A technique for converting design shapes into pixel values is provided. The technique may be used to control a direct-write or other lithographic process performed on a workpiece. In an exemplary embodiment, the method includes receiving, at a computing system, a design database specifying a feature having more than four vertices. The computing system also receives a pixel grid. A set of rectangles corresponding to the feature is determined, and the computing system determines an area of a pixel of the pixel grid overlapped by the feature based on the set of rectangles. In some such embodiments, a lithographic exposure intensity is determined for the pixel based on the area overlapped by the feature, and the lithographic exposure intensity is provided for patterning of a workpiece.