From 5ecd62c0f29fd50f966b7ab78e8c4434d915cb4f Mon Sep 17 00:00:00 2001
From: RandomityGuy <31925790+RandomityGuy@users.noreply.github.com>
Date: Sat, 15 Nov 2025 18:49:59 +0000
Subject: [PATCH] implement momentum based scroll for touch

---
 src/MarbleGame.hx               |  2 +-
 src/gui/GuiConsoleScrollCtrl.hx | 51 ++++++++++++++++++++++++++++++++-
 src/gui/GuiScrollCtrl.hx        |  6 ++--
 3 files changed, 54 insertions(+), 5 deletions(-)

diff --git a/src/MarbleGame.hx b/src/MarbleGame.hx
index 09b160b6..0837e3c1 100644
--- a/src/MarbleGame.hx
+++ b/src/MarbleGame.hx
@@ -180,7 +180,7 @@ class MarbleGame {
 		});
 
 		pointercontainer.addEventListener('touchend', (e:js.html.TouchEvent) -> {
-			// @:privateAccess Key.keyPressed[Key.MOUSE_LEFT] = -Key.getFrame();
+			@:privateAccess Key.keyPressed[Key.MOUSE_LEFT] = -Key.getFrame();
 		});
 
 		pointercontainer.addEventListener('touchmove', (e:js.html.TouchEvent) -> {
diff --git a/src/gui/GuiConsoleScrollCtrl.hx b/src/gui/GuiConsoleScrollCtrl.hx
index 6e1973ba..b79aafc3 100644
--- a/src/gui/GuiConsoleScrollCtrl.hx
+++ b/src/gui/GuiConsoleScrollCtrl.hx
@@ -10,6 +10,7 @@ import h2d.Tile;
 import h2d.Graphics;
 import src.MarbleGame;
 import src.Util;
+import haxe.Timer;
 
 class GuiConsoleScrollCtrl extends GuiControl {
 	public var scrollY:Float = 0;
@@ -43,6 +44,11 @@ class GuiConsoleScrollCtrl extends GuiControl {
 
 	var scrollUpButton:GuiButton;
 	var scrollDownButton:GuiButton;
+	var scrollVelocity:Float = 0;
+	var lastMoveStamp:Float = 0;
+	var momentumActive:Bool = false;
+
+	static inline var MOMENTUM_DAMPING:Float = 8;
 
 	public function new(scrollBar:Tile) {
 		super();
@@ -266,6 +272,9 @@ class GuiConsoleScrollCtrl extends GuiControl {
 			this.dirty = true;
 			this.updateScrollVisual();
 			this.prevMousePos = mouseState.position;
+			this.scrollVelocity = 0;
+			this.momentumActive = false;
+			this.lastMoveStamp = Timer.stamp();
 		}
 	}
 
@@ -274,6 +283,18 @@ class GuiConsoleScrollCtrl extends GuiControl {
 			this.pressed = false;
 			this.dirty = true;
 			this.updateScrollVisual();
+			this.momentumActive = Math.abs(scrollVelocity) > 0.01;
+			this.lastMoveStamp = 0;
+		}
+	}
+
+	public override function onMouseLeave(mouseState:MouseState) {
+		if (Util.isTouchDevice()) {
+			this.pressed = false;
+			this.dirty = true;
+			this.updateScrollVisual();
+			this.momentumActive = Math.abs(scrollVelocity) > 0.01;
+			this.lastMoveStamp = 0;
 		}
 	}
 
@@ -281,14 +302,42 @@ class GuiConsoleScrollCtrl extends GuiControl {
 		if (Util.isTouchDevice()) {
 			super.onMouseMove(mouseState);
 			if (this.pressed) {
-				var dy = mouseState.position.y - this.prevMousePos.y;
+				var renderRect = this.getRenderRectangle();
+				var scrollExtentY = renderRect.extent.y - 34 * Settings.uiScale;
+				var dy = (mouseState.position.y - this.prevMousePos.y) / ((maxScrollY * Settings.uiScale) / scrollExtentY);
 				this.scrollY -= dy;
 				this.prevMousePos = mouseState.position;
+				var now = Timer.stamp();
+				if (lastMoveStamp > 0) {
+					var dt = now - lastMoveStamp;
+					if (dt > 0)
+						scrollVelocity = -dy / dt;
+				}
+				lastMoveStamp = now;
+				momentumActive = false;
 				this.updateScrollVisual();
 			}
 		}
 	}
 
+	public override function update(dt:Float, mouseState:MouseState) {
+		super.update(dt, mouseState);
+		if (!pressed && momentumActive) {
+			var damping = Math.exp(-MOMENTUM_DAMPING * dt);
+			scrollVelocity *= damping;
+			if (Math.abs(scrollVelocity) < 0.01) {
+				scrollVelocity = 0;
+				momentumActive = false;
+				return;
+			}
+			var before = scrollY;
+			scrollY += scrollVelocity * dt;
+			updateScrollVisual();
+			if (scrollY == 0 || scrollY == before)
+				momentumActive = false;
+		}
+	}
+
 	// public override function onMouseDown(mouseState:MouseState) {
 	// 	var renderRect = this.getHitTestRect();
 	// 	if (mouseState.position.x >= renderRect.position.x + renderRect.extent.x - 10) {
diff --git a/src/gui/GuiScrollCtrl.hx b/src/gui/GuiScrollCtrl.hx
index 7828fd54..1ce67742 100644
--- a/src/gui/GuiScrollCtrl.hx
+++ b/src/gui/GuiScrollCtrl.hx
@@ -232,10 +232,10 @@ class GuiScrollCtrl extends GuiControl {
 		if (Util.isTouchDevice()) {
 			super.onMouseMove(mouseState);
 			if (this.pressed) {
-				var dy = (mouseState.position.y - this.prevMousePos.y) * scrollSpeed / this.maxScrollY;
-				deltaY = -dy;
-				this.scrollY -= dy;
+				this.scrollY -= (mouseState.position.y - this.prevMousePos.y) / (maxScrollY * Settings.uiScale);
+				deltaY = -(mouseState.position.y - this.prevMousePos.y) / (maxScrollY * Settings.uiScale);
 				this.prevMousePos = mouseState.position;
+
 				this.updateScrollVisual();
 			}
 		}