From 1f81e13d81f0e405e887cddd06d7e1f8bf49c9d3 Mon Sep 17 00:00:00 2001
From: Mike <7153163+hackbar@users.noreply.github.com>
Date: Wed, 1 Nov 2017 18:29:33 -0700
Subject: [PATCH] Android: Ignore joystick axis movements in the flat area.

Now that all inputs are corrected to zero-centered, we can use getFlat()
to ignore movements that are just noise.

This eliminates a lot of drift when the controller is at rest, notably
on the character select screen in Melee.
---
 .../dolphinemu/activities/EmulationActivity.java      | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/activities/EmulationActivity.java b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/activities/EmulationActivity.java
index 4688cbce05..7fede2a7d4 100644
--- a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/activities/EmulationActivity.java
+++ b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/activities/EmulationActivity.java
@@ -735,7 +735,16 @@ public final class EmulationActivity extends AppCompatActivity
 			int axis = range.getAxis();
 			float origValue = event.getAxisValue(axis);
 			float value = mControllerMappingHelper.scaleAxis(input, axis, origValue);
-			NativeLibrary.onGamePadMoveEvent(input.getDescriptor(), axis, value);
+			// If the input is still in the "flat" area, that means it's really zero.
+			// This is used to compensate for imprecision in joysticks.
+			if (Math.abs(value) > range.getFlat())
+			{
+				NativeLibrary.onGamePadMoveEvent(input.getDescriptor(), axis, value);
+			}
+			else
+			{
+				NativeLibrary.onGamePadMoveEvent(input.getDescriptor(), axis, 0.0f);
+			}
 		}
 
 		return true;