glPopMatrix, glPushMatrix - push and pop the current matrix stack
There is a stack of matrices for each of the matrix modes. In GL_MOD‐
ELVIEW 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 option is
set and no other change is made to GL state.
GL_STACK_OVERFLOW is generated if glPushMatrix() is called while the
current matrix stack is full.
GL_STACK_UNDERFLOW is generated if glPopMatrix() is called while the
current matrix stack contains only a single matrix.
GL_INVALID_OPERATION is generated if glPushMatrix() or glPopMatrix() is
executed between the execution of glBegin() and the corresponding exe‐
cution of glEnd().
ASSOCIATED GETSglGet() 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 ALSOglFrustum(3), glLoadIdentity(3), glLoadMatrix(3), glMatrixMode(3),
glMultMatrix(3), glOrtho(3), glRotate(3), glScale(3), glTranslate(3),