给图形赋予颜色时，采用纹理贴图的方式。
每个顶点关联一个纹理坐标(Texture Coordinate),然后在图形的其他片段上进行片段插值(Fragment Interpolation)
顶点坐标如下：
float vertices[] = {
// positions // colors // texture coords
0.2f, 0.2f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // top right
0.2f, -0.2f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // bottom right
-0.2f, -0.2f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, // bottom left
-0.2f, 0.2f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f // top left
};
unsigned int indices[] = { // note that we start from 0!
0, 1, 3, // first triangle
1, 2, 3 // second triangle
};
initializeGL()函数代码：

	initializeOpenGLFunctions();//创建VBO和VAO对象，并赋予IDglGenVertexArrays(1, &VAO);glGenBuffers(1, &VBO);//绑定VBO和VAO对象glBindVertexArray(VAO);glBindBuffer(GL_ARRAY_BUFFER, VBO);//为当前绑定到target的缓冲区对象创建一个新的数据存储。//如果data不是NULL，则使用来自此指针的数据初始化数据存储glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);//告知显卡如何解析缓冲里的属性值glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);//开启VAO管理的第一个属性值glEnableVertexAttribArray(0);glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));glEnableVertexAttribArray(1);glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));glEnableVertexAttribArray(2);glBindBuffer(GL_ARRAY_BUFFER, 0);bool success;shaderProgram.addShaderFromSourceFile(QOpenGLShader::Vertex, "shaders/shapes.vert");shaderProgram.addShaderFromSourceFile(QOpenGLShader::Fragment, "shaders/shapes.frag");success = shaderProgram.link();if (!success)qDebug() << "ERR:" << shaderProgram.log();// glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);glGenBuffers(1, &EBO);glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);textureWall = new QOpenGLTexture(QImage("images/wall.jpg").mirrored());shaderProgram.bind();shaderProgram.setUniformValue("textureWall", 0);glBindVertexArray(0);

paintGL()函数：

	glClearColor(0.2f, 0.3f, 0.3f, 1.0f);glClear(GL_COLOR_BUFFER_BIT);shaderProgram.bind();glBindVertexArray(VAO);textureWall->bind(0);glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, NULL);