写一个cpp函数,参数有QRect, 图像宽高, 然后转换为opengl可用顶点矩阵, 结果放入GLfloat*

好的，下面是将给定的QRect和图像宽高转换为opengl可用的顶点矩阵的cpp函数：

void transformQRectToOpenGLVertices(QRect rect, int imageWidth, int imageHeight, GLfloat* vertices) {
    // 计算rect的四个顶点的坐标
    float leftX = (float)rect.left() / (float)imageWidth * 2.0f - 1.0f;
    float rightX = (float)(rect.right() + 1) / (float)imageWidth * 2.0f - 1.0f;
    float topY = 1.0f - (float)rect.top() / (float)imageHeight * 2.0f;
    float bottomY = 1.0f - (float)(rect.bottom() + 1) / (float)imageHeight * 2.0f;

    // 将四个顶点的坐标存入vertices数组
    vertices[0] = leftX; vertices[1] = topY;
    vertices[2] = leftX; vertices[3] = bottomY;
    vertices[4] = rightX; vertices[5] = bottomY;
    vertices[6] = rightX; vertices[7] = topY;
}

可以将结果存入提供的GLfloat数组中。顶点顺序为左上角，左下角，右下角和右上角。