From 32401de7f1b69e9f27e0bfd7aa6c867421b7a6b7 Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Sun, 11 Oct 2026 12:35:19 +0000
Subject: [PATCH] [patch] Stop ValueSlider reporting a change on held frames
 that move nothing

A drag is held as a double, and a float slider compared that double with
the float it was handed, so a value a float cannot hold exactly read as a
fresh change on every frame the pointer rested. Values are now compared
as they are stored.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018BGac9LmQV495Bsnrmo1b7
---
 ImGui.Widgets/ValueSlider.cs                  |  5 ++-
 .../ImGui.Widgets.UITests/ValueSliderTests.cs | 36 +++++++++++++++++++
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/ImGui.Widgets/ValueSlider.cs b/ImGui.Widgets/ValueSlider.cs
index 2b3bd0ba..b0d2aa44 100644
--- a/ImGui.Widgets/ValueSlider.cs
+++ b/ImGui.Widgets/ValueSlider.cs
@@ -259,7 +259,10 @@ private static bool Drag(ValueSliderState state, ref double value, Spec spec, fl
 
 		private static bool SetValue(ref double value, double target, double min, double max, bool isInteger)
 		{
-			double next = Math.Clamp(isInteger ? Math.Round(target, MidpointRounding.AwayFromZero) : target, min, max);
+			// The value is stored as a float or an int, so it is compared as one: a drag held as a double
+			// that a float cannot hold exactly would otherwise read as a fresh change on every held frame.
+			double stored = isInteger ? Math.Round(target, MidpointRounding.AwayFromZero) : (float)target;
+			double next = Math.Clamp(stored, min, max);
 			if (IsSameValue(next, value))
 			{
 				return false;
diff --git a/tests/ImGui.Widgets.UITests/ValueSliderTests.cs b/tests/ImGui.Widgets.UITests/ValueSliderTests.cs
index 52d82062..cc887f00 100644
--- a/tests/ImGui.Widgets.UITests/ValueSliderTests.cs
+++ b/tests/ImGui.Widgets.UITests/ValueSliderTests.cs
@@ -344,6 +344,42 @@ public void ValueSlider_APrefixIsDrawnButNotTyped()
 		Assert.AreEqual(30f, value, "A typed value with the prefix in front was not read.");
 	}
 
+	[TestMethod]
+	public void ValueSlider_AHeldPointerThatStopsReportsNoChange()
+	{
+		// 0..1 over 200 px, so a 7 px drag lands on 0.035, which a float cannot hold exactly.
+		float fraction = 0.5f;
+		int changes = 0;
+		Start(() =>
+		{
+			ImGui.PushItemWidth(FrameWidth);
+			if (ImGuiWidgets.ValueSlider(Label, ref fraction, 0f, 1f))
+			{
+				changes++;
+			}
+
+			ImGui.PopItemWidth();
+		});
+
+		Rectangle rect = RectOf(Label);
+		float x = rect.MinX + (FrameWidth / 2f);
+		float y = rect.MinY + (rect.Height / 2f);
+		Harness.Mouse.MoveTo(x, y);
+		Step();
+		HarnessMouse.Down(0);
+		Step();
+		Harness.Mouse.MoveTo(x + 7f, y);
+		Step(2);
+
+		Assert.AreNotEqual(0.5f, fraction, "The drag did not move the value.");
+		changes = 0;
+		Step(5);
+		HarnessMouse.Up(0);
+		Step();
+
+		Assert.AreEqual(0, changes, "The slider reported a change on frames the held pointer did not move.");
+	}
+
 	[TestMethod]
 	public void ValueSlider_ReportsTheFrameItChangedOn()
 	{