openGL GLFW白色屏幕，带运行中的加载光标

Question

问题：启动时，GLWindow仅显示白屏，并且光标显示加载圆圈，表示仍在加载某些内容。 此后不久，窗口显示“无响应”。

我曾尝试将其降级到openGL 3.3，并很乐意提供帮助，但问题仍然存在。

大家好，

我一直在使用顶点着色器创建具有交替颜色的球体。

我在下面共享的代码与用于阴影四边形的代码略有不同，效果很好。 我希望会有类似的逻辑用于阴影圆或构建球体并对其着色的问题。 但是我现在还没有。 某些原因使我的GL窗口无法正确显示，我希望有人可以帮助我处理我的GLFW，并提供逻辑信息，以分享窗口无法加载的原因。

注意：我已经编辑了这段代码，在每个步骤中都包含了注释，这使它看起来比实际的要长得多。 我将不胜感激。

小学班

#include <iostream>
#include <sstream>
#define GLEW_STATIC
    //always GLEW before GLFW
#include "GL/glew.h"    
#include "GLFW/glfw3.h"
#include "glm/glm.hpp"

#include "ShaderProgram.h"

#ifndef M_PI
# define M_PI 3.141592653
#endif


/////gLOBAL
GLFWwindow* w = NULL;
const int wWidth = 800;
const int wHeight = 600;

void key_callback(GLFWwindow *w, int key, int scancode, int action, int mode);
//update colors based on average framerate
void averageFPS(GLFWwindow* window);
//screen resizing
void glfw_onFramebufferSize(GLFWwindow* window, int width, int height);
bool initOpenGL();


static void error(int error, const char *desc)
{
    fputs(desc, stderr);
}
//setting up values for keys


int main() {

    if (!initOpenGL())  ///5IMPR
    {
        // An error occured
        std::cerr << "GLFW not initialized" << std::endl;
        return -1;
    }

    glfwSetErrorCallback(error);


    GLfloat vertices[] = {
        -0.5f,  0.5f, 0.0f,     
        0.5f,  0.5f, 0.0f,      
        -0.5f, 1.0f, 0.0f       
    };

    GLuint indices[] = {
        0, 1, 2,  
        0, 2, 3   
    };

    // 2. Set up buffers on the GPU
    GLuint vbo, ibo, vao;                       

    glGenBuffers(1, &vbo);                  // Generate an empty vertex buffer on the GPU
    glBindBuffer(GL_ARRAY_BUFFER, vbo);     // "bind" or set as the current buffer we are working with
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);  // copy the data from CPU to GPU

    glGenVertexArrays(1, &vao);             // Tell OpenGL to create new Vertex Array Object
    glBindVertexArray(vao);                 // Make it the current one
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL);   // Define a layout for the first vertex buffer "0"
    glEnableVertexAttribArray(0);           // Enable the first attribute or attribute "0"

                                            // Set up index buffer
    glGenBuffers(1, &ibo);  // Create buffer space on the GPU for the index buffer
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);

    glBindVertexArray(0);                   // unbind to make sure other code doesn't change it

    ShaderProgram shaderProgram;        
    shaderProgram.assignShaders("shaders/ColorShader.vert", "shaders/ColorShader.frag"); 

            ////////SETUP RENDERING
    while (!glfwWindowShouldClose(w))
    {
        averageFPS(w);

            //process events
        glfwPollEvents();           

            // Clear the screen
        glClear(GL_COLOR_BUFFER_BIT);   

        shaderProgram.use();    

        GLfloat time = (GLfloat)glfwGetTime();          
        GLfloat blueSetting = (sin(time) / 2) + 0.5f;       
        glm::vec2 pos;
        pos.x = sin(time) / 2;
        pos.y = cos(time) / 2;
        shaderProgram.setUniform("vertColor", glm::vec4(0.0f, 0.0f, blueSetting, 1.0f));    
        shaderProgram.setUniform("posOffset", pos);

            /////COLOR OF CIRCLE OUTLINE
        //glColor4f(0.0, 0.0, 1.0, 1.0); //RGBA

            //PRIMARY BODY
                    // Draw our line
        glBegin(GL_LINE_LOOP);

        //glColor3f(0,0,1);


        static double iteration = 0;
        // The x, y offset onto the screen -- this should later be centered
        static const int offset = 150;

        static const float radius = 50;


        // Calculate our x, y cooredinates
        double x1 = offset + radius + 100 * cos(1);
        double y1 = offset + radius + 100 * sin(1);
        static double wobble = 0.0;


