C# Edge.oppositeEdge方法代码示例

		/// <summary>
		/// gets a list of all the tiles intersecting bounds. The returned list is ordered for collision detection based on the
		/// direction passed in so they can be processed in order.
		/// </summary>
		/// <returns>The colliding tiles.</returns>
		/// <param name="bounds">Bounds.</param>
		/// <param name="direction">Direction.</param>
		void populateCollidingTiles( Rectangle bounds, Edge direction )
		{
			_collidingTiles.Clear();
			var isHorizontal = direction.isHorizontal();
			var primaryAxis = isHorizontal ? Axis.X : Axis.Y;
			var oppositeAxis = primaryAxis == Axis.X ? Axis.Y : Axis.X;

			var oppositeDirection = direction.oppositeEdge();
			var firstPrimary = worldToTilePosition( bounds.getSide( oppositeDirection ), primaryAxis );
			var lastPrimary = worldToTilePosition( bounds.getSide( direction ), primaryAxis );
			var primaryIncr = direction.isMax() ? 1 : -1;

			var min = worldToTilePosition( isHorizontal ? bounds.Top : bounds.Left, oppositeAxis );
			var mid = worldToTilePosition( isHorizontal ? bounds.getCenter().Y : bounds.getCenter().X, oppositeAxis );
			var max = worldToTilePosition( isHorizontal ? bounds.Bottom : bounds.Right, oppositeAxis );

			var isPositive = mid - min < max - mid;
			var secondaryIncr = isPositive ? 1 : -1;
			var firstSecondary = isPositive ? min : max;
			var lastSecondary = !isPositive ? min : max;

			for( var primary = firstPrimary; primary != lastPrimary + primaryIncr; primary += primaryIncr )
			{
				for( var secondary = firstSecondary; secondary != lastSecondary + secondaryIncr; secondary += secondaryIncr )
				{
					var col = isHorizontal ? primary : secondary;
					var row = !isHorizontal ? primary : secondary;
					_collidingTiles.Add( collisionLayer.getTile( col, row ) );

					#if DEBUG_MOVER
					if( direction.isHorizontal() )
					{
						var pos = tiledMap.tileToWorldPosition( new Point( col, row ) );
						_debugTiles.Add( new Rectangle( (int)pos.X, (int)pos.Y, 16, 16 ) );
					}
					#endif
				}
			}
		}

		/// <summary>
		/// Tests the tile for a collision. Returns via out the position in world space where the collision occured.
		/// </summary>
		/// <returns>The tile collision.</returns>
		/// <param name="tile">Tile.</param>
		/// <param name="edgeToTest">the opposite side of movement, the side the leading edge will collide with</param>
		/// <param name="perpindicularPosition">Perpindicular position.</param>
		/// <param name="leadingPosition">Leading position.</param>
		/// <param name="shouldTestSlopes">Should test slopes.</param>
		/// <param name="collisionResponse">Collision response.</param>
		bool testTileCollision( TiledTile tile, Edge edgeToTest, int perpindicularPosition, int leadingPosition, bool shouldTestSlopes, out int collisionResponse )
		{
			collisionResponse = leadingPosition;

			// one way platforms are only collideable from the top when the player is already above them
			if( tile.isOneWayPlatform() )
			{
				// only the top edge of one way platforms are checked for collisions
				if( edgeToTest != Edge.Top )
					return false;

				// our response should be the top of the platform
				collisionResponse = tiledMap.tileToWorldPositionX( tile.y );
				return _boxColliderBounds.Bottom <= collisionResponse;
			}

			var forceSlopedTileCheckAsWall = false;

			// when moving horizontally the only time a slope is considered for collision testing is when its closest side is the tallest side
			// and we were not intesecting the tile before moving.
			// this prevents clipping through a tile when hitting its edge: -> |\
			if( edgeToTest.isHorizontal() && tile.isSlope() && tile.getNearestEdge( leadingPosition ) == tile.getHighestSlopeEdge() )
			{
				var moveDir = edgeToTest.oppositeEdge();
				var leadingPositionPreMovement = _boxColliderBounds.getSide( moveDir );

				// we need the tile x position that is on the opposite side of our move direction. Moving right we want the left edge
				var tileX = moveDir == Edge.Right ? tiledMap.tileToWorldPositionX( tile.x ) : tiledMap.tileToWorldPositionX( tile.x + 1 );

