Note: NDC is based on SRGP (Simple Raster Graphics Package) by David Frederick Sklar and described in the book Computer Graphics: Principles and Practices 2nd Edition, by Foley, van Dam, Feiner and Hughes, Addison-Wesley 1990.
The files described here were written by me during the 1993 spring semester while I was teaching a computer graphics course at Shepherd College. That semester we were working with Turbo Pascal on IBM PC's and I wanted to give the students experience with a package like SRGP but I wanted a version of it that used normalized device coordinates, hence the name NDC.
Most of the functionality of SRGP has been implemented, including various line and polygon fill styles. It is also possible to use event mode for iteractive programs, however this is implemented using an event queue that is polled by the NDC_WaitEvent procedure.
The source file for the NDC unit is ndc.pas (shift-left mouse button in Netscape to download). There are also some demonstration programs in several subdirectories:
demos contains a program to draw two-dimensional bezier curves and a implementation of a button widget.
fractal contains an interactive self-similar curve generation program and some associated data files.
manip has a program to do interactive three-dimensional wire-frame manipulations. This directory also has the source Turbo Pascal Unit called threed.pas to help with three-dimensional graphing.