/*
 *      Gem-graph OpenGL experiments
 *
 *      Desc: OpenGL utils header
 *
 *  Copyright (C) 2023 Arthur Menges <arthur.menges@a-lec.org>
 *  Copyright (C) 2023 Adrien Bourmault <neox@a-lec.org>
 *
 *  This file is part of Gem-graph.
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#pragma once
#include <unistd.h>
#include <stdbool.h>
#include <GL/glu.h>

/*
 * Structure describing a gl_area and its parameters, used to create a table
 * of Gem-graph client current gl_areas
 */
struct gl_area_entry {
    char name[16];
    GLuint vao;             //  init_buffers
    GLuint position_buffer; //  shutdown, draw
    GLuint color_buffer;    //  shutdown, draw
    GLuint program;         //  shutdown, init_shaders, draw
    GLuint m;               //  init_shaders, draw
    GLuint v;               //  init_shaders, draw
    GLuint p;               //  init_shaders, draw
    GLuint line_indices_nb; //  init_buffers, draw, compute_space, arrow_2D, 3D
    GLuint plan_indices_nb; //  init_buffers, draw, compute_space, arrow_2D, 3D
};

/*
 * Initializes a gl_area
 *
 * @param   gl_area, ptr to the gl_area widget
 *
 * @return  true if initialized
 */
bool graphics_init(const char *gl_area);

/*
 * Draws the current buffer to a gl_area
 *
 * @param   gl_area, ptr to the gl_area widget
 *
 * @return  void
 */
void graphics_draw(const void *gl_area);

/*
 * Shutdowns a gl_area
 *
 * @param   gl_area, ptr to the gl_area widget
 *
 * @return  true if success
 */
bool graphics_shutdown(const void *gl_area);

/*
 * Initializes the shaders of a gl_area and link them to a program
 *
 * @param   gl_area, ptr to the gl_area widget
 *
 *
 * @return  true if initialized
 */
bool graphics_init_shaders(const void *gl_area);

/*
 * Initializes the buffer of a gl_area
 *
 * @param   gl_area, ptr to the gl_area widget
 *
 * Note : indices[] is defined in graphics_cube.h
 *
 * @return  void
 */
void graphics_init_buffers(const void *gl_area);