Graphics: Legacy Library

1`` | Basic Commands
2`` | Position Operations
3`` | Color Operations
4`` | Draw, Clear, and Flip Operations
5`` | World Operations
6`` | Miscellaneous Operations
7`` | An Example
8`` | A More Complicated Example
9`` | Protecting Graphics Operations
10`` | Mouse Operations
11`` | Keyboard Operations
12`` | Flushing
13`` | Graphics Library as a Unit

On this page:

open-graphics
close-graphics
open-viewport
open-pixmap
close-viewport
viewport?

Version: 4.0.2
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### 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.

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