Creating and modifying curves on a computer display
US6111588A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 5, 1996 |
| Grant date | Aug 29, 2000 |
| Priority date | — |
| Expiry date | Dec 5, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T11/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A computer-implemented method modifies a curve in response to a user action through a graphical user interface in the computer system, with the curve being defined by control points. Each of the control points is identified in response to user input as a fixed control point, a selected control point, or a free control point. A displacement of selected points is received, and a free slope control point of the curve is mapped to a point Tp on a line t. An interpolation curve IC(t) is defined on the line t, and a point Tp is projected to the value of the interpolation curve IC(t) at t equals Tp to find a scale factor. The scale factor is multiplied by the displacement of the selected points to determine the displacement of the free control point. A computer-implemented graphical user interface method creates a Bezier curve segment on a display in a computer system. A selection of a first segment end point is received through a graphical user interface in the computer system. The position of a cursor on the computer display is received as a second segment end point. The first and second slope points are calculated so that the Bezier segment defined by the first and second segment end p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.