From 5eee726d92abf6b60c70eebc3258e7253cb1d139 Mon Sep 17 00:00:00 2001
From: Luan Nico <luanpotter27@gmail.com>
Date: Sat, 30 Dec 2017 21:59:45 -0200
Subject: [PATCH] Adding a rotate method to Position and a drawWhere method to
 utils

---
 lib/position.dart | 8 ++++++++
 lib/util.dart     | 8 ++++++++
 2 files changed, 16 insertions(+)

diff --git a/lib/position.dart b/lib/position.dart
index 4f3244426..482fd0d03 100644
--- a/lib/position.dart
+++ b/lib/position.dart
@@ -22,4 +22,12 @@ class Position {
   double length() {
     return math.sqrt(math.pow(this.x, 2) + math.pow(this.y, 2));
   }
+
+  Position rotate(double angle) {
+    double nx = math.cos(angle) * this.x - math.sin(angle) * this.y;
+    double ny = math.sin(angle) * this.x + math.cos(angle) * this.y;
+    this.x = nx;
+    this.y = ny;
+    return this;
+  }
 }
diff --git a/lib/util.dart b/lib/util.dart
index 40e750ccb..77523d780 100644
--- a/lib/util.dart
+++ b/lib/util.dart
@@ -5,6 +5,8 @@ import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart' as material;
 import 'package:flutter/services.dart';
 
+import 'position.dart';
+
 class Util {
   void fullScreen() {
     SystemChrome.setEnabledSystemUIOverlays([]);
@@ -46,4 +48,10 @@ class Util {
       }
     });
   }
+
+  void drawWhere(Canvas c, Position p, void Function(Canvas) fn) {
+    c.translate(p.x, p.y);
+    fn(c);
+    c.translate(-p.x, -p.y);
+  }
 }