ELLIPTICAL CURVE GRAPHIC GENERATING METHOD

• Main Author: HOSHINA HIDEO
• Format: Patent
• Language: English
• Published: 09.05.1991
• Subjects: ADVERTISING; ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICESUSING STATIC MEANS TO PRESENT VARIABLE INFORMATION; CALCULATING; COMPUTING; COUNTING; CRYPTOGRAPHY; DISPLAY; EDUCATION; IMAGE DATA PROCESSING OR GENERATION, IN GENERAL; PHYSICS; SEALS

PURPOSE:To plot a graphic similar to an ideal curve by designating one plotting point out of three candidate points after finding out a direction to retrieve the next plotting point when the (x) or (y) coordinate of the present plotting point coincides with that of the center point of a graphic to be plotted. CONSTITUTION:Elliptical curve generating algorithm is set at an arithmetic part 1, and is executed with a graphic controller 2 via an internal bus b1, and a plotting operation is performed by referring to a color pallet 4 on an image memory 3, then, a desired graphic is displayed on a CRT 5. At this time, when the (x) or (y) coordinate of the present plotting point coincides with that of the center point of an elliptical curve graphic, the candidate point is set only in an (x) or (y) direction, and an (x) direction incremental/decremental value or a (y) direction incremental/decremental value is updated corresponding to the plotting point nearer to the elliptical curve graphic expressed in a multilevel equation, and after that, the three points in the (x), (y), and (x-y) directions are set as the candidate points, and a point nearest to a real multilevel curve is designated as the next plotting point. In such a way, it is possible to plot an elliptical curve graphic as one close to the ideal curve even when it is an elliptical curve graphic of any shape.