protected void _TestMove(ref float dt, Vector2 velocity, T2DCollisionImage theirImage, List<T2DCollisionInfo> list, bool theyMove)
{
Assert.Fatal(SceneObject is T2DTileLayer, "Not a tile layer");
T2DTileLayer tileLayer = (T2DTileLayer)SceneObject;
_polyImage._sceneObject = tileLayer;
T2DSceneObject theirObj = theirImage.SceneObject;
Vector2 theirPos = theirObj.Position;
Vector2 theirSize = theirObj.Size;
Vector2 searchMin = theirPos - 0.5f * theirSize;
Vector2 searchMax = searchMin + theirSize;
Vector2 searchDelta = theyMove ? velocity * dt : -velocity * dt;
// adjust search area by velocity
if (searchDelta.X > 0.0f)
searchMax.X += searchDelta.X;
else
searchMin.X += searchDelta.X;
if (searchDelta.Y > 0.0f)
searchMax.Y += searchDelta.Y;
else
searchMin.Y += searchDelta.Y;
ReadOnlyArray<T2DTileObject> matchedTiles = tileLayer.GetCollisionMatches(searchMin, searchMax);
Vector2[] savePoly = _polyImage.CollisionPolyBasis;
for (int i = 0; i < matchedTiles.Count; i++)
{
T2DTileObject tile = matchedTiles[i];
if (!tile.TileType.CollisionsEnabled ||
!(tile.TileType.ObjectType & theirImage.SceneObject.Collision.CollidesWith))
continue;
// Build collision poly for this tile
Vector2 scenePos = tileLayer.Position;
Vector2 tileSize = tileLayer.TileSize;
Vector2 tilePos = tile.GetTileLocalPosition(tileLayer.MapSize, tileSize);
Vector2 flip = new Vector2(tile.FlipX ? -1.0f : 1.0f, tile.FlipY ? -1.0f : 1.0f);
tileSize *= flip;
if (tile.TileType.CollisionPolyBasis == null)
{
// no custom poly so just use the tile's bounds
_polyImage.CollisionPolyBasis = savePoly; // restore to original poly image poly
_polyImage.CollisionPolyBasis[0] = tilePos - 0.5f * tileSize;
_polyImage.CollisionPolyBasis[1] = _polyImage.CollisionPolyBasis[2] = _polyImage.CollisionPolyBasis[3] = _polyImage.CollisionPolyBasis[0];
_polyImage.CollisionPolyBasis[1].X += tileSize.X;
_polyImage.CollisionPolyBasis[2] += tileSize;
_polyImage.CollisionPolyBasis[3].Y += tileSize.Y;
}
else
{
// see if we need to create a new PolyVertices array for this TileType
if (tile.TileType._polyVertices == null || tile.TileType._polyVertices.Length != tile.TileType.CollisionPolyBasis.Length)
{
tile.TileType._polyVertices = new Vector2[tile.TileType.CollisionPolyBasis.Length];
}
for (int j = 0; j < tile.TileType.CollisionPolyBasis.Length; j++)
tile.TileType._polyVertices[j] = 0.5f * tile.TileType.CollisionPolyBasis[j] * tileSize + tilePos;
// assign our TileType's PolyVertices to the TileLayer's _polyImage array
_polyImage.CollisionPolyBasis = tile.TileType._polyVertices;
}
if (_polyImage.Priority == theirImage.Priority)
{
// same priority, prefer "TestMove" version -- this ensures
// we only use TestMove version of poly collision image,
// saving us from implementing move against version.
