From 9178206c950226ea6c4814443e29e52112c72846 Mon Sep 17 00:00:00 2001
From: Flyinghead <raphael.jean@gmail.com>
Date: Fri, 8 Mar 2019 19:56:17 +0100
Subject: [PATCH] add 10% dead zone to analog sticks

---
 core/input/gamepad_device.cpp | 21 +++++++++++++++++++--
 core/input/gamepad_device.h   |  1 +
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/core/input/gamepad_device.cpp b/core/input/gamepad_device.cpp
index 996159c4d..29cb1436a 100644
--- a/core/input/gamepad_device.cpp
+++ b/core/input/gamepad_device.cpp
@@ -117,12 +117,29 @@ bool GamepadDevice::gamepad_axis_input(u32 code, int value)
 	else if (((int)key >> 16) == 2) // Analog axes
 	{
 		//printf("AXIS %d Mapped to %d -> %d\n", key, value, v);
+		s8 *this_axis;
+		s8 *other_axis;
 		if (key == DC_AXIS_X)
-			joyx[_maple_port] = (s8)v;
+		{
+			this_axis = &joyx[_maple_port];
+			other_axis = &joyy[_maple_port];
+		}
 		else if (key == DC_AXIS_Y)
-			joyy[_maple_port] = (s8)v;
+		{
+			this_axis = &joyy[_maple_port];
+			other_axis = &joyx[_maple_port];
+		}
 		else
 			return false;
+		// Radial dead zone
+		// FIXME compute both axes at the same time
+		if ((float)(v * v + *other_axis * *other_axis) < _dead_zone * _dead_zone * 128.f * 128.f * 2.f)
+		{
+			*this_axis = 0;
+			*other_axis = 0;
+		}
+		else
+			*this_axis = (s8)v;
 	}
 	else
 		return false;
diff --git a/core/input/gamepad_device.h b/core/input/gamepad_device.h
index b8f7e269d..e11c5e90d 100644
--- a/core/input/gamepad_device.h
+++ b/core/input/gamepad_device.h
@@ -106,6 +106,7 @@ private:
 	bool _detecting_button = false;
 	input_detected_cb _input_detected;
 	bool _remappable;
+	float _dead_zone = 0.1f;
 
 	static std::vector<std::shared_ptr<GamepadDevice>> _gamepads;
 	static std::mutex _gamepads_mutex;