// Link statically with GLEW #define GLEW_STATIC // Headers #include #include #include #include #include #include #include // Shader sources const GLchar* vertexSource = R"glsl( #version 150 core in vec2 position; in vec3 color; in vec2 texcoord; out vec3 Color; out vec2 Texcoord; uniform mat4 model; uniform mat4 view; uniform mat4 proj; void main() { Color = color; Texcoord = texcoord; gl_Position = proj * view * model * vec4(position, 0.0, 1.0); } )glsl"; const GLchar* fragmentSource = R"glsl( #version 150 core in vec3 Color; in vec2 Texcoord; out vec4 outColor; uniform sampler2D texKitten; uniform sampler2D texPuppy; void main() { outColor = mix(texture(texKitten, Texcoord), texture(texPuppy, Texcoord), 0.5); } )glsl"; int main() { auto t_start = std::chrono::high_resolution_clock::now(); sf::ContextSettings settings; settings.depthBits = 24; settings.stencilBits = 8; settings.majorVersion = 3; settings.minorVersion = 2; sf::Window window(sf::VideoMode(800, 600, 32), "OpenGL", sf::Style::Titlebar | sf::Style::Close, settings); // Initialize GLEW glewExperimental = GL_TRUE; glewInit(); // Create Vertex Array Object GLuint vao; glGenVertexArrays(1, &vao); glBindVertexArray(vao); // Create a Vertex Buffer Object and copy the vertex data to it GLuint vbo; glGenBuffers(1, &vbo); GLfloat vertices[] = { // Position Color Texcoords -0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, // Top-left 0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // Top-right 0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, // Bottom-right -0.5f, -0.5f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f // Bottom-left }; glBindBuffer(GL_ARRAY_BUFFER, vbo); glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW); // Create an element array GLuint ebo; glGenBuffers(1, &ebo); GLuint elements[] = { 0, 1, 2, 2, 3, 0 }; glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo); glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(elements), elements, GL_STATIC_DRAW); // Create and compile the vertex shader GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER); glShaderSource(vertexShader, 1, &vertexSource, NULL); glCompileShader(vertexShader); // Create and compile the fragment shader GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER); glShaderSource(fragmentShader, 1, &fragmentSource, NULL); glCompileShader(fragmentShader); // Link the vertex and fragment shader into a shader program GLuint shaderProgram = glCreateProgram(); glAttachShader(shaderProgram, vertexShader); glAttachShader(shaderProgram, fragmentShader); glBindFragDataLocation(shaderProgram, 0, "outColor"); glLinkProgram(shaderProgram); glUseProgram(shaderProgram); // Specify the layout of the vertex data GLint posAttrib = glGetAttribLocation(shaderProgram, "position"); glEnableVertexAttribArray(posAttrib); glVertexAttribPointer(posAttrib, 2, GL_FLOAT, GL_FALSE, 7 * sizeof(GLfloat), 0); GLint colAttrib = glGetAttribLocation(shaderProgram, "color"); glEnableVertexAttribArray(colAttrib); glVertexAttribPointer(colAttrib, 3, GL_FLOAT, GL_FALSE, 7 * sizeof(GLfloat), (void*)(2 * sizeof(GLfloat))); GLint texAttrib = glGetAttribLocation(shaderProgram, "texcoord"); glEnableVertexAttribArray(texAttrib); glVertexAttribPointer(texAttrib, 2, GL_FLOAT, GL_FALSE, 7 * sizeof(GLfloat), (void*)(5 * sizeof(GLfloat))); // Load textures GLuint textures[2]; glGenTextures(2, textures); int width, height; unsigned char* image; glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, textures[0]); image = SOIL_load_image("sample.png", &width, &height, 0, SOIL_LOAD_RGB); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image); SOIL_free_image_data(image); glUniform1i(glGetUniformLocation(shaderProgram, "texKitten"), 0); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, textures[1]); image = SOIL_load_image("sample2.png", &width, &height, 0, SOIL_LOAD_RGB); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image); SOIL_free_image_data(image); glUniform1i(glGetUniformLocation(shaderProgram, "texPuppy"), 1); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); GLint uniModel = glGetUniformLocation(shaderProgram, "model"); // Set up projection glm::mat4 view = glm::lookAt( glm::vec3(1.2f, 1.2f, 1.2f), glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f, 0.0f, 1.0f) ); GLint uniView = glGetUniformLocation(shaderProgram, "view"); glUniformMatrix4fv(uniView, 1, GL_FALSE, glm::value_ptr(view)); glm::mat4 proj = glm::perspective(glm::radians(45.0f), 800.0f / 600.0f, 1.0f, 10.0f); GLint uniProj = glGetUniformLocation(shaderProgram, "proj"); glUniformMatrix4fv(uniProj, 1, GL_FALSE, glm::value_ptr(proj)); bool running = true; while (running) { sf::Event windowEvent; while (window.pollEvent(windowEvent)) { switch (windowEvent.type) { case sf::Event::Closed: running = false; break; } } // Clear the screen to black glClearColor(0.0f, 0.0f, 0.0f, 1.0f); glClear(GL_COLOR_BUFFER_BIT); // Calculate transformation auto t_now = std::chrono::high_resolution_clock::now(); float time = std::chrono::duration_cast>(t_now - t_start).count(); glm::mat4 model = glm::mat4(1.0f); model = glm::rotate( model, time * glm::radians(180.0f), glm::vec3(0.0f, 0.0f, 1.0f) ); glUniformMatrix4fv(uniModel, 1, GL_FALSE, glm::value_ptr(model)); // Draw a rectangle from the 2 triangles using 6 indices glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0); // Swap buffers window.display(); } glDeleteTextures(2, textures); glDeleteProgram(shaderProgram); glDeleteShader(fragmentShader); glDeleteShader(vertexShader); glDeleteBuffers(1, &ebo); glDeleteBuffers(1, &vbo); glDeleteVertexArrays(1, &vao); window.close(); return 0; }