https://learnopengl.com 를 구현 프로젝트 입니다.
하나의 솔루션 아래 여러가지 프로젝트로 구성되어 있습니다.
cmake로 빌드된 glfw3.lib가 필요합니다.
윈도우를 생성한후 배경색을 설정함
...
//glfw window 생성
GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
if (window == NULL) {
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
...
//render loop
...
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
...
기본 삼각형
float vertices[] = {
-0.5f, -0.5f, 0.0f,
0.5f, -0.5f, 0.0f,
0.0f, 0.5f, 0.0f
};
...
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
...
//render loop
...
//삼각형 그리기
glUseProgram(orangeTriangle);
glBindVertexArray(VAO[0]);
glDrawArrays(GL_TRIANGLES, 0, 3);
...
float firstTriangle[] = {
-0.9f, -0.5f, 0.0f, // left
-0.0f, -0.5f, 0.0f, // right
-0.45f, 0.5f, 0.0f, // top
};
float secondTriangle[] = {
0.0f, -0.5f, 0.0f, // left
0.9f, -0.5f, 0.0f, // right
0.45f, 0.5f, 0.0f // top
};
...
//render loop
...
glUseProgram(shaderProgram);
glBindVertexArray(VAO);
glDrawArrays(GL_TRIANGLES, 0, 6);
...
unsigned int orangeTriangle = CompileShader(vertexShaderSource, fragmentShaderSource);
unsigned int greenTriangle = CompileShader(vertexShaderSource, fragmentShaderSource2);
...
//삼각형 정점 설정
float vertices[] = {
-0.9f, -0.5f, 0.0f, // left
-0.0f, -0.5f, 0.0f, // right
-0.45f, 0.5f, 0.0f, // top
};
float vertice2[] = {
0.0f, 0.5f, 0.0f, // left
0.9f, 0.5f, 0.0f, // right
0.45f,-0.5f, 0.0f // top
};
...
//render loop
glUseProgram(orangeTriangle);
glBindVertexArray(VAO[0]);
glDrawArrays(GL_TRIANGLES, 0, 3);
glUseProgram(greenTriangle);
glBindVertexArray(VAO[1]);
glDrawArrays(GL_TRIANGLES, 0, 3);
...
float vertices[] = {
0.5f, 0.5f, 0.0f, // 우측 상단
0.5f, -0.5f, 0.0f, // 우측 하단
-0.5f, -0.5f, 0.0f, // 좌측 하단
-0.5f, 0.5f, 0.0f // 좌측 상단
};
unsigned int indices[] = { // 0부터 시작한다는 것을 명심하세요!
0, 1, 3, // 첫 번째 삼각형
1, 2, 3 // 두 번째 삼각형
};
//Vertex Buffer object(VBO),Vertex Array Object(VAO)
unsigned int VBO, VAO, EBO;
//gen
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
glGenBuffers(1, &EBO);
//bind
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
...
//render loop
...
glUseProgram(shaderProgram);
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
shader클래스 추가
//render loop
while (!glfwWindowShouldClose(window))
{
processInput(window);
//gl배경색
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
//삼각형 그리기
progame.use();
float timeValue = glfwGetTime();
float greenValue = sin(timeValue) / 2.0f + 0.5f; //항상 양수
int vertexColorLocation = glGetUniformLocation(progame.ID, "ourColor");
glUniform4f(vertexColorLocation, 0.0f, greenValue, 0.0f, 1.0f);
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0);
glfwSwapBuffers(window);
glfwPollEvents();
}유니폼을 사용한 shader
