| 摘要 |
PURPOSE:To draw an ellipse with exact thickness by providing a raster image prepar ing mechanism, inner/outer circle calculating formula mechanism, maximum/minimum value setting mechanism, setting mechanism for dots in upper outer circle, setting mechanism for dots in lower outer circle and setting mechanism for dots between outer the and the inner circles. CONSTITUTION:A maximum/minimum value setting mechanism 3 calculates maximum and minimum values 32 and 33 in an outer circle and maximum and minimum values 34 and 35 in an inner circle. A dot in upper outer circle setting mechanism 4 sets a dot in a range 41 on the inside of the outer circle from the minimum value 33 of the outer circle on a raster image to coordinates less than the minimum value 35 of the inner circle. A dot in lower outer circle setting mechanism 5 sets the dot in a range 51 on the inside of the outer circle on the raster image from the maximum valve 32 of the outer circle to coordinates exceeding the maximum value 34 of the inner circle. A dot in outer circle between circles setting mechanism 6 sets the dot in a range 61 between the outer and inner circles from the minimum value 35 of the inner circle on the raster image to the maximum value 34 of the inner circle. Thus, by setting bits in the ranges 41, 51, and 61, the exact ellipse can be drawn on the raster image. |
