Patent ID: 7684641

Claim:
A method of identifying pixels that are inside of a path using a derivative mask, comprising: receiving a first segment of a set of segments that approximates the path; receiving a control point that defines a curve between a first endpoint and a second endpoint of the first segment; identifying one or more covered pixels, wherein each covered pixel constitutes a pixel that is covered by the curve; writing segment data in locations of the derivative mask that is stored in a graphics memory, wherein each location corresponds to one of the covered pixels, and the segment data includes a slope direction for each covered pixel that is based on a direction of the path; shading each pixel that is inside the path using a graphics processor to produce shaded pixels of an image, wherein the pixels that are shaded correspond to locations of the fill mask that contain odd values, and pixels that are not shaded correspond to locations of the fill mask that contain zero or even values; and storing the shaded pixels of the image in the graphics memory.