Methods and systems for rendering line and point features for display

Abstract

A method and system for rendering a feature, such as a line, for display on an array of pixels. With this method, the line is identified on the pixel array, the line is expanded into a polygon, and color values are determined for the pixels within the polygon. Also, an antialiasing region is identified in the polygon, and blend values are computed for the pixels in this antialiasing region. Then, the color values determined for the pixels in the antialiasing region are modified as a function of these computed blend values. The pixels in the antialiasing region may then be shown at their modified color values, while the pixels that are in the polygon but not in the antialising region may be shown at their original determined color value. Preferably, the blend values for the pixels in the antialiasing region are calculated as a function of the locations of the pixels in that region. For example, the blend value for each of these pixels may be calculated as a function of four values, each one representing the Manhattan distance from the pixel to a respective one of the edges of the polygon. Also, preferably the antialiasing region has a uniform width, and this region extends inward from side edges and outward from end edges of the formed polygon.