/** Unwraps the funnel portals from 3D space to 2D space.
* The result is stored in the \a left and \a right arrays which must have lengths equal to the funnel.left and funnel.right lists.
*
* The input is a funnel like in the image below. It may be rotated and twisted.
* \shadowimage{funnel_unwrap_input.png}
* The output will be a funnel in 2D space like in the image below. All twists and bends will have been straightened out.
* \shadowimage{funnel_unwrap_output.png}
*
* \see Calculate(FunnelPortals,bool,bool)
*/
public static void Unwrap(FunnelPortals funnel, Vector2[] left, Vector2[] right)
{
var normal = Vector3.Cross(funnel.right[1] - funnel.left[0], funnel.left[1] - funnel.left[0]);
left[0] = right[0] = Vector2.zero;
var portalLeft = funnel.left[1];
var portalRight = funnel.right[1];
var prevPoint = funnel.left[0];
// The code below is equivalent to this matrix (but a lot faster)
// This represents a rotation around a line in 3D space
// Matrix4x4 m = Matrix4x4.TRS(Vector3.zero, Quaternion.FromToRotation(normal, Vector3.forward), Vector3.one) * Matrix4x4.TRS(-funnel.right[0], Quaternion.identity, Vector3.one);
Quaternion mRot = Quaternion.FromToRotation(normal, Vector3.forward);
Vector3 mOffset = mRot * (-funnel.right[0]);
for (int i = 1; i < funnel.left.Count; i++)
{
if (UnwrapHelper(portalLeft, portalRight, prevPoint, funnel.left[i], ref mRot, ref mOffset))
{
prevPoint = portalLeft;
portalLeft = funnel.left[i];
}
left[i] = mRot * funnel.left[i] + mOffset;
if (UnwrapHelper(portalLeft, portalRight, prevPoint, funnel.right[i], ref mRot, ref mOffset))
{
prevPoint = portalRight;
portalRight = funnel.right[i];
}
right[i] = mRot * funnel.right[i] + mOffset;
}
}
public static void ShrinkPortals(FunnelPortals portals, float shrink)
{
if (shrink <= 0.00001f)
{
return;
}
for (int i = 0; i < portals.left.Count; i++)
{
var left = portals.left[i];
var right = portals.right[i];
var length = (left - right).magnitude;
if (length > 0)
{
float s = Mathf.Min(shrink / length, 0.4f);
//Good Game
/*portals.left[i] = Vector3.Lerp(left, right, s);
* portals.right[i] = Vector3.Lerp(left, right, 1 - s);*/
portals.left[i] = VInt3.Lerp(left, right, s);
portals.right[i] = VInt3.Lerp(left, right, 1 - s);
}
}
}
/** Unwraps the funnel portals from 3D space to 2D space.
* The result is stored in the \a left and \a right arrays which must be at least as large as the funnel.left and funnel.right lists.
*
* The input is a funnel like in the image below. It may be rotated and twisted.
* \shadowimage{funnel_unwrap_input.png}
* The output will be a funnel in 2D space like in the image below. All twists and bends will have been straightened out.
* \shadowimage{funnel_unwrap_output.png}
*
* \see #Calculate(FunnelPortals,bool,bool)
*/
//Good Game
//public static void Unwrap (FunnelPortals funnel, Vector2[] left, Vector2[] right) {
public static void Unwrap(FunnelPortals funnel, VInt2[] left, VInt2[] right)
{
int startingIndex = 1;
//Good Game
//var normal = Vector3.Cross(funnel.right[1] - funnel.left[0], funnel.left[1] - funnel.left[0]);
var normal = VInt3.Cross(funnel.right[1] - funnel.left[0], funnel.left[1] - funnel.left[0]);
// This handles the case when the starting point is colinear with the first portal.
// Note that left.Length is only guaranteed to be at least as large as funnel.left.Count, it may be larger.
