Start v1.0 apis (sprite, animation, box2d, etc)

lib/sprite.dart

@@ -0,0 +1,35 @@
+import 'dart:ui';
+
+import 'package:flame/flame.dart';
+import 'package:flutter/material.dart' show Colors;
+
+class Sprite {
+  Image image;
+  Rect src;
+
+  static final Paint paint = new Paint()..color = Colors.white;
+
+  Sprite(String fileName, {double x = 0.0, double y = 0.0, double width = -1.0, double height = -1.0}) {
+    Flame.images.load(fileName).then((img) {
+      if (width == -1.0) {
+        width = img.width as double;
+      }
+      if (height == -1.0) {
+        width = img.height as double;
+      }
+      this.image = img;
+      this.src = new Rect.fromLTWH(x, y, width, height);
+    });
+  }
+
+  bool loaded() {
+    return image != null && src != null;
+  }
+
+  void render(Canvas canvas, double width, double height) {
+    if (this.loaded()) {
+      Rect dst = new Rect.fromLTWH(0.0, 0.0, width, height);
+      canvas.drawImageRect(image, src, dst, paint);
+    }
+  }
+}