Shadow map vertex shader

precision mediump float;

attribute vec3 position;
attribute vec3 normal;
attribute vec2 tex_coord;

// Perspective * View * Model
uniform mat4 scene_mat;

uniform mat4 model_mat;

// transpose(inverse(Model))
uniform mat4 normal_mat;

uniform int has_diffuse;

// Interpolated vertex properties
varying vec3 var_position; // world-space position
varying vec3 var_normal;
varying vec2 var_tex_coord;

void main() {
  gl_Position = scene_mat * vec4(position, 1.0);

  var_position = (model_mat * vec4(position, 1.0)).xyz;
  var_normal = (normal_mat * vec4(normal, 1.0)).xyz;
  if (has_diffuse != 0)
    var_tex_coord = tex_coord;
  else
    var_tex_coord = vec2(0);
}