				// using the edge before movement, we see if we were colliding before moving.
				var wasCollidingBeforeMove = moveDir == Edge.Right ? leadingPositionPreMovement > tileX : leadingPositionPreMovement < tileX;

				// if we were not colliding before moving we need to consider this tile for a collision check as if it were a wall tile
				forceSlopedTileCheckAsWall = !wasCollidingBeforeMove;
			}


			if( forceSlopedTileCheckAsWall || !tile.isSlope() )
			{				
				switch( edgeToTest )
				{
					case Edge.Top:
						collisionResponse = tiledMap.tileToWorldPositionY( tile.y );
						break;
					case Edge.Bottom:
						collisionResponse = tiledMap.tileToWorldPositionY( tile.y + 1 );
						break;
					case Edge.Left:
						collisionResponse = tiledMap.tileToWorldPositionX( tile.x );
						break;
					case Edge.Right:
						collisionResponse = tiledMap.tileToWorldPositionX( tile.x + 1 );
						break;
				}

				return true;
			}

			if( shouldTestSlopes )
			{
				var tileWorldX = tiledMap.tileToWorldPositionX( tile.x );
				var tileWorldY = tiledMap.tileToWorldPositionX( tile.y );
				var slope = tile.getSlope();
				var offset = tile.getSlopeOffset();

				// calculate the point on the slope at perpindicularPosition
				collisionResponse = (int)( edgeToTest.isVertical() ? slope * ( perpindicularPosition - tileWorldX ) + offset + tileWorldY : ( perpindicularPosition - tileWorldY - offset ) / slope + tileWorldX );
				var isColliding = edgeToTest.isMax() ? leadingPosition <= collisionResponse : leadingPosition >= collisionResponse;

				// this code ensures that we dont consider collisions on a slope while jumping up that dont intersect our collider.
				// It also makes sure when testing the bottom edge that the leadingPosition is actually above the collisionResponse.
				// HACK: It isn't totally perfect but it does the job
				if( isColliding && edgeToTest == Edge.Bottom && leadingPosition <= collisionResponse )
					isColliding = false;
				
				return isColliding;
			}

			return false;
		}

        bool testMapCollision( Rectangle collisionRect, Edge direction, out int collisionResponse )
        {
            collisionResponse = 0;
            var side = direction.oppositeEdge();
            var perpindicularPosition = side.isVertical() ? collisionRect.Center.X : collisionRect.Center.Y;
            var leadingPosition = collisionRect.getSide( direction );
            var shouldTestSlopes = side.isVertical();
            populateCollidingTiles( collisionRect, direction );

            for( var i = 0; i < _collidingTiles.Count; i++ )
            {
                if( _collidingTiles[i] == null )
                    continue;

                // TODO: is this necessary? seems to work without it
                // disregard horizontal collisions  if the last tile we were grounded on was a slope
                // this is not a fantastic solution
                if( direction.isHorizontal() && _lastGroundTile != null && _lastGroundTile.isSlope() )
                    continue;

                if( testTileCollision( _collidingTiles[i], side, perpindicularPosition, leadingPosition, shouldTestSlopes, out collisionResponse ) )
                {
                    // store off our last ground tile if we collided below
                    if( direction == Edge.Bottom )
                        _lastGroundTile = _collidingTiles[i];

                    return true;
                }

                // special case for sloped ground tiles
                if( _lastGroundTile != null && direction == Edge.Bottom )
                {
                    // if grounded on a slope and intersecting a slope or if grounded on a wall and intersecting a tall slope we go sticky
                    // tall slope here means one where the the slopeTopLeft/Right is 0, i.e. it connects to a wall
                    if( ( _lastGroundTile.isSlope() && _collidingTiles[i].isSlope() ) || ( !_lastGroundTile.isSlope() && _collidingTiles[i].isSlope() /* should be tall slope check */ ) )
                    {
                        // store off our last ground tile if we collided below
                        _lastGroundTile = _collidingTiles[i];

