Panda3D
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00001 #include "zgl.h" 00002 #include <math.h> 00003 00004 static inline PN_stdfloat clampf(PN_stdfloat a,PN_stdfloat min,PN_stdfloat max) 00005 { 00006 if (a<min) return min; 00007 else if (a>max) return max; 00008 else return a; 00009 } 00010 00011 /* non optimized lighting model */ 00012 void gl_shade_vertex(GLContext *c,GLVertex *v) 00013 { 00014 PN_stdfloat R,G,B,A; 00015 GLMaterial *m; 00016 GLLight *l; 00017 V3 n,s,d; 00018 PN_stdfloat dist,tmp,att,dot,dot_spot,dot_spec; 00019 int twoside = c->light_model_two_side; 00020 00021 m=&c->materials[0]; 00022 00023 n.v[0]=v->normal.v[0]; 00024 n.v[1]=v->normal.v[1]; 00025 n.v[2]=v->normal.v[2]; 00026 00027 R=m->emission.v[0]+m->ambient.v[0]*c->ambient_light_model.v[0]; 00028 G=m->emission.v[1]+m->ambient.v[1]*c->ambient_light_model.v[1]; 00029 B=m->emission.v[2]+m->ambient.v[2]*c->ambient_light_model.v[2]; 00030 A=clampf(m->diffuse.v[3],0,1); 00031 00032 for(l=c->first_light;l!=NULL;l=l->next) { 00033 PN_stdfloat lR,lB,lG; 00034 00035 /* ambient */ 00036 lR=l->ambient.v[0] * m->ambient.v[0]; 00037 lG=l->ambient.v[1] * m->ambient.v[1]; 00038 lB=l->ambient.v[2] * m->ambient.v[2]; 00039 00040 if (l->position.v[3] == 0) { 00041 /* light at infinity */ 00042 d.v[0]=l->position.v[0]; 00043 d.v[1]=l->position.v[1]; 00044 d.v[2]=l->position.v[2]; 00045 att=1; 00046 } else { 00047 /* distance attenuation */ 00048 d.v[0]=l->position.v[0]-v->ec.v[0]; 00049 d.v[1]=l->position.v[1]-v->ec.v[1]; 00050 d.v[2]=l->position.v[2]-v->ec.v[2]; 00051 dist = sqrtf(d.v[0]*d.v[0]+d.v[1]*d.v[1]+d.v[2]*d.v[2]); 00052 if (dist>1E-3) { 00053 tmp=1/dist; 00054 d.v[0]*=tmp; 00055 d.v[1]*=tmp; 00056 d.v[2]*=tmp; 00057 } 00058 att=1.0f/(l->attenuation[0]+dist*(l->attenuation[1]+ 00059 dist*l->attenuation[2])); 00060 } 00061 dot=d.v[0]*n.v[0]+d.v[1]*n.v[1]+d.v[2]*n.v[2]; 00062 if (twoside && dot < 0) dot = -dot; 00063 if (dot>0) { 00064 /* diffuse light */ 00065 lR+=dot * l->diffuse.v[0] * m->diffuse.v[0]; 00066 lG+=dot * l->diffuse.v[1] * m->diffuse.v[1]; 00067 lB+=dot * l->diffuse.v[2] * m->diffuse.v[2]; 00068 00069 /* spot light */ 00070 if (l->spot_cutoff != 180) { 00071 dot_spot=-(d.v[0]*l->norm_spot_direction.v[0]+ 00072 d.v[1]*l->norm_spot_direction.v[1]+ 00073 d.v[2]*l->norm_spot_direction.v[2]); 00074 if (twoside && dot_spot < 0) dot_spot = -dot_spot; 00075 if (dot_spot < l->cos_spot_cutoff) { 00076 /* no contribution */ 00077 continue; 00078 } else { 00079 /* TODO: optimize */ 00080 if (l->spot_exponent > 0) { 00081 att=att*pow(dot_spot,l->spot_exponent); 00082 } 00083 } 00084 } 00085 00086 /* specular light */ 00087 00088 if (c->local_light_model) { 00089 V3 vcoord; 00090 vcoord.v[0]=v->ec.v[0]; 00091 vcoord.v[1]=v->ec.v[1]; 00092 vcoord.v[2]=v->ec.v[2]; 00093 gl_V3_Norm(&vcoord); 00094 s.v[0]=d.v[0]-vcoord.v[0]; 00095 s.v[1]=d.v[1]-vcoord.v[0]; 00096 s.v[2]=d.v[2]-vcoord.v[0]; 00097 } else { 00098 s.v[0]=d.v[0]; 00099 s.v[1]=d.v[1]; 00100 s.v[2]=d.v[2]+1.0f; 00101 } 00102 dot_spec=n.v[0]*s.v[0]+n.v[1]*s.v[1]+n.v[2]*s.v[2]; 00103 if (twoside && dot_spec < 0) dot_spec = -dot_spec; 00104 if (dot_spec>0) { 00105 GLSpecBuf *specbuf; 00106 int idx; 00107 tmp=sqrt(s.v[0]*s.v[0]+s.v[1]*s.v[1]+s.v[2]*s.v[2]); 00108 if (tmp > 1E-3) { 00109 dot_spec=dot_spec / tmp; 00110 } 00111 00112 /* TODO: optimize */ 00113 /* testing specular buffer code */ 00114 /* dot_spec= pow(dot_spec,m->shininess);*/ 00115 specbuf = specbuf_get_buffer(c, m->shininess_i, m->shininess); 00116 idx = (int)(dot_spec*SPECULAR_BUFFER_SIZE); 00117 if (idx > SPECULAR_BUFFER_SIZE) idx = SPECULAR_BUFFER_SIZE; 00118 dot_spec = specbuf->buf[idx]; 00119 lR+=dot_spec * l->specular.v[0] * m->specular.v[0]; 00120 lG+=dot_spec * l->specular.v[1] * m->specular.v[1]; 00121 lB+=dot_spec * l->specular.v[2] * m->specular.v[2]; 00122 } 00123 } 00124 00125 R+=att * lR; 00126 G+=att * lG; 00127 B+=att * lB; 00128 } 00129 00130 v->color.v[0]=clampf(R,0,1); 00131 v->color.v[1]=clampf(G,0,1); 00132 v->color.v[2]=clampf(B,0,1); 00133 v->color.v[3]=A; 00134 } 00135