Attachment of lines to objects in interactive draw graphics

• US 4,663,616 A
• Filed: 06/25/1985
• Issued: 05/05/1987
• Est. Priority Date: 06/25/1985
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Christensen, Carol S.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Kovalick, Vincent P.
• Application Number:
  US06/748,590
• Time in Patent Office: 679 Days
• Field of Search: 340/707, 340/709, 340/710, 340/723, 340/724, 340/727, 340/751, 340/747, 364/512, 364/521
• US Class Current: 345/681
• CPC Class Codes: G06T 11/00 2D [Two Dimensional] image generation
• CPC Class Codes: G06T 19/00 Manipulating 3D models or images for computer graphics
• CPC Class Codes: G06T 2219/004 Annotating, labelling
• CPC Class Codes: G06T 2219/2016 Rotation, translation, scaling

Abstract

A technique is provided the user of an interactive computer graphics application which allows the user to attach lines to objects such that when the objects move, the lines will rubber-band to follow the object. The objects are provided with an attribute that describes their "stickiness". If an object is given the "sticky" attribute, then lines which touch or overlay the object will rubber-band to follow the object'"'"'s movement. It is also possible to provide end points of lines with the "sticky" attribute so that the end points of lines can be attached to objects. Further, objects of arbitrary geometric shape can be attached to other objects of arbitrary geometric shape using the "sticky" attribute. The feature facilitates editing and revision of graphic files.

Claims

1. A technique for an interactive computer graphics application which provides the user with a way to attach ends of lines to a graphic object displayed on a screen such that when said graphic object is moved on the screen, the ends of the lines attached to said graphic object will follow the object while other ends of the lines will remain fixed on the screen, said technique comprising the steps of:

selecting a graphic object or the ends of one or more lines on said screen;

providing the selected graphic object or the selected ends of one or more lines with an attribute indicating that ends of lines touching or overlying the graphic object stay attached when the graphic object is moved;

determining if the graphic object is to be moved on said screen;

identifying the ends of lines touching or overlying the graphic object which are to stay attached to said graphic object; and

moving the graphic object on the screen while maintaining the identified ends of lines attached to the graphic object while at the same time maintaining other ends of the lines at fixed locations on the screen.

2. The technique recited in claim 1 wherein the step of moving said graphic object is performed by translating, rotating, scaling or stretching said graphic object on said screen.

3. The technique recited in claim 1 wherein the steps of maintaining ends of lines attached to the graphic object while maintaining the other ends of the lines at fixed locations on the screen is performed by drawing the lines on the screen between the ends attached to the graphic object and the ends fixed at locations on the graphics screen.