                        return true;
                    }
                }
            }

            return false;
        }

		bool testMapCollision( Rectangle collisionRect, Edge direction, CollisionState collisionState, out int collisionResponse )
		{
			collisionResponse = 0;
			var side = direction.oppositeEdge();
			var perpindicularPosition = side.isVertical() ? collisionRect.Center.X : collisionRect.Center.Y;
			var leadingPosition = collisionRect.getSide( direction );
			var shouldTestSlopes = side.isVertical();
			populateCollidingTiles( collisionRect, direction );

			for( var i = 0; i < _collidingTiles.Count; i++ )
			{
				if( _collidingTiles[i] == null )
					continue;

				// disregard horizontal collisions if the last tile we were grounded on was a slope. Our y movement will push us up on the slope.
				// this is not a fantastic solution
				if( direction.isHorizontal() && collisionState._lastGroundTile != null && collisionState._lastGroundTile.isSlope() && _collidingTiles[i].isSlope() )
					return false;
				
				if( testTileCollision( _collidingTiles[i], side, perpindicularPosition, leadingPosition, shouldTestSlopes, out collisionResponse ) )
				{
					// store off our last ground tile if we collided below
					if( direction == Edge.Bottom )
					{
						collisionState._lastGroundTile = _collidingTiles[i];
						collisionState.isGroundedOnOneWayPlatform = collisionState._lastGroundTile.isOneWayPlatform();
					}
					
					return true;
				}

				// special case for sloped ground tiles
				if( collisionState._lastGroundTile != null && direction == Edge.Bottom )
				{
					// if grounded on a slope and intersecting a slope or if grounded on a wall and intersecting a tall slope we go sticky.
					// tall slope here means one where the the slopeTopLeft/Right is 0, i.e. it connects to a wall
					var isHighSlopeNearest = _collidingTiles[i].getNearestEdge( perpindicularPosition ) == _collidingTiles[i].getHighestSlopeEdge();
					if( ( collisionState._lastGroundTile.isSlope() && _collidingTiles[i].isSlope() ) || ( !collisionState._lastGroundTile.isSlope() && isHighSlopeNearest ) )
					{
						// store off our last ground tile if we collided below
						collisionState._lastGroundTile = _collidingTiles[i];
						return true;
					}
				}
			}

			return false;
		}

        /// <summary>
        /// gets a list of all the tiles intersecting bounds. The returned list is ordered for collision detection based on the
        /// direction passed in so they can be processed in order.
        /// </summary>
        /// <returns>The colliding tiles.</returns>
        /// <param name="bounds">Bounds.</param>
        /// <param name="direction">Direction.</param>
        void populateCollidingTiles( Rectangle bounds, Edge direction )
        {
            _collidingTiles.Clear();
            var isHorizontal = direction.isHorizontal();
            var primaryAxis = isHorizontal ? Axis.X : Axis.Y;
            var oppositeAxis = primaryAxis == Axis.X ? Axis.Y : Axis.X;

            // if we are going up or left we subtract 1 from our opposite edge so that it doesnt get the column/row of tiles when we are against them
            var oppositeDirection = direction.oppositeEdge();
            var minSidePad = direction.isMin() ? -1 : 0;
            var firstPrimary = worldToTilePosition( bounds.getSide( oppositeDirection ) + minSidePad, primaryAxis );
            var lastPrimary = worldToTilePosition( bounds.getSide( direction ), primaryAxis );
            var primaryIncr = direction.isMax() ? 1 : -1;

            var min = worldToTilePosition( isHorizontal ? bounds.Top : bounds.Left, oppositeAxis );
            var mid = worldToTilePosition( isHorizontal ? bounds.getCenter().Y : bounds.getCenter().X, oppositeAxis );
            // same as above here. we subtract 1 to not grab an extra column/row of tiles which will mess up collisions
            var max = worldToTilePosition( isHorizontal ? bounds.Bottom - 1 : bounds.Right - 1, oppositeAxis );

            var isPositive = mid - min < max - mid;
            var secondaryIncr = isPositive ? 1 : -1;
            var firstSecondary = isPositive ? min : max;
            var lastSecondary = !isPositive ? min : max;

            for( var primary = firstPrimary; primary != lastPrimary + primaryIncr; primary += primaryIncr )
            {
                for( var secondary = firstSecondary; secondary != lastSecondary + secondaryIncr; secondary += secondaryIncr )
                {
                    var col = isHorizontal ? primary : secondary;
                    var row = !isHorizontal ? primary : secondary;
                    _collidingTiles.Add( _collisionLayer.getTile( col, row ) );
                }
            }
        }