This guide has looked at how the use of depth testing and depth-aware sprite techniques can be used to significantly accelerate 2D scene rendering using 3D graphics hardware.
Remember that adding vertices to provide the partition between opaque and transparent regions of each sprite does create additional computational complexity. Therefore, be careful to minimize the number of vertices used for each sprite. Otherwise, the costs of the extra vertex processing and small triangle sizes will outweigh the benefits.
For cases in which the additional geometry required to fit the sprint is too complicated, or the screen region covered is too small, simply fall back to back-to-front rendering on a per-sprite basis by omitting the opaque geometry and rendering the whole sprite as transparent.