1 Basic Commands

(open-graphics) → void?

Initializes the library’s graphics routines. It must be called before any other graphics operations.

(close-graphics) → void?

Closes all of the windows. Until open-graphics is called again, no graphics routines will work.

(open-viewport name horiz vert) → viewport?

name : string?

horiz : exact-nonnegative-integer?

vert : exact-nonnegative-integer?

(open-viewport name dimensions) → viewport?

name : string?

dimensions : posn?

Creates a new window called name. The window is horiz pixels wide and vert pixels high. For backward compatibility, a single posn value can be submitted in the place of horiz and vert. The result is a viewport descriptor.

(open-pixmap name horiz vert) → viewport?

name : string?

horiz : exact-nonnegative-integer?

vert : exact-nonnegative-integer?

(open-pixmap name dimensions) → viewport?

name : string?

dimensions : posn?

Like open-viewport, but the resulting viewport is not displayed on the screen. Offscreen pixmaps are useful for executing a sequence of drawing commands and displaying them all at once with copy-viewport.

Offscreen pixmaps are also useful in conjunction with viewport->snip (see below). This allows functions to compute with graphical objects and view the graphics when results are returned to the interactions window.

(close-viewport viewport) → void?

viewport : viewport?

Removes the viewport from the screen and makes subsequent operations dealing with the viewport illegal.

(viewport? v) → boolean?

v : any/c

Returns #t if v is a viewport (i.e., a destination for drawing), #f otherwise.