transform_lights_vs.glsl

Go to the documentation of this file.

/**
 * @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
}