist;
+
+ if (dist > light->radius)
+ {
+ R_MarkLights (light, bit, node->children[0]);
+ return;
+ }
+ if (dist < -light->radius)
+ {
+ R_MarkLights (light, bit, node->children[1]);
+ return;
+ }
+
+// mark the polygons
+ surf = cl.worldmodel->surfaces + node->firstsurface;
+ for (i=0 ; i<node->numsurfaces ; i++, surf++)
+ {
+ if (surf->dlightframe != r_dlightframecount)
+ {
+ surf->dlightbits = 0;
+ surf->dlightframe = r_dlightframecount;
+ }
+ surf->dlightbits |= bit;
+ }
+
+ R_MarkLights (light, bit, node->children[0]);
+ R_MarkLights (light, bit, node->children[1]);
+}
+
+
+/*
+=============
+R_PushDlights
+=============
+*/
+void R_PushDlights (void)
+{
+ int i;
+ dlight_t *l;
+
+ r_dlightframecount = r_framecount + 1; // because the count hasn't
+ // advanced yet for this frame
+ l = cl_dlights;
+
+ for (i=0 ; i<MAX_DLIGHTS ; i++, l++)
+ {
+ if (l->die < cl.time || !l->radius)
+ continue;
+ R_MarkLights ( l, 1<<i, cl.worldmodel->nodes );
+ }
+}
+
+
+/*
+=============================================================================
+
+LIGHT SAMPLING
+
+=============================================================================
+*/
+
+int RecursiveLightPoint (mnode_t *node, vec3_t start, vec3_t end)
+{
+ int r;
+ float front, back, frac;
+ int side;
+ mplane_t *plane;
+ vec3_t mid;
+ msurface_t *surf;
+ int s, t, ds, dt;
+ int i;
+ mtexinfo_t *tex;
+ byte *lightmap;
+ unsigned scale;
+ int maps;
+
+ if (node->contents < 0)
+ return -1; // didn't hit anything
+
+// calculate mid point
+
+// FIXME: optimize for axial
+ plane = node->plane;
+ front = DotProduct (start, plane->normal) - plane->dist;
+ back = DotProduct (end, plane->normal) - plane->dist;
+ side = front < 0;
+
+ if ( (back < 0) == side)
+ return RecursiveLightPoint (node->children[side], start, end);
+
+ frac = front / (front-back);
+ mid[0] = start[0] + (end[0] - start[0])*frac;
+ mid[1] = start[1] + (end[1] - start[1])*frac;
+ mid[2] = start[2] + (end[2] - start[2])*frac;
+
+// go down front side
+ r = RecursiveLightPoint (node->children[side], start, mid);
+ if (r >= 0)
+ return r; // hit something
+
+ if ( (back < 0) == side )
+ return -1; // didn't hit anuthing
+
+// check for impact on this node
+
+ surf = cl.worldmodel->surfaces + node->firstsurface;
+ for (i=0 ; i<node->numsurfaces ; i++, surf++)
+ {
+ if (surf->flags & SURF_DRAWTILED)
+ continue; // no lightmaps
+
+ tex = surf->texinfo;
+
+ s = DotProduct (mid, tex->vecs[0]) + tex->vecs[0][3];
+ t = DotProduct (mid, tex->vecs[1]) + tex->vecs[1][3];;
+
+ if (s < surf->texturemins[0] ||
+ t < surf->texturemins[1])
+ continue;
+
+ ds = s - surf->texturemins[0];
+ dt = t - surf->texturemins[1];
+
+ if ( ds > surf->extents[0] || dt > surf->extents[1] )
+ continue;
+
+ if (!surf->samples)
+ return 0;
+
+ ds >>= 4;
+ dt >>= 4;
+
+ lightmap = surf->samples;
+ r = 0;
+ if (lightmap)
+ {
+
+ lightmap += dt * ((surf->extents[0]>>4)+1) + ds;
+
+ for (maps = 0 ; maps < MAXLIGHTMAPS && surf->styles[maps] != 255 ;
+ maps++)
+ {
+ scale = d_lightstylevalue[surf->styles[maps]];
+ r += *lightmap * scale;
+ lightmap += ((surf->extents[0]>>4)+1) *
+ ((surf->extents[1]>>4)+1);
+ }
+
+ r >>= 8;
+ }
+
+ return r;
+ }
+
+// go down back side
+ return RecursiveLightPoint (node->children[!side], mid, end);
+}
+
+int R_LightPoint (vec3_t p)
+{
+ vec3_t end;
+ int r;
+
+ if (!cl.worldmodel->lightdata)
+ return 255;
+
+ end[0] = p[0];
+ end[1] = p[1];
+ end[2] = p[2] - 2048;
+
+ r = RecursiveLightPoint (cl.worldmodel->nodes, p, end);
+
+ if (r == -1)
+ r = 0;
+
+ if (r < r_refdef.ambientlight)
+ r = r_refdef.ambientlight;
+
+ return r;
+}
+