diff --git a/init.c.todo b/init.c.todo new file mode 100644 index 0000000..0a6c3cc --- /dev/null +++ b/init.c.todo @@ -0,0 +1,175 @@ +/* + * Gem-graph OpenGL experiments + * + * Desc: GL functions + * + * Copyright (C) 2023 Arthur Menges + * Copyright (C) 2023 Adrien Bourmault + * + * 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 . + */ + +/* -------------------------------------------------------------------------- */ + +#include +#include +#include "base.h" +#include "contain.h" // instead of "ui.h" +#include "graph_area.h" + +/* Initializes the buffer of a gl_area + * Calls according to the user preferences + * @param gl_area, ptr to the gl_area widget + * @return void + */ +void graphics_init_buffers(const int stack_id) +{ + struct graphic_stack_t *stack = &graphic_stack[stack_id]; + + //XXX + graphics_model_setup(stack_id); + + GLuint vao, vertex_buffer, color_buffer; + + glGenBuffers(1, &vertex_buffer); + glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer); + glBufferData(GL_ARRAY_BUFFER, + stack->buffer_vertex_size * + sizeof(stack->buffer_vertex_origin[0]), + stack->buffer_vertex_origin, + GL_STATIC_DRAW); + glBindBuffer(GL_ARRAY_BUFFER, 0); + + + // colors + glGenBuffers(1, &color_buffer); + glBindBuffer(GL_ARRAY_BUFFER, color_buffer); + glBufferData(GL_ARRAY_BUFFER, stack->buffer_colors_size * + sizeof(stack->buffer_colors_origin[0]), + stack->buffer_colors_origin, + GL_STATIC_DRAW); + glBindBuffer(GL_ARRAY_BUFFER, 0); + + // We only use one VAO, so we always keep it bound + glGenVertexArrays(1, &vao); + glBindVertexArray(vao); + + stack->vao = vao; + stack->position_buffer = vertex_buffer; + stack->color_buffer = color_buffer; +} + +/* + * 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 int stack_id) +{ + struct graphic_stack_t *stack = &graphic_stack[stack_id]; + char *vertex_shader; + char *fragment_shader; + int status; + GLuint vertex, fragment; + GLuint program = 0; + GLuint m = 0; + GLuint v = 0; + GLuint p = 0; + + // Load vertex shader file + vertex_shader = read_file(VERTEX_SHADER_FILE); + if (vertex_shader == NULL) + return false; +////////////////////////// vertex = create_shader(stack_id, GL_VERTEX_SHADER, vertex_shader); + + if(vertex == 0) { + stack->program = 0; + g_free(vertex_shader); + return false; + } + + // Load fragment shader file + fragment_shader = read_file(FRAG_SHADER_FILE); + if (fragment_shader == NULL) + return false; + fragment = create_shader(stack_id, GL_FRAGMENT_SHADER, fragment_shader); + + if(fragment == 0) { + glDeleteShader(vertex); + stack->program = 0; + g_free(vertex_shader); + g_free(fragment_shader); + return false; + } + + // Link shaders to program + program = glCreateProgram(); + glAttachShader(program, vertex); + glAttachShader(program, fragment); + + glLinkProgram(program); + + glGetProgramiv(program, GL_LINK_STATUS, &status); + + if(status == GL_FALSE) { + int log_len; + char *buffer; + + glGetProgramiv(program, GL_INFO_LOG_LENGTH, &log_len); + + buffer = g_malloc(log_len + 1); + assert(buffer); + glGetProgramInfoLog(program, log_len, NULL, buffer); + + g_warning("Linking failure:\n%s", buffer); + + g_free(buffer); + + glDeleteProgram(program); + program = 0; + + glDeleteShader(vertex); + glDeleteShader(fragment); + + g_free(vertex_shader); + g_free(fragment_shader); + + return false; + } + + /* Get the location of the "mvp" uniform */ + m = glGetUniformLocation(program, "model_matrix"); + v = glGetUniformLocation(program, "view_matrix"); + p = glGetUniformLocation(program, "projection_matrix"); + + glDetachShader(program, vertex); + glDetachShader(program, fragment); + + glDeleteShader(vertex); + glDeleteShader(fragment); + + stack->program = program; + stack->m = m; + stack->v = v; + stack->p = p; + + g_free(vertex_shader); + g_free(fragment_shader); + + return true; +}