GLPUSHMATRIX() MachTen Programmer’s Manual GLPUSHMATRIX()

NAME
glPushMatrix, glPopMatrix - push and pop the current
matrix stack

C SPECIFICATION
void glPushMatrix( void )

C SPECIFICATION
void 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 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.

glPushMatrix pushes the current matrix stack down by one,
duplicating the current matrix. That is, after a glPush-
Matrix 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 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 execution of glEnd.

ASSOCIATED GETS
glGet with argument GL_MATRIX_MODE
glGet with argument GL_MODELVIEW_MATRIX
glGet with argument GL_PROJECTION_MATRIX
glGet with argument GL_TEXTURE_MATRIX
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

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