transform_lights_vs.glsl

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/**
 * @file
 * @brief Transform lights to the tangent space. Requires light_vs.glsl and lerp_vs.glsl.
 */
 
uniform vec3 SUNDIRECTION;
out_qualifier vec3 sunDir; /** < Direction towards the sun, in tangent space */
 
out_qualifier vec3 eyedir;
 
#define R_DYNAMIC_LIGHTS #replace r_dynamic_lights
#if r_dynamic_lights
uniform vec3 LIGHTPOSITIONS[R_DYNAMIC_LIGHTS];
out_qualifier vec3 lightDirs[R_DYNAMIC_LIGHTS];
#endif
 
/**
 * @brief TransformLights
 */
void TransformLights(void) {
    /* Load the tangent.*/
    vec3 tangent = normalize(gl_NormalMatrix * Tangent.xyz);
    /* Compute the bitangent.*/
    vec3 bitangent = normalize(cross(normal, tangent)) * Tangent.w;
 
    /* Transform the eye direction into tangent space.*/
    vec3 v;
    v.x = dot(-point, tangent);
    v.y = dot(-point, bitangent);
    v.z = dot(-point, normal);
 
    eyedir = normalize(v);
 
    /* transform sun direction to tangent space */
    sunDir.x = dot(SUNDIRECTION, tangent);
    sunDir.y = dot(SUNDIRECTION, bitangent);
    sunDir.z = dot(SUNDIRECTION, normal);
 
    /* Transform relative light positions into tangent space.*/
    vec3 lpos;
#unroll r_dynamic_lights
    lpos = LIGHTPOSITIONS[$] - point;
 
    lightDirs[$].x = dot(lpos, tangent);
    lightDirs[$].y = dot(lpos, bitangent);
    lightDirs[$].z = dot(lpos, normal);
#endunroll
}