[游戏开发]Qt-OpenGL-02 着色器Shader类

????????qt已经封装好着色器类，而且挺好用，所以不用自己封装和教程一样的类。包含以下头文件：

?????????#include <QOpenGLShaderProgram>

?????????QOpenGLShaderProgram

?????????QOpenGLShader

? ? ? ? 但在工程里不想重复一些代码，所以还是简单的封装了一个Shader类：

????????

#ifndef SHADER_H
#define SHADER_H

#include <QOpenGLShaderProgram>

class Shader
{
public:
     Shader(const QString &vertexShaderFile,const QString &fragmentShaderFile)
     {
         QOpenGLShader vShader(QOpenGLShader::Vertex);
         bool ret = vShader.compileSourceFile(vertexShaderFile);

         if(!ret){
             qDebug() << "ERROR::SHADER::VERTEX::COMPILATION_FAILED";
         }
         QOpenGLShader fShader(QOpenGLShader::Fragment);
         ret = fShader.compileSourceFile(fragmentShaderFile);

         if(!ret){
             qDebug() << "ERROR::SHADER::FRAGMENT::LINKING_FAILED";
         }

         m_shaderProgram.addShader(&vShader);
         m_shaderProgram.addShader(&fShader);
         ret = m_shaderProgram.link();
         if(!ret){
             qDebug() << "ERROR::SHADER::PROGRAM::LINKING_FAILED";
         }
     }

     ~Shader(){}

     QOpenGLShaderProgram m_shaderProgram;
};

#endif // SHADER_H

在资源文件里加上glsl文件，如图：

?

 m_shader = new Shader(":/shader/res/shaders/getting_started/3.3.shader.vs"
    ,":/shader/res/shaders/getting_started/3.3.shader.fs");

然后在每个教程中使用一行代码就可以初始化着色器，美滋滋。代替以下代码块

       //顶点这色器
        int vertexShader = glCreateShader(GL_VERTEX_SHADER);
        glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
        glCompileShader(vertexShader);

        int success;
        char infoLog[512];
        glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
        if (!success)
        {
            glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
            qDebug() << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog ;
        }

        //片段着色器
        int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
        glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
        glCompileShader(fragmentShader);

        glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
        if (!success)
        {
            glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
            qDebug() << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog;
        }
        m_shaderProgramId = glCreateProgram();
        //附加以上两个着色器
        glAttachShader(m_shaderProgramId, vertexShader);
        glAttachShader(m_shaderProgramId, fragmentShader);
        //链接
        glLinkProgram(m_shaderProgramId);

        //检测是否链接成功
        glGetProgramiv(m_shaderProgramId, GL_LINK_STATUS, &success);
        if (!success) {
            glGetProgramInfoLog(m_shaderProgramId, 512, NULL, infoLog);
            qDebug() << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog;
        }
        glDeleteShader(vertexShader);
        glDeleteShader(fragmentShader);

之前的三角形代码修改为以下：

   //VAO，VBO数据部分
    GLfloat vertices[] = {
        //vertex    //color
        -0.5f, -0.5f, 0.0f, 1.0f ,0.0f,0.0f,
        0.5f, -0.5f, 0.0f,  0.0f, 1.0f ,0.0f,
        0.0f,  0.5f, 0.0f, 0.0f, 0.0f ,1.0f
    };

    glGenVertexArrays(1, &VAO);
    glGenBuffers(1, &VBO);
    glBindVertexArray(VAO);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

    // position attribute
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    // color attribute
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);

即可得到以下效果：

?