static inline void validate_light(ogles_context_t* c)
{
// if colorMaterial is enabled, we get the color from the vertex
if (!c->lighting.colorMaterial.enable) {
material_t& material = c->lighting.front;
uint32_t en = c->lighting.enabledLights;
while (en) {
const int i = 31 - gglClz(en);
en &= ~(1<<i);
light_t& l = c->lighting.lights[i];
vmul3(l.implicitAmbient.v, material.ambient.v, l.ambient.v);
vmul3(l.implicitDiffuse.v, material.diffuse.v, l.diffuse.v);
vmul3(l.implicitSpecular.v, material.specular.v, l.specular.v);
// this is just a flag to tell if we have a specular component
l.implicitSpecular.v[3] =
l.implicitSpecular.r |
l.implicitSpecular.g |
l.implicitSpecular.b;
l.rConstAttenuation = (l.attenuation[1] | l.attenuation[2])==0;
if (l.rConstAttenuation)
l.rConstAttenuation = gglRecipFast(l.attenuation[0]);
}
// emission and ambient for the whole scene
vmla3( c->lighting.implicitSceneEmissionAndAmbient.v,
c->lighting.lightModel.ambient.v,
material.ambient.v,
material.emission.v);
c->lighting.implicitSceneEmissionAndAmbient.a = material.diffuse.a;
}
validate_light_mvi(c);
}
void lightVertexMaterial(ogles_context_t* c, vertex_t* v)
{
// fetch the material color
const GLvoid* cp = c->arrays.color.element(
v->index & vertex_cache_t::INDEX_MASK);
c->arrays.color.fetch(c, v->color.v, cp);
// acquire the color-material from the vertex
material_t& material = c->lighting.front;
material.ambient =
material.diffuse = v->color;
// implicit arguments need to be computed per/vertex
uint32_t en = c->lighting.enabledLights;
while (en) {
const int i = 31 - gglClz(en);
en &= ~(1<<i);
light_t& l = c->lighting.lights[i];
vmul3(l.implicitAmbient.v, material.ambient.v, l.ambient.v);
vmul3(l.implicitDiffuse.v, material.diffuse.v, l.diffuse.v);
vmul3(l.implicitSpecular.v, material.specular.v, l.specular.v);
// this is just a flag to tell if we have a specular component
l.implicitSpecular.v[3] =
l.implicitSpecular.r |
l.implicitSpecular.g |
l.implicitSpecular.b;
}
// emission and ambient for the whole scene
vmla3( c->lighting.implicitSceneEmissionAndAmbient.v,
c->lighting.lightModel.ambient.v,
material.ambient.v,
material.emission.v);
c->lighting.implicitSceneEmissionAndAmbient.a = material.diffuse.a;
// now we can light our vertex as usual
lightVertex(c, v);
}
static void
compute_lighting (GLcontext *g, GL_float color[4], GL_float position[4],
GL_float normal[3], GL_material *material)
{
GL_float projpos[4];
GL_float primary[4];
GL_float secondary[4];
GL_float ambient[3];
GL_float diffuse[3] = { 0.0f, 0.0f, 0.0f };
GL_float specular[3] = { 0.0f, 0.0f, 0.0f };
GL_float temp[3];
GL_float E[3];
int i;
/* projected position */
if (position[3] == 0.0f) {
if (position[3] < 0.0f)
vscale3(projpos, position, -1.0f);
else
vcopy3(projpos, position);
vnorm3(projpos, projpos);
}
else {
GL_float scale = 1.0f / position[3];
vscale3(projpos, position, scale);
}
/* global ambient */
vinit3_col(ambient, g->lighting.lightmodelambient);
/* eye vector */
if (g->lighting.lightmodellocalviewer) {
vscale3(E, projpos, -1.0f);
vnorm3(E, E);
}
else {
vinit3(E, 0.0f, 0.0f, 1.0f);
}
/* lights */
for (i = 0; i < g->lighting.maxlights; i++) {
GLlight *light = &g->lighting.light[i];
if (light->enable) {
GL_float lightpos[4];
GL_float L[3], H[3];
GL_float kd, ks;
GL_float atten = 1.0f;
GL_float dist, distsq;
/* light position */
vinit_vec(lightpos, light->position);
/* light vector */
if (lightpos[3] == 0.0f) {
if (lightpos[3] < 0.0f)
vscale3(L, lightpos, -1.0f);
else
vcopy3(L, lightpos);
vnorm3(L, L);
if (position[3] == 0.0f) {
vsub3(L, L, projpos);
vnorm3(L, L);
}
}
else {
if (position[3] == 0.0f)
vscale3(L, projpos, -1.0f);
else {
GL_float scale = 1.0f / lightpos[3];
vscale3(L, lightpos, scale);
vsub3(L, L, projpos);
distsq = vdot3(L, L);
dist = sqrt(distsq);
scale = 1.0f / dist;
vscale(L, L, scale);
}
}
/* halfangle vector */
vadd3(H, L, E);
vnorm3(H, H);
/* diffuse reflection coefficient */
kd = vdot3(normal, L);
kd = max(kd, 0.0f);
/* specular reflection coefficient */
ks = vdot3(normal, H);
ks = max(ks, 0.0f);
ks = (kd > 0.0f) * pow(ks, material->shininess);
/* attenuation */
if (lightpos[3] != 0.0f) {
GL_float ac = light->constantattenuation;
GL_float al = light->linearattenuation;
GL_float aq = light->quadraticattenuation;
if (position[3] != 0.0f)
atten /= (ac + al * dist + aq * distsq);
else if (al == 0.0f && aq == 0.0f)
atten /= ac;
else
atten = 0.0f;
}
/* spot factor */
if (light->spotcutoff != 180.0f) {
GL_float S[3], exponent, cutoffcos, anglecos;
vinit3_vec(S, light->spotdirection);
exponent = light->spotexponent;
cutoffcos = cos(light->spotcutoff);
anglecos = -vdot3(L, S);
anglecos = max(anglecos, 0.0f);
if (anglecos < cutoffcos)
atten *= pow(anglecos, exponent);
else
atten = 0.0f;
}
/* accumulate ambient */
vinit3_col(temp, light->ambient);
vscale3(temp, temp, atten);
vadd3(ambient, ambient, temp);
/* accumulate diffuse */
vinit3_col(temp, light->diffuse);
vscale3(temp, temp, kd * atten);
vadd3(diffuse, diffuse, temp);
/* accumulate specular */
vinit3_col(temp, light->specular);
vscale3(temp, temp, ks * atten);
vadd3(specular, specular, temp);
}
}
/* primary color */
vcopy3(primary, material->emission);
vmul3(ambient, ambient, material->ambient);
vadd3(primary, primary, ambient);
vmul3(diffuse, diffuse, material->diffuse);
vadd3(primary, primary, diffuse);
primary[3] = material->diffuse[3];
/* secondary color */
vmul3(secondary, specular, material->specular);
secondary[3] = 0.0f;
/* computer overall color, no separate specular */
vadd(color, primary, secondary);
}
