A display control device comprises a work memory including at least a plurality of memory bits each for storing one-bit data indicating whether or not each pixel is inside a figure of plane geometry having a contour such as a polygon, a control unit for scanning each of a plurality of raster scan lines and searching for at least one pixel which can be assumed to form a line segment which partially constructs the contour of the figure so as to generate a control signal for controlling bit inversion to determine the inside of the figure, a selecting unit for receiving the one-bit data of each pixel which is sequentially delivered by the work memory and inverting the one-bit data so as to select one from among the original one-bit data and the inverted one-bit data according to the control signal from the control unit, and output the selected data; a unit for writing the selected data from the selecting unit into a corresponding one of the plural memory bits of the work memory.