| //======================================================================== |
| // OpenGL triangle example |
| // Copyright (c) Camilla Löwy <elmindreda@glfw.org> |
| // |
| // This software is provided 'as-is', without any express or implied |
| // warranty. In no event will the authors be held liable for any damages |
| // arising from the use of this software. |
| // |
| // Permission is granted to anyone to use this software for any purpose, |
| // including commercial applications, and to alter it and redistribute it |
| // freely, subject to the following restrictions: |
| // |
| // 1. The origin of this software must not be misrepresented; you must not |
| // claim that you wrote the original software. If you use this software |
| // in a product, an acknowledgment in the product documentation would |
| // be appreciated but is not required. |
| // |
| // 2. Altered source versions must be plainly marked as such, and must not |
| // be misrepresented as being the original software. |
| // |
| // 3. This notice may not be removed or altered from any source |
| // distribution. |
| // |
| //======================================================================== |
| //! [code] |
| |
| #define GLAD_GL_IMPLEMENTATION |
| #include <glad/gl.h> |
| #define GLFW_INCLUDE_NONE |
| #include <GLFW/glfw3.h> |
| |
| #include "linmath.h" |
| |
| #include <stdlib.h> |
| #include <stddef.h> |
| #include <stdio.h> |
| |
| typedef struct Vertex |
| { |
| vec2 pos; |
| vec3 col; |
| } Vertex; |
| |
| static const Vertex vertices[3] = |
| { |
| { { -0.6f, -0.4f }, { 1.f, 0.f, 0.f } }, |
| { { 0.6f, -0.4f }, { 0.f, 1.f, 0.f } }, |
| { { 0.f, 0.6f }, { 0.f, 0.f, 1.f } } |
| }; |
| |
| static const char* vertex_shader_text = |
| "#version 330\n" |
| "uniform mat4 MVP;\n" |
| "in vec3 vCol;\n" |
| "in vec2 vPos;\n" |
| "out vec3 color;\n" |
| "void main()\n" |
| "{\n" |
| " gl_Position = MVP * vec4(vPos, 0.0, 1.0);\n" |
| " color = vCol;\n" |
| "}\n"; |
| |
| static const char* fragment_shader_text = |
| "#version 330\n" |
| "in vec3 color;\n" |
| "out vec4 fragment;\n" |
| "void main()\n" |
| "{\n" |
| " fragment = vec4(color, 1.0);\n" |
| "}\n"; |
| |
| static void error_callback(int error, const char* description) |
| { |
| fprintf(stderr, "Error: %s\n", description); |
| } |
| |
| static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods) |
| { |
| if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS) |
| glfwSetWindowShouldClose(window, GLFW_TRUE); |
| } |
| |
| int main(void) |
| { |
| glfwSetErrorCallback(error_callback); |
| |
| if (!glfwInit()) |
| exit(EXIT_FAILURE); |
| |
| glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); |
| glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); |
| glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); |
| |
| GLFWwindow* window = glfwCreateWindow(640, 480, "OpenGL Triangle", NULL, NULL); |
| if (!window) |
| { |
| glfwTerminate(); |
| exit(EXIT_FAILURE); |
| } |
| |
| glfwSetKeyCallback(window, key_callback); |
| |
| glfwMakeContextCurrent(window); |
| gladLoadGL(glfwGetProcAddress); |
| glfwSwapInterval(1); |
| |
| // NOTE: OpenGL error checks have been omitted for brevity |
| |
| GLuint vertex_buffer; |
| glGenBuffers(1, &vertex_buffer); |
| glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer); |
| glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW); |
| |
| const GLuint vertex_shader = glCreateShader(GL_VERTEX_SHADER); |
| glShaderSource(vertex_shader, 1, &vertex_shader_text, NULL); |
| glCompileShader(vertex_shader); |
| |
| const GLuint fragment_shader = glCreateShader(GL_FRAGMENT_SHADER); |
| glShaderSource(fragment_shader, 1, &fragment_shader_text, NULL); |
| glCompileShader(fragment_shader); |
| |
| const GLuint program = glCreateProgram(); |
| glAttachShader(program, vertex_shader); |
| glAttachShader(program, fragment_shader); |
| glLinkProgram(program); |
| |
| const GLint mvp_location = glGetUniformLocation(program, "MVP"); |
| const GLint vpos_location = glGetAttribLocation(program, "vPos"); |
| const GLint vcol_location = glGetAttribLocation(program, "vCol"); |
| |
| GLuint vertex_array; |
| glGenVertexArrays(1, &vertex_array); |
| glBindVertexArray(vertex_array); |
| glEnableVertexAttribArray(vpos_location); |
| glVertexAttribPointer(vpos_location, 2, GL_FLOAT, GL_FALSE, |
| sizeof(Vertex), (void*) offsetof(Vertex, pos)); |
| glEnableVertexAttribArray(vcol_location); |
| glVertexAttribPointer(vcol_location, 3, GL_FLOAT, GL_FALSE, |
| sizeof(Vertex), (void*) offsetof(Vertex, col)); |
| |
| while (!glfwWindowShouldClose(window)) |
| { |
| int width, height; |
| glfwGetFramebufferSize(window, &width, &height); |
| const float ratio = width / (float) height; |
| |
| glViewport(0, 0, width, height); |
| glClear(GL_COLOR_BUFFER_BIT); |
| |
| mat4x4 m, p, mvp; |
| mat4x4_identity(m); |
| mat4x4_rotate_Z(m, m, (float) glfwGetTime()); |
| mat4x4_ortho(p, -ratio, ratio, -1.f, 1.f, 1.f, -1.f); |
| mat4x4_mul(mvp, p, m); |
| |
| glUseProgram(program); |
| glUniformMatrix4fv(mvp_location, 1, GL_FALSE, (const GLfloat*) &mvp); |
| glBindVertexArray(vertex_array); |
| glDrawArrays(GL_TRIANGLES, 0, 3); |
| |
| glfwSwapBuffers(window); |
| glfwPollEvents(); |
| } |
| |
| glfwDestroyWindow(window); |
| |
| glfwTerminate(); |
| exit(EXIT_SUCCESS); |
| } |
| |
| //! [code] |