Add FlxG.center() and camera.center()

flixel/FlxCamera.hx

@@ -1901,6 +1901,50 @@ class FlxCamera extends FlxBasic
 		setScale(scaleX, scaleY);
 	}
 
+	/**
+	 * Centers `FlxSprite` by graphic size in this camera view, either by the x axis, y axis, or both.
+	 * 
+	 * @param   sprite       The sprite to center.
+	 * @param   axes         On what axes to center the sprite (e.g. `X`, `Y`, `XY`) - default is both.
+	 * @return  Centered sprite for chaining.
+	 * @since TBA
+	 */
+	public function center<T:FlxSprite>(sprite:T, axes:FlxAxes = XY):T
+	{
+		if (axes.x)
+		{
+			final graphicWidth = sprite.frameWidth * Math.abs(sprite.scale.x);
+			sprite.x = viewX + (viewWidth - graphicWidth) / 2;
+		}
+
+		if (axes.y)
+		{
+			final graphicHeight = sprite.frameHeight * Math.abs(sprite.scale.y);
+			sprite.y = viewY + (viewHeight - graphicHeight) / 2;
+		}
+
+		return sprite;
+	}
+
+	/**
+	 * Centers `FlxObject` by hitbox size in this camera view, either by the x axis, y axis, or both.
+	 * 
+	 * @param   sprite       The object to center.
+	 * @param   axes         On what axes to center the object (e.g. `X`, `Y`, `XY`) - default is both.
+	 * @return  Centered object for chaining.
+	 * @since TBA
+	 */
+	public function centerHitbox<T:FlxObject>(object:T, axes:FlxAxes = XY):T
+	{
+		if (axes.x)
+			object.x = viewX + (viewWidth - object.width) / 2;
+
+		if (axes.y)
+			object.y = viewY + (viewHeight - object.height) / 2;
+
+		return object;
+	}
+
 	/**
 	 * The size and position of this camera's margins, via `viewMarginLeft`, `viewMarginTop`, `viewWidth`
 	 * and `viewHeight`.

flixel/FlxG.hx

@@ -21,6 +21,7 @@ import flixel.system.frontEnds.VCRFrontEnd;
 import flixel.system.frontEnds.WatchFrontEnd;
 import flixel.system.scaleModes.BaseScaleMode;
 import flixel.system.scaleModes.RatioScaleMode;
+import flixel.util.FlxAxes;
 import flixel.util.FlxCollision;
 import flixel.util.FlxSave;
 import flixel.util.typeLimit.NextState;
@@ -510,7 +511,51 @@ class FlxG
 	{
 		return overlap(objectOrGroup1, objectOrGroup2, notifyCallback, FlxObject.separate);
 	}
-
+
+	/**
+	 * Centers `FlxSprite` by graphic size in game space, either by the x axis, y axis, or both.
+	 * 
+	 * @param   sprite       The sprite to center.
+	 * @param   axes         On what axes to center the sprite (e.g. `X`, `Y`, `XY`) - default is both.
+	 * @return  Centered sprite for chaining.
+	 * @since TBA
+	 */
+	public static function center<T:FlxSprite>(sprite:T, axes:FlxAxes = XY):T
+	{
+		if (axes.x)
+		{
+			final graphicWidth = sprite.frameWidth * Math.abs(sprite.scale.x);
+			sprite.x = (FlxG.width - graphicWidth) / 2;
+		}
+
+		if (axes.y)
+		{
+			final graphicHeight = sprite.frameHeight * Math.abs(sprite.scale.y);
+			sprite.y = (FlxG.height - graphicHeight) / 2;
+		}
+
+		return sprite;
+	}
+
+	/**
+	 * Centers `FlxObject` by hitbox size in game space, either by the x axis, y axis, or both.
+	 * 
+	 * @param   sprite       The object to center.
+	 * @param   axes         On what axes to center the object (e.g. `X`, `Y`, `XY`) - default is both.
+	 * @return  Centered object for chaining.
+	 * @since TBA
+	 */
+	public static function centerHitbox<T:FlxObject>(object:T, axes:FlxAxes = XY):T
+	{
+		if (axes.x)
+			object.x = (FlxG.width - object.width) / 2;
+
+		if (axes.y)
+			object.y = (FlxG.height - object.height) / 2;
+
+		return object;
+	}
+
 	/**
 	 * Regular `DisplayObject`s are normally displayed over the Flixel cursor and the Flixel debugger if simply
 	 * added to `stage`. This function simplifies things by adding a `DisplayObject` directly below mouse level.

