LispWorks CAPI User Guide > 12 Graphics Ports


12.4 Graphics state transforms

Coordinate systems for windows generally have the origin (0,0) positioned at the upper left corner of the window with X positive to the right and Y positive downwards. This is the "window coordinates" system. Generalized coordinates are implemented using scaling, rotation and translation operations such that any Cartesian coordinates can be used within a window. The Graphics Ports system uses a transform object to achieve this.

12.4.1 Generalized points

12.4.2 Drawing functions

LispWorks CAPI User Guide (Unix version) - 22 Dec 2009