        // A = (π * r²)
        double a = M_PI * (100 * 2);    //area
                                        // C = (2 * π * r)
        double c = 2 * M_PI * 100;  //circumference

        static double b = 128;

        for (double i = 0; i < 2 * M_PI; i = i + ((2 * M_PI) / b))
        {
            double x = x1 + radius * cos(i);

            double y = y1 + radius * sin(i);

            glVertex2f(x, y);

            glVertex2f(x, y);
        }

        iteration += 0.01;

        ////PRIMARY BODY End

        glBindVertexArray(vao);

        glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
            //glDrawElements(GL_LINE_LOOP, 6, GL_UNSIGNED_INT, 0);
        glBindVertexArray(0);
        // Swap buffers and look for events

        glfwSwapBuffers(w);


    }
        //clean up
    glDeleteVertexArrays(1, &vao);
    glDeleteBuffers(1, &vbo);
    glDeleteBuffers(1, &ibo);

    //glfwDestroyWindow(w);
    glfwTerminate();

    return 0;
    }


            ///////START Initializing glfw glew etc
bool initOpenGL(){

    //this method will exit on these conditions
    GLuint error = glfwInit();
    if (!error)
        return false;

    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);


    w = glfwCreateWindow(wWidth, wHeight, "Exercise", NULL, NULL);

    //Filling  Window

    if (w== NULL)
    {
        std::cerr << "glfw window not created" << std::endl;
        glfwTerminate();
        return false;
    }

        //update context
    glfwMakeContextCurrent(w);

    // Initialize GLEWunifor
    glewExperimental = GL_TRUE;
    GLuint err = glewInit();
    if (err != GLEW_OK)
    {
        std::cerr << "initialize GLEW Failed" << std::endl;
        return false;
    }

        //setup key callbacks
    glfwSetKeyCallback(w, key_callback);
    glfwSetFramebufferSizeCallback(w, glfw_onFramebufferSize);

    while (!glfwWindowShouldClose(w))
    {
        //int width, height;
    //  glfwGetFramebufferSize(w, &width, &height); //move out of while??

        // glViewport(0, 0, width, height); //remove??
    }
    glClearColor(0.23f, 0.38f, 0.47f, 1.0f);    ///5ADD

                                                // Define the viewport dimensions
    glViewport(0, 0, wWidth, wHeight);  //necessary?

    return true;

}

void key_callback(GLFWwindow *w, int key, int scancode, int action, int mode)
{
    // See http://www.glfw.org/docs/latest/group__keys.html
    if ((key == GLFW_KEY_ESCAPE || key == GLFW_KEY_Q) && action == GLFW_PRESS)
        glfwSetWindowShouldClose(w, GL_TRUE);

    if (key == GLFW_KEY_W && action == GLFW_PRESS)
    {
        bool showWires = false;
        if (showWires)
            glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
        else
            glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
    }

}

    //whever window resizes, do this
void glfw_onFramebufferSize(GLFWwindow* window, int width, int height)
{
    glViewport(0, 0, width, height);
}

void averageFPS(GLFWwindow* window) ///5ADDdown
{
    static double previousSeconds = 0.0;
    static int frameCount = 0;
    double passedSeconds;
    double currentSeconds = glfwGetTime(); //seconds since GLFW started

    passedSeconds = currentSeconds - previousSeconds;

    // Limit time updates to 4 times per second
    if (passedSeconds > 0.25)
    {
        previousSeconds = currentSeconds;
        double fps = (double)frameCount / passedSeconds;
    //  double frameInMilSecs = 1000.0 / fps;
         frameCount = 0;} 
    frameCount++;
}

着色管理器/处理程序类

#include "ShaderProgram.h"
#include <fstream>
#include <iostream>
#include <sstream>


ShaderProgram::ShaderProgram()
    : mProgram(0){
}


ShaderProgram::~ShaderProgram()
{
    glDeleteProgram(mProgram);
}

bool ShaderProgram::assignShaders(const char* vertFileName, const char* fragFileName)
{
    //Shaders output objects called programs that define their relationship and lead to .exe functionality

    //assigning pointer to the shader

        string vsString = readFile(vertFileName);
        string fsString = readFile(fragFileName);

    const GLchar* fsSourcePtr = fsString.c_str();
    const GLchar* vsSourcePtr = vsString.c_str();

    //creating vertex shader(vs) shader object
    GLuint vs = glCreateShader(GL_VERTEX_SHADER);
    GLuint fs = glCreateShader(GL_FRAGMENT_SHADER);

