universe@44: /*
universe@44:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@44:  * Copyright 2023 Mike Becker. All rights reserved.
universe@44:  *
universe@44:  * Redistribution and use in source and binary forms, with or without
universe@44:  * modification, are permitted provided that the following conditions are met:
universe@44:  *
universe@44:  *   1. Redistributions of source code must retain the above copyright
universe@44:  *      notice, this list of conditions and the following disclaimer.
universe@44:  *
universe@44:  *   2. Redistributions in binary form must reproduce the above copyright
universe@44:  *      notice, this list of conditions and the following disclaimer in the
universe@44:  *      documentation and/or other materials provided with the distribution.
universe@44:  *
universe@44:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@44:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@44:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@44:  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@44:  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@44:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@44:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@44:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@44:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@44:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@44:  * POSSIBILITY OF SUCH DAMAGE.
universe@44:  */
universe@44: 
universe@44: #include "ascension/glcontext.h"
universe@44: #include "ascension/error.h"
universe@44: 
universe@44: #include <cx/printf.h>
universe@44: 
universe@44: #include <GL/glew.h>
universe@44: 
universe@44: static void asc_gl_debug_callback(
universe@44:         GLenum source, GLenum type, GLuint id, GLenum severity,
universe@44:         GLsizei length, const GLchar* message,
universe@44:         const void* userParam
universe@44: ) {
universe@44:     cxmutstr buf = cx_asprintf(
universe@44:             "source = %d, id = %u, type = %d, severity= %d, message = %.*s",
universe@44:             source, id, type, severity, length, message);
universe@44:     if (type == GL_DEBUG_TYPE_ERROR) {
universe@44:         asc_error(buf.ptr);
universe@44:     } else {
universe@44:         asc_dprintf("GL debug: %.*s", (int)buf.length, buf.ptr);
universe@44:     }
universe@44:     cx_strfree(&buf);
universe@44: }
universe@44: 
universe@44: static void asc_shader_initialize_predefined(AscGLContext *ctx) {
universe@44:     AscShaderSprite *sprite = &ctx->shader.sprite;
universe@44:     sprite->base = asc_shader_easy_compile_and_link("shader/sprite_vtx.glsl", "shader/sprite_frag.glsl");
universe@44:     sprite->depth = glGetUniformLocation(sprite->base.id, "depth");
universe@50:     sprite->tex = glGetUniformLocation(sprite->base.id, "texture");
universe@44: }
universe@44: 
universe@44: static void asc_shader_destroy_predefined(AscGLContext *ctx) {
universe@44:     asc_shader_program_destroy(ctx->shader.sprite.base);
universe@44: }
universe@44: 
universe@44: bool asc_gl_context_initialize(
universe@44:         AscGLContext *ctx,
universe@44:         SDL_Window *window,
universe@44:         AscGLContextSettings const *settings
universe@44: ) {
universe@44:     SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
universe@44:     SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, settings->gl_major_version);
universe@44:     SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, settings->gl_minor_version);
universe@44:     SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, settings->depth_size);
universe@44:     SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
universe@44:     ctx->glctx = SDL_GL_CreateContext(window);
universe@44:     if (ctx->glctx == NULL) return false;
universe@44:     ctx->window = window;
universe@44: 
universe@44:     glewExperimental = GL_TRUE;
universe@44:     GLenum err = glewInit();
universe@44:     if (err == GLEW_OK) {
universe@44:         SDL_GL_SetSwapInterval(settings->vsync);
universe@44: 
universe@44:         glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
universe@44:         glEnable(GL_DEBUG_OUTPUT);
universe@44:         glDebugMessageCallback(asc_gl_debug_callback, NULL);
universe@44: 
universe@44:         if (!asc_primitives_init(&ctx->primitives)) {
universe@44:             asc_error("Creating primitive meshes failed");
universe@44:             SDL_GL_DeleteContext(ctx->glctx);
universe@44:             return false;
universe@44:         }
universe@44: 
universe@44:         asc_shader_initialize_predefined(ctx);
universe@44: 
universe@44:         return true;
universe@44:     } else {
universe@44:         asc_error(glewGetErrorString(err));
universe@44:         SDL_GL_DeleteContext(ctx->glctx);
universe@44:         return false;
universe@44:     }
universe@44: }
universe@44: 
universe@44: void asc_gl_context_destroy(AscGLContext *ctx) {
universe@44:     if (ctx->glctx == NULL) return;
universe@44:     SDL_GL_MakeCurrent(ctx->window, ctx->glctx);
universe@44: 
universe@44:     asc_shader_destroy_predefined(ctx);
universe@44:     asc_primitives_destroy(&ctx->primitives);
universe@44: 
universe@44:     // destroy the GL context and the window
universe@44:     SDL_GL_DeleteContext(ctx->glctx);
universe@44:     ctx->glctx = NULL;
universe@44: }