#pragma once

#include <GL/glew.h>
#include <glm/glm.hpp>


typedef uint32_t u32;


struct gl_uniform
{
	GLenum id;
	GLenum data_type;
};

struct gl_buffer
{
	GLuint id;
	GLenum data_type;
};

struct shader
{
	GLuint prog_id;
	GLuint xforms_ubo_id;
};

struct transforms
{
	glm::mat4 view_xform;
	glm::mat4 proj_xform;
	glm::mat4 normal_xform;
};

enum glsl_layout
{
	POSITION,
	NORMAL,
	UV,
	COLOR
};

struct mesh
{
	u32 num_vertices;
	u32 num_indices;
	glm::vec3* vertices;
	glm::vec3* normals;
	glm::vec3* uvs;
	glm::vec3* colors;
	u32* indices;
};

struct gl_mesh
{
	u32 num_indices;
	GLuint vao_id;
	GLuint tex_id;
	GLenum draw_mode;

	glm::mat4* model_xform;
	GLuint model_xform_id;

	GLuint vert_buf_id;
	GLuint norm_buf_id;
	GLuint uv_buf_id;
	GLuint clr_buf_id;
	GLuint idx_buf_id;
};

struct node;
struct entity;
struct light;
struct animation;


const float DEFAULT_FOV = 60.f;
const float NEAR_CLIP_PLANE = 5.f;
const float DEFAULT_ASPECT_RATIO = 16.f / 9.f;
const glm::vec3 DEFAULT_CAM_POS = { 0, 0, -30.f };
const glm::vec3 DEFAULT_LOOK_POS = { 0, 0, 0 };


bool loadShaderProgram(const char* vs, const char* fs, shader* s);
transforms initXformUBO(shader* s,
	float fov = DEFAULT_FOV,
	float near_clip_plane = NEAR_CLIP_PLANE,
	float aspect_ratio = DEFAULT_ASPECT_RATIO,
	glm::vec3 cam_pos = DEFAULT_CAM_POS,
	glm::vec3 look_pos = DEFAULT_LOOK_POS);
mesh initCubeMesh();
gl_mesh loadGLMesh(shader* s, const mesh& m, const glm::vec3& pos);
void loop(shader* s, gl_mesh* mesh_arr, u32 num_meshes);
void quit(shader* s);