Method for determining computer image generation display pixels occupied by a circular feature

Claim 1

A method for illuminating pixels of at least a portion of a scene raster, displayable by a computerized image generator, as part of a plurality of raster line cells covered by a circular feature to be displayed, comprising the steps of; (a) providing data storage means and data processing means in the computerized image generator; (b) providing, to the processing means from the storage means, a set of electronic data signals specifying both a centroid location P and a radius length R of the circular feature; (c) causing the processing means to determine, using a first radial component of the feature in a direction substantially perpendicular to a common scan direction of the raster, a maximum line range to include those raster lines encompassing the feature to opposite sides of the feature centroid in the direction of the first radial component, and within a maximum distance set by the feature radius; (d) for each line of raster cells within the determined range, then generating within the processing means another electronic data signal determining a length of a segment of each of the plurality of raster cell lines, with each segment extending from a feature radial line to an edge of the feature in that cell line, along which lie cells which will be present in the scene to be displayed, by the substeps of: generating, from the feature centroid data signal, for each identified cell line, an electronic data signal specifying an offset distance ΔI from that cell line to a cell line including the feature centroid; generating a line segment distance L data signal dependent upon the offset distance data signal; and utilizing the data signals to determine specification data signals specifying start and stop parameters of the data signals specifying the range of sells along each identified cell line segment; (e) generating raster line segment length output data signals using pixel information obtained responsive to the electronic data signals for all cells determined in step (c); (f) causing the processor means to generate display scene data signals using in part the line segment data signals obtained in step (d); and (g) displaying each display scene responsive to the generated display video data signals.

Claim 2

A method for illuminating pixels of at least a portion of a scene raster, displayable by a computerized image generator, as part of a plurality of raster line cells covered by a circular feature to be displayed, comprising the steps of; (a) providing data storage means and data processing means in the computerized image generator; (b) providing, to the processing means from the storage means, a set of electronic data signals specifying both a centroid location P and a radius length R of the circular feature; (c) causing the processing means to determine, using a first radial component of the feature in a direction substantially perpendicular to a common scan direction of the raster, a maximum line range to include those raster lines encompassing the feature to opposite sides of the feature centroid in the direction of the first radial component, and within a maximum distance set by the feature radius; (d) for each line of raster cells within the determined range, then generating within the processing means another electronic data signal determining a length of a segment of each of the plurality of raster cell lines, with each segment extending from a feature radial line to an edge of the feature in that cell line, along which lie cells which will be present in the scene to be displayed, by the substeps of: generating, from the feature centroid data signal, for each identified cell line, an electronic data signal specifying an offset distance ΔI from that cell line to a cell line including the feature centroid; generating a line segment distance L data signal dependent upon the offset distance data signal; and utilizing the data signals to determine specification data signals specifying start and stop parameters of the data signals specifying the range of sells along each identified cell line segment; (e) generating raster line segment length output data signals using pixel information obtained responsive to the electronic data signals for all cells determined in step (c); (f) causing the processor means to generate display scene data signals using in part the line segment data signals obtained in step (d); and (g) displaying each display scene responsive to the generated display video data signals.