Device context

A device context is an abstraction of all the devices that can be drawn onto, such as PostScript file, canvas, printer, metafile, and bitmap. Instead of drawing directly on one of these devices, the application programmer can write a function that writes to a device context, and then pass any device context to that function. The frequently-used device context is probably the canvas device context. This cannot be created by an application but can be retrieved from a canvas by calling canvas-get-dc.

The following functions can be used with any device context identifier.

dc-clear

dc-destroy-clipping-region

dc-draw-ellipse

dc-draw-line

dc-draw-lines

dc-draw-point

dc-draw-polygon

dc-draw-rectangle

dc-draw-rounded-rectangle

dc-draw-text

dc-draw-spline

dc-set-brush

dc-set-clipping-region

dc-set-font

dc-set-logical-function

dc-set-pen

dc-set-text-foreground

dc-set-text-background