ref: ad3df4d5903c43c9ae12e2d3fb7176f074d84eec
dir: /src/light.c/
#include "msghandling.h"
#include "zgl.h"
void glopMaterial(GLContext* c, GLParam* p) {
GLint mode = p[1].i;
GLint type = p[2].i;
GLfloat v[4];
v[0] = p[3].f;
v[1] = p[4].f;
v[2] = p[5].f;
v[3] = p[6].f;
GLint 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] = clampf(v[i],0,1);
break;
case GL_AMBIENT:
for (i = 0; i < 4; i++)
m->ambient.v[i] = clampf(v[i],0,1);
break;
case GL_DIFFUSE:
for (i = 0; i < 4; i++)
m->diffuse.v[i] = clampf(v[i],0,1);
break;
case GL_SPECULAR:
for (i = 0; i < 4; i++)
m->specular.v[i] = clampf(v[i],0,1);
break;
case GL_SHININESS:
m->shininess = v[0];
#if TGL_FEATURE_SPECULAR_BUFFERS == 1
m->shininess_i = (v[0] / 128.0f) * SPECULAR_BUFFER_SIZE;
#endif
break;
case GL_AMBIENT_AND_DIFFUSE:
for (i = 0; i < 4; i++)
m->diffuse.v[i] = clampf(v[i],0,1);
for (i = 0; i < 4; i++)
m->ambient.v[i] = clampf(v[i],0,1);
break;
#if TGL_FEATURE_ERROR_CHECK == 1
default:
#define ERROR_FLAG GL_INVALID_ENUM
#include "error_check.h"
#else
//default: return;
#endif
}
}
void glopColorMaterial(GLContext* c, GLParam* p) {
GLint mode = p[1].i;
GLint type = p[2].i;
c->current_color_material_mode = mode;
c->current_color_material_type = type;
}
void glopLight(GLContext* c, GLParam* p) {
GLint light = p[1].i;
GLint type = p[2].i;
V4 v;
GLLight* l;
GLint i;
//assert(light >= GL_LIGHT0 && light < GL_LIGHT0 + MAX_LIGHTS);
#if TGL_FEATURE_ERROR_CHECK == 1
if(!(light >= GL_LIGHT0 && light < GL_LIGHT0 + MAX_LIGHTS))
#define ERROR_FLAG GL_INVALID_OPERATION
#include "error_check.h"
#else
// if(!(light >= GL_LIGHT0 && light < GL_LIGHT0 + MAX_LIGHTS)) return;
#endif
l = &c->lights[light - GL_LIGHT0];
for (i = 0; i < 4; i++)
if(type != GL_POSITION && type != GL_SPOT_DIRECTION && type != GL_SPOT_EXPONENT &&
type != GL_SPOT_CUTOFF &&
type != GL_LINEAR_ATTENUATION && type != GL_CONSTANT_ATTENUATION && type != GL_QUADRATIC_ATTENUATION)
v.v[i] = clampf(p[3 + i].f,0,1);
else
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);
gl_V3_Norm_Fast(&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_Fast(&l->norm_spot_direction);
break;
case GL_SPOT_EXPONENT:
l->spot_exponent = v.v[0];
break;
case GL_SPOT_CUTOFF: {
GLfloat a = v.v[0];
#if TGL_FEATURE_ERROR_CHECK == 1
#define ERROR_FLAG GL_INVALID_VALUE
#include "error_check.h"
#else
//assert(a == 180 || (a >= 0 && a <= 90));
#endif
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:
#if TGL_FEATURE_ERROR_CHECK == 1
#define ERROR_FLAG GL_INVALID_ENUM
#include "error_check.h"
#endif
return;
}
}
void glopLightModel(GLContext* c, GLParam* p) {
GLint pname = p[1].i;
GLint* v = &p[2].i;
GLint i;
switch (pname) {
case GL_LIGHT_MODEL_AMBIENT:
for (i = 0; i < 4; i++)
c->ambient_light_model.v[i] = p[2 + i].f;
break;
case GL_LIGHT_MODEL_LOCAL_VIEWER:
c->local_light_model = (GLint)v[0];
break;
case GL_LIGHT_MODEL_TWO_SIDE:
c->light_model_two_side = (GLint)v[0];
break;
default:
#if TGL_FEATURE_ERROR_CHECK == 1
#define ERROR_FLAG GL_INVALID_ENUM
#include "error_check.h"
#endif
// tgl_warning("glopLightModel: illegal pname: 0x%x\n", pname);
// assert(0);
break;
}
}
void gl_enable_disable_light(GLContext* c, GLint light, GLint 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
void glSetEnableSpecular(GLint s) {
#include "error_check_no_context.h"
gl_get_context()->zEnableSpecular = s;
}
/* non optimized lightening model */
void gl_shade_vertex(GLContext* c, GLVertex* v) {
GLfloat R, G, B, A;
GLMaterial* m;
GLLight* l;
V3 n, s, d;
GLfloat dist, tmp, att, dot, dot_spot, dot_spec;
GLint 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 = m->diffuse.v[3];
for (l = c->first_light; l != NULL; l = l->next) {
GLfloat 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 */
// Fixed by Gek, it used to use the unnormalized position?
