/*
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
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;
}