Abstract

In inter-active computer graphics systems a pointing device, such as a mouse, is generally used to move a cursor over a displayed image to point to a particular image element. An action may then be initiated by clicking a mouse button. In order for an application (110) using the graphics system (11, 100) to understand what action is required, the graphics system must translate the image position pointed to by the mouse into the identity of the corresponding image element. To facilitate this translation, the present graphics system (11,100) in generating the output image from a stored group of graphic segments (20), also generates and stores a compact image representation (60) relating image position to the corresponding segment. This image representation (60) is then subsequently used to translate an input image position back into a segment identity. Furthermore, the input image position is also subject to the reverse of the spatial transformation undergone by the segment during generation of the output image whereby to determine the position in the segment corresponding to the input image position.

Other References

• Eurographics '88, Proceedings Of The European Computer Graphics Conference And Exhibition Editor(s), 12 Sep. 1988, Nice, France, pp. 381-392; M. Slater and A. Davison et al, "Liberation from Rectanges: A Tiling Method for Dynamic Modification of Objects on Raster Displays"
• Computer Display Architecture, Peter Hemingway, Aug. 1987 Principles Of Interactive Computer Graphics, William Newman et al., 2nd Edition, 198