d.X = l->norm_position.v[0];
d.Y = l->norm_position.v[1];
d.Z = l->norm_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];
#if TGL_FEATURE_FISR == 1
tmp = fastInvSqrt(d.X * d.X + d.Y * d.Y + d.Z * d.Z); //FISR IMPL, MATCHED!
dist = 1.0f/tmp;
if (dist > 1E-3) {
d.X *= tmp;
d.Y *= tmp;
d.Z *= tmp;
}
#else
dist = sqrt(d.X * d.X + d.Y * d.Y + d.Z * d.Z);
//dist = 1.0f/tmp;
if (dist > 1E-3) {
tmp = 1 / dist;
d.X *= tmp;
d.Y *= tmp;
d.Z *= tmp;
}
#endif
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: pow table for spot_exponent?*/
if (l->spot_exponent > 0) {
att = att * pow(dot_spot, l->spot_exponent);
}
}
// GEK SAYS TO REMOVE THIS
// printf("\nThis should not be being called.");
}
/* specular light */
if (c->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);
gl_V3_Norm_Fast(&vcoord);
s.X = d.X - vcoord.X;
s.Y = d.Y - vcoord.X;
s.Z = d.Z - vcoord.X;
} else {
//BLINN-PHONG SHADING: We're doing lighting calculations in Eye coordinates, this is ViewDir + LightDir
s.X = d.X; //+0.0
s.Y = d.Y; //+0.0
s.Z = d.Z - 1.0;
//s.Z = d.Z + 1.0; //Verified that this is... "supposed" to be the right thing...
//s.Z = d.Z;
}
//dot_spec is dot(surfaceNormal, H)
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) {
#if TGL_FEATURE_SPECULAR_BUFFERS == 1
GLSpecBuf* specbuf;
GLint idx;
#endif
dot_spec = clampf(dot_spec, 0, 1);
#if TGL_FEATURE_FISR == 1
tmp = fastInvSqrt(s.X * s.X + s.Y * s.Y + s.Z * s.Z); //FISR IMPL, MATCHED!
if (tmp < 1E+3) {
dot_spec = dot_spec * tmp;
} else dot_spec = 0;
#else
//reference implementation.
tmp= sqrt(s.X*s.X+s.Y*s.Y+s.Z*s.Z);
if (tmp > 1E-3) {
dot_spec=dot_spec / tmp;
} else dot_spec = 0;
#endif
/* dot_spec= pow(dot_spec,m->shininess);*/
#if TGL_FEATURE_SPECULAR_BUFFERS == 1
specbuf = specbuf_get_buffer(c, m->shininess_i, m->shininess);
//Check for GL_OUT_OF_MEMORY
#if TGL_FEATURE_ERROR_CHECK == 1
#include "error_check.h"
#endif
#else
dot_spec= pow(dot_spec,m->shininess);
#endif
#if TGL_FEATURE_SPECULAR_BUFFERS == 1
idx = (GLint)(dot_spec * SPECULAR_BUFFER_SIZE);
if (idx > SPECULAR_BUFFER_SIZE)
idx = SPECULAR_BUFFER_SIZE; //NOTE by GEK: this is poorly written, it's actually 1 larger.
dot_spec = specbuf->buf[idx];
#endif
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;
}