ref: ed82668431413cf8d5389a631cad56a6c4d2d6da
dir: /ref/r_light.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.
*/
#include <u.h>
#include <libc.h>
#include <stdio.h>
#include "../q_shared.h"
int r_dlightframecount;
/*
=============================================================================
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 != -1)
return;
splitplane = node->plane;
dist = DotProduct (light->origin, splitplane->normal) - splitplane->dist;
//=====
//PGM
i=light->intensity;
if(i<0)
i=-i;
//PGM
//=====
if (dist > i) // PGM (dist > light->intensity)
{
R_MarkLights (light, bit, node->children[0]);
return;
}
if (dist < -i) // PGM (dist < -light->intensity)
{
R_MarkLights (light, bit, node->children[1]);
return;
}
// mark the polygons
surf = r_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 (model_t *model)
{
int i;
dlight_t *l;
r_dlightframecount = r_framecount;
for (i=0, l = r_newrefdef.dlights ; i<r_newrefdef.num_dlights ; i++, l++)
{
R_MarkLights ( l, 1<<i,
model->nodes + model->firstnode);
}
}
/*
=============================================================================
LIGHT SAMPLING
=============================================================================
*/
vec3_t pointcolor;
mplane_t *lightplane; // used as shadow plane
vec3_t lightspot;
int RecursiveLightPoint (mnode_t *node, vec3_t start, vec3_t end)
{
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;
float *scales;
int maps;
float samp;
int r;
if (node->contents != -1)
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;
if (plane->type < 3) // axial planes
mid[plane->type] = plane->dist;
// 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
VectorCopy (mid, lightspot);
lightplane = plane;
surf = r_worldmodel->surfaces + node->firstsurface;
for (i=0 ; i<node->numsurfaces ; i++, surf++)
{
if (surf->flags&(SURF_DRAWTURB|SURF_DRAWSKY))
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;
VectorCopy (vec3_origin, pointcolor);
if (lightmap)
{
lightmap += dt * ((surf->extents[0]>>4)+1) + ds;
for (maps = 0 ; maps < MAXLIGHTMAPS && surf->styles[maps] != 255 ;
maps++)
{
samp = *lightmap * /* 0.5 * */ (1.0/255); // adjust for gl scale
scales = r_newrefdef.lightstyles[surf->styles[maps]].rgb;
VectorMA (pointcolor, samp, scales, pointcolor);
lightmap += ((surf->extents[0]>>4)+1) *
((surf->extents[1]>>4)+1);
}
}
return 1;
}
// go down back side
return RecursiveLightPoint (node->children[!side], mid, end);
}
/*
===============
R_LightPoint
===============
*/
void R_LightPoint (vec3_t p, vec3_t color)
{
vec3_t end;
float r;
int lnum;
dlight_t *dl;
vec3_t dist;
float add;
if (!r_worldmodel->lightdata)
{
color[0] = color[1] = color[2] = 1.0;
return;
}
end[0] = p[0];
end[1] = p[1];
end[2] = p[2] - 2048;
r = RecursiveLightPoint (r_worldmodel->nodes, p, end);
if (r == -1)
{
VectorCopy (vec3_origin, color);
}
else
{
VectorCopy (pointcolor, color);
}
//
// add dynamic lights
//
for (lnum=0 ; lnum<r_newrefdef.num_dlights ; lnum++)
{
dl = &r_newrefdef.dlights[lnum];
VectorSubtract (currententity->origin,
dl->origin,
dist);
add = dl->intensity - VectorLength(dist);
add *= (1.0/256);
if (add > 0)
{
VectorMA (color, add, dl->color, color);
}
}
}
//===================================================================
unsigned blocklights[1024]; // allow some very large lightmaps
/*
===============
R_AddDynamicLights
===============
*/
void R_AddDynamicLights (void)
{
msurface_t *surf;
int lnum;
int sd, td;
float dist, rad, minlight;
vec3_t impact, local;
int s, t;
int i;
int smax, tmax;
mtexinfo_t *tex;
dlight_t *dl;
int negativeLight; //PGM
surf = r_drawsurf.surf;
smax = (surf->extents[0]>>4)+1;
tmax = (surf->extents[1]>>4)+1;
tex = surf->texinfo;
for (lnum=0 ; lnum<r_newrefdef.num_dlights ; lnum++)
{
if ( !(surf->dlightbits & (1<<lnum) ) )
continue; // not lit by this light
dl = &r_newrefdef.dlights[lnum];
rad = dl->intensity;
//=====
//PGM
negativeLight = 0;
if(rad < 0)
{
negativeLight = 1;
rad = -rad;
}
//PGM
//=====
dist = DotProduct (dl->origin, surf->plane->normal) -
surf->plane->dist;
rad -= fabs(dist);
minlight = 32; // dl->minlight;
if (rad < minlight)
continue;
minlight = rad - minlight;
for (i=0 ; i<3 ; i++)
{
impact[i] = dl->origin[i] -
surf->plane->normal[i]*dist;
}
local[0] = DotProduct (impact, tex->vecs[0]) + tex->vecs[0][3];
local[1] = DotProduct (impact, tex->vecs[1]) + tex->vecs[1][3];
local[0] -= surf->texturemins[0];
local[1] -= surf->texturemins[1];
for (t = 0 ; t<tmax ; t++)
{
td = local[1] - t*16;
if (td < 0)
td = -td;
for (s=0 ; s<smax ; s++)
{
sd = local[0] - s*16;
if (sd < 0)
sd = -sd;
if (sd > td)
dist = sd + (td>>1);
else
dist = td + (sd>>1);
//====
//PGM
if(!negativeLight)
{
if (dist < minlight)
blocklights[t*smax + s] += (rad - dist)*256;
}
else
{
if (dist < minlight)
blocklights[t*smax + s] -= (rad - dist)*256;
if(blocklights[t*smax + s] < minlight)
blocklights[t*smax + s] = minlight;
}
//PGM
//====
}
}
}
}
/*
===============
R_BuildLightMap
Combine and scale multiple lightmaps into the 8.8 format in blocklights
===============
*/
void R_BuildLightMap (void)
{
int smax, tmax;
int t;
int i, size;
byte *lightmap;
unsigned scale;
int maps;
msurface_t *surf;
surf = r_drawsurf.surf;
smax = (surf->extents[0]>>4)+1;
tmax = (surf->extents[1]>>4)+1;
size = smax*tmax;
if (r_fullbright->value || !r_worldmodel->lightdata)
{
for (i=0 ; i<size ; i++)
blocklights[i] = 0;
return;
}
// clear to no light
for (i=0 ; i<size ; i++)
blocklights[i] = 0;
// add all the lightmaps
lightmap = surf->samples;
if (lightmap)
for (maps = 0 ; maps < MAXLIGHTMAPS && surf->styles[maps] != 255 ;
maps++)
{
scale = r_drawsurf.lightadj[maps]; // 8.8 fraction
for (i=0 ; i<size ; i++)
blocklights[i] += lightmap[i] * scale;
lightmap += size; // skip to next lightmap
}
// add all the dynamic lights
if (surf->dlightframe == r_framecount)
R_AddDynamicLights ();
// bound, invert, and shift
for (i=0 ; i<size ; i++)
{
t = (int)blocklights[i];
if (t < 0)
t = 0;
t = (255*256 - t) >> (8 - VID_CBITS);
if (t < (1 << 6))
t = (1 << 6);
blocklights[i] = t;
}
}