Once I had stopped congratulating myself for reducing the generated triangle count in the previous post, I realized that I still needed to trim the vertex, normal and uv arrays down to include only the vertices used in the triangle array. This is not completely trivial as the indices of the vertices will change which means that the triangle array indices have to be mapped. Nothing too tragic though. Anyway, the result is shown in the screen capture above, using a wireframe shader to illustrate the triangles generated. The vertex count was reduced from 150801 to 34 in this particular case.
Code is here. It’s clearly not completely optimal as it missed the fact that it could have used two big triangles at the top, just like the bottom. It could be made much smarter and in fact get rid of the step quantization entirely. However, this algorithm is easy to understand and good enough for my purposes.