const int n_lights = 2;
struct LightParams
{
	vec3 direction;
	vec3 color;
};
uniform Lighting
{
	LightParams lights[n_lights];
};
uniform vec3 ambient;
uniform mat4 model_matrix;
uniform mat4 view_matrix;
uniform mat4 proj_matrix;

#pragma MSP stage(vertex)
layout(location=0) in vec4 position;
layout(location=1) in vec3 normal;
out vec3 eye_light_dir[n_lights];
void main()
{
	for(int i=0; i<n_lights; ++i)
		eye_light_dir[i] = mat3(view_matrix)*lights[i].direction;
	out vec3 eye_normal = mat3(view_matrix*model_matrix)*normal;
	gl_Position = proj_matrix*view_matrix*model_matrix*position;
}

#pragma MSP stage(fragment)
layout(location=0) out vec4 frag_color;
void main()
{
	vec3 color = ambient;
	for(int i=0; i<n_lights; ++i)
		color += max(dot(normalize(eye_normal), eye_light_dir[i]), 0.0)*lights[i].color;
	frag_color = vec4(color, 1.0);
}

/* Expected output: vertex
struct LightParams
{
  vec3 direction;
  vec3 color;
};
layout(binding=5) uniform Lighting
{
  LightParams lights[2];
};
layout(location=0) uniform mat4 model_matrix;
layout(location=4) uniform mat4 view_matrix;
layout(location=8) uniform mat4 proj_matrix;
layout(location=0) in vec4 position;
layout(location=1) in vec3 normal;
layout(location=0) out vec3 eye_light_dir[2];
layout(location=2) out vec3 eye_normal;
void main()
{
  for(int i = 0; i<2; ++i)
    eye_light_dir[i] = mat3(view_matrix[0].xyz, view_matrix[1].xyz, view_matrix[2].xyz)*lights[i].direction;
  mat4 _temp = view_matrix*model_matrix;
  eye_normal = mat3(_temp[0].xyz, _temp[1].xyz, _temp[2].xyz)*normal;
  gl_Position = proj_matrix*view_matrix*model_matrix*position;
}
*/

/* Expected output: fragment
struct LightParams
{
  vec3 direction;
  vec3 color;
};
layout(binding=5) uniform Lighting
{
  LightParams lights[2];
};
layout(location=12) uniform vec3 ambient;
layout(location=0) out vec4 frag_color;
layout(location=2) in vec3 eye_normal;
layout(location=0) in vec3 eye_light_dir[2];
void main()
{
  vec3 color = ambient;
  for(int i = 0; i<2; ++i)
    color += max(dot(normalize(eye_normal), eye_light_dir[i]), 0.0)*lights[i].color;
  frag_color = vec4(color, 1.0);
}
*/