We found the MIDP 1.0 specifications is missing important features for videogaming and multimedia. It's important to optimize the code for triangles plotting. In fact, most of the 3d is plotted via triangles and there are special drawing algorithms to speed-up the special case of oplygons with 3 vertexes. This is foundamental for paint programs, video games, and other applications. Where it's possible to plot rectangles within the array at given x,y position and with given width.
Double buffer is also useful but it's another matter.
With no big extra implementation efforts, it's possible to create specific versions of methods, which the developer can call after detecting the display type. However, we could do a more general system without create special methods for Gray, Indexed etc. etc. 0 for white and 1 for black, for example. With an i.e. 256 colors display, we may choose colors from 0 to 255, that avoids slow conversions from 0xrrggbb format to the nearest color in available palette. Also 65535 colors displays require conversion from 0xrrggbb.