private void UpdateTriangleCoords()
{
IndexedTriangle t = CurrentTriangle;
// triangleCoords[0] is always (0, 0)
triangleCoords[1] = worldToSurface.MultiplyPoint3x4(vertices[t.i2]);
triangleCoords[2] = worldToSurface.MultiplyPoint3x4(vertices[t.i3]);
}
// TODO: implement mesh.GetRawTriangle(int index)
public static void DrawTriangle(this Mesh mesh, int index, Color color)
{
IndexedTriangle triangle = mesh.GetSaneTriangles(0)[index];
Vector3[] vertices = mesh.vertices;
for (int i = 0; i < 3; ++i)
{
Vector3 start = vertices[triangle[i]];
Vector3 end = vertices[triangle[(i + 1) % 3]];
Debug.DrawLine(start, end, color, 0, false);
}
}
private void GenerateIndex(Mesh mesh)
{
TriangleArray triangles = mesh.GetSaneTriangles(0);
for (int i = 0; i < triangles.Length; ++i)
{
IndexedTriangle triangle = triangles[i];
for (int j = 0; j < 3; ++j)
{
var edge = new IndexedEdge(
triangle[j],
triangle[(j + 1) % 3]
);
edgeToTriangleMap.Add(edge, i);
}
}
}
/**
* Moves IWalker forward by \param distance, stopping if an edge has been reached
* (in which case \param distanceLeft > 0)
*/
public void StepUntilEdge(float distance, out float distanceLeft)
{
bool[] filteredEdges = new bool[3];
CullBackEdges(ref filteredEdges);
int intersectedEdge;
Vector2 intersectionPoint = GetEdgeIntersection(filteredEdges, out intersectedEdge);
// Have we reached the edge?
{
float edgeDistance = (surfaceTransform.localPosition - intersectionPoint).magnitude;
distanceLeft = distance - edgeDistance;
if (distanceLeft < 0)
{
// The step haven't reached triangle sides
distanceLeft = 0;
surfaceTransform.localPosition += LocalDirection * distance;
return;
}
}
// The edge had been reached, now we should move to the neighbor triangle
int neighbor = GetNeighborTriangle(intersectedEdge);
// Get coordinates and angle in neighbor triangle space
{
// Intersected edge direction in old triangle's space
Vector2 edgeDirection = triangleCoords[(intersectedEdge + 1) % 3]
- triangleCoords[intersectedEdge];
// Index of intersected edge end vertex, to find corresponding edge
// in the neighbor triangle (it will be the start vertex index there)
int intersectedEdgeEnd = CurrentTriangle[(intersectedEdge + 1) % 3];
// "Intermediate" angle (the angle which is equal between both triangle's coordinate systems)
float beta = surfaceTransform.angle - (-edgeDirection).GetAngle();
Vector3 worldPosition = surfaceToWorld.MultiplyPoint3x4(intersectionPoint);
surfaceTransform.triangleIndex = neighbor;
UpdateMatrices(surfaceTransform.triangleIndex);
UpdateTriangleCoords();
surfaceTransform.localPosition = worldToSurface.MultiplyPoint3x4(worldPosition);
// Intersected edge direction in new triangle's space
int intersectedEdgeNew = 0;
IndexedTriangle triangle = CurrentTriangle;
for (int i = 0; i < 3; i++)
{
if (triangle[i] == intersectedEdgeEnd)
{
intersectedEdgeNew = i;
}
}
Vector2 edgeDirectionNew = triangleCoords[(intersectedEdgeNew + 1) % 3]
- triangleCoords[intersectedEdgeNew];
float newAngle = MathUtils.NormalizeAngle(beta + edgeDirectionNew.GetAngle());
float angleDelta = newAngle - surfaceTransform.angle;
surfaceTransform.angle = newAngle;
OnTriangleChanged?.Invoke(angleDelta);
#if UNITY_EDITOR
if (debugDrawEnabled)
{
Vector2 center = (triangleCoords[1] + triangleCoords[2]) / 3;
Vector2 start = triangleCoords[intersectedEdgeNew];
Vector2 end = triangleCoords[(intersectedEdgeNew + 1) % 3];
start = Vector2.Lerp(start, center, 0.2f);
end = Vector2.Lerp(end, center, 0.2f);
DrawLocalLine(start, end, Color.magenta);
}
#endif
}
}
