Patent ID: 7164430

Claim:
A method in a computer graphics system for rendering and displaying on an output device, having a finite number of pixels, a non-zero thickness line segment with reduced aliasing, comprising: expanding an edge of the line segment touching but not covering a pixel center of the line segment to be rendered on the output device so that the expanded line segment covers the center of the pixel touched; determining, using the pixel centers, the pixels to be included in the expanded line segment, the line segment being distinguishable from a background over which said line segment is rendered by having a shade different from a shade of the background; for each pixel that is included in said non-zero thickness expanded line segment, determining the area of the pixel partially or fully covered by said line segment, and based on the area of the pixel covered, determining a shading value for the pixel by interpolating between the shade of said line segment and the shade of the background; and displaying on the output device the reduced-aliased line segment; wherein the output device has a x-y coordinate system established thereon and the pixels of the output device each have centers with an x-y coordinate; wherein an edge of said line segment has an equation ax+by +c=0; and wherein the step of expanding an edge includes altering the equation of an edge of said line segment by adding an amount (|a|+|b|)/2 to the c parameter of the equation, where a, b and c are coefficients of the equation ax+by+c=0 of the edge of the line segment.