Abstract: A computer method and apparatus for combining a brush object element with a trajectory object element in a graphics display system. The brush has a reference point that moves along a trajectory, and any point in application coordinates that is at any position covered by the brush, is assigned an -inside- indication. The trajectory may be non-closed or closed, in which latter case it may also govern an -inside- indication. The approach is point driven, which leads itself to acceleration by means of array calculations.

Abstract: A multiprocessor system for forming a color picture from object elements defined in a hierarchic data structure. The object elements are Bezier polygons each of the sides of which forms a Bezier curve. There is provided an array of parallel connected point processors which perform three functions. First of all, from the highest level of the data structure they determine the relevance of each object element to a point in question until either irrelevance is detected or one or more elementary object elements remain. Furthermore, for each point and each relevant elementary object element a binary inside/outside determination is made. Finally, the color is implemented by a priority determination of the elementary object elements determined to be "inside". The inside/outside decision is made in that during successive steps the relevant polygon sides are divided and in that the contribution to the inside/outside determination by the parallelogram diagonalized by the current side portion is decided.