Question

首先，我是开放式的初学者，我正在从learnopengl.com学习opengl。所以我理解主要方法中的代码中发生了什么。代码在main方法中工作。但是当我试图为它创建一个类时，它不会呈现任何东西！我完全不知道什么是错的！

Sprite.h

    #pragma once

#include"Shader.h"
#include<GL\glew.h>

class Sprite {
    GLuint vao;
    GLuint vbo;

    int vertexCount;

    Shader shader;

public:

    Sprite(const GLfloat vertices[9], int noOfVertices, Shader s = Shader()) : vertexCount(noOfVertices) , shader(s)
    {

        glGenVertexArrays(1, &vao);
        glGenBuffers(1, &vbo);

        glBindVertexArray(vao);
        glBindBuffer(GL_ARRAY_BUFFER, vbo);
        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

        glVertexAttribPointer(0, this->vertexCount, GL_FLOAT, GL_FALSE, 0, nullptr);
        glEnableVertexAttribArray(0);
        glBindBuffer(GL_ARRAY_BUFFER, 0);

        glBindVertexArray(0);
    }

    void draw() {
        glBindVertexArray(this->vao);
        glDrawArrays(GL_TRIANGLES, 0, this->vertexCount);
        glBindVertexArray(0);
    }
};

Shader.h

#pragma once
#include<iostream>
#include<fstream>
#include<sstream>
#include<string>
#include<vector>

#include<GL\glew.h>

class Shader {
    GLuint programID;

    GLuint vertID;
    GLuint fragID;

public:
    Shader(std::string vertex = "Shaders/Dvert.vert", std::string fragment = "Shaders/Dfrag.frag")
    {
        this->programID = glCreateProgram();
        this->vertID = glCreateShader(GL_VERTEX_SHADER);
        this->fragID = glCreateShader(GL_FRAGMENT_SHADER);

        this->CompileShaders(vertex, fragment);
        this->LinkProgram();
    }

    GLuint getProgramId() {
        return this->programID;
    }

private:

    void CompileShaders(std::string vertexShaderPath, std::string FragShaderPath) {

        std::string vCode = GetContentsFrom(vertexShaderPath).c_str();
        const char * vertexCode = vCode.c_str();
        glShaderSource(this->vertID, 1, &vertexCode, NULL);
        glCompileShader(this->vertID);

        this->HandleShaderErrors(this->vertID);

        std::string fCode = GetContentsFrom(FragShaderPath).c_str();
        const char * fragCode = fCode.c_str();
        glShaderSource(this->fragID, 1, &fragCode, NULL);
        glCompileShader(this->fragID);

        std::cout << fragCode << std::endl;

        this->HandleShaderErrors(this->fragID);
    }

    void LinkProgram() {
        glAttachShader(this->programID, this->vertID);
        glAttachShader(this->programID, this->fragID);

        glLinkProgram(this->programID);
        this->HandleLinkErrors();
    }

    std::string GetContentsFrom(std::string path) {
        std::ifstream file(path);
        std::ostringstream stream;

        if (!file) {
            std::cout << "Specified file path is invalid" << std::endl;
            return "";
        }
        stream << file.rdbuf();

        std::cout << stream.str() << std::endl << std::endl;

        return stream.str();
    }

    void HandleLinkErrors() {
        int result;
        glGetProgramiv(this->programID, GL_LINK_STATUS, &result);

        if (result == GL_FALSE) {
            int length;
            glGetProgramiv(this->programID, GL_INFO_LOG_LENGTH, &length);

            std::vector<char> error(length);

            glGetProgramInfoLog(this->programID, length , &length, &error[0]);
            std::cout << &error[0] << std::endl;

            glDetachShader(this->programID, this->vertID);
            glDetachShader(this->programID, this->fragID);
        }
    }

    void HandleShaderErrors(GLuint shader) {
        int status;
        glGetShaderiv(shader, GL_COMPILE_STATUS, &status);

        if (status == GL_FALSE) {
            int length;
            glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &length);

            std::vector<char> error(length);

            glGetShaderInfoLog(shader, length, &length, &error[0]);
            std::cout << &error[0] << std::endl;

            glDeleteShader(shader);
        }
    }
};

Main.cpp的

#include<GL\glew.h>
#include<GLFW\glfw3.h>

#include"Console.h"
#include"Headers\Shader.h"
#include"Headers\Sprite.h"

#include<iostream>

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

 int main() {
     if (!glfwInit()) {
         Console.Log("GLFW could not be initialised!!");
         Console.Wait();
     }

     GLFWwindow *window = glfwCreateWindow(600, 400, "Open GL", nullptr, nullptr);
     glfwMakeContextCurrent(window);

     if (glewInit() != GLEW_OK) {
         Console.Log("GLEW could not be initialised!!");
         Console.Wait();
     }

     Sprite s(vertices, 3);

     glClearColor(0, 0, 0, 1);
     glfwWindowHint(GLFW_VERSION_MAJOR, 3);
     glfwWindowHint(GLFW_VERSION_MINOR, 3);

     while (!glfwWindowShouldClose(window)) {
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
         glfwPollEvents();
         s.draw();
         glfwSwapBuffers(window);
     }
 }

请帮帮我!!

注意： - main方法中的代码渲染没有的白色三角形着色器，所以我的显卡没有着色器。

我创建的Console类也只是打印到控制台而与opengl没什么关系。 Console.Log isstd :: cout＆lt;＆lt;和Console.Wait是std :: cin.get（）;

Answer 1

至少有两个问题。第一个是Sprite中的sizeof(vertices)产生错误的结果，因为它给出了指针的大小，而不是数组的大小。要解决此问题，请将其替换为sizeof(GLfloat) * 9。

第二个问题是，在创建窗口和上下文之后，您太晚指定了OpenGL上下文版本。要解决此问题，请在glfwCreateWindow之前调用这些方法，而不是在之后：

glfwWindowHint(GLFW_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_VERSION_MINOR, 3);

打开gl sprite类不起作用

1 个答案: