2 GP Reference Entries

create-pixmap-port

Function

Summary
: Creates a pixmap port and its window system representation.
Signature

create-pixmap-port pane width height &key background collect relative clear => pixmap-port

Arguments

pane: A graphics port for a window
width: An integer
height: An integer
background: A color designator
collect: A boolean
relative: A boolean
clear: A list ort

Values

pixmap-port: A pixmap graphics port

Description

Thecreate-pixmap-port function creates a pixmap-port and its window system representation. The pane argument specifies the color-user, used for color conversions, and its representation may also be used by the library to match the pixmap port properties. The value of background is used to initialize thegraphics-state-background.

If clear ist, the pixmap is cleared to its background color, otherwise the initial pixel values will be non-deterministic. If clear is a list of the form(x y width height), only that part of the pixmap is cleared initially. The default value isnil.

If relative is non-nil, the pixmap graphics port collects pixel coordinates corresponding to the left, top, right, and bottom extremes of the drawing operations taking place within the body forms, and if these extend beyond the edges of the pixmap (into negative coordinates for example) the entire drawing is offset by an amount which ensures it remains within the port. It is as if the port moves its relative origin in order to accommodate the drawing. If the drawing size is greater than the screen size, then some of it is lost. The default value isnil.

If collect is non-nil, this causes the drawing extremes to be collected but without having the pixmap shift to accommodate the drawing, as relative does. The extreme values can be read using theget-bounds function, andmake-image-from-port.