| 摘要 |
PURPOSE:To omit processing for converting input data into a Bezier curve and to attain rapid display by converting a curve defined by a parameter expression into the data of an expression type whose display processing is easy, storing the converted data, and at the time of repeatedly displaying curves, displaying the curves based on the data of the expression type of easy processing. CONSTITUTION:A curve defined by the parameter expression is transformed into a Bezier curve by a polynomial expansion means 1a and a Bezier transfor mation means 1b and the transformed result is stored in a Bezier storing means 1c. A Bezier control point coordinate transformation means 1d fetches a Bezier control point from the means 1c by using coordinate transformation matrix applied so as to execute required visual field transformation, executes coordinate transformation and sends the transformed result to a Bezier generating means 1e. The means 1e expands the Bezier curve into a segment string, which is displayed by an ordinary method. Since it becomes unnecessary to transform the same curve or curved surface to a Bezier curve when it is displayed repeatedly, rapid display can be attained. |
