Function dtOverlapPolyPoly2D

3rdparty/recast/DetourCommon.cpp:294–328

@par All vertices are projected onto the xz-plane, so the y-values are ignored.

///
/// All vertices are projected onto the xz-plane, so the y-values are ignored.
bool dtOverlapPolyPoly2D(const float* polya, const int npolya,
						 const float* polyb, const int npolyb)
{
	const float eps = 1e-4f;
	
	for (int i = 0, j = npolya-1; i < npolya; j=i++)
	{
		const float* va = &polya[j*3];
		const float* vb = &polya[i*3];
		const float n[3] = { vb[2]-va[2], 0, -(vb[0]-va[0]) };
		float amin,amax,bmin,bmax;
		projectPoly(n, polya, npolya, amin,amax);
		projectPoly(n, polyb, npolyb, bmin,bmax);
		if (!overlapRange(amin,amax, bmin,bmax, eps))
		{
			// Found separating axis
			return false;
		}
	}
	for (int i = 0, j = npolyb-1; i < npolyb; j=i++)
	{
		const float* va = &polyb[j*3];
		const float* vb = &polyb[i*3];
		const float n[3] = { vb[2]-va[2], 0, -(vb[0]-va[0]) };
		float amin,amax,bmin,bmax;
		projectPoly(n, polya, npolya, amin,amax);
		projectPoly(n, polyb, npolyb, bmin,bmax);
		if (!overlapRange(amin,amax, bmin,bmax, eps))
		{
			// Found separating axis
			return false;
		}
	}
	return true;
}

// Returns a random point in a convex polygon.
// Adapted from Graphics Gems article.