OpenGL的glClearColor總是黑屏

我試圖運行在C++中，打開一個窗口，我的第一個OpenGL圖像，設置背景顏色，並給出了一個標題，從終端在Mac OS XOpenGL的glClearColor總是黑屏

的代碼編譯和鏈接很好。當我運行該程序時，窗口和標題可以正常打開，但背景顏色始終爲黑色。

據我瞭解，功能glClearColor設置背景顏色。但是，無論我傳遞給函數的參數是什麼，窗口的背景顏色都是黑色的。

如果有人能向我解釋我所犯的錯誤，我將非常感激。感謝和下面是代碼：

#include <iostream> 

#define GLEW_STATIC 
#include <GL/glew.h> 

#include <GLFW/glfw3.h> 

const GLint WIDTH = 800, HEIGHT = 600; 

int main() 
{ 
    glfwInit(); 

    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); 
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); 
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); 
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); 
    glfwWindowHint(GLFW_RESIZABLE, GL_FALSE); 

    GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, "Learn OpenGL", nullptr, nullptr); 

    int screenWidth, screenHeight; 
    glfwGetFramebufferSize(window, &screenWidth, &screenHeight); 

    if(nullptr == window) 
    { 
     std::cout << "Failed to create GLFW window" << '\n'; 
     glfwTerminate(); 

     return -1; 
    } 

    glewExperimental = GL_TRUE; 
    GLenum err=glewInit(); 

    if(err != glewInit()) 
    { 
     std::cout << "Failed to initialize GLEW" << '\n'; 

     return -1; 
    } 

    glViewport(0, 0, screenWidth, screenHeight); 

    while(!glfwWindowShouldClose(window)) 
    { 
     glfwPollEvents(); 

     glClearColor(0.2f, 0.2f, 0.9f, 0.5f); 
     glClear(GL_COLOR_BUFFER_BIT); 

     glfwSwapBuffers(window); 
    } 

    glfwTerminate(); 

    return 0; 
}

來源

2016-11-21 user7147804