//Good Game
//while (normal.sqrMagnitude <= 0.00000001f && startingIndex + 1 < funnel.left.Count) {
while (normal.sqrMagnitude <= 0.000001 && startingIndex + 1 < funnel.left.Count)
{
startingIndex++;
//Good Game
//normal = Vector3.Cross(funnel.right[startingIndex] - funnel.left[0], funnel.left[startingIndex] - funnel.left[0]);
normal = VInt3.Cross(funnel.right[startingIndex] - funnel.left[0], funnel.left[startingIndex] - funnel.left[0]);
}
left[0] = right[0] = VInt2.zero;
var portalLeft = funnel.left[1];
var portalRight = funnel.right[1];
var prevPoint = funnel.left[0];
// The code below is equivalent to this matrix (but a lot faster)
// This represents a rotation around a line in 3D space
// Matrix4x4 m = Matrix4x4.TRS(Vector3.zero, Quaternion.FromToRotation(normal, Vector3.forward), Vector3.one) * Matrix4x4.TRS(-funnel.right[0], Quaternion.identity, Vector3.one);
Quaternion mRot = Quaternion.FromToRotation((Vector3)normal, Vector3.forward);
Vector3 mOffset = mRot * (-(Vector3)funnel.right[0]);
for (int i = 1; i < funnel.left.Count; i++)
{
//Good Game
//if (UnwrapHelper((Vector3)portalLeft, (Vector3)portalRight, (Vector3)prevPoint, (Vector3)funnel.left[i], ref mRot, ref mOffset)) {
if (UnwrapHelper((Vector3)portalLeft, (Vector3)portalRight, (Vector3)prevPoint, (Vector3)funnel.left[i], ref mRot, ref mOffset))
{
prevPoint = portalLeft;
portalLeft = funnel.left[i];
}
left[i] = VInt2.FromInt3XZ((VInt3)(mRot * (Vector3)funnel.left[i] + mOffset));
//Good Game
//if (UnwrapHelper(portalLeft, portalRight, prevPoint, funnel.right[i], ref mRot, ref mOffset)) {
if (UnwrapHelper((Vector3)portalLeft, (Vector3)portalRight, (Vector3)prevPoint, (Vector3)funnel.right[i], ref mRot, ref mOffset))
{
prevPoint = portalRight;
portalRight = funnel.right[i];
}
right[i] = VInt2.FromInt3XZ((VInt3)(mRot * (Vector3)funnel.right[i] + mOffset));
}
}
/// <summary>
/// Calculate the shortest path through the funnel.
///
/// If the unwrap option is disabled the funnel will simply be projected onto the XZ plane.
/// If the unwrap option is enabled then the funnel may be oriented arbitrarily and may have twists and bends.
/// This makes it possible to support the funnel algorithm in XY space as well as in more complicated cases, such
/// as on curved worlds.
/// [Open online documentation to see images]
///
/// [Open online documentation to see images]
///
/// See: Unwrap
/// </summary>
/// <param name="funnel">The portals of the funnel. The first and last vertices portals must be single points (so for example left[0] == right[0]).</param>
/// <param name="unwrap">Determines if twists and bends should be straightened out before running the funnel algorithm.</param>
/// <param name="splitAtEveryPortal">If true, then a vertex will be inserted every time the path crosses a portal
/// instead of only at the corners of the path. The result will have exactly one vertex per portal if this is enabled.
/// This may introduce vertices with the same position in the output (esp. in corners where many portals meet).</param>
public static List <Vector3> Calculate(FunnelPortals funnel, bool unwrap, bool splitAtEveryPortal)
{
if (funnel.left.Count != funnel.right.Count)
{
throw new System.ArgumentException("funnel.left.Count != funnel.right.Count");
}
// Get arrays at least as large as the number of portals
var leftArr = ArrayPool <Vector2> .Claim(funnel.left.Count);
var rightArr = ArrayPool <Vector2> .Claim(funnel.left.Count);
if (unwrap)
{
Unwrap(funnel, leftArr, rightArr);
}
else
{
// Copy to arrays
for (int i = 0; i < funnel.left.Count; i++)
{
leftArr[i] = ToXZ(funnel.left[i]);
rightArr[i] = ToXZ(funnel.right[i]);
}
}
int startIndex = FixFunnel(leftArr, rightArr, funnel.left.Count);
var intermediateResult = ListPool <int> .Claim();
if (startIndex == -1)
{
// If funnel algorithm failed, fall back to a simple line
intermediateResult.Add(0);
intermediateResult.Add(funnel.left.Count - 1);
}
else
{
bool lastCorner;
Calculate(leftArr, rightArr, funnel.left.Count, startIndex, intermediateResult, int.MaxValue, out lastCorner);
}
// Get list for the final result
var result = ListPool <Vector3> .Claim(intermediateResult.Count);
Vector2 prev2D = leftArr[0];
var prevIdx = 0;
for (int i = 0; i < intermediateResult.Count; i++)
{
var idx = intermediateResult[i];
if (splitAtEveryPortal)
{
// Check intersections with every portal segment
var next2D = idx >= 0 ? leftArr[idx] : rightArr[-idx];
for (int j = prevIdx + 1; j < System.Math.Abs(idx); j++)
{
var factor = VectorMath.LineIntersectionFactorXZ(FromXZ(leftArr[j]), FromXZ(rightArr[j]), FromXZ(prev2D), FromXZ(next2D));
result.Add(Vector3.Lerp(funnel.left[j], funnel.right[j], factor));
}
prevIdx = Mathf.Abs(idx);
prev2D = next2D;
}
if (idx >= 0)
{
result.Add(funnel.left[idx]);
}
else
{
result.Add(funnel.right[-idx]);
}
}
// Release lists back to the pool
ListPool <int> .Release(ref intermediateResult);
ArrayPool <Vector2> .Release(ref leftArr);
ArrayPool <Vector2> .Release(ref rightArr);
return(result);
}
/** Calculate the shortest path through the funnel.
