#version 330 corelayout (location = 0) in vec3 aPos; //位置变量的属性位置值为0
layout (location = 1) in vec3 aColor; //颜色变量的属性位置值为1
layout (location = 2) in vec2 aTexture; //纹理变量的属性位置值为2out vec3 ourColor; //向片段着色器输出一个颜色坐标
out vec2 ourTexture; //向片段着色器输出一个纹理坐标uniform mat4 RotationMatrix; //变换矩阵void main()
{//矩阵与向量相乘，使向量进行旋转、缩放、位移等gl_Position = RotationMatrix * vec4(aPos, 1.0);ourColor = aColor;ourTexture = aTexture;
}

在myopenglwidget.h文件中创建定时器对象m_timer和定时器响应槽函数函数onTimeout

#ifndef MYOPENGLWIDGET_H
#define MYOPENGLWIDGET_H
#include <QOpenGLWidget>
#include <QOpenGLFunctions_3_3_Core>
#include <QOpenGLShaderProgram>
#include <QOpenGLTexture>
#include <QTimer>class MyOpenGLWidget : public QOpenGLWidget,QOpenGLFunctions_3_3_Core
{Q_OBJECTpublic:explicit MyOpenGLWidget(QWidget *parent = nullptr);~MyOpenGLWidget();protected:virtual void initializeGL();virtual void resizeGL(int w, int h);virtual void paintGL();void keyPressEvent(QKeyEvent *event);private slots:void onTimeout();private:QOpenGLShaderProgram m_shaderProgram;QOpenGLTexture *m_textureWall;QOpenGLTexture *m_textureSmile;QOpenGLTexture *m_textureSmall;float mixValue = 0.5;QTimer m_timer;
};#endif // MYOPENGLWIDGET_H

