FlxFrame: make sorting consistent across platforms

The behavior when Std.parseInt() fails (because of incorrect prefix or postfix input values) was inconsistent. On Neko it crashed, on Flash the sorting order changed.
closes HaxeFlixel#1926

flixel/animation/FlxAnimationController.hx

@@ -700,7 +700,7 @@ class FlxAnimationController implements IFlxDestroyable
 		var name:String = AnimFrames[0].name;
 		var postIndex:Int = name.indexOf(".", Prefix.length);
 		var postFix:String = name.substring(postIndex == -1 ? name.length : postIndex, name.length);
-		AnimFrames.sort(FlxFrame.sortByName.bind(_, _, Prefix.length, postFix.length));
+		FlxFrame.sort(AnimFrames, Prefix.length, postFix.length);
 
 		for (animFrame in AnimFrames)
 		{

flixel/graphics/frames/FlxFrame.hx

@@ -11,6 +11,7 @@ import flixel.util.FlxColor;
 import flixel.util.FlxDestroyUtil;
 import flixel.util.FlxStringUtil;
 import haxe.ds.Vector;
+import haxe.ds.ArraySort;
 
 /**
  * Base class for all frame types
@@ -23,17 +24,26 @@ class FlxFrame implements IFlxDestroyable
 	private var matrix:FlxMatrix = new FlxMatrix();
 
 	/**
-	 * Sorting function for Array<FlxFrame>#sort(),
-	 * e.g. "tiles-001.png", "tiles-003.png", "tiles-002.png".
+	 * Sorts an array of `FlxFrame` objects by their name, e.g.
+	 * `["tiles-001.png", "tiles-003.png", "tiles-002.png"]`
+	 * with `"tiles-".length == prefixLength` and `".png".length == postfixLength`.
 	 */
+	public static function sort(frames:Array<FlxFrame>, prefixLength:Int, postfixLength:Int):Void
+	{
+		ArraySort.sort(frames, sortByName.bind(_, _, prefixLength, postfixLength));
+	}
+
 	public static function sortByName(frame1:FlxFrame, frame2:FlxFrame, prefixLength:Int, postfixLength:Int):Int
 	{
 		var name1:String = frame1.name;
 		var name2:String = frame2.name;
-
-		var num1:Int = Std.parseInt(name1.substring(prefixLength, name1.length - postfixLength));
-		var num2:Int = Std.parseInt(name2.substring(prefixLength, name2.length - postfixLength));
-
+		var num1:Null<Int> = Std.parseInt(name1.substring(prefixLength, name1.length - postfixLength));
+		var num2:Null<Int> = Std.parseInt(name2.substring(prefixLength, name2.length - postfixLength));
+		if (num1 == null)
+			num1 = 0;
+		if (num2 == null)
+			num2 = 0;
+
 		return num1 - num2;
 	}
 

flixel/graphics/frames/FlxTileFrames.hx

@@ -238,7 +238,7 @@ class FlxTileFrames extends FlxFramesCollection
 			var postIndex:Int = name.indexOf(".", Prefix.length);
 			var postFix:String = name.substring(postIndex == -1 ? name.length : postIndex, name.length);
 
-			framesToAdd.sort(FlxFrame.sortByName.bind(_, _, Prefix.length, postFix.length));
+			FlxFrame.sort(framesToAdd, Prefix.length, postFix.length);
 			return FlxTileFrames.fromFrames(framesToAdd);
 		}
 

