FIGURE DISPLAYING DEVICE

摘要

Figure Displaying Device A figure displaying device operates to display a plurality of fundamental figures, each defined by a preset number of vectors, on a device of the raster scanning type. The figure displaying device stores the start and end point coordinates of the vectors of the respective fundamental figures and the gradient vectors of the data of the respective fundamental figures and determines whether the respective vectors are located on a horizontal scanning line or not for each fundamental figure prior to the scanning operation of the horizontal scanning line. If the vectors are located on the horizontal scanning line the gradient data corresponding to the vectors on the aforementioned horizontal scanning line are read out and added to the start point coordinates whereby to renew the start point coordinates. A line memory is provided having a capacity corresponding to the number of picture elements in one horizontal scanning line so that preset data can be stored therein at the address corresponding to the added results. A control circuit consecutively reads the data out of the address in the line memory, which corresponds to the position of the horizontal scanning line being scanned, whereby to effect the display in accordance with the read results.