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#include "light.h"
/*
============
CastRay
Returns the distance between the points, or -1 if blocked
=============
*/
vec_t CastRay (vec3_t p1, vec3_t p2)
{
int i;
vec_t t;
qboolean trace;
trace = TestLine (p1, p2);
if (!trace)
return -1; // ray was blocked
t = 0;
for (i=0 ; i< 3 ; i++)
t += (p2[i]-p1[i]) * (p2[i]-p1[i]);
if (t == 0)
t = 1; // don't blow up...
return sqrt(t);
}
/*
===============================================================================
SAMPLE POINT DETERMINATION
void SetupBlock (dface_t *f) Returns with surfpt[] set
This is a little tricky because the lightmap covers more area than the face.
If done in the straightforward fashion, some of the
sample points will be inside walls or on the other side of walls, causing
false shadows and light bleeds.
To solve this, I only consider a sample point valid if a line can be drawn
between it and the exact midpoint of the face. If invalid, it is adjusted
towards the center until it is valid.
(this doesn't completely work)
===============================================================================
*/
#define SINGLEMAP (18*18*4)
typedef struct
{
vec_t lightmaps[MAXLIGHTMAPS][SINGLEMAP];
int numlightstyles;
vec_t *light;
vec_t facedist;
vec3_t facenormal;
int numsurfpt;
vec3_t surfpt[SINGLEMAP];
vec3_t texorg;
vec3_t worldtotex[2]; // s = (world - texorg) . worldtotex[0]
vec3_t textoworld[2]; // world = texorg + s * textoworld[0]
vec_t exactmins[2], exactmaxs[2];
int texmins[2], texsize[2];
int lightstyles[256];
int surfnum;
dface_t *face;
} lightinfo_t;
/*
================
CalcFaceVectors
Fills in texorg, worldtotex. and textoworld
================
*/
void CalcFaceVectors (lightinfo_t *l)
{
texinfo_t *tex;
int i, j;
vec3_t texnormal;
float distscale;
vec_t dist, len;
tex = &texinfo[l->face->texinfo];
// convert from float to vec_t
for (i=0 ; i<2 ; i++)
for (j=0 ; j<3 ; j++)
l->worldtotex[i][j] = tex->vecs[i][j];
// calculate a normal to the texture axis. points can be moved along this
// without changing their S/T
texnormal[0] = tex->vecs[1][1]*tex->vecs[0][2]
- tex->vecs[1][2]*tex->vecs[0][1];
texnormal[1] = tex->vecs[1][2]*tex->vecs[0][0]
- tex->vecs[1][0]*tex->vecs[0][2];
texnormal[2] = tex->vecs[1][0]*tex->vecs[0][1]
- tex->vecs[1][1]*tex->vecs[0][0];
VectorNormalize (texnormal);
// flip it towards plane normal
distscale = DotProduct (texnormal, l->facenormal);
if (!distscale)
Error ("Texture axis perpendicular to face");
if (distscale < 0)
{
distscale = -distscale;
VectorSubtract (vec3_origin, texnormal, texnormal);
}
// distscale is the ratio of the distance along the texture normal to
// the distance along the plane normal
distscale = 1/distscale;
for (i=0 ; i<2 ; i++)
{
len = VectorLength (l->worldtotex[i]);
dist = DotProduct (l->worldtotex[i], l->facenormal);
dist *= distscale;
VectorMA (l->worldtotex[i], -dist, texnormal, l->textoworld[i]);
VectorScale (l->textoworld[i], (1/len)*(1/len), l->textoworld[i]);
}
// calculate texorg on the texture plane
for (i=0 ; i<3 ; i++)
l->texorg[i] = -tex->vecs[0][3]* l->textoworld[0][i] - tex->vecs[1][3] * l->textoworld[1][i];
// project back to the face plane
dist = DotProduct (l->texorg, l->facenormal) - l->facedist - 1;
dist *= distscale;
VectorMA (l->texorg, -dist, texnormal, l->texorg);
}
/*
================
CalcFaceExtents
Fills in s->texmins[] and s->texsize[]
also sets exactmins[] and exactmaxs[]
================
*/
void CalcFaceExtents (lightinfo_t *l)
{
dface_t *s;
vec_t mins[2], maxs[2], val;
int i,j, e;
dvertex_t *v;
texinfo_t *tex;
s = l->face;
mins[0] = mins[1] = 999999;
maxs[0] = maxs[1] = -99999;
tex = &texinfo[s->texinfo];
for (i=0 ; i<s->numedges ; i++)
{
e = dsurfedges[s->firstedge+i];
if (e >= 0)
v = dvertexes + dedges[e].v[0];
else
v = dvertexes + dedges[-e].v[1];
for (j=0 ; j<2 ; j++)
{
val = v->point[0] * tex->vecs[j][0] +
v->point[1] * tex->vecs[j][1] +
v->point[2] * tex->vecs[j][2] +
tex->vecs[j][3];
if (val < mins[j])
mins[j] = val;
if (val > maxs[j])
maxs[j] = val;
}
}
for (i=0 ; i<2 ; i++)
{
l->exactmins[i] = mins[i];
l->exactmaxs[i] = maxs[i];
mins[i] = floor(mins[i]/16);
maxs[i] = ceil(maxs[i]/16);
l->texmins[i] = mins[i];
l->texsize[i] = maxs[i] - mins[i];
if (l->texsize[i] > 17)
Error ("Bad surface extents");
}
}
/*
=================
CalcPoints
For each texture aligned grid point, back project onto the plane
to get the world xyz value of the sample point
=================
*/
int c_bad;
void CalcPoints (lightinfo_t *l)
{
int i;
int s, t, j;
int w, h, step;
vec_t starts, startt, us, ut;
vec_t *surf;
vec_t mids, midt;
vec3_t facemid, move;
//
// fill in surforg
// the points are biased towards the center of the surface
// to help avoid edge cases just inside walls
//
surf = l->surfpt[0];
mids = (l->exactmaxs[0] + l->exactmins[0])/2;
midt = (l->exactmaxs[1] + l->exactmins[1])/2;
for (j=0 ; j<3 ; j++)
facemid[j] = l->texorg[j] + l->textoworld[0][j]*mids + l->textoworld[1][j]*midt;
if (extrasamples)
{ // extra filtering
h = (l->texsize[1]+1)*2;
w = (l->texsize[0]+1)*2;
starts = (l->texmins[0]-0.5)*16;
startt = (l->texmins[1]-0.5)*16;
step = 8;
}
else
{
h = l->texsize[1]+1;
w = l->texsize[0]+1;
starts = l->texmins[0]*16;
startt = l->texmins[1]*16;
step = 16;
}
l->numsurfpt = w * h;
for (t=0 ; t<h ; t++)
{
for (s=0 ; s<w ; s++, surf+=3)
{
us = starts + s*step;
ut = startt + t*step;
// if a line can be traced from surf to facemid, the point is good
for (i=0 ; i<6 ; i++)
{
// calculate texture point
for (j=0 ; j<3 ; j++)
surf[j] = l->texorg[j] + l->textoworld[0][j]*us
+ l->textoworld[1][j]*ut;
if (CastRay (facemid, surf) != -1)
break; // got it
if (i & 1)
{
if (us > mids)
{
us -= 8;
if (us < mids)
us = mids;
}
else
{
us += 8;
if (us > mids)
us = mids;
}
}
else
{
if (ut > midt)
{
ut -= 8;
if (ut < midt)
ut = midt;
}
else
{
ut += 8;
if (ut > midt)
ut = midt;
}
}
// move surf 8 pixels towards the center
VectorSubtract (facemid, surf, move);
VectorNormalize (move);
VectorMA (surf, 8, move, surf);
}
if (i == 2)
c_bad++;
}
}
}
/*
===============================================================================
FACE LIGHTING
===============================================================================
*/
int c_culldistplane, c_proper;
/*
================
SingleLightFace
================
*/
void SingleLightFace (entity_t *light, lightinfo_t *l)
{
vec_t dist;
vec3_t incoming;
vec_t angle;
vec_t add;
vec_t *surf;
qboolean hit;
int mapnum;
int size;
int c, i;
vec3_t rel;
vec3_t spotvec;
vec_t falloff;
vec_t *lightsamp;
VectorSubtract (light->origin, bsp_origin, rel);
dist = scaledist * (DotProduct (rel, l->facenormal) - l->facedist);
// don't bother with lights behind the surface
if (dist <= 0)
return;
// don't bother with light too far away
if (dist > light->light)
{
c_culldistplane++;
return;
}
if (light->targetent)
{
VectorSubtract (light->targetent->origin, light->origin, spotvec);
VectorNormalize (spotvec);
if (!light->angle)
falloff = -cos(20*Q_PI/180);
else
falloff = -cos(light->angle/2*Q_PI/180);
}
else
falloff = 0; // shut up compiler warnings
mapnum = 0;
for (mapnum=0 ; mapnum<l->numlightstyles ; mapnum++)
if (l->lightstyles[mapnum] == light->style)
break;
lightsamp = l->lightmaps[mapnum];
if (mapnum == l->numlightstyles)
{ // init a new light map
if (mapnum == MAXLIGHTMAPS)
{
printf ("WARNING: Too many light styles on a face\n");
return;
}
size = (l->texsize[1]+1)*(l->texsize[0]+1);
for (i=0 ; i<size ; i++)
lightsamp[i] = 0;
}
//
// check it for real
//
hit = false;
c_proper++;
surf = l->surfpt[0];
for (c=0 ; c<l->numsurfpt ; c++, surf+=3)
{
dist = CastRay(light->origin, surf)*scaledist;
if (dist < 0)
continue; // light doesn't reach
VectorSubtract (light->origin, surf, incoming);
VectorNormalize (incoming);
angle = DotProduct (incoming, l->facenormal);
if (light->targetent)
{ // spotlight cutoff
if (DotProduct (spotvec, incoming) > falloff)
continue;
}
angle = (1.0-scalecos) + scalecos*angle;
add = light->light - dist;
add *= angle;
if (add < 0)
continue;
lightsamp[c] += add;
if (lightsamp[c] > 1) // ignore real tiny lights
hit = true;
}
if (mapnum == l->numlightstyles && hit)
{
l->lightstyles[mapnum] = light->style;
l->numlightstyles++; // the style has some real data now
}
}
/*
============
FixMinlight
============
*/
void FixMinlight (lightinfo_t *l)
{
int i, j;
float minlight;
minlight = minlights[l->surfnum];
// if minlight is set, there must be a style 0 light map
if (!minlight)
return;
for (i=0 ; i< l->numlightstyles ; i++)
{
if (l->lightstyles[i] == 0)
break;
}
if (i == l->numlightstyles)
{
if (l->numlightstyles == MAXLIGHTMAPS)
return; // oh well..
for (j=0 ; j<l->numsurfpt ; j++)
l->lightmaps[i][j] = minlight;
l->lightstyles[i] = 0;
l->numlightstyles++;
}
else
{
for (j=0 ; j<l->numsurfpt ; j++)
if ( l->lightmaps[i][j] < minlight)
l->lightmaps[i][j] = minlight;
}
}
/*
============
LightFace
============
*/
void LightFace (int surfnum)
{
dface_t *f;
lightinfo_t l;
int s, t;
int i,j,c;
vec_t total;
int size;
int lightmapwidth, lightmapsize;
byte *out;
vec_t *light;
int w, h;
f = dfaces + surfnum;
//
// some surfaces don't need lightmaps
//
f->lightofs = -1;
for (j=0 ; j<MAXLIGHTMAPS ; j++)
f->styles[j] = 255;
if ( texinfo[f->texinfo].flags & TEX_SPECIAL)
{ // non-lit texture
return;
}
memset (&l, 0, sizeof(l));
l.surfnum = surfnum;
l.face = f;
//
// rotate plane
//
VectorCopy (dplanes[f->planenum].normal, l.facenormal);
l.facedist = dplanes[f->planenum].dist;
if (f->side)
{
VectorSubtract (vec3_origin, l.facenormal, l.facenormal);
l.facedist = -l.facedist;
}
CalcFaceVectors (&l);
CalcFaceExtents (&l);
CalcPoints (&l);
lightmapwidth = l.texsize[0]+1;
size = lightmapwidth*(l.texsize[1]+1);
if (size > SINGLEMAP)
Error ("Bad lightmap size");
for (i=0 ; i<MAXLIGHTMAPS ; i++)
l.lightstyles[i] = 255;
//
// cast all lights
//
l.numlightstyles = 0;
for (i=0 ; i<num_entities ; i++)
{
if (entities[i].light)
SingleLightFace (&entities[i], &l);
}
FixMinlight (&l);
if (!l.numlightstyles)
{ // no light hitting it
return;
}
//
// save out the values
//
for (i=0 ; i <MAXLIGHTMAPS ; i++)
f->styles[i] = l.lightstyles[i];
lightmapsize = size*l.numlightstyles;
out = GetFileSpace (lightmapsize);
f->lightofs = out - filebase;
// extra filtering
h = (l.texsize[1]+1)*2;
w = (l.texsize[0]+1)*2;
for (i=0 ; i< l.numlightstyles ; i++)
{
if (l.lightstyles[i] == 0xff)
Error ("Wrote empty lightmap");
light = l.lightmaps[i];
c = 0;
for (t=0 ; t<=l.texsize[1] ; t++)
for (s=0 ; s<=l.texsize[0] ; s++, c++)
{
if (extrasamples)
{ // filtered sample
total = light[t*2*w+s*2] + light[t*2*w+s*2+1]
+ light[(t*2+1)*w+s*2] + light[(t*2+1)*w+s*2+1];
total *= 0.25;
}
else
total = light[c];
total *= rangescale; // scale before clamping
if (total > 255)
total = 255;
if (total < 0)
Error ("light < 0");
*out++ = total;
}
}
}
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