v4k-git-backup/engine/art/shaderlib/light.glsl

136 lines
3.7 KiB
GLSL

uniform int u_num_lights;
struct light_t {
int type;
vec3 diffuse;
vec3 specular;
vec3 ambient;
vec3 pos;
vec3 dir;
float power;
float radius;
float innerCone;
float outerCone;
// falloff
float constant;
float linear;
float quadratic;
};
#define MAX_LIGHTS 16
const int LIGHT_DIRECTIONAL = 0;
const int LIGHT_POINT = 1;
const int LIGHT_SPOT = 2;
uniform light_t u_lights[MAX_LIGHTS];
#ifdef SHADING_PHONG
vec3 shading_phong(light_t l) {
vec3 lightDir;
float attenuation = 1.0;
if (l.type == LIGHT_DIRECTIONAL) {
lightDir = normalize(-l.dir);
} else if (l.type == LIGHT_POINT || l.type == LIGHT_SPOT) {
vec3 toLight = l.pos - v_position_ws;
lightDir = normalize(toLight);
float distance = length(toLight);
/* fast-reject based on radius */
if (l.radius != 0.0 && distance > l.radius) {
return vec3(0,0,0);
}
attenuation = 1.0 / (l.constant + l.linear * distance + l.quadratic * (distance * distance));
if (l.type == LIGHT_SPOT) {
float angle = dot(l.dir, -lightDir);
if (angle > l.outerCone) {
float intensity = (angle-l.outerCone)/(l.innerCone-l.outerCone);
attenuation *= clamp(intensity, 0.0, 1.0);
} else {
attenuation = 0.0;
}
}
}
// fast-rejection for faraway vertices
if (attenuation <= 0.01) {
return vec3(0,0,0);
}
vec3 n = normalize(v_normal_ws);
float diffuse = max(dot(n, lightDir), 0.0);
vec3 halfVec = normalize(lightDir + u_cam_dir);
float specular = pow(max(dot(n, halfVec), 0.0), l.power);
return (attenuation*l.ambient + diffuse*attenuation*l.diffuse + specular*attenuation*l.specular);
}
#endif
#ifdef SHADING_VERTEXLIT
vec3 shading_vertexlit(light_t l) {
vec3 lightDir;
float attenuation = 1.0;
if (l.type == LIGHT_DIRECTIONAL) {
lightDir = normalize(-l.dir);
} else if (l.type == LIGHT_POINT || l.type == LIGHT_SPOT) {
vec3 toLight = l.pos - v_position_ws;
lightDir = normalize(toLight);
float distance = length(toLight);
/* fast-reject based on radius */
if (l.radius != 0.0 && distance > l.radius) {
return vec3(0,0,0);
}
attenuation = 1.0 / (l.constant + l.linear * distance + l.quadratic * (distance * distance));
if (l.type == LIGHT_SPOT) {
float angle = dot(l.dir, -lightDir);
if (angle > l.outerCone) {
float intensity = (angle-l.outerCone)/(l.innerCone-l.outerCone);
attenuation *= clamp(intensity, 0.0, 1.0);
} else {
attenuation = 0.0;
}
}
}
// fast-rejection for faraway vertices
if (attenuation <= 0.01) {
return vec3(0,0,0);
}
vec3 n = normalize(v_normal_ws);
float diffuse = max(dot(n, lightDir), 0.0);
vec3 halfVec = normalize(lightDir + u_cam_dir);
float specular = pow(max(dot(n, halfVec), 0.0), l.power);
return (attenuation*l.ambient + diffuse*attenuation*l.diffuse + specular*attenuation*l.specular);
}
#endif
vec3 lighting() {
vec3 lit = vec3(0,0,0);
#ifndef SHADING_NONE
#ifdef SHADING_PHONG
for (int i=0; i<u_num_lights; i++) {
lit += shading_phong(u_lights[i]);
}
#endif
#ifdef SHADING_VERTEXLIT
for (int i=0; i<u_num_lights; i++) {
lit += shading_vertexlit(u_lights[i]);
}
#endif
#ifdef SHADING_PBR
#endif
#endif
return lit;
}