OpenGL 程序不断崩溃？

Question

This code returns 3 errors (literally all the errors) GLEW init failed; GLFW init failed; Window creation failed GLEW init failed; GLFW init failed; Window creation failed GLEW init failed; GLFW init failed; Window creation failed :

#include "GL/glew.h"
#include "GLFW/glfw3.h"

#include <iostream>


//Window dimensions
const GLint SCREEN_WIDTH = 800, SCREEN_HEIGHT = 600;


int main() {
    //Initialize GLFW
    if (glfwInit() != GLEW_OK) { 
        std::cout << "GLFW init failed\n"; 
        glfwTerminate(); 
    }


    //Setup GLFW window properties
    //OpenGL version
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); //Large version
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); //Small version 
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); //Detects any old OpenGL code, this will throw an error
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); //Allows forward compatibility (between differnt OS) 


    //Creating window
    GLFWwindow* window; 
    window = glfwCreateWindow(SCREEN_WIDTH, SCREEN_HEIGHT, "OpenGL Test Window", NULL, NULL);
    if (window == NULL) {
        std::cout << "GLFW window creation failed!\n";
        glfwTerminate();
    }

    //Get buffer size information
    int BUFFER_WIDTH, BUFFER_HEIGHT;
    glfwGetFramebufferSize(window, &BUFFER_WIDTH, &BUFFER_HEIGHT);

    //Set context for GLEW to use (can change between which window)
    glfwMakeContextCurrent(window);

    //Allow modern extension features
    glewExperimental = GL_TRUE;


    if (glfwInit() != GLEW_OK) {
        std::cout << "Glew init failed!\n";
        glfwDestroyWindow(window);
        glfwTerminate();
    }


    //Setup viewport size
    glViewport(0, 0, BUFFER_WIDTH, BUFFER_HEIGHT);



    //Main game loop
    while (!glfwWindowShouldClose(window)) {
        //Get + Handle user input events
        glfwPollEvents();

        //Clear window
        glClearColor(1.f, 0.f, 0.f, 1.f);
        glClear(GL_COLOR_BUFFER_BIT);

        glfwSwapBuffers(window);
    }
}

Answer 1

This is wrong:

 if (glfwInit():= GLEW_OK) { std:;cout << "GLFW init failed\n"; glfwTerminate(); }

GLEW_OK is defined as 0 (See https://github.com/nigels-com/glew/blob/master/auto/src/glew_tail.h )

So this is evaluated as follows: if (glfwInit() != 0) which will only be true if GLFW did initialize properly.

So change that part to:

if (glfwInit() == 0) { 
    std::cout << "GLFW init failed\n"; 
    glfwTerminate(); 
}

Answer 2

Try this, you need to initialize Glew.

GLenum GlewInitResult;
GlewInitResult = glewInit();
if ( GLEW_OK != GlewInitResult) 
{
    glfwTerminate();
    return -1;
}

Answer 3

There are 2 issues.

glfwInit returns GLFW_TRUE if it succeeds ( GLFW_TRUE is 1). So it has to be:

if (glfwInit() != GLFW_TRUE) { 
    std::cout << "GLFW init failed\n"; 
}

(Note, if GLFW failed to initialize, then there is no need to call glfwTerminate() )

If you want to install GLEW , then you've to call glewInit rather than glfwInit . glewInit returns GLEW_OK , if it succeeds (see Initializing GLEW ). GLEW_OK is 0. So it has to be:

if (glewInit() != GLEW_OK) {

    std::cout << "Glew init failed!\n";
    glfwDestroyWindow(window);
    glfwTerminate();
}