T03_UseShaderClass.cpp

#include "T03_UseShaderClass.h"

void T03_UseShaderClass() {
    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    GLFWwindow *pWindow = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "T03_UseShaderClass", nullptr, nullptr);
    glfwMakeContextCurrent(pWindow);
    glfwSetFramebufferSizeCallback(pWindow, framebuffer_size_callback);
    gladLoadGLLoader((GLADloadproc)glfwGetProcAddress);

    Shader ourShader(GLSL"T03_shader.vs", GLSL"T03_shader.fs"); // you can name your shader files however you like

    float vertices[] = {
        // positions         // colors
        0.5f, -0.5f, 0.0f,  1.0f, 0.0f, 0.0f,  // bottom right
        -0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f,  // bottom left
        0.0f,  0.5f, 0.0f,  0.0f, 0.0f, 1.0f   // top
    };
    unsigned int VBO, VAO;
    glGenVertexArrays(1, &VAO);
    glGenBuffers(1, &VBO);
    // bind the Vertex Array Object first, then bind and set vertex buffer(s), and then configure vertex attributes(s).
    glBindVertexArray(VAO);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
    // position attribute
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void *)0);
    glEnableVertexAttribArray(0);
    // color attribute
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void *)(3* sizeof(float)));
    glEnableVertexAttribArray(1);

    // 激活
    ourShader.use();
    float offset = 0.5f;
    glUniform1f(glGetUniformLocation(ourShader.m_progID, "xOffset"), offset);

    while (!glfwWindowShouldClose(pWindow)) {
        processInput(pWindow);

        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        // render the triangle
        ourShader.use();
        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES, 0, 3);

        glfwSwapBuffers(pWindow);
        glfwPollEvents();
    }
    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);
    glfwTerminate();
}