* \param funnel The portals of the funnel. The first and last vertices portals must be single points (so for example left[0] == right[0]).
* \param unwrap Determines if twists and bends should be straightened out before running the funnel algorithm.
* \param splitAtEveryPortal If true, then a vertex will be inserted every time the path crosses a portal
* instead of only at the corners of the path. The result will have exactly one vertex per portal if this is enabled.
* This may introduce vertices with the same position in the output (esp. in corners where many portals meet).
*
* If the unwrap option is disabled the funnel will simply be projected onto the XZ plane.
* If the unwrap option is enabled then the funnel may be oriented arbitrarily and may have twists and bends.
* This makes it possible to support the funnel algorithm in XY space as well as in more complicated cases, such
* as on curved worlds.
* \shadowimage{funnel_unwrap_illustration.png}
*
* \shadowimage{funnel_split_at_every_portal.png}
*
* \see Unwrap
*/
public static List <Vector3> Calculate(FunnelPortals funnel, bool unwrap, bool splitAtEveryPortal)
{
var leftArr = new Vector2[funnel.left.Count];
var rightArr = new Vector2[funnel.left.Count];
if (unwrap)
{
Unwrap(funnel, leftArr, rightArr);
}
else
{
// Copy to arrays
for (int i = 0; i < leftArr.Length; i++)
{
leftArr[i] = ToXZ(funnel.left[i]);
rightArr[i] = ToXZ(funnel.right[i]);
}
}
var origLeft = leftArr;
int startIndex = FixFunnel(ref leftArr, ref rightArr);
var left3D = funnel.left;
var right3D = funnel.right;
if (origLeft != leftArr)
{
// Flipped order
left3D = funnel.right;
right3D = funnel.left;
}
var intermediateResult = ListPool <int> .Claim();
if (startIndex == -1)
{
// If funnel algorithm failed, degrade to simple line
intermediateResult.Add(0);
intermediateResult.Add(funnel.left.Count - 1);
}
else
{
bool lastCorner;
Calculate(leftArr, rightArr, startIndex, intermediateResult, int.MaxValue, out lastCorner);
}
// Get list for the final result
var result = ListPool <Vector3> .Claim(intermediateResult.Count);
Vector2 prev2D = leftArr[0];
var prevIdx = 0;
for (int i = 0; i < intermediateResult.Count; i++)
{
var idx = intermediateResult[i];
if (splitAtEveryPortal)
{
// Check intersections with every portal segment
var next2D = idx >= 0 ? leftArr[idx] : rightArr[-idx];
for (int j = prevIdx + 1; j < System.Math.Abs(idx); j++)
{
var factor = VectorMath.LineIntersectionFactorXZ(FromXZ(leftArr[j]), FromXZ(rightArr[j]), FromXZ(prev2D), FromXZ(next2D));
result.Add(Vector3.Lerp(left3D[j], right3D[j], factor));
}
prevIdx = Mathf.Abs(idx);
prev2D = next2D;
}
if (idx >= 0)
{
result.Add(left3D[idx]);
}
else
{
result.Add(right3D[-idx]);
}
}
// Release lists back to the pool
ListPool <Vector3> .Release(funnel.left);
ListPool <Vector3> .Release(funnel.right);
ListPool <int> .Release(intermediateResult);
return(result);
}
