src/ascension/glcontext.h

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * Copyright 2023 Mike Becker. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef ASCENSION_GLCONTEXT_H
#define ASCENSION_GLCONTEXT_H

#include <SDL2/SDL.h>

#include "primitives.h"
#include "shader.h"
#include "texture.h"

#include <cx/mempool.h>

typedef struct AscGLContextSettings {
    int gl_major_version;
    int gl_minor_version;
    int vsync;
    int depth_size;
} AscGLContextSettings;

enum AscDefaultPrimitives {
    ASC_PRIMITIVE_PLANE_IDX = 0,
    ASC_PRIMITIVE_COUNT
};

enum AscDefaultTextures2d {
    ASC_TEXTURE_2D_EMPTY_1X1_IDX = 0,
    ASC_TEXTURE_2D_COUNT
};

enum AscDefaultTexturesRect {
    ASC_TEXTURE_RECT_EMPTY_1X1_IDX = 0,
    ASC_TEXTURE_RECT_COUNT
};

typedef struct AscGLContext {
    SDL_Window *window;
    CxMempool *mpool;
    SDL_GLContext glctx;
    AscMesh primitives[ASC_PRIMITIVE_COUNT];
    AscTexture textures_2d[ASC_TEXTURE_2D_COUNT];
    AscTexture textures_rect[ASC_TEXTURE_RECT_COUNT];
    struct {
        AscShaderSprite sprite;
    } shader;
} AscGLContext;

#define asc_active_glctx (&asc_active_window->glctx)
#define asc_active_glctx_mpool asc_active_window->glctx.mpool
#define ASC_PRIMITIVE_PLANE (&asc_active_glctx->primitives[ASC_PRIMITIVE_PLANE_IDX])
#define ASC_TEXTURE_2D_EMPTY_1X1 (&asc_active_glctx->textures_2d[ASC_TEXTURE_2D_EMPTY_1X1_IDX])
#define ASC_TEXTURE_RECT_EMPTY_1X1 (&asc_active_glctx->textures_rect[ASC_TEXTURE_RECT_EMPTY_1X1_IDX])
#define ASC_SHADER_SPRITE (&asc_active_glctx->shader.sprite)

__attribute__((__nonnull__, __warn_unused_result__))
bool asc_gl_context_initialize(
        AscGLContext *ctx,
        SDL_Window *window,
        AscGLContextSettings const *settings
);

__attribute__((__nonnull__))
void asc_gl_context_destroy(AscGLContext *ctx);

__attribute__((__nonnull__))
static inline void asc_gl_context_activate(AscGLContext *ctx) {
    SDL_GL_MakeCurrent(ctx->window, ctx->glctx);
}

#endif //ASCENSION_GLCONTEXT_H