CompuServe Thread

Lynn, I agree with Jack's definition, except that I would use the term "paint" program where he uses "draw". I reserve "drawing program" for a specific kind of CAD program. The way _I_ see the terminology is thus: 1. CAD program – a program that creates "draftsman-type" drawings, i.e. very precise, usually line-oriented drawings for architecture, engineering layout, specifications, etc. These drawings may be limited to 2-D or they may be 3-D, which has no exact "paper" equivalent. CAD programs can be special-purpose for one discipline, as in a schematic capture program that can create a complete circuit netlist, parts list, etc. and cross-reference to a PC board layout. The objects in the CAD drawing are almost always stored as vector-based descriptions, which will be displayed and plotted at the maximum available resolution of the output device. Amiga examples of CAD are Aegis Draw, IntroCAD, X-CAD, Pro-Net, and to some degree several of the 3-D solid modeling programs. 2. Drawing program – this is a lot like a CAD program in that the objects are stored as a database of numerical descriptions. The main thing that makes a "draw" program different than a "CAD" program is that a "draw" program emphasizes artistic illustration or sketches for graphic arts or office-publishing purposes. So a drawing program will have somewhat less emphasis on absolute precision of vertices and more on things like shading, pattern fills, extensive typeface manipulation, complex curve drawing, etc. Amiga examples of draw programs are Professional Draw and the built-in graphics capabilities of PageStream. Although the drawing is object-oriented, the output device is usually raster-oriented (e.g. PostScript printer or phototypesetter). Pen plotters are not emphasized because they are not suited for subtle shading and complex pattern fills. 3. Paint program – This is what I _think_ Jack termed a drawing program. Paint programs are usually raster oriented – you cannot usually pick an object up and resize or move it once it is imprinted onto the screen's bitmap. The resolution is no better than the original drawing, i.e. a painting will not necessarily reproduce with more detail on a higher-resolution output device, unless some kind of filtering or processing is used to "fill in" the original bitmap and give the appearance of higher resolution. Amiga examples of paint programs are Deluxe Paint, Photon Paint, Express Paint, Aegis Images.