When working with big number of sprites (Good example is lot of rotation frames of locomotive), you can imagine, that in diagonal directions, very big part of the image is not used (is transparent).
I could imagine some algorithm, that could split sprites into smaller ones and draw those parts separatly.
Have you been experiencing with this kind of stuff?
Could it be not only memory vise, but also performance vice?
Imagine sprite S divided in x sprites that have (S pixel count)*y pixels combined, could the pixel drawing saving save enough to beat the extra cost of drawing more sprites? If so, how to relate x and y to keep it reasonable?
I guess it depends on the ratio of cost of drawing one pixel and drawing bitmap as whole.