glutSetWindow man page

glutSetWindow — Select the <i>current window</i>

Library

OpenGLUT - window

Synopsis

#include <openglut.h>

void
glutSetWindow(int ID);

Parameters


ID


Window identifier

Description

Sets the


current window


to


ID.

All OpenGL rendering goes to the


current window


. Many OpenGLUT functions also implicitly use the


current window


.

Many OpenGLUT callback operations are tied to a window. When your callback is invoked, OpenGLUT will set that particular window to be the


current window


. However, some callbacks---such as that registered via glutIdleFunc()---do not have associated windows. If a callback is not associated to a particular window, then when OpenGLUT invokes that callback you should


always


use glutSetWindow() to select the appropriate window before doing any OpenGL rendering or doing any OpenGLUT window-related operations.

There may be cases when you can get away with assuming that the


current window


is unchanged since some prior time, but OpenGLUT has considerable liberaty with respect to when it invokes your functions. Also, your program may add more windows or more operations on other windows as you develop it.

Lastly, this is a convenient way to select among multiple windows for drawing without actually waiting for that window's display callback. Simply set the


current window


and draw immediately. This is not always advisable, but may be practical.

It is an error to set the


current window


to a non-existant window (e.g., one that you have closed). A warning will be printed on


stderr


if you try to do so, and the


current window


should be unchanged.

See Also

glutGetWindow(3)

 

Referenced By

glutGetWindow(3).