From 91a5ff9dc37615ec98d6ffbdd0165ef135662d80 Mon Sep 17 00:00:00 2001
From: Hugo Locurcio <hugo.locurcio@hugo.pro>
Date: Sat, 31 Jul 2021 21:49:52 +0200
Subject: [PATCH] Fix Xbox controllers in Bluetooth mode on macOS

This prevents the D-pad up arrow from being registered as pressed
when it isn't, and pressing any direction from activating the next
arrow clockwise of it.

Co-authored-by: Scott Wadden <scott.wadden@gmail.com>
---
 platform/osx/joypad_osx.cpp | 16 ++++++++++++++--
 platform/osx/joypad_osx.h   |  1 +
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/platform/osx/joypad_osx.cpp b/platform/osx/joypad_osx.cpp
index d778271350f..e67d2b0e91e 100644
--- a/platform/osx/joypad_osx.cpp
+++ b/platform/osx/joypad_osx.cpp
@@ -143,6 +143,8 @@ void joypad::add_hid_element(IOHIDElementRef p_element) {
 						switch (usage) {
 							case kHIDUsage_Sim_Rudder:
 							case kHIDUsage_Sim_Throttle:
+							case kHIDUsage_Sim_Accelerator:
+							case kHIDUsage_Sim_Brake:
 								if (!has_element(cookie, &axis_elements)) {
 									list = &axis_elements;
 								}
@@ -332,6 +334,13 @@ bool JoypadOSX::configure_joypad(IOHIDDeviceRef p_device_ref, joypad *p_joy) {
 		p_joy->add_hid_elements(array);
 		CFRelease(array);
 	}
+	// Xbox controller hat values start at 1 rather than 0.
+	p_joy->offset_hat = vendor == 0x45e &&
+						(product_id == 0x0b05 ||
+								product_id == 0x02e0 ||
+								product_id == 0x02fd ||
+								product_id == 0x0b13);
+
 	return true;
 }
 
@@ -388,13 +397,16 @@ bool joypad::check_ff_features() {
 	return false;
 }
 
-static int process_hat_value(int p_min, int p_max, int p_value) {
+static int process_hat_value(int p_min, int p_max, int p_value, bool p_offset_hat) {
 	int range = (p_max - p_min + 1);
 	int value = p_value - p_min;
 	int hat_value = HatMask::HAT_MASK_CENTER;
 	if (range == 4) {
 		value *= 2;
 	}
+	if (p_offset_hat) {
+		value -= 1;
+	}
 
 	switch (value) {
 		case 0:
@@ -468,7 +480,7 @@ void JoypadOSX::process_joypads() {
 		for (int j = 0; j < joy.hat_elements.size(); j++) {
 			rec_element &elem = joy.hat_elements.write[j];
 			int value = joy.get_hid_element_state(&elem);
-			int hat_value = process_hat_value(elem.min, elem.max, value);
+			int hat_value = process_hat_value(elem.min, elem.max, value, joy.offset_hat);
 			input->joy_hat(joy.id, (HatMask)hat_value);
 		}
 
diff --git a/platform/osx/joypad_osx.h b/platform/osx/joypad_osx.h
index bf7e8949df7..c060c3d523e 100644
--- a/platform/osx/joypad_osx.h
+++ b/platform/osx/joypad_osx.h
@@ -64,6 +64,7 @@ struct joypad {
 	Vector<rec_element> hat_elements;
 
 	int id = 0;
+	bool offset_hat = false;
 
 	io_service_t ffservice = 0; /* Interface for force feedback, 0 = no ff */
 	FFCONSTANTFORCE ff_constant_force;