    //assigning shader source using address. Replaces the source code in a shader object //@arg (shader, count Strings, pointer to const File ,size)
    glShaderSource(vs, 1, &vsSourcePtr, NULL);
    glShaderSource(fs, 1, &fsSourcePtr, NULL);

    glCompileShader(vs);
    glCompileShader(fs);

    testProgramCompile();
    testShaderCompile(vs);
    testShaderCompile(fs);


    //createProgram returns GLUint which is basically an unsigned int... we will use This Handler to create a program object
    mProgram = glCreateProgram();
    if (mProgram == 0)
    {
        std::cerr << "Shader cannot be created" << std::endl;
        return false;
    }
    //assign the program object(mProgram) to the Shader
    glAttachShader(mProgram, vs);
    glAttachShader(mProgram, fs);

    //this method accepts a GLuint "program" . If its an object of type GL_VERTEX_SHADER,
    //itll create a .exe that runs on the programmable vertex processor. same goes for geometric and fragment shaders if they were included
    //it will also bind all user defined uniform variables and attributes to the program 
    //The program can then be made part of a defined state by calling useProgram
    glLinkProgram(mProgram);
    testProgramCompile();
    testShaderCompile(vs);
    testShaderCompile(vs);

    //cleaning up the elements we already used
    glDeleteShader(vs);
    glDeleteShader(fs);

        //clear the identifier lookup map(in this case, there's only one)
    mUniformIdentifiers.clear();

    return true;
}//end main

    //Read the shaderFile. strngstream for reading multiple lines
string ShaderProgram:: readFile(const string& filename) {

    std::stringstream strgstream;
    std::ifstream file;

    try
    {
        file.open(filename, std::ios::in);

        if (!file.fail())
        {
            strgstream << file.rdbuf();
        }

        file.close();
    }
    catch (std::exception e)
    {
        std::cerr << "Error: File or File Name Issues" << std::endl;
    }

    return strgstream.str();
}
    //use the Program Object we created in this current state(color)
void ShaderProgram::use()
{
    if (mProgram != 0)
        glUseProgram(mProgram);
}

void ShaderProgram::testProgramCompile() {
    int status = 0;

    GLuint program = mProgram;

        // ///CHECKING GL_LINK_STATUS to see if Program Link was successul. Link Status will return GL_TRUE if it was
        glGetProgramiv( mProgram, GL_LINK_STATUS, &status); //requesting the status
        if (status == GL_FALSE)
        {

            std::cerr << "Linking Error with Program " << std::endl;
        }

}
void ShaderProgram :: testShaderCompile(GLuint shader) {
    int status = 0;


    // ///CHECKING GL_LINK_STATUS to see if Program Link was successul. Link Status will return GL_TRUE if it was
    glGetProgramiv(shader, GL_LINK_STATUS, &status); //requesting the status
    if (status == GL_FALSE)
    {

        std::cerr << "Linking Error with Shader " << std::endl;
    }

}
////GETTERS AND SETTERS

GLuint ShaderProgram::getProgram() const
{
    return mProgram;
}



void ShaderProgram::setUniform(const GLchar* name, const glm::vec2& v)
{
    GLint address = getUniformIdentifier(name);
    glUniform2f(address, v.x, v.y);
}

void ShaderProgram::setUniform(const GLchar* name, const glm::vec3& v)
{
    GLint address = getUniformIdentifier(name);
    glUniform3f(address, v.x, v.y, v.z);
}

void ShaderProgram:: setUniform(const GLchar* name, const glm::vec4& v) {
    GLint address = getUniformIdentifier(name);
    glUniform4f(address, v.x, v.y, v.z, v.w);
}

//Maybe need to switch places with setUniform
GLint ShaderProgram :: getUniformIdentifier(const GLchar* name) {

    std::map<std::string, GLint>::iterator it;
    it = mUniformIdentifiers.find(name);
    //std::map<std::string, GLint>


        // Only need to query the shader program IF it doesn't already exist.
        if (it == mUniformIdentifiers.end())
        {
            // Find it and add it to the map
            mUniformIdentifiers[name] = glGetUniformLocation(mProgram, name);
        }

        // Return it
        return mUniformIdentifiers[name];
    }

Answer 1

您的init函数中有此功能。

while (!glfwWindowShouldClose(w))
{
    //int width, height;
//  glfwGetFramebufferSize(w, &width, &height); //move out of while??

    // glViewport(0, 0, width, height); //remove??
}

您的代码可能挂在这里了。