if (theyMove)
theirImage.TestMove(ref dt, velocity, _polyImage, list);
else
_polyImage.TestMoveAgainst(ref dt, velocity, theirImage, list);
}
else if (_polyImage.Priority < theirImage.Priority)
{
// gotta use our image
if (theyMove)
_polyImage.TestMoveAgainst(ref dt, velocity, theirImage, list);
else
_polyImage.TestMove(ref dt, velocity, theirImage, list);
}
else
{
// gotta use their image
if (theyMove)
theirImage.TestMove(ref dt, velocity, _polyImage, list);
else
theirImage.TestMoveAgainst(ref dt, velocity, _polyImage, list);
}
}
_polyImage.CollisionPolyBasis = savePoly;
}
public override void TestMove(ref float dt, Vector2 ourVelocity, T2DCollisionImage theirImage, List<T2DCollisionInfo> list)
{
// entire tile layer is moving, find all potential tile collisions
_TestMove(ref dt, ourVelocity, theirImage, list, false);
}
public override void TestMoveAgainst(ref float dt, Vector2 theirVelocity, T2DCollisionImage theirImage, List<T2DCollisionInfo> list)
{
// find all potential tile collisions
_TestMove(ref dt, theirVelocity, theirImage, list, true);
}
public override void TestMoveAgainst(ref float dt, Vector2 theirVelocity, T2DCollisionImage theirImage, List<T2DCollisionInfo> list)
{
// we'll need to make sure theirCollider is of the right type here...and maybe switch based on one of a few types
// We don't know how to collide with other types, so if we get here no collision...or should we assert?
}
public override void TestMove(ref float dt, Vector2 ourVelocity, T2DCollisionImage theirImage, List<T2DCollisionInfo> list)
{
// we'll need to make sure theirCollider is of the right type here...and maybe switch based on one of a few types
T2DPolyImage theirPoly = theirImage as T2DPolyImage;
Assert.Fatal(theirPoly != null, "T2DPolyImage.TestMove: don't know how to test against this image type");
Vector2 pos = Vector2.Zero;
float rot = 0.0f;
if (SceneObject != null)
{
pos = SceneObject.Position;
rot = SceneObject.Rotation;
}
Vector2 theirPos = Vector2.Zero;
float theirRot = 0.0f;
Vector2 theirVel = Vector2.Zero;
if (theirImage.SceneObject != null)
{
theirPos = theirImage.SceneObject.Position;
theirRot = theirImage.SceneObject.Rotation;
if (theirImage.SceneObject.Physics != null && Vector2.Dot(theirPos - pos, theirImage.SceneObject.Physics.Velocity) > 0.0f)
// only use their velocity if they are moving away from us (i.e., if this can prevent a collision)
theirVel = theirImage.SceneObject.Physics.Velocity;
}
float collisionTime = 0.0f;
Vector2 collisionNormal = Vector2.Zero;
Vector2 collisionPoint = Vector2.Zero;
Vector2 collisionPenetration = Vector2.Zero;
bool collisionTest = Collision2D.IntersectMovingPolyPoly(
dt, CollisionPoly, theirPoly.CollisionPoly,
pos, theirPos,
rot, theirRot,
ourVelocity, theirVel,
ref collisionPoint, ref collisionNormal, ref collisionPenetration, ref collisionTime);
if (collisionTest)
_AddCollisionPoint(ref dt, collisionTime, collisionPoint, collisionNormal, collisionPenetration, theirImage.SceneObject, 0, list);
}
/// <summary>
/// Test whether other collision image collides with this image when moving at given velocity for given amount of time.
/// Collisions are added to 'list'.
/// </summary>
/// <param name="dt">Time spent moving, in seconds.</param>
/// <param name="theirVelocity">Other image velocity.</param>
/// <param name="theirImage">Collision image to test against</param>
/// <param name="list">List of collision information to which current collisions will be added to.</param>
public virtual void TestMoveAgainst(ref float dt, Vector2 theirVelocity, T2DCollisionImage theirImage, List<T2DCollisionInfo> list)
{
// we'll need to make sure theirCollider is of the right type here...and maybe switch based on one of a few types
// base collider component never collides with anything
}
/// <summary>
/// Remove a collision image previously installed.
/// </summary>
/// <param name="image">Collision image to remove.</param>
public void RemoveImage(T2DCollisionImage image)
{
_collisionImages.Remove(image);
}
/// <summary>
/// Install a new collision image. When moving, the object checks each collision image installed against all
/// the collision images of whatever objects it moves toward.
/// </summary>
/// <param name="image">The collision image to add.</param>
public void InstallImage(T2DCollisionImage image)
{
image._sceneObject = SceneObject;
_collisionImages.Add(image);
}