glPushMatrix or glPopMatrix Subroutine

OpenGL 1.1 for AIX: Reference Manual

glPushMatrix or glPopMatrix Subroutine

Purpose

Pushes and pops the current matrix stack.

Library

OpenGL C bindings library: libGL.a

C Syntax

void glPushMatrix(void)

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.

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

The glPopMatrix subroutine 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.

Error Codes

GL_STACK_OVERFLOW	The glPushMatrix subroutine is called while the current matrix stack is full.
GL_STACK_UNDERFLOW	The glPopMatrix subroutine is called while the current matrix stack contains only a single matrix.
GL_INVALID_OPERATION	The glPushMatrix subroutine is called between a call to glBegin and the corresponding call to glEnd.

Associated Gets

Associated gets for the glPushMatrix or glPopMatrix subroutine are as follows. (See the glGet subroutine for more information.)

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.

Files

/usr/include/GL/gl.h

Contains C language constants, variable type definitions, and ANSI function prototypes for OpenGL.

Related Information

The glBegin or glEnd subroutine, glFrustum subroutine, glLoadIdentity subroutine, glLoadMatrix subroutine, glMatrixMode subroutine, glMultMatrix subroutine, glOrtho subroutine, glRotate subroutine, glScale subroutine, glTranslate subroutine, glViewport subroutine.

OpenGL Overview.