VDict mobile



A program that allowed users to draw on a screen with a lightpen. It supported constraints (e.g. drawing a constrained
ellipse produced a circle). It also had some computer aideddesign features (e.g. computing loads on beams).
Sketchpad was the subject of Ivan E. Sutherland's 1963 MIT
PhD thesis, which opened the field of computer graphics. It
was the progenitor of computer drawing packages like MacDraw
or Adobe Illustrator. There is a film of Sketchpad in
action.
It solved constraints using value inference and introduced
the "ring" list structure.
["Sketchpad: A Man-Machine Graphical Communication System",
I.e. Sutherland, MIT Lincoln Lab, TR 296 (Jan 1963)].
[Sammet 1969, p. 678].
(1995-02-14)