The Commons

Back to Results

Patent Title: Method and system for slope correcting line stipples/styles

Assignee: IBM
Patent Number: US6304274
Issue Date: 10-16-2001
Application Number:
File Date:08-03-1998


Abstract: Accurate display of line stipple in line segments, situated off the vertical or horizontal planes, is achieved by employing a calculated constant as a slope correction factor. The calculated constant, termed line style count, is determined utilizing the absolute length of the line segment, a ratio implementing the absolute length of the line segment, the major axis component of the line segment and fraction bits in the line counter. For each step along the major axis on a data processing system display, a constant value of 1.0 and the calculated constant, line style count, is added to a line style pointer to slope correct line stipple. A pre-computed square-root table is stored in texture memory and accessed for pre-calculated values to assist in reducing the time required to calculate accurate line style pointers. A standard Bresenham line steps the line counter for every step along the major axis, so that the corrected line style count equals the ratio of the true line length and the rasterized (major axis) length.

Notes:

Link to USPTO

IBM Pledge dated 1/11/2005