hexgame/src/render_group.h

// TODO: put type info into seperate header from hexgame.h
//#include "types.h"
#include "hexgame.h"


// TODO: can these structs be used as opaque pointers?
struct gl_buffer
{
	GLuint buffer_id = 0;
	size_t buffer_len = 0; // NOTE: number of elements in buffer
	GLfloat* buffer = nullptr;
};

struct gl_index_buffer
{
	GLuint buffer_id = 0;
	size_t buffer_len = 0;
	uint* indices = nullptr;
};

struct gl_render_group
{
	// NOTE: For now the renderFrame function will assume these are the same size
	gl_buffer vertex_buffer;
	gl_buffer color_buffer;
	gl_index_buffer index_buffer;
	GLuint program_id = 0;
	GLuint model_matrix_id = 0;
	GLuint view_matrix_id = 0;
	GLuint projection_matrix_id = 0;
	GLuint vertex_array_id = 0;
};

typedef struct gl_buffer gl_buffer;
typedef struct gl_index_buffer gl_index_buffer;
typedef struct gl_render_group gl_render_group;

gl_render_group* rgCreateGroup();

// NOTE: model_name, view_name, and projection_name should match the matrix variable
// 	names in the shader source
bool rgInitShaderProgram(gl_render_group* rg, const char * vertex_code, const char * frag_code,
	const char* model_name, const char* view_name, const char* projection_name);

void rgInitGLBufferObject(gl_buffer* buf_obj, int len, GLenum usage, GLenum target, GLfloat data[]);

bool rgInitEntity(gl_render_group* rg, Entity* e);

void rgFillColorBuffer(GLfloat buf[], int len, std::vector<hex_info>* hexes);

void rgDraw(gl_render_group* rg, GLenum draw_mode, glm::mat4 model_matrix,
		glm::mat4 view_matrix, glm::mat4 projection_matrix, bool update_vertex_data = false);

void rgDrawIndexed(gl_render_group* rg, GLenum draw_mode, glm::mat4 model_matrix,
		glm::mat4 view_matrix, glm::mat4 projection_matrix, bool update_vertex_data = false);

void rgFree(gl_render_group* rg);