Friday, March 25, 2011

Detour API Changes

Once you update to R289 you will notice that the Detour API has changed a bit. This change was necessary so that Detour could support multiple layers per tile location.

Here's quick migration guide you should follow when switching to the latest code.

1) There is no need to remove the padding of the polymesh coordinates before the vertices are passed to dtCreateNavMeshData(). So if you had code, like this before, remove it! If you are not using tiles, this does not apply.
 // Remove padding from the polymesh data. TODO: Remove this odditity.
for (int i = 0; i < m_pmesh->nverts; ++i)
unsigned short* v = &m_pmesh->verts[i*3];
v[0] -= (unsigned short)m_cfg.borderSize;
v[2] -= (unsigned short)m_cfg.borderSize;

2) Since the polymesh data is not offset anymore, you can feed the polymesh bounding box directly to navmesh builder:
 rcVcopy(params.bmin, m_pmesh->bmin);
rcVcopy(params.bmax, m_pmesh->bmax);
3) I made the BV-tree building optional as it is not needed for tiles which has just a couple of polygons. To keep the old behavior, you need to add this line to your navmesh build params:
 params.buildBvTree = true;
4) When you access tiles, you need to specify tile x, y and layer indices. If you don't use layers, just pass 0 (zero) as layer index. For example:

That's it. The navmesh data number bumped so you will need to rebuild your data too.

I also removed the test code from Sample_TileMesh. From now on the Sample_TempObstacles will be my sandbox. The code to build tiles at runtime will live under DetourTileCache. It is all a bit of mess still, I'll keep you updated about the progress.

I think I will move back to numbered releases so that I can keep the SVN a bit dirty when I need to. Once the temp obstacle stuff is done, I think it is time to release Recast & Detour 1.9.

Oh, and I updated the VC project too!