1. A method for rendering rectangle drawing objects, comprising: receiving, by at least one processor, print data including data representing a plurality of rectangle drawing objects, the plurality of rectangle drawing objects including at least a first rectangle drawing object and a second rectangle drawing object; determining, by the at least one processor, if the first rectangle drawing object and the second rectangle drawing object satisfy a predetermined condition; if the predetermined condition is satisfied, (i) generating, by the at least one processor, one-line raster image data associated with the first and second rectangle drawing objects, and storing, by the at least one processor, the one-line raster image data in a data buffer, wherein the one-line raster image data indicates a first filling color of the first rectangle drawing object over a first extent along a first direction and a second filling color of the second rectangle drawing object over a second extent in the first direction, and (ii) generating, by the at least one processor, a clip region corresponding to the first and second rectangle drawing objects; using, by the at least one processor, the one-line raster image data together with the clip region to fill a clipped drawing region corresponding to the first and second rectangle drawing objects, the clipped drawing region being filled along a second direction that is perpendicular to the first direction; producing, by the at least one processor, one-line printing image data based on the one-line raster image data; and printing, by the at least one processor, the first and second rectangle drawing objects using the one-line printing image data.