selector

doc/examples/isometric/lib/main.dart

@@ -24,11 +24,7 @@ class Selector extends SpriteComponent {
   bool show = false;
 
   Selector(double s)
-      : super.fromSprite(
-          s,
-          s,
-          Sprite('tiles.png', x: 64, y: 0, width: 32, height: 32),
-        );
+      : super.fromSprite(s, s, Sprite('selector.png', width: 32, height: 32));
 
   @override
   void render(Canvas canvas) {
@@ -50,7 +46,7 @@ class MyGame extends BaseGame with MouseMovementDetector {
   void init() async {
     final tileset = await IsometricTileset.load('tiles.png', 32);
     final layer0 = [
-      [-1, 1, 1, 1, 0, 0],
+      [3, 1, 1, 1, 0, 0],
       [-1, 1, 2, 1, 0, 0],
       [-1, 0, 1, 1, 0, 0],
       [-1, 1, 1, 1, 0, 0],
@@ -91,13 +87,24 @@ class MyGame extends BaseGame with MouseMovementDetector {
     add(selector = Selector(s.toDouble()));
   }
 
+  @override
+  void render(Canvas canvas) {
+    super.render(canvas);
+
+    canvas.drawRect(
+      const Rect.fromLTWH(x - 1, y - 1, 3, 3),
+      Paint()..color = const Color(0xFFFF00FF),
+    );
+  }
+
   @override
   void onMouseMove(PointerHoverEvent event) {
+    if (base == null || selector == null) {
+      return; // loading
+    }
     final screenPosition = Position.fromOffset(event.position);
-    final blockCoords = base.getBlock(screenPosition);
-    final blockPosition =
-        base.cartToIso(Position.fromInts(blockCoords.x * s, blockCoords.y * s));
-    selector.setByPosition(blockPosition.add(topLeft));
-    selector.show = true;
+    final block = base.getBlock(screenPosition);
+    selector.show = base.containsBlock(block);
+    selector.setByPosition(base.getBlockPosition(block).add(topLeft));
   }
 }

doc/examples/isometric/pubspec.yaml

@@ -19,3 +19,4 @@ dev_dependencies:
 flutter:
   assets:
     - assets/images/tiles.png
+    - assets/images/selector.png

lib/components/isometric_tile_map_component.dart

@@ -54,7 +54,6 @@ class IsometricTileMapComponent extends PositionComponent {
   void render(Canvas c) {
     prepareCanvas(c);
 
-    final s = effectiveTileSize.toDouble() / 2;
     final size = Position.fromInts(effectiveTileSize, effectiveTileSize);
     matrix.asMap().forEach((i, line) {
       line.asMap().forEach((j, element) {
@@ -63,12 +62,21 @@ class IsometricTileMapComponent extends PositionComponent {
         }
 
         final sprite = tileset.getTile(element);
-        final p = cartToIso(Position(j * s, i * s));
+        final p = getBlockPositionInts(j, i);
         sprite.renderRect(c, Position.rectFrom(p, size));
       });
     });
   }
 
+  Position getBlockPosition(Block block) {
+    return getBlockPositionInts(block.x, block.y);
+  }
+
+  Position getBlockPositionInts(int i, int j) {
+    final s = effectiveTileSize.toDouble() / 2;
+    return cartToIso(Position(i * s, j * s)).minus(Position(s, 0));
+  }
+
   Position isoToCart(Position p) {
     final x = (2 * p.y + p.x) / 2;
     final y = (2 * p.y - p.x) / 2;
@@ -82,11 +90,17 @@ class IsometricTileMapComponent extends PositionComponent {
   }
 
   Block getBlock(Position p) {
-    final s = effectiveTileSize.toDouble();
+    final s = effectiveTileSize.toDouble() / 2;
     final cart = isoToCart(p.clone().minus(toPosition()));
-    print(cart);
     final px = cart.x ~/ s;
     final py = cart.y ~/ s;
     return Block(px, py);
   }
+
+  bool containsBlock(Block block) {
+    return block.x >= 0 &&
+        block.x < matrix.length &&
+        block.y >= 0 &&
+        block.y < matrix[block.x].length;
+  }
 }