Computer Graphics Primitives and the Scan-Line Algorithm

• Main Author: Myjak, Michael D. (Michael David)
• Other Authors: Swigger, Kathleen M.
• Format: Others
• Language: English
• Published: University of North Texas 1988
• Subjects: scan-line algorithm; computer graphics; lisp machine; Computer graphics.; Algorithms.; Lisp Machine (Computer) > Programming.; Lisp Machine (Computer)
• Online Access: https://digital.library.unt.edu/ark:/67531/metadc500544/

This paper presents the scan-line algorithm which has been implemented on the Lisp Machine. The scan-line algorithm resides beneath a library of primitive software routines which draw more fundamental objects: lines, triangles and rectangles. This routine, implemented in microcode, applies the A(BC)*D approach to word boundary alignments in order to create an extremely fast, efficient, and general purpose drawing primitive. The scan-line algorithm improves on previous methodologies by limiting the number of CPU intensive instructions and by minimizing the number of words referenced. This paper will describe how to draw scan-lines and the constraints imposed upon the scan-line algorithm by the Lisp Machine's hardware and software.