void lambert() { #if LIGHTING_IN_WORLD_SPACE const vec3 POSITION = surface.position.world; const vec3 NORMAL = surface.normal.world; #else const vec3 POSITION = surface.position.eye; const vec3 NORMAL = surface.normal.eye; #endif // outcoming light from surface to eye const vec3 Lo = normalize( -POSITION ); for ( uint i = 0, shadows = 0; i < MAX_LIGHTS; ++i ) { #if BAKING // skip if surface is a dynamic light, we aren't baking dynamic lights if ( lights[i].type < 0 ) continue; // shouldn't ever need this, but in the event we hit the end of the buffer and everything after is corrupted if ( lights[i].type <= 0 ) break; #else // skip if surface is already baked, and this isn't a dynamic light if ( surface.material.lightmapped && lights[i].type >= 0 ) continue; #endif // incoming light to surface (non-const to normalize it later) #if LIGHTING_IN_WORLD_SPACE vec3 Li = lights[i].position - POSITION; #else vec3 Li = vec3(VIEW_MATRIX * vec4(lights[i].position, 1)) - POSITION; #endif // magnitude of incoming light vector (for inverse-square attenuation) const float Lmagnitude = dot(Li, Li); // distance incoming light travels (reuse from above) const float Ldistance = sqrt(Lmagnitude); // "free" normalization, since we need to compute the above values anyways Li = Li / Ldistance; // attenuation factor const float Lattenuation = 1.0 / (1 + Lmagnitude); // skip if attenuation factor is too low // if ( Lattenuation <= LIGHT_POWER_CUTOFF ) continue; // ray cast if our surface is occluded from the light const float Lshadow = shadowFactor( lights[i], 0.0 ); // skip if our shadow factor is too low // if ( Lshadow <= LIGHT_POWER_CUTOFF ) continue; // in case of any divergence // light radiance const vec3 Lr = lights[i].color.rgb * lights[i].power * Lattenuation * Lshadow; // skip if our radiance is too low // if ( Lr <= LIGHT_POWER_CUTOFF ) continue; // angle of incoming light const float cosLi = DOT(NORMAL, Li); const vec3 diffuse = surface.material.albedo.rgb; const vec3 specular = vec3(0); surface.light.rgb += (diffuse + specular) * Lr * cosLi; surface.light.a += lights[i].power * Lattenuation * Lshadow; } }