Obtaining current ModelView matrix

问题

In OpenGL, how do I read the current x/y translation in the modelview matrix? I know that you have to load the current matrix into an array and read the floats from there, but I don't know precisely how to do it.

回答1:

In order to retrieve the current modelview matrix you have to call the glGetFloatv function with GL_MODELVIEW_MATRIX parameter.

GLfloat matrix[16]; 
glGetFloatv (GL_MODELVIEW_MATRIX, matrix); 

From the documentation:

GL_MODELVIEW_MATRIX

params returns sixteen values: the modelview matrix on the top of the modelview matrix stack. Initially this matrix is the identity matrix.

回答2:

Use glGlet

GLfloat matrixf[16];
glGetFloatv(GL_MODELVIEW_MATRIX, matrixf);

GLdouble matrixd[16];
glGetDoublev(GL_MODELVIEW_MATRIX, matrixd);

GLint matrixi[16];
glGetIntegerv(GL_MODELVIEW_MATRIX, matrixi);

来源：https://stackoverflow.com/questions/766127/obtaining-current-modelview-matrix