From 4caa6a0688b3a31cb6a2885238f1eba954ce4574 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Tue, 10 Mar 2020 16:41:42 -0700
Subject: [PATCH] Fixed bug 4921 - Do not swap B/X buttons on GameCube
 controller unless it's requested

Ethan Lee

Basically replicating the solution of the Switch Controller's button label issue. Physical layout should take priority unless it's explicitly requested by the user or application!
---
 src/joystick/hidapi/SDL_hidapi_gamecube.c | 37 +++++++++++++++++++++--
 1 file changed, 34 insertions(+), 3 deletions(-)

diff --git a/src/joystick/hidapi/SDL_hidapi_gamecube.c b/src/joystick/hidapi/SDL_hidapi_gamecube.c
index 480014101..6cd6659ba 100644
--- a/src/joystick/hidapi/SDL_hidapi_gamecube.c
+++ b/src/joystick/hidapi/SDL_hidapi_gamecube.c
@@ -29,6 +29,7 @@
 #include "SDL_haptic.h"
 #include "SDL_joystick.h"
 #include "SDL_gamecontroller.h"
+#include "../../SDL_hints_c.h"
 #include "../SDL_sysjoystick.h"
 #include "SDL_hidapijoystick_c.h"
 #include "SDL_hidapi_rumble.h"
@@ -47,6 +48,7 @@ typedef struct {
     Uint8 rumble[1+MAX_CONTROLLERS];
     /* Without this variable, hid_write starts to lag a TON */
     SDL_bool rumbleUpdate;
+    SDL_bool m_bUseButtonLabels;
 } SDL_DriverGameCube_Context;
 
 static SDL_bool
@@ -95,6 +97,27 @@ static float RemapVal(float val, float A, float B, float C, float D)
     return C + (D - C) * (val - A) / (B - A);
 }
 
+static void SDLCALL SDL_GameControllerButtonReportingHintChanged(void *userdata, const char *name, const char *oldValue, const char *hint)
+{
+    SDL_DriverGameCube_Context *ctx = (SDL_DriverGameCube_Context *)userdata;
+    ctx->m_bUseButtonLabels = SDL_GetStringBoolean(hint, SDL_TRUE);
+}
+
+static Uint8 RemapButton(SDL_DriverGameCube_Context *ctx, Uint8 button)
+{
+    if (ctx->m_bUseButtonLabels) {
+        switch (button) {
+        case SDL_CONTROLLER_BUTTON_B:
+            return SDL_CONTROLLER_BUTTON_X;
+        case SDL_CONTROLLER_BUTTON_X:
+            return SDL_CONTROLLER_BUTTON_B;
+        default:
+            break;
+        }
+    }
+    return button;
+}
+
 static SDL_bool
 HIDAPI_DriverGameCube_InitDevice(SDL_HIDAPI_Device *device)
 {
@@ -164,6 +187,9 @@ HIDAPI_DriverGameCube_InitDevice(SDL_HIDAPI_Device *device)
         }
     }
 
+    SDL_AddHintCallback(SDL_HINT_GAMECONTROLLER_USE_BUTTON_LABELS,
+                        SDL_GameControllerButtonReportingHintChanged, ctx);
+
     return SDL_TRUE;
 
 error:
@@ -244,12 +270,12 @@ HIDAPI_DriverGameCube_UpdateDevice(SDL_HIDAPI_Device *device)
             #define READ_BUTTON(off, flag, button) \
                 SDL_PrivateJoystickButton( \
                     joystick, \
-                    button, \
+                    RemapButton(ctx, button), \
                     (curSlot[off] & flag) ? SDL_PRESSED : SDL_RELEASED \
                 );
             READ_BUTTON(1, 0x01, 0) /* A */
-            READ_BUTTON(1, 0x04, 1) /* B */
-            READ_BUTTON(1, 0x02, 2) /* X */
+            READ_BUTTON(1, 0x02, 1) /* B */
+            READ_BUTTON(1, 0x04, 2) /* X */
             READ_BUTTON(1, 0x08, 3) /* Y */
             READ_BUTTON(1, 0x10, 4) /* DPAD_LEFT */
             READ_BUTTON(1, 0x20, 5) /* DPAD_RIGHT */
@@ -352,9 +378,14 @@ HIDAPI_DriverGameCube_CloseJoystick(SDL_HIDAPI_Device *device, SDL_Joystick *joy
 static void
 HIDAPI_DriverGameCube_FreeDevice(SDL_HIDAPI_Device *device)
 {
+    SDL_DriverGameCube_Context *ctx = (SDL_DriverGameCube_Context *)device->context;
+
     hid_close(device->dev);
     device->dev = NULL;
 
+    SDL_DelHintCallback(SDL_HINT_GAMECONTROLLER_USE_BUTTON_LABELS,
+                        SDL_GameControllerButtonReportingHintChanged, ctx);
+
     SDL_free(device->context);
     device->context = NULL;
 }