flixel/FlxObject.hx

@@ -1256,24 +1256,19 @@ class FlxObject extends FlxBasic
 			kill();
 	}
 	#end
-
+	
 	/**
 	 * Centers this `FlxObject` on the screen, either by the x axis, y axis, or both.
-	 *
+	 * 
 	 * @param   axes   On what axes to center the object (e.g. `X`, `Y`, `XY`) - default is both. 
 	 * @return  This FlxObject for chaining
 	 */
+	@:deprecated("screenCenter is deprecated, use FlxG.centerHitbox instead")
 	public inline function screenCenter(axes:FlxAxes = XY):FlxObject
 	{
-		if (axes.x)
-			x = (FlxG.width - width) / 2;
-
-		if (axes.y)
-			y = (FlxG.height - height) / 2;
-
-		return this;
+		return FlxG.centerHitbox(this, axes);
 	}
-
+	
 	/**
 	 * Helper function to set the coordinates of this object.
 	 * Handy since it only requires one line of code.

tests/unit/src/flixel/FlxCameraTest.hx

@@ -1,5 +1,6 @@
 package flixel;
 
+import flixel.math.FlxPoint;
 import flixel.util.FlxColor;
 import massive.munit.Assert;
 
@@ -89,7 +90,79 @@ class FlxCameraTest extends FlxTest
 		camera.follow(new FlxObject());
 		Assert.areEqual(defaultLerp, camera.followLerp);
 	}
-
+
+	@Test
+	function testCenter()
+	{
+		final sprite = new FlxSprite();
+		sprite.makeGraphic(10, 10);
+		sprite.scale.set(-2, -4);
+		final cam = FlxG.camera;
+		cam.scroll.set(100, 100);
+		cam.zoom *= 2;
+		final graphicWidth = sprite.frameWidth * Math.abs(sprite.scale.x);
+		final graphicHeight = sprite.frameHeight * Math.abs(sprite.scale.y);
+		final center = FlxPoint.get(cam.viewX + (cam.viewWidth - graphicWidth) / 2, cam.viewY + (cam.viewHeight - graphicHeight) / 2);
+		final offCenter = center.copyTo().add(1000, 1000);
+
+		sprite.setPosition(offCenter.x, offCenter.y);
+		cam.center(sprite, X);
+		Assert.areEqual(sprite.x, center.x);
+		Assert.areEqual(sprite.y, offCenter.y);
+
+		sprite.setPosition(offCenter.x, offCenter.y);
+		cam.center(sprite, Y);
+		Assert.areEqual(sprite.x, offCenter.x);
+		Assert.areEqual(sprite.y, center.y);
+
+		sprite.setPosition(offCenter.x, offCenter.y);
+		cam.center(sprite, XY);
+		Assert.areEqual(sprite.x, center.x);
+		Assert.areEqual(sprite.y, center.y);
+
+		sprite.setPosition(offCenter.x, offCenter.y);
+		cam.center(sprite);
+		Assert.areEqual(sprite.x, center.x);
+		Assert.areEqual(sprite.y, center.y);
+
+		offCenter.put();
+		center.put();
+	}
+
+	@Test
+	function testCenterHitbox()
+	{
+		final object = new FlxObject(0, 0, 10, 10);
+		final cam = FlxG.camera;
+		cam.scroll.set(100, 100);
+		cam.zoom *= 2;
+		final center = FlxPoint.get(cam.viewX + (cam.viewWidth - object.width) / 2, cam.viewY + (cam.viewHeight - object.height) / 2);
+		final offCenter = center.copyTo().add(1000, 1000);
+
+		object.setPosition(offCenter.x, offCenter.y);
+		cam.centerHitbox(object, X);
+		Assert.areEqual(object.x, center.x);
+		Assert.areEqual(object.y, offCenter.y);
+
+		object.setPosition(offCenter.x, offCenter.y);
+		cam.centerHitbox(object, Y);
+		Assert.areEqual(object.x, offCenter.x);
+		Assert.areEqual(object.y, center.y);
+
+		object.setPosition(offCenter.x, offCenter.y);
+		cam.centerHitbox(object, XY);
+		Assert.areEqual(object.x, center.x);
+		Assert.areEqual(object.y, center.y);
+
+		object.setPosition(offCenter.x, offCenter.y);
+		cam.centerHitbox(object);
+		Assert.areEqual(object.x, center.x);
+		Assert.areEqual(object.y, center.y);
+
+		offCenter.put();
+		center.put();
+	}
+
 	@Test
 	function testFadeInFadeOut()
 	{

tests/unit/src/flixel/FlxGTest.hx

@@ -1,5 +1,6 @@
 package flixel;
 
