将投影变换矩阵存储到一个一维数组中，与函数glFrustum，glOrtho，gluPerspective的相应参数相同，并比较当前投影矩阵和用所设计的函数所得结果。在屏幕上输出两个矩阵并进行比较。可使用glGetFloatv(GL_PROJECTION_MATRIX, ...)获得当前投影矩阵。-projection matrix storage to a one-dimensional arrays, and functions glFrustum. glOrtho, gluPerspective same as the corresponding parameters, and to compare the current projection matrix, and the use of design as a function of the results. On the screen two output matrix and compared. Use glGetFloatv (GL_PROJECTION_MATRIX. ...) access to current projection matrix.