OpenGL 读取,使用 .vert .frag 着色器 文件 C++

本文作用：

　　写一个读取OpenGL里面 .vert .frag 这些文件的读取器。

　　

读取函数代码:

//.frag .vert文件读取
char* readTheFile(string strSource) {
    //fstream 中判断是否成功打开文件
    //https://blog.csdn.net/fruitz/article/details/41624921
    std::ifstream myfile(strSource);
    //打开失败
    if (myfile.fail()) {
        std::cout << "Can not open it " << std::endl;
        throw new runtime_error("IO stream corrupted");
    }
    //转换成字符串
    std::string str((std::istreambuf_iterator<char>(myfile)),
        std::istreambuf_iterator<char>());
    //关闭文件处理器
    myfile.close();
    //str数组长度一定要 +1,
    /*原因: https://blog.csdn.net/ShiQW5696/article/details/80676290 */
    int len = str.length();
    char* result = new char[len];
    strcpy_s(result, len + 1, str.c_str());
    return result;
}

　　

另一种的着色器 Shader类管理方法(读取方法类似)

https://www.cnblogs.com/--zz/p/9704454.html

完整测试代码:

vertexShaderSource.vert

#version 330 core
layout(location = 0) in vec3 aPos;

OpenGLDemo.cpp

// OpenGLDemo.cpp: 定义控制台应用程序的入口点。

#include "stdafx.h"
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <fstream>
#include <string>
#include <cstring>

using namespace std;

void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow* window);
char* readTheFile(string strSource);

//读取函数代码
const char* vertexShaderSource = readTheFile("vertexShaderSource.vert");

class MyTriangle {
public:
    float vertices[9] = {
        .5f,.5f,.0f,
        -.5f,.5f,.0f,
        .0f,-.5f,.0f
    };
    void draw() {
        //生成缓冲对象 ID:VBO
        unsigned int VBO;
        glGenBuffers(1, &VBO);
        //将缓冲对象 绑定到GL_ARRAY_BUFFER目标
        glBindBuffer(GL_ARRAY_BUFFER, VBO);
        //定义顶点数据复制到缓冲内存
        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

        //创建一个顶点着色器对象
        unsigned int vertexShader;
        vertexShader = glCreateShader(GL_VERTEX_SHADER);

        //着色器源码附着到着色器对象上
        glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
        //编译着色器对象
        glCompileShader(vertexShader);
        
        //检测着色编译是否成功
        int success;
        char infoLog[22];
        glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
        if (!success) {
            glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
            std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED
" << infoLog << std::endl;
        }
    }
};

int main()
{
    printf("%sA", vertexShaderSource);
    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR,3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR,3);
    glfwWindowHint(GLFW_OPENGL_PROFILE,GLFW_OPENGL_CORE_PROFILE);
    GLFWwindow* window = glfwCreateWindow(800, 600, "Oh!I see you!", NULL, NULL);
    if (window == NULL) {
        std::cout << "Failed to create the windows" << std::endl;
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);
    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
        std::cout << "Failed to initialize GLAD" << std::endl;
        return -1;
    }

    MyTriangle myTriangle;
    myTriangle.draw();

    while (!glfwWindowShouldClose(window)) {

        //输入处理
        processInput(window);

        //渲染指令
        glClearColor(0.2f,0.3f,0.3f,1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    glfwTerminate();
    return 0;
}

void framebuffer_size_callback(GLFWwindow* windows, int width, int height) {
    glViewport(0, 0, width, height);
}

void processInput(GLFWwindow* window) {
    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) {
        glfwSetWindowShouldClose(window, true);
    }
}

//.frag .vert文件读取
char* readTheFile(string strSource) {
    std::ifstream t(strSource);
    std::string str((std::istreambuf_iterator<char>(t)),
        std::istreambuf_iterator<char>());
    //str数组长度一定要 +1,
    /*原因: https://blog.csdn.net/ShiQW5696/article/details/80676290 */
    int len = str.length();
    char* result = new char[len];
    strcpy_s(result, len + 1, str.c_str());
    return result;
}