| 摘要 |
The present invention relates to a method and apparatus for generating cursors for display by a color raster graphic system. The cursors displayed can assume any one of a plurality of forms. Each cursor has predetermined boundaries and includes all pixel positions of the raster within its boundaries. One pixel position is designated as the origin of the cursor and selected ones of the pixel positions for each form of the cursor will display the cursor color and intensity. The address of the origin of a cursor and its form are designated by a graphic controller (10) of the system. The address of the origin is compared within a cursor display logic (18) with the addresses of the pixels produced by a raster scan logic (20), and, when the same, the form number and the x and y coordinates, the addresses of the pixel positions of the cursor relative to the origin thereof, are produced and applied to a read-only memory (56) which produces cursor control signals stored at the addressed locations of the cursor memory. The cursor control signals are produced in synchronization with the scanning of pixels, the position of which correspond to selected pixel positions of the cursor and are applied to the color look-up memory (16) of the system. Such pixel control signals cause the color look-up memory to produce color control signals which cause pixels corresponding to a designated pixel position of the given pixel and form of cursor, to be displayed in the cursor color and intensity. |
