创建一个全局的纹理类 本程序利用纹理类载入纹理文件 创建绘制带纹理坐标的三棱锥的函数 设置当前的纹理并启用它，绘制带纹理坐标的三棱锥 -Texture to create a global category of this type of loading procedure using texture mapping to create texture coordinates with texture pyramid function of the three set the