Function constraintSplit

TheForceEngine/TFE_Polygon/polygon.cpp:498–594

	}
		
	void constraintSplit(s32 i0, s32 i1, s32 newVtx, Triangle* tri, Vec2f it, const Vec2f* c0, const Vec2f* c1, f32 prevConstIt)
	{
		// Find the matching edge.
		s32 startIndex = -1;
		s32 t0, t1;
		for (s32 i = 0; i < 3; i++)
		{
			s32 a = i, b = (i + 1) % 3;
			if ((tri->idx[a] == i0 && tri->idx[b] == i1) || (tri->idx[a] == i1 && tri->idx[b] == i0))
			{
				startIndex = i;
				t0 = tri->idx[a];
				t1 = tri->idx[b];
				break;
			}
		}
		if (startIndex < 0) { return; }

		// Now see if the line intersects either of the other two edges.
		for (s32 i = 1; i < 3; i++)
		{
			s32 a = (i + startIndex) % 3;
			s32 b = (a + 1) % 3;

			s32 A = tri->idx[a];
			s32 B = tri->idx[b];

			const Vec2f* v0 = &s_vertices[A];
			const Vec2f* v1 = &s_vertices[B];

			// Compute the intersection between line segment c0->c1 and v0->v1
			f32 constInter, triEdgeInter;
			if (!TFE_Math::lineSegmentIntersect(c0, c1, v0, v1, &constInter, &triEdgeInter))
			{
				continue;
			}

			if (constInter - prevConstIt < FLT_EPSILON)
			{
				// We aren't making any progress...
				// Abort to avoid a long running or infinite loop.
				PolyAssert(0);
				return;
			}

			// Constraint ends at vertex 'v0' or 'v1'
			const bool atV0 = triEdgeInter <= eps;
			const bool atV1 = triEdgeInter >= 1.0f - eps;
			if (atV0 || atV1)
			{
				PolyAssert(i != 1 || !atV0);
				PolyAssert(i != 2 || !atV1);
				s32 endVertex = atV0 ? A : B;
				// Triangles are:
				// T(newVtx, endVertex, t0)
				// T(newVtx, t1, endVertex)

				deleteTriangle(tri);