在myopenglwidget.h文件中构造函数进行定时器的信号与槽函数的绑定，并启动100ms的定时器；析构函数中停止定时器：

#include "myopenglwidget.h"
#include <QDebug>
#include <QKeyEvent>
#include <QTime>unsigned int VBO; //顶点缓冲对象
unsigned int VAO; //顶点数组对象
unsigned int EBO; //元素缓冲对象MyOpenGLWidget::MyOpenGLWidget(QWidget *parent) : QOpenGLWidget(parent)
{setFocusPolicy(Qt::StrongFocus);connect(&m_timer, &QTimer::timeout, this, &MyOpenGLWidget::onTimeout);m_timer.start(100); //100ms
}MyOpenGLWidget::~MyOpenGLWidget()
{if(m_timer.isActive())m_timer.stop();makeCurrent();glDeleteBuffers(1, &VBO);glDeleteVertexArrays(1, &VAO);glDeleteBuffers(1, &EBO);doneCurrent();
}void MyOpenGLWidget::onTimeout()
{update();
}void MyOpenGLWidget::initializeGL()
{//初始化OpenGL函数initializeOpenGLFunctions();//创建VBO，并赋予IDglGenBuffers(1, &VBO);//绑定VBO对象glBindBuffer(GL_ARRAY_BUFFER, VBO);//顶点数据float vertices[] = {//位置              //颜色             //纹理0.5f,  0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, //右上角0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, //右下角-0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, //左下角-0.5f,  0.5f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f //左上角};//把顶点数据复制到显存中glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);//创建VAO对象，并赋予IDglGenVertexArrays(1, &VAO);//绑定VAO对象glBindVertexArray(VAO);//创建EBO对象，并赋予IDglGenBuffers(1, &EBO);glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);unsigned int indices[] = {0, 1, 3, //第一个三角形1, 2, 3 //第二个三角形};glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);//位置属性glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);glEnableVertexAttribArray(0); //开启VAO管理的第一个属性值//颜色属性glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));glEnableVertexAttribArray(1); //开启VAO管理的第二个属性值//纹理属性glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));glEnableVertexAttribArray(2); //开启VAO管理的第三个属性值//解绑VBOglBindBuffer(GL_ARRAY_BUFFER, 0);//解绑VAOglBindVertexArray(0);//创建一个程序对象m_shaderProgram.addShaderFromSourceFile(QOpenGLShader::Vertex,":/shaders/shapes.vert");m_shaderProgram.addShaderFromSourceFile(QOpenGLShader::Fragment,":/shaders/shapes.frag");bool success = m_shaderProgram.link();if(!success)qDebug()<<"ERR:" << m_shaderProgram.log();m_shaderProgram.bind();m_shaderProgram.setUniformValue("vertexColor", 0.0, 1.0, 0.0, 1.0);m_textureWall = new QOpenGLTexture(QImage(":/images/wall.jpg").mirrored()); //mirrored消除镜像m_shaderProgram.setUniformValue("textureWall", 0); //把纹理单元传给片段着色器中的采样器m_textureSmile = new QOpenGLTexture(QImage(":/images/awesomeface.png").mirrored()); //mirrored消除镜像m_shaderProgram.setUniformValue("textureSmile", 1); //把纹理单元传给片段着色器中的采样器m_textureSmall = new QOpenGLTexture(QImage(":/images/small.png").mirrored()); //mirrored消除镜像m_shaderProgram.setUniformValue("textureSmall", 2); //把纹理单元传给片段着色器中的采样器m_shaderProgram.setUniformValue("mixValue", mixValue);
}void MyOpenGLWidget::resizeGL(int w, int h)
{Q_UNUSED(w);Q_UNUSED(h);//glViewport(0, 0, w, h);
}void MyOpenGLWidget::paintGL()
{//设置墨绿色背景glClearColor(0.2f, 0.3f, 0.3f, 1.0f); //状态设置glClear(GL_COLOR_BUFFER_BIT); //状态使用//变换矩阵QMatrix4x4 matrix; //创建单位矩阵unsigned int time = QTime::currentTime().msec();matrix.translate(0.5, -0.5, 0.0); //位移matrix.rotate(time, 0.0f, 0.0f, 1.0f); //旋转m_shaderProgram.setUniformValue("RotationMatrix", matrix);//绘制m_shaderProgram.bind(); //激活程序对象glBindVertexArray(VAO); //绑定VAOm_textureWall->bind(0); //绑定激活纹理单元0m_textureSmile->bind(1); //绑定激活纹理单元1m_textureSmall->bind(2); //绑定激活纹理单元2glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, NULL); //绘图
}void MyOpenGLWidget::keyPressEvent(QKeyEvent *event)
{if(event->key() == Qt::Key_Up)mixValue+=0.1;else if(event->key() == Qt::Key_Down)mixValue-=0.1;elsereturn;if(mixValue > 1.0)mixValue = 1.0;if(mixValue < 0.0)mixValue = 0.0;makeCurrent();m_shaderProgram.setUniformValue("mixValue", mixValue);doneCurrent();update();QOpenGLWidget::keyPressEvent(event);
}

定时器的槽函数中进行界面更新

void MyOpenGLWidget::onTimeout()
{update();
}

更改一下顶点数据中位置数据，使矩形变小（此处不是要实现的缩放功能，只是为展示效果更看）

//顶点数据
float vertices[] = {//位置              //颜色             //纹理0.5f,  0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, //右上角0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, //右下角-0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, //左下角-0.5f,  0.5f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f //左上角
};

在paintGL()函数中创建matrix变量，对matrix进行旋转和位移操作，之后把值传递给顶点着色器的RotationMatrix变量。

    //变换矩阵QMatrix4x4 matrix;unsigned int time = QTime::currentTime().msec();matrix.translate(0.5, -0.5, 0.0); //位移matrix.rotate(time, 0.0f, 0.0f, 1.0f); //旋转m_shaderProgram.setUniformValue("RotationMatrix", matrix);

在上面的代码中旋转代码在位移代码的下一行，变量matrix会先和旋转矩阵进行运算然后再和位移矩阵进行计算，达到先旋转后位移的效果。

运行结果如下，矩形会移动到界面的右下角，同时每隔100ms进行一次旋转

注：观看OpenGL中文官网（https://learnopengl-cn.github.io/）和阿西拜的现代OpenGL入门（https://ke.qq.com/course/3999604#term_id=104150693）学习OpenGL