Add random to the Color and Paint extensions (#1081)

* Add `randomColor` to the `Color` extension

* Add flame rive package to monorepo (#1048)

Add flame rive package to monorepo

* Add random to PaintExtension

* Update examples/pubspec.yaml

Co-authored-by: Erick <erickzanardoo@gmail.com>

Co-authored-by: Renan <6718144+renancaraujo@users.noreply.github.com>
Co-authored-by: Erick <erickzanardoo@gmail.com>

examples/lib/stories/components/priority.dart

@@ -1,11 +1,9 @@
-import 'dart:math';
 import 'dart:ui';
 
 import 'package:flame/components.dart';
 import 'package:flame/extensions.dart';
 import 'package:flame/game.dart';
 import 'package:flame/input.dart';
-import 'package:flame/palette.dart';
 
 const priorityInfo = '''
 On this example, click on the square to bring them to the front by changing the
@@ -18,7 +16,7 @@ class Square extends PositionComponent with HasGameRef<Priority>, Tappable {
   Square(Vector2 position) {
     this.position.setFrom(position);
     size.setValues(100, 100);
-    paint = _randomPaint();
+    paint = PaintExtension.random(withAlpha: 0.9, base: 100);
   }
 
   @override
@@ -35,17 +33,6 @@ class Square extends PositionComponent with HasGameRef<Priority>, Tappable {
     super.render(canvas);
     canvas.drawRect(size.toRect(), paint);
   }
-
-  static Paint _randomPaint() {
-    final rng = Random();
-    final color = Color.fromRGBO(
-      rng.nextInt(256),
-      rng.nextInt(256),
-      rng.nextInt(256),
-      0.9,
-    );
-    return PaletteEntry(color).paint();
-  }
 }
 
 class Priority extends FlameGame with HasTappableComponents {

examples/lib/stories/input/overlapping_tappables.dart

@@ -1,26 +1,13 @@
-import 'dart:math' as math;
-
 import 'package:flame/components.dart';
+import 'package:flame/extensions.dart';
 import 'package:flame/game.dart';
-import 'package:flame/palette.dart';
 import 'package:flutter/material.dart';
 
 class TappableSquare extends PositionComponent with Tappable {
-  static Paint _randomPaint() {
-    final rng = math.Random();
-    final color = Color.fromRGBO(
-      rng.nextInt(256),
-      rng.nextInt(256),
-      rng.nextInt(256),
-      0.9,
-    );
-    return PaletteEntry(color).paint();
-  }
-
   Paint currentPaint;
 
   TappableSquare({Vector2? position})
-      : currentPaint = _randomPaint(),
+      : currentPaint = PaintExtension.random(withAlpha: 0.9, base: 100),
         super(
           position: position ?? Vector2.all(100),
           size: Vector2.all(100),

packages/flame/CHANGELOG.md

@@ -17,6 +17,7 @@
  - Create default implementations of `RectangleComponent`, `CircleComponent` and `PolygonComponent`
  - Streamlined the argument list for all components extending `PositionComponent`
  - Improved interaction between viewport and isHud components
+ - `randomColor` method in the `Color` extension
  - Calling super-method in `.render()` is now optional
  - Components that manipulate canvas state are now responsible for saving/restoring that state
 

packages/flame/lib/extensions.dart

@@ -3,6 +3,7 @@ export 'src/extensions/color.dart';
 export 'src/extensions/image.dart';
 export 'src/extensions/matrix4.dart';
 export 'src/extensions/offset.dart';
+export 'src/extensions/paint.dart';
 export 'src/extensions/rect.dart';
 export 'src/extensions/rectangle.dart';
 export 'src/extensions/size.dart';

packages/flame/lib/palette.dart

@@ -1 +1,3 @@
+export 'src/extensions/color.dart';
+export 'src/extensions/paint.dart';
 export 'src/palette.dart';

packages/flame/lib/src/extensions/color.dart

@@ -1,3 +1,4 @@
+import 'dart:math';
 import 'dart:ui';
 
 export 'dart:ui' show Color;
@@ -101,4 +102,27 @@ extension ColorExtension on Color {
       components[3],
     );
   }
+
+  /// Generates a random [Color] with the set [withAlpha] or the default (1.0).
+  /// You can pass in a random number generator [rng], if omitted the function
+  /// will create a new [Random] object without a seed and use that.
+  /// [base] can be used to get the random colors in only a lighter spectrum, it
+  /// should be between [0-256].
+  static Color random({
+    double withAlpha = 1.0,
+    int base = 0,
+    Random? rng,
+  }) {
+    assert(
+      base >= 0 && base <= 256,
+      'The base argument should be between 0-256',
+    );
+    rng ??= Random();
+    return Color.fromRGBO(
+      base + (base == 256 ? 0 : rng.nextInt(256 - base)),
+      base + (base == 256 ? 0 : rng.nextInt(256 - base)),
+      base + (base == 256 ? 0 : rng.nextInt(256 - base)),
+      withAlpha,
+    );
+  }
 }

packages/flame/lib/src/extensions/paint.dart

@@ -0,0 +1,81 @@
+import 'dart:math';
+import 'dart:ui';
+
+import 'color.dart';
+
+export 'dart:ui' show Color;
+
+extension PaintExtension on Paint {
+  /// Darken the shade of the [Color] in the [Paint] object by the [amount].
+  ///
+  /// [amount] is a double between 0 and 1.
+  ///
+  /// Based on: https://stackoverflow.com/a/60191441.
+  void darken(double amount) {
+    color = color.darken(amount);
+  }
+
+  /// Brighten the shade of the [Color] in the [Paint] object by the [amount].
+  ///
+  /// [amount] is a double between 0 and 1.
+  ///
+  /// Based on: https://stackoverflow.com/a/60191441.
+  void brighten(double amount) {
+    color = color.brighten(amount);
+  }
+
+  /// Parses an RGB color from a valid hex string (e.g. #1C1C1C).
+  ///
+  /// The `#` is optional.
+  /// The short-hand syntax is support, e.g.: #CCC.
+  /// Lower-case letters are supported.
+  ///
+  /// Examples of valid inputs:
+  /// ccc, CCC, #ccc, #CCC, #c1c1c1, #C1C1C1, c1c1c1, C1C1C1
+  ///
+  /// If the string is not valid, an error is thrown.
+  ///
+  /// Note: if you are hardcoding colors, use Dart's built-in hexadecimal
+  /// literals instead.
+  static Paint fromRGBHexString(String hexString) {
+    final color = ColorExtension.fromRGBHexString(hexString);
+    return Paint()..color = color;
+  }
+
+  /// Parses an ARGB color from a valid hex string (e.g. #1C1C1C).
+  ///
+  /// The `#` is optional.
+  /// The short-hand syntax is support, e.g.: #CCCC.
+  /// Lower-case letters are supported.
+  ///
+  /// Examples of valid inputs:
+  /// fccc, FCCC, #fccc, #FCCC, #ffc1c1c1, #FFC1C1C1, ffc1c1c1, FFC1C1C1
+  ///
+  /// If the string is not valid, an error is thrown.
+  ///
+  /// Note: if you are hardcoding colors, use Dart's built-in hexadecimal
+  /// literals instead.
+  static Paint fromARGBHexString(String hexString) {
+    final color = ColorExtension.fromARGBHexString(hexString);
+    return Paint()..color = color;
+  }
+
+  /// Generates a random [Color] in a new [Paint] object with the set
+  /// alpha as [withAlpha] or the default (1.0).
+  /// You can pass in a random number generator [rng], if omitted the function
+  /// will create a new [Random] object without a seed and use that.
+  /// [base] can be used to get the random colors in only a lighter spectrum, it
+  /// should be between [0-256].
+  static Paint random({
+    double withAlpha = 1.0,
+    int base = 0,
+    Random? rng,
+  }) {
+    final color = ColorExtension.random(
+      withAlpha: withAlpha,
+      base: base,
+      rng: rng,
+    );
+    return Paint()..color = color;
+  }
+}

packages/flame_forge2d/example/lib/balls.dart

@@ -1,5 +1,3 @@
-import 'dart:math' as math;
-
 import 'package:flame/palette.dart';
 import 'package:flame_forge2d/body_component.dart';
 import 'package:flame_forge2d/contact_callbacks.dart';
@@ -23,17 +21,7 @@ class Ball extends BodyComponent {
     paint = originalPaint;
   }
 
-  Paint randomPaint() {
-    final rng = math.Random();
-    return PaletteEntry(
-      Color.fromARGB(
-        100 + rng.nextInt(155),
-        100 + rng.nextInt(155),
-        100 + rng.nextInt(155),
-        255,
-      ),
-    ).paint();
-  }
+  Paint randomPaint() => PaintExtension.random(withAlpha: 0.9, base: 100);
 
   @override
   Body createBody() {

packages/flame_rive/example/lib/main.dart

@@ -1,6 +1,5 @@
-import 'dart:math';
-
 import 'package:flame/components.dart';
+import 'package:flame/extensions.dart';
 import 'package:flame/game.dart';
 import 'package:flame/input.dart';
 import 'package:flame/palette.dart';
@@ -85,7 +84,7 @@ class Square extends PositionComponent with HasGameRef<RiveExampleGame> {
   Square(Vector2 position) {
     this.position.setFrom(position);
     size.setValues(100, 100);
-    paint = _randomPaint();
+    paint = PaintExtension.random(withAlpha: 0.9, base: 100);
   }
 
   @override
@@ -93,15 +92,4 @@ class Square extends PositionComponent with HasGameRef<RiveExampleGame> {
     super.render(canvas);
     canvas.drawRect(size.toRect(), paint);
   }
-
-  static Paint _randomPaint() {
-    final rng = Random();
-    final color = Color.fromRGBO(
-      rng.nextInt(256),
-      rng.nextInt(256),
-      rng.nextInt(256),
-      0.9,
-    );
-    return PaletteEntry(color).paint();
-  }
 }