tests/unit/src/flixel/graphics/frames/FlxAtlasFramesTest.hx

@@ -8,18 +8,17 @@ class FlxAtlasFramesTest extends FlxTest
 	@Test
 	function testTexturePackerJson()
 	{
-		var bmd:BitmapData = new BitmapData(1, 1);
+		var bmd = new BitmapData(1, 1);
 		var arrJson = '{"frames":[{"filename":"alien.png","frame":{"x":2,"y":2,"w":46,"h":16},"rotated":false,"trimmed":true,"spriteSourceSize":{"x":1,"y":0,"w":46,"h":16},"sourceSize":{"w":48,"h":16},"pivot":{"x":0.5,"y":0.5}},{"filename":"medium.png","frame":{"x":2,"y":20,"w":32,"h":32},"rotated":false,"trimmed":false,"spriteSourceSize":{"x":0,"y":0,"w":32,"h":32},"sourceSize":{"w":32,"h":32},"pivot":{"x":0.5,"y":0.5}},{"filename":"ship.png","frame":{"x":36,"y":38,"w":12,"h":8},"rotated":true,"trimmed":false,"spriteSourceSize":{"x":0,"y":0,"w":12,"h":8},"sourceSize":{"w":12,"h":8},"pivot":{"x":0.5,"y":0.5}},{"filename":"small.png","frame":{"x":36,"y":20,"w":16,"h":16},"rotated":false,"trimmed":false,"spriteSourceSize":{"x":0,"y":0,"w":16,"h":16},"sourceSize":{"w":16,"h":16},"pivot":{"x":0.5,"y":0.5}}]}';
 		var hashJson = '{"frames":{"alien.png":{"frame":{"x":2,"y":2,"w":46,"h":16},"rotated":false,"trimmed":true,"spriteSourceSize":{"x":1,"y":0,"w":46,"h":16},"sourceSize":{"w":48,"h":16},"pivot":{"x":0.5,"y":0.5}},"medium.png":{"frame":{"x":2,"y":20,"w":32,"h":32},"rotated":false,"trimmed":false,"spriteSourceSize":{"x":0,"y":0,"w":32,"h":32},"sourceSize":{"w":32,"h":32},"pivot":{"x":0.5,"y":0.5}},"ship.png":{"frame":{"x":36,"y":38,"w":12,"h":8},"rotated":true,"trimmed":false,"spriteSourceSize":{"x":0,"y":0,"w":12,"h":8},"sourceSize":{"w":12,"h":8},"pivot":{"x":0.5,"y":0.5}},"small.png":{"frame":{"x":36,"y":20,"w":16,"h":16},"rotated":false,"trimmed":false,"spriteSourceSize":{"x":0,"y":0,"w":16,"h":16},"sourceSize":{"w":16,"h":16},"pivot":{"x":0.5,"y":0.5}}}}';
-		var atlasArray:FlxAtlasFrames = FlxAtlasFrames.fromTexturePackerJson(bmd, arrJson);
-		var atlasHash:FlxAtlasFrames = FlxAtlasFrames.fromTexturePackerJson(bmd, hashJson);
+		var atlasArray = FlxAtlasFrames.fromTexturePackerJson(bmd, arrJson);
+		var atlasHash = FlxAtlasFrames.fromTexturePackerJson(bmd, hashJson);
 
 		Assert.areEqual(atlasArray.numFrames, atlasHash.numFrames);
 
-		var hashArr:FlxFrame;
 		for (frameArr in atlasArray.frames)
 		{
-			hashArr = atlasHash.framesHash.get(frameArr.name);
+			var hashArr = atlasHash.framesHash.get(frameArr.name);
 			Assert.areEqual(frameArr.name, hashArr.name);
 			Assert.isTrue(frameArr.sourceSize.equals(hashArr.sourceSize));
 		}

tests/unit/src/flixel/graphics/frames/FlxFrameTest.hx

@@ -1,25 +1,20 @@
 package flixel.graphics.frames;
 
+import massive.munit.Assert;
+
+@:access(flixel.graphics.frames.FlxFrame.new)
 class FlxFrameTest extends FlxTest
 {
 	@Test
-	@:access(flixel.graphics.frames.FlxFrame.new)
-	function testSortByName()
+	function testSort()
 	{
 		var indices = [3, 5, 8, 1, 6];
-		var frames:Array<FlxFrame> = [];
 		var prefix = "tiles-";
 		var postfix = ".png";
 
-		for (index in indices)
-		{
-			var frame = new FlxFrame(null);
-			frame.name = prefix + "00" + index + postfix;
-			frames.push(frame);
-		}
-
-		frames.sort(FlxFrame.sortByName.bind(_, _, prefix.length, postfix.length));
-
+		var frames = [for (i in indices) createFrame(prefix + "00" + i + postfix)];
+		FlxFrame.sort(frames, prefix.length, postfix.length);
+
 		var resultingIndices:Array<Null<Int>> = [];
 		for (frame in frames)
 		{
@@ -29,4 +24,22 @@ class FlxFrameTest extends FlxTest
 		}
 		FlxAssert.arraysEqual([1, 3, 5, 6, 8], resultingIndices);
 	}
+
+	@Test // #1926
+	function testSortNoPrefix()
+	{
+		var length = 5;
+		var frames:Array<FlxFrame> = [for (i in 0...length) createFrame("split/" + i)];
+		FlxFrame.sort(frames, 0, 0);
+
+		for (i in 0...length)
+			Assert.areEqual("split/" + i, frames[i].name);
+	}
+
+	function createFrame(name:String):FlxFrame
+	{
+		var frame = new FlxFrame(null);
+		frame.name = name;
+		return frame;
+	}
 }