From 90d9503789d9c312c5f32e958752f747138ebfdd Mon Sep 17 00:00:00 2001
From: Dietrich Epp <depp@zdome.net>
Date: Sat, 30 Jul 2022 16:40:40 -0400
Subject: [PATCH] SDL: Use scancodes for keyboard bindings (#905)

Core key bindings for SDL >= 2.0 are now independent of the keyboard
layout. QWERTY users get ZXAS, German users get YXAS, French layouts get
WXQS, etc. Existing customizations will be ignored, users with
customized bindings for SDL will get the new defaults and have to create
a new configuration.

Existing functionality is preserved for SDL 1.x.
---
 src/platform/sdl/sdl-events.c | 37 +++++++++++++++++++++++++++++++++++
 src/platform/sdl/sdl-events.h |  5 ++++-
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/src/platform/sdl/sdl-events.c b/src/platform/sdl/sdl-events.c
index a675ff2c093..8d2f2f63492 100644
--- a/src/platform/sdl/sdl-events.c
+++ b/src/platform/sdl/sdl-events.c
@@ -21,6 +21,13 @@
 #define GUI_MOD KMOD_CTRL
 #endif
 
+#if SDL_VERSION_ATLEAST(2, 0, 0)
+#define USE_SCANCODES 1
+#define SDL_BINDING_KEY SDL_BINDING_SCANCODE
+#else
+#define SDL_BINDING_KEY SDL_BINDING_KEYCODE
+#endif
+
 #define GYRO_STEPS 100
 #define RUMBLE_PWM 16
 #define RUMBLE_STEPS 2
@@ -143,6 +150,31 @@ void mSDLEventsLoadConfig(struct mSDLEvents* context, const struct Configuration
 }
 
 void mSDLInitBindingsGBA(struct mInputMap* inputMap) {
+#if USE_SCANCODES
+#ifdef BUILD_PANDORA
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_PAGEDOWN, GBA_KEY_A);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_END, GBA_KEY_B);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_RSHIFT, GBA_KEY_L);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_RCTRL, GBA_KEY_R);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_LALT, GBA_KEY_START);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_LCTRL, GBA_KEY_SELECT);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_UP, GBA_KEY_UP);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_DOWN, GBA_KEY_DOWN);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_LEFT, GBA_KEY_LEFT);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_RIGHT, GBA_KEY_RIGHT);
+#else
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_X, GBA_KEY_A);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_Z, GBA_KEY_B);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_A, GBA_KEY_L);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_S, GBA_KEY_R);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_RETURN, GBA_KEY_START);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_BACKSPACE, GBA_KEY_SELECT);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_UP, GBA_KEY_UP);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_DOWN, GBA_KEY_DOWN);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_LEFT, GBA_KEY_LEFT);
+	mInputBindKey(inputMap, SDL_BINDING_KEY, SDL_SCANCODE_RIGHT, GBA_KEY_RIGHT);
+#endif
+#else
 #ifdef BUILD_PANDORA
 	mInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_PAGEDOWN, GBA_KEY_A);
 	mInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_END, GBA_KEY_B);
@@ -165,6 +197,7 @@ void mSDLInitBindingsGBA(struct mInputMap* inputMap) {
 	mInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_DOWN, GBA_KEY_DOWN);
 	mInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_LEFT, GBA_KEY_LEFT);
 	mInputBindKey(inputMap, SDL_BINDING_KEY, SDLK_RIGHT, GBA_KEY_RIGHT);
+#endif
 #endif
 
 	struct mInputAxis description = { GBA_KEY_RIGHT, GBA_KEY_LEFT, 0x4000, -0x4000 };
@@ -463,9 +496,13 @@ static void _pauseAfterFrame(struct mCoreThread* context) {
 
 static void _mSDLHandleKeypress(struct mCoreThread* context, struct mSDLPlayer* sdlContext, const struct SDL_KeyboardEvent* event) {
 	int key = -1;
+#if USE_SCANCODES
+	key = mInputMapKey(sdlContext->bindings, SDL_BINDING_KