ref: 51f5f5fa41dcfba8d4308cdecf327e29e6129aa1
dir: /src/light.c/
#include "zgl.h"
#include "msghandling.h"
void glopMaterial(GLContext *c,GLParam *p)
{
int mode=p[1].i;
int type=p[2].i;
float *v=&p[3].f;
int i;
GLMaterial *m;
if (mode == GL_FRONT_AND_BACK) {
p[1].i=GL_FRONT;
glopMaterial(c,p);
mode=GL_BACK;
}
if (mode == GL_FRONT) m=&c->materials[0];
else m=&c->materials[1];
switch(type) {
case GL_EMISSION:
for(i=0;i<4;i++)
m->emission.v[i]=v[i];
break;
case GL_AMBIENT:
for(i=0;i<4;i++)
m->ambient.v[i]=v[i];
break;
case GL_DIFFUSE:
for(i=0;i<4;i++)
m->diffuse.v[i]=v[i];
break;
case GL_SPECULAR:
for(i=0;i<4;i++)
m->specular.v[i]=v[i];
break;
case GL_SHININESS:
m->shininess=v[0];
m->shininess_i = (v[0]/128.0f)*SPECULAR_BUFFER_RESOLUTION;
break;
case GL_AMBIENT_AND_DIFFUSE:
for(i=0;i<4;i++)
m->diffuse.v[i]=v[i];
for(i=0;i<4;i++)
m->ambient.v[i]=v[i];
break;
default:
assert(0);
}
}
void glopColorMaterial(GLContext *c,GLParam *p)
{
int mode=p[1].i;
int type=p[2].i;
c->current_color_material_mode=mode;
c->current_color_material_type=type;
}
void glopLight(GLContext *c,GLParam *p)
{
int light=p[1].i;
int type=p[2].i;
V4 v;
GLLight *l;
int i;
assert(light >= GL_LIGHT0 && light < GL_LIGHT0+MAX_LIGHTS );
l=&c->lights[light-GL_LIGHT0];
for(i=0;i<4;i++) v.v[i]=p[3+i].f;
switch(type) {
case GL_AMBIENT:
l->ambient=v;
break;
case GL_DIFFUSE:
l->diffuse=v;
break;
case GL_SPECULAR:
l->specular=v;
break;
case GL_POSITION:
{
V4 pos;
gl_M4_MulV4(&pos,c->matrix_stack_ptr[0],&v);
l->position=pos;
if (l->position.v[3] == 0) {
l->norm_position.X=pos.X;
l->norm_position.Y=pos.Y;
l->norm_position.Z=pos.Z;
gl_V3_Norm(&l->norm_position);
}
}
break;
case GL_SPOT_DIRECTION:
for(i=0;i<3;i++) {
l->spot_direction.v[i]=v.v[i];
l->norm_spot_direction.v[i]=v.v[i];
}
gl_V3_Norm(&l->norm_spot_direction);
break;
case GL_SPOT_EXPONENT:
l->spot_exponent=v.v[0];
break;
case GL_SPOT_CUTOFF:
{
float a=v.v[0];
assert(a == 180 || (a>=0 && a<=90));
l->spot_cutoff=a;
if (a != 180) l->cos_spot_cutoff=cos(a * M_PI / 180.0);
}
break;
case GL_CONSTANT_ATTENUATION:
l->attenuation[0]=v.v[0];
break;
case GL_LINEAR_ATTENUATION:
l->attenuation[1]=v.v[0];
break;
case GL_QUADRATIC_ATTENUATION:
l->attenuation[2]=v.v[0];
break;
default:
assert(0);
}
}
void glopLightModel(GLContext *c,GLParam *p)
{
int pname=p[1].i;
float *v=&p[2].f;
int i;
switch(pname) {
case GL_LIGHT_MODEL_AMBIENT:
for(i=0;i<4;i++)
c->ambient_light_model.v[i]=v[i];
break;
case GL_LIGHT_MODEL_LOCAL_VIEWER:
c->local_light_model=(int)v[0];
break;
case GL_LIGHT_MODEL_TWO_SIDE:
c->light_model_two_side = (int)v[0];
break;
default:
tgl_warning("glopLightModel: illegal pname: 0x%x\n", pname);
//assert(0);
break;
}
}
static inline float clampf(float a,float min,float max)
{
if (a<min) return min;
else if (a>max) return max;
else return a;
}
void gl_enable_disable_light(GLContext *c,int light,int v)
{
GLLight *l=&c->lights[light];
if (v && !l->enabled) {
l->enabled=1;
l->next=c->first_light;
c->first_light=l;
l->prev=NULL;
} else if (!v && l->enabled) {
l->enabled=0;
if (l->prev == NULL) c->first_light=l->next;
else l->prev->next=l->next;
if (l->next != NULL) l->next->prev=l->prev;
}
}
//FEATURES
int zEnableSpecular = 1; //Enable specular lighting
void glSetEnableSpecular(int s){
zEnableSpecular = s;
}
/* non optimized lightening model */
void gl_shade_vertex(GLContext *c,GLVertex *v)
{
float R,G,B,A;
GLMaterial *m;
GLLight *l;
V3 n,s,d;
float dist,tmp,att,dot,dot_spot,dot_spec;
int twoside = c->light_model_two_side;
m=&c->materials[0];
n.X=v->normal.X;
n.Y=v->normal.Y;
n.Z=v->normal.Z;
R=m->emission.v[0]+m->ambient.v[0]*c->ambient_light_model.v[0];
G=m->emission.v[1]+m->ambient.v[1]*c->ambient_light_model.v[1];
B=m->emission.v[2]+m->ambient.v[2]*c->ambient_light_model.v[2];
A=clampf(m->diffuse.v[3],0,1);
for(l=c->first_light;l!=NULL;l=l->next) {
float lR,lB,lG;
/* ambient */
lR=l->ambient.v[0] * m->ambient.v[0];
lG=l->ambient.v[1] * m->ambient.v[1];
lB=l->ambient.v[2] * m->ambient.v[2];
if (l->position.v[3] == 0) {
/* light at infinity */
d.X=l->position.v[0];
d.Y=l->position.v[1];
d.Z=l->position.v[2];
att=1;
} else {
/* distance attenuation */
d.X=l->position.v[0]-v->ec.v[0];
d.Y=l->position.v[1]-v->ec.v[1];
d.Z=l->position.v[2]-v->ec.v[2];
dist=sqrt(d.X*d.X+d.Y*d.Y+d.Z*d.Z);
if (dist>1E-3) {
tmp=1/dist;
d.X*=tmp;
d.Y*=tmp;
d.Z*=tmp;
}
att=1.0f/(l->attenuation[0]+dist*(l->attenuation[1]+
dist*l->attenuation[2]));
}
dot=d.X*n.X+d.Y*n.Y+d.Z*n.Z;
if (twoside && dot < 0) dot = -dot;
if (dot>0) {
/* diffuse light */
lR+=dot * l->diffuse.v[0] * m->diffuse.v[0];
lG+=dot * l->diffuse.v[1] * m->diffuse.v[1];
lB+=dot * l->diffuse.v[2] * m->diffuse.v[2];
/* spot light */
if (l->spot_cutoff != 180) {
dot_spot=-(d.X*l->norm_spot_direction.v[0]+
d.Y*l->norm_spot_direction.v[1]+
d.Z*l->norm_spot_direction.v[2]);
if (twoside && dot_spot < 0) dot_spot = -dot_spot;
if (dot_spot < l->cos_spot_cutoff) {
/* no contribution */
continue;
} else {
/* TODO: optimize */
if (l->spot_exponent > 0) {
att=att*pow(dot_spot,l->spot_exponent);
}
}
}
/* specular light */
if (zEnableSpecular){
if (c->local_light_model) {
V3 vcoord;
vcoord.X=v->ec.X;
vcoord.Y=v->ec.Y;
vcoord.Z=v->ec.Z;
gl_V3_Norm(&vcoord);
s.X=d.X-vcoord.X;
s.Y=d.Y-vcoord.X;
s.Z=d.Z-vcoord.X;
} else {
s.X=d.X;
s.Y=d.Y;
s.Z=d.Z+1.0;
}
dot_spec=n.X*s.X+n.Y*s.Y+n.Z*s.Z;
if (twoside && dot_spec < 0) dot_spec = -dot_spec;
if (dot_spec>0) {
GLSpecBuf *specbuf;
int idx;
tmp=sqrt(s.X*s.X+s.Y*s.Y+s.Z*s.Z);
if (tmp > 1E-3) {
dot_spec=dot_spec / tmp;
}
/* TODO: optimize */
/* testing specular buffer code */
/* dot_spec= pow(dot_spec,m->shininess);*/
specbuf = specbuf_get_buffer(c, m->shininess_i, m->shininess);
idx = (int)(dot_spec*SPECULAR_BUFFER_SIZE);
if (idx > SPECULAR_BUFFER_SIZE) idx = SPECULAR_BUFFER_SIZE;
dot_spec = specbuf->buf[idx];
lR+=dot_spec * l->specular.v[0] * m->specular.v[0];
lG+=dot_spec * l->specular.v[1] * m->specular.v[1];
lB+=dot_spec * l->specular.v[2] * m->specular.v[2];
}//EOF if dot_spec>0
}//EOF zEnableSpecular
} //EOF if dot > 0
R+=att * lR;
G+=att * lG;
B+=att * lB;
} //End of light loop.
v->color.v[0]=clampf(R,0,1);
v->color.v[1]=clampf(G,0,1);
v->color.v[2]=clampf(B,0,1);
v->color.v[3]=A;
}