| 摘要 |
<p>A graphics generator operates on the digital co-ordinates of resolution points of a display device by recursive calculation of a Taylor expansion from a starting point about nearby resolution points to generate display figures such as vectors, circles and arcs. Absolute values of decision variables (f<x>, f<y>, f<xy>) corresponding to terms of the Taylor expansion are derived in arithmetic circuits (30,34; 32,36; 40, 42, 44). The values are supplied to a selector circuit (38) which selects by comparison of the values the resolution point associated with the smallest value, and causes running co-ordinate counters (64, 66) to be updated accordingly. The decision variable associated with the selected point is also used as basis f<x> for calculating the next group of decision variables. The co-ordinates stored in the counters (64,66) are applied to control the display device (82).
<??>The generator provides real time generation of display figures and may be used with raster scan or beam position CRT displays. </p> |
