c++ - 在 Ubuntu 上使用 OpenGL 显示闪烁

Question

我目前正在使用 GLFW3 和 GLAD 生成器使用 C++ 开发一个简单的 OpenGl 应用程序。当我运行该程序时，我的整个显示屏都在闪烁黑色。我该如何解决这个问题？

#include "include/glad.h"
#include <GLFW/glfw3.h>

#include <iostream>


void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow *window);

// settings
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;

int main()
{
    // glfw: initialize and configure
    // ------------------------------
    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT,           "LearnOpenGL", NULL, NULL);
if (window == NULL)
{
    std::cout << "Failed to create GLFW window" << std::endl;
    glfwTerminate();
    return -1;
}
glfwMakeContextCurrent(window);
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

// glad: load all OpenGL function pointers
// ---------------------------------------
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
{
    std::cout << "Failed to initialize GLAD" << std::endl;
    return -1;
}

// render loop
// -----------
while (!glfwWindowShouldClose(window))
{
    // input
    // -----
    processInput(window);

    // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
    // -------------------------------------------------------------------------------
    glfwSwapBuffers(window);
    glfwPollEvents();
}

// glfw: terminate, clearing all previously allocated GLFW resources.
// ------------------------------------------------------------------
glfwTerminate();
return 0;
}

// process all input: query GLFW whether relevant keys are     pressed/released this frame and react accordingly
// ---------------------------------------------------------------------------------------------------------
void processInput(GLFWwindow *window)
{
    if(glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
        glfwSetWindowShouldClose(window, true);
}

// glfw: whenever the window size changed (by OS or user resize) this callback function executes
// ---------------------------------------------------------------------------------------------
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
    // make sure the viewport matches the new window dimensions; note that width and
    // height will be significantly larger than specified on retina displays.
    glViewport(0, 0, width, height);
}

这是我的 glxinfo | grep OpenGl

OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Sandybridge Mobile 
OpenGL core profile version string: 3.3 (Core Profile) Mesa 17.0.7
OpenGL core profile shading language version string: 3.30
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
OpenGL version string: 3.0 Mesa 17.0.7
OpenGL shading language version string: 1.30
OpenGL context flags: (none)
OpenGL extensions:
OpenGL ES profile version string: OpenGL ES 3.0 Mesa 17.0.7
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.00
OpenGL ES profile extensions:

我想这个问题与 OpenGL 设置不仅影响我的项目，而且影响整个系统这一事实有关。所以我想知道，这是我的代码问题还是我的硬件问题 - 只有系统升级才能解决这种可怕的闪烁问题。

Answer 1

您的代码缺少绘图命令。您应该在处理输入之后但在交换缓冲区之前将绘图命令添加到渲染循环中。

例如用蓝色填充背景

    ...
    while (!glfwWindowShouldClose(window))
    {
        processInput(window);

        glClearColor(0.0f, 0.0f, 1.0f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        glfwSwapBuffers(window);
        glfwPollEvents();
    }
    ...