/// <summary>
/// Transform minimum and maximum bounds from one space to another. For example,
/// this is useful to find the minimum and maximum bounds of a tile collider
/// within local space of tile system.
/// </summary>
/// <param name="bounds">Bounds that are to be transformed.</param>
/// <param name="mat">Space-to-space transformation matrix.</param>
/// <returns>
/// The transformed bounds.
/// </returns>
private static BoxBounds SpaceToSpace(BoxBounds bounds, Matrix4x4 mat)
{
return(new BoxBounds(
mat.MultiplyPoint3x4(bounds.Min),
mat.MultiplyPoint3x4(bounds.Max)
));
}
public bool Encapsulate(BoxBounds other)
{
int matchCount = 0;
for (int i = 0; i < 8 && matchCount != 4; ++i)
{
var p = this[i];
for (int j = 0; j < 8; ++j)
{
var q = other[j];
if (Approx(p, q, ErrorThreshold))
{
++matchCount;
break;
}
}
}
if (matchCount != 4)
{
return(false);
}
this.min = Vector3.Min(this.min, other.min);
this.max = Vector3.Max(this.max, other.max);
return(true);
}
/// <summary>
/// Gather collider information from 3D <see cref="BoxCollider"/> component.
/// </summary>
/// <param name="info">Collider information instance.</param>
/// <param name="collider">Component which resides somewhere within tile.</param>
private void GatherInfo_BoxCollider3D(ColliderInfo info, BoxCollider collider)
{
var tileToSystemMatrix = this.worldToSystem * collider.transform.localToWorldMatrix;
info.IsTrigger = collider.isTrigger;
info.Material = collider.sharedMaterial;
info.Collider = collider;
info.Bounds = SpaceToSpace(BoxBounds.FromBounds(collider.center, collider.size), tileToSystemMatrix);
}
/// <summary>
/// Create new "Combined Collider" game object which covers bounds of tiles that
/// have been reduced. Reduced tile game objects are stripped if they nolonger
/// contain any useful components.
/// </summary>
/// <param name="info">Information about reduced collider.</param>
/// <param name="reducedBounds">Bounding area of all reduced colliders.</param>
private void Reduce(ColliderInfo info, BoxBounds reducedBounds)
{
var reducedGO = new GameObject("Combined Collider");
// Can only copy layer and tag from collider information when the collider
// information actually contains a game object!
if (info.Tile.gameObject != null)
{
if (this.separateByLayer)
{
reducedGO.layer = info.Tile.gameObject.layer;
}
if (this.separateByTag)
{
reducedGO.tag = info.Tile.gameObject.tag;
}
}
var reducedTransform = reducedGO.transform;
reducedTransform.SetParent(this.system.transform, false);
reducedBounds = SpaceToSpace(reducedBounds, reducedTransform.worldToLocalMatrix * this.systemToWorld);
switch (info.Type)
{
case ColliderType.BoxCollider2D: {
var collider = reducedGO.AddComponent <BoxCollider2D>();
collider.offset = reducedBounds.center;
collider.size = reducedBounds.size;
collider.isTrigger = info.IsTrigger;
collider.sharedMaterial = info.Material as PhysicsMaterial2D;
this.DestroyTrackedColliders();
}
break;
case ColliderType.BoxCollider3D: {
var collider = reducedGO.AddComponent <BoxCollider>();
collider.center = reducedBounds.center;
collider.size = reducedBounds.size;
collider.isTrigger = info.IsTrigger;
collider.sharedMaterial = info.Material as PhysicMaterial;
this.DestroyTrackedColliders();
}
break;
default:
Debug.LogWarning(string.Format("Collider reduction not implemented for '{0}'.", info.Type));
break;
}
}
/// <summary>
/// Gather hypothetical collider information from solid flag.
/// </summary>
/// <param name="info">Collider information instance.</param>
private void GatherInfo_SolidFlag(ColliderInfo info)
{
info.IsTrigger = false;
// Bounds of 2D colliders need to be consistent.
Vector3 boundsSize = this.system.CellSize;
if (info.Type == ColliderType.BoxCollider2D)
{
boundsSize.z = 1f;
}
info.Bounds = BoxBounds.FromBounds(this.system.LocalPositionFromTileIndex(info.Row, info.Column), boundsSize);
}
/// <summary>
/// Gather collider information from <see cref="BoxCollider2D"/> component.
/// </summary>
/// <param name="info">Collider information instance.</param>
/// <param name="collider">Component which resides somewhere within tile.</param>
private void GatherInfo_BoxCollider2D(ColliderInfo info, BoxCollider2D collider)
{
var tileToSystemMatrix = this.worldToSystem * collider.transform.localToWorldMatrix;
// Bounds of 2D colliders need to be consistent.
