C SPECIFICATION
       void GLAPIENTRY glPopMatrix( void )

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  modes,
       GL_COLOR,  const(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.

       glPushMatrix  pushes  the  current matrix stack down by one, duplicating
       the current matrix.  That is, after a glPushMatrix call, the  matrix  on
       top of the stack is identical to the one below it.

       glPopMatrix  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 glPushMatrix is called while the  cur‐
       rent matrix stack is full.

       GL_STACK_UNDERFLOW  is generated if glPopMatrix is called while the cur‐
       rent matrix stack contains only a single matrix.

       GL_INVALID_OPERATION is generated if glPushMatrix or glPopMatrix is exe‐
       cuted  between  the execution of glBegin and the corresponding execution
       of glEnd.

ASSOCIATED GETS
       glGet with argument GL_MATRIX_MODE
       glGet with argument GL_COLOR_MATRIX
       glGet with argument GL_MODELVIEW_MATRIX
       glGet with argument GL_PROJECTION_MATRIX
       glGet with argument GL_TEXTURE_MATRIX
       glGet with argument GL_COLOR_STACK_DEPTH
       glGet with argument GL_MODELVIEW_STACK_DEPTH
       glGet with argument GL_PROJECTION_STACK_DEPTH
       glGet with argument GL_TEXTURE_STACK_DEPTH
       glGet with argument GL_MAX_MODELVIEW_STACK_DEPTH
       glGet with argument GL_MAX_PROJECTION_STACK_DEPTH
       glGet with argument GL_MAX_TEXTURE_STACK_DEPTH

SEE ALSO
       glFrustum,  glLoadIdentity,  glLoadMatrix,  glMatrixMode,  glMultMatrix,
       glOrtho, glRotate, glScale, glTranslate, glViewport