ZoomFactor in FunkinText, Early Implementation (#1011)

Author: HeroEyad

source/funkin/backend/FunkinText.hx

@@ -1,19 +1,98 @@
 package funkin.backend;
 
+import flixel.FlxCamera;
+import flixel.FlxG;
+import flixel.math.FlxMath;
 import flixel.text.FlxText;
 import flixel.util.FlxColor;
 import funkin.backend.system.Flags;
 
-class FunkinText extends FlxText {
-	public function new(X:Float = 0, Y:Float = 0, FieldWidth:Float = 0, ?Text:String, ?Size:Int, Border:Bool = true) {
-		if (Size == null) Size = Flags.DEFAULT_FONT_SIZE;
+class FunkinText extends FlxText
+{
+	public var zoomFactor:Float = 1;
+	public var zoomFactorEnabled:Bool = true;
+
+	public function new(X:Float = 0, Y:Float = 0, FieldWidth:Float = 0, ?Text:String, ?Size:Int, Border:Bool = true)
+	{
+		if (Size == null)
+			Size = Flags.DEFAULT_FONT_SIZE;
 
 		super(X, Y, FieldWidth, Text, Size);
+
 		setFormat(Paths.font(Flags.DEFAULT_FONT), Size, FlxColor.WHITE);
-		if (Border) {
+
+		if (Border)
+		{
 			borderStyle = OUTLINE;
 			borderSize = 1;
 			borderColor = 0xFF000000;
 		}
 	}
+
+	private inline function __shouldDoZoomFactor():Bool
+	{
+		return zoomFactorEnabled && zoomFactor != 1;
+	}
+
+	private inline function __getZoomScaleX(camera:FlxCamera):Float
+	{
+		return (camera.scaleX > 0 ? Math.max : Math.min)(0, FlxMath.lerp(1 / camera.scaleX, 1, zoomFactor));
+	}
+
+	private inline function __getZoomScaleY(camera:FlxCamera):Float
+	{
+		return (camera.scaleY > 0 ? Math.max : Math.min)(0, FlxMath.lerp(1 / camera.scaleY, 1, zoomFactor));
+	}
+
+	private inline function __getZoomAnchorX(camera:FlxCamera):Float
+	{
+		if (Flags.USE_LEGACY_ZOOM_FACTOR)
+			return camera.width * 0.5;
+
+		return camera.width * 0.5 + camera.scroll.x * scrollFactor.x;
+	}
+
+	private inline function __getZoomAnchorY(camera:FlxCamera):Float
+	{
+		if (Flags.USE_LEGACY_ZOOM_FACTOR)
+			return camera.height * 0.5;
+
+		return camera.height * 0.5 + camera.scroll.y * scrollFactor.y;
+	}
+
+	override public function draw():Void
+	{
+		if (!__shouldDoZoomFactor())
+		{
+			super.draw();
+			return;
+		}
+
+		var camera:FlxCamera = this.camera;
+
+		if (camera == null)
+			camera = FlxG.camera;
+
+		var oldX:Float = x;
+		var oldY:Float = y;
+		var oldScaleX:Float = scale.x;
+		var oldScaleY:Float = scale.y;
+
+		var zoomScaleX:Float = __getZoomScaleX(camera);
+		var zoomScaleY:Float = __getZoomScaleY(camera);
+
+		var anchorX:Float = __getZoomAnchorX(camera);
+		var anchorY:Float = __getZoomAnchorY(camera);
+
+		x = (x - anchorX) * zoomScaleX + anchorX;
+		y = (y - anchorY) * zoomScaleY + anchorY;
+
+		scale.set(scale.x * zoomScaleX, scale.y * zoomScaleY);
+
+		super.draw();
+
+		x = oldX;
+		y = oldY;
+		scale.set(oldScaleX, oldScaleY);
+	}
 }