Vector3 boundsSize = collider.size;
boundsSize.z = 1f;
Vector3 center = collider.offset;
info.IsTrigger = collider.isTrigger;
info.Material = collider.sharedMaterial;
info.Collider = collider;
info.Bounds = SpaceToSpace(BoxBounds.FromBounds(center, boundsSize), tileToSystemMatrix);
}
/// <summary>
/// Scans for and applies reductions if specified anchor tile contains a collider.
/// </summary>
/// <remarks>
/// <para>This method searches from left-to-right from specified anchor tile to
/// find furthest tile horizontally that it can be reduced with. Once the initial
/// horizontal sequence is known this method proceeds to scan vertically for other
/// sequences of colliders that can further reduce the initial horizontal sequence.</para>
/// </remarks>
/// <param name="anchor">Index of anchor tile.</param>
/// <returns></returns>
private int Scan(TileIndex anchor)
{
ColliderInfo anchorInfo = null;
this.GetColliderInfo(ref anchorInfo, anchor);
if (anchorInfo == null)
{
return(anchor.column);
}
ColliderInfo info = null, firstInfo = null, lastInfo = null;
// Begin tracking list of collider components which will be combined.
this.ResetReducedColliderTracking();
this.TrackReducedCollider(anchorInfo.Row, anchorInfo.Column, anchorInfo.Collider);
try {
TileIndex target = anchor;
BoxBounds reducedBounds = anchorInfo.Bounds;
// Scan rightwards for colliders which can be combined with anchor.
for (int column = anchor.column + 1; column < this.system.ColumnCount; ++column)
{
if (this.markedTiles[anchor.row, column])
{
break;
}
this.GetColliderInfo(ref info, anchor.row, column);
if (!this.CanReduce(info, anchorInfo))
{
break;
}
// Can candidate collider be combined with anchor?
if (!reducedBounds.Encapsulate(info.Bounds))
{
break;
}
target.column = column;
this.TrackReducedCollider(info.Row, info.Column, info.Collider);
}
this.GetColliderInfo(ref info, target);
var prevFirstBounds = anchorInfo.Bounds;
var prevLastBounds = info.Bounds;
// Extend downwards if possible, though avoid crossing T-junctions since splitting
// a T-junction will often cause more colliders to occur in result.
for (int row = anchor.row + 1; row < this.system.RowCount; ++row)
{
this.GetColliderInfo(ref firstInfo, row, anchor.column);
this.GetColliderInfo(ref lastInfo, row, target.column);
if (firstInfo == null || lastInfo == null || !this.CanReduce(firstInfo, anchorInfo) || this.CheckForTJunction(firstInfo, lastInfo))
{
goto FinishedExtendingDownards;
}
// Does first and last tile from previous row extend downwards?
if (!prevFirstBounds.Encapsulate(firstInfo.Bounds) || !prevLastBounds.Encapsulate(lastInfo.Bounds))
{
goto FinishedExtendingDownards;
}
// No need to track collider from `lastInfo` since it will be included
// within the following loop.
this.candidateColliders.Clear();
this.candidateColliders.Add(firstInfo.Collider);
// Reduce bounds for strip.
BoxBounds stripBounds = firstInfo.Bounds;
for (int column = anchor.column + 1; column <= target.column; ++column)
{
this.GetColliderInfo(ref info, row, column);
if (!this.CanReduce(info, anchorInfo) || !stripBounds.Encapsulate(info.Bounds))
{
goto FinishedExtendingDownards;
}
this.candidateColliders.Add(info.Collider);
}
// The following should not fail, but let's just be safe!
if (!reducedBounds.Encapsulate(stripBounds))
{
Debug.LogWarning("Unable to encapsulate collider on reduce.");
goto FinishedExtendingDownards;
}
target.row = row;
// Accept and track candidate colliders!
for (int i = 0; i < this.candidateColliders.Count; ++i)
{
this.TrackReducedCollider(row, anchor.column + i, this.candidateColliders[i]);
}
prevFirstBounds = firstInfo.Bounds;
prevLastBounds = lastInfo.Bounds;
}
FinishedExtendingDownards:
;
bool hasManyColliders = (this.reducedColliderCount > 1);
bool hasOneHypotheticalCollider = (this.reducedColliderCount == 1 && this.reducedColliderComponents.Count == 0);
if (hasManyColliders || hasOneHypotheticalCollider)
{
this.Reduce(anchorInfo, reducedBounds);
}
return(target.column);
}
finally {
ColliderInfo.Despawn(anchorInfo);
ColliderInfo.Despawn(info);
ColliderInfo.Despawn(firstInfo);
ColliderInfo.Despawn(lastInfo);
}
}
