| 摘要 |
A method for mapping a source pixel image to a destination pixel space enables all destination pixels within boundaries of the source image to be rendered in a single pass. The method first derives source image edge intersection coordinate values in the destination pixel space, for both a primary edge and a secondary edge of the source pixel image. One of the source coordinate values is selected as a starting coordinate. The method next determines a first occurring line of destination pixels in a direction along a major axis from the starting coordinate. Clip points are derived at intersections of the first occurring line of destination pixels and the primary and secondary edges of the source data. The same action is performed with respect to a next occurring line of destination pixels. A display value is then assigned to each pixel in a first minor direction along the first occurring line of destination pixels until a next destination pixel exceeds a clip point. A display value is then assigned to a pixel along the next occurring line of destination pixels which falls within the clip points previously derived for the next occurring line. A display value is assigned to each pixel in a second minor direction along the next occurring line until a next destination pixel exceeds a clip point. The process is repeated for each next occurring line of pixels falling within bounds of the source pixel image, with the minor direction reversing at each next occurring line of destination pixels.
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