NAME fglPushMatrix, fglPopMatrix - push and pop the current matrix stack FORTRAN SPECIFICATION SUBROUTINE fglPushMatrix( ) FORTRAN SPECIFICATION SUBROUTINE fglPopMatrix( ) DESCRIPTION There is a stack of matrices for each of the matrix modes. In GL_MODELVIEW mode, the stack depth is at least 32. In the other two modes, GL_PROJECTION and GL_TEXTURE, the depth is at least 2. The current matrix in any mode is the matrix on the top of the stack for that mode. fglPushMatrix pushes the current matrix stack down by one, duplicating the current matrix. That is, after a fglPushMatrix call, the matrix on top of the stack is identical to the one below it. fglPopMatrix pops the current matrix stack, replacing the current matrix with the one below it on the stack. Initially, each of the stacks contains one matrix, an identity matrix. It is an error to push a full matrix stack, or to pop a matrix stack that contains only a single matrix. In either case, the error flag is set and no other change is made to GL state. ERRORS GL_STACK_OVERFLOW is generated if fglPushMatrix is called while the current matrix stack is full. GL_STACK_UNDERFLOW is generated if fglPopMatrix is called while the current matrix stack contains only a single matrix. GL_INVALID_OPERATION is generated if fglPushMatrix or fglPopMatrix is executed between the execution of fglBegin and the corresponding execution of fglEnd. ASSOCIATED GETS fglGet with argument GL_MATRIX_MODE fglGet with argument GL_MODELVIEW_MATRIX fglGet with argument GL_PROJECTION_MATRIX fglGet with argument GL_TEXTURE_MATRIX fglGet with argument GL_MODELVIEW_STACK_DEPTH fglGet with argument GL_PROJECTION_STACK_DEPTH fglGet with argument GL_TEXTURE_STACK_DEPTH fglGet with argument GL_MAX_MODELVIEW_STACK_DEPTH fglGet with argument GL_MAX_PROJECTION_STACK_DEPTH fglGet with argument GL_MAX_TEXTURE_STACK_DEPTH SEE ALSO fglFrustum, fglLoadIdentity, fglLoadMatrix, fglMatrixMode, fglMultMatrix, fglOrtho, fglRotate, fglScale, fglTranslate, fglViewport