+import flixel.math.FlxPoint;
 import massive.munit.Assert;
 
 @:access(flixel.FlxG)
@@ -104,4 +105,70 @@ class FlxGTest extends FlxTest
 	{
 		Assert.areEqual(480, FlxG.height);
 	}
+
+	@Test
+	function testCenter()
+	{
+		final sprite = new FlxSprite();
+		sprite.makeGraphic(10, 10);
+		sprite.scale.set(-2, -4);
+		final graphicWidth = sprite.frameWidth * Math.abs(sprite.scale.x);
+		final graphicHeight = sprite.frameHeight * Math.abs(sprite.scale.y);
+		final center = FlxPoint.get((FlxG.width - graphicWidth) / 2, (FlxG.height - graphicHeight) / 2);
+		final offCenter = center.copyTo().add(1000, 1000);
+
+		sprite.setPosition(offCenter.x, offCenter.y);
+		FlxG.center(sprite, X);
+		Assert.areEqual(sprite.x, center.x);
+		Assert.areEqual(sprite.y, offCenter.y);
+
+		sprite.setPosition(offCenter.x, offCenter.y);
+		FlxG.center(sprite, Y);
+		Assert.areEqual(sprite.x, offCenter.x);
+		Assert.areEqual(sprite.y, center.y);
+
+		sprite.setPosition(offCenter.x, offCenter.y);
+		FlxG.center(sprite, XY);
+		Assert.areEqual(sprite.x, center.x);
+		Assert.areEqual(sprite.y, center.y);
+
+		sprite.setPosition(offCenter.x, offCenter.y);
+		FlxG.center(sprite);
+		Assert.areEqual(sprite.x, center.x);
+		Assert.areEqual(sprite.y, center.y);
+
+		offCenter.put();
+		center.put();
+	}
+
+	@Test
+	function testCenterHitbox()
+	{
+		final object = new FlxObject(0, 0, 10, 10);
+		final center = FlxPoint.get((FlxG.width - object.width) / 2, (FlxG.height - object.height) / 2);
+		final offCenter = center.copyTo().add(1000, 1000);
+
+		object.setPosition(offCenter.x, offCenter.y);
+		FlxG.centerHitbox(object, X);
+		Assert.areEqual(object.x, center.x);
+		Assert.areEqual(object.y, offCenter.y);
+
+		object.setPosition(offCenter.x, offCenter.y);
+		FlxG.centerHitbox(object, Y);
+		Assert.areEqual(object.x, offCenter.x);
+		Assert.areEqual(object.y, center.y);
+
+		object.setPosition(offCenter.x, offCenter.y);
+		FlxG.centerHitbox(object, XY);
+		Assert.areEqual(object.x, center.x);
+		Assert.areEqual(object.y, center.y);
+
+		object.setPosition(offCenter.x, offCenter.y);
+		FlxG.centerHitbox(object);
+		Assert.areEqual(object.x, center.x);
+		Assert.areEqual(object.y, center.y);
+
+		offCenter.put();
+		center.put();
+	}
 }

tests/unit/src/flixel/FlxObjectTest.hx

@@ -341,6 +341,7 @@ class FlxObjectTest extends FlxTest
 	}
 
 	@Test
+	@:haxe.warning("-WDeprecated") // TODO: remove this test?
 	function testScreenCenter()
 	{
 		var center = FlxPoint.get((FlxG.width - object1.width) / 2, (FlxG.height - object1.height) / 2);
@@ -350,17 +351,17 @@ class FlxObjectTest extends FlxTest
 		object1.screenCenter(X);
 		Assert.areEqual(object1.x, center.x);
 		Assert.areEqual(object1.y, offCenter.y);
-
+		
 		object1.setPosition(offCenter.x, offCenter.y);
 		object1.screenCenter(Y);
 		Assert.areEqual(object1.x, offCenter.x);
 		Assert.areEqual(object1.y, center.y);
-
+		
 		object1.setPosition(offCenter.x, offCenter.y);
 		object1.screenCenter(XY);
 		Assert.areEqual(object1.x, center.x);
 		Assert.areEqual(object1.y, center.y);
-
+		
 		object1.setPosition(offCenter.x, offCenter.y);
 		object1.screenCenter();
 		Assert.areEqual(object1.x, center.x);
@@ -369,7 +370,7 @@ class FlxObjectTest extends FlxTest
 		offCenter.put();
 		center.put();
 	}
-
+	
 	@Test
 	function testgetRotatedBounds()
 	{