libTangerine/include/shader_program.h

#pragma once

#include <GL/glew.h>


struct default_shader_program
{
	GLuint program_id;

	GLuint model_matrix_id;
	GLuint view_matrix_id;
	GLuint projection_matrix_id;
	GLuint normal_matrix_id;

	GLuint vertex_array_id;
	GLuint sampler_id;
	GLuint num_lights_id;
};

struct simple_shader_program
{
	GLuint program_id;
	GLuint MVP_id;
	GLuint vertex_array_id;
};

enum shader_type
{
	SIMPLE_SHADER = 0,
	DEFAULT_SHADER = 1
};

struct shader_wrapper
{
	shader_type type;
	default_shader_program* default_shader;
	simple_shader_program* simple_shader;
};


// TODO: find a way to initialize different shaders with different
// 	uniform layouts with a single function
//	look at using uniform blocks and retrieving locations with
//	glGetUniformBlockIndex() and their size with glGetActiveUniformBlockiv()
//	see chapter 2 in the red book
simple_shader_program*
shaderInitSimple(const char* vertex_code, const char* frag_code);

default_shader_program*
shaderInitDefault(const char* vertex_code, const char* frag_code);

void shaderFree(uint program_id);