refactor: Minimize Vector2 creation in IsometricTileMapComponent (#…

…3018)

The `IsometricTileMapComponent` was creating a lot of new `Vector2`
objects, this PR minimizes the creation of them.

packages/flame/lib/src/components/isometric_tile_map_component.dart

@@ -90,10 +90,10 @@ class IsometricTileMapComponent extends PositionComponent {
  final element = matrix[i][j];
  if (element != -1) {
  _renderSprite = tileset.getSpriteById(element);
- final p = getBlockRenderPositionInts(j, i);
+ final blockPosition = getBlockRenderPositionInts(j, i);
  _renderSprite.render(
  canvas,
- position: p,
+ position: blockPosition,
  size: size,
  );
  }
@@ -110,15 +110,21 @@ class IsometricTileMapComponent extends PositionComponent {
  return getBlockRenderPositionInts(block.x, block.y);
  }
 
+ final Vector2 _blockRenderPositionCache = Vector2.zero();
+ final Vector2 _cartesianPositionCache = Vector2.zero();
+
  /// Same as getBlockRenderPosition but the arguments are exploded as integers.
  Vector2 getBlockRenderPositionInts(int i, int j) {
- final halfTile = Vector2(
- effectiveTileSize.x / 2,
- (effectiveTileSize.y / 2) / scalingFactor,
- )..multiply(scale);
- final cartesianPosition = Vector2(i.toDouble(), j.toDouble())
+ final halfTile = _blockRenderPositionCache
+ ..setValues(
+ effectiveTileSize.x / 2,
+ (effectiveTileSize.y / 2) / scalingFactor,
+ )
+ ..multiply(scale);
+ final cartesianPosition = _cartesianPositionCache
+ ..setValues(i.toDouble(), j.toDouble())
  ..multiply(halfTile);
- return cartToIso(cartesianPosition) - halfTile;
+ return cartToIso(cartesianPosition)..sub(halfTile);
  }
 
  /// Get the position of the center of the surface of the isometric tile in
@@ -127,10 +133,11 @@ class IsometricTileMapComponent extends PositionComponent {
  /// This is the opposite of [getBlock].
  Vector2 getBlockCenterPosition(Block block) {
  final tile = effectiveTileSize;
- final result = getBlockRenderPosition(block) +
- (Vector2(tile.x / 2, tile.y - effectiveTileHeight - tile.y / 4)
- ..multiply(scale));
- return result;
+ return getBlockRenderPosition(block)
+ ..translate(
+ (tile.x / 2) * scale.x,
+ (tile.y - effectiveTileHeight - tile.y / 4) * scale.y,
+ );
  }
 
  /// Converts a coordinate from the isometric space to the cartesian space.
@@ -147,29 +154,42 @@ class IsometricTileMapComponent extends PositionComponent {
  return Vector2(x, y);
  }
 
+ final Vector2 _getBlockCache = Vector2.zero();
+ final Vector2 _getBlockIsoCache = Vector2.zero();
+
  /// Get which block's surface is at isometric position [p].
  ///
  /// This can be used to handle clicks or hovers.
  /// This is the opposite of [getBlockCenterPosition].
  Block getBlock(Vector2 p) {
- final halfTile = (effectiveTileSize / 2)..multiply(scale);
+ final halfTile = _getBlockCache
+ ..setFrom(effectiveTileSize)
+ ..multiply(scale / 2);
  final multiplier = 1 - halfTile.y / (2 * effectiveTileHeight * scale.x);
- final delta = halfTile.clone()..multiply(Vector2(1, multiplier));
- final cart = isoToCart(p - position + delta);
+ final iso = _getBlockIsoCache
+ ..setFrom(p)
+ ..sub(position)
+ ..translate(halfTile.x, halfTile.y * multiplier);
+ final cart = isoToCart(iso);
  final px = (cart.x / halfTile.x - 1).ceil();
  final py = (cart.y / halfTile.y).ceil();
  return Block(px, py);
  }
 
+ final Vector2 _blockPositionCache = Vector2.zero();
+
  /// Get which block should be rendered on position [p].
  ///
  /// This is the opposite of [getBlockRenderPosition].
  Block getBlockRenderedAt(Vector2 p) {
  final tile = effectiveTileSize;
  return getBlock(
- p +
- (Vector2(tile.x / 2, tile.y - effectiveTileHeight - tile.y / 4)
- ..multiply(scale)),
+ _blockPositionCache
+ ..setFrom(p)
+ ..translate(
+ (tile.x / 2) * scale.x,
+ (tile.y - effectiveTileHeight - tile.y / 4) * scale.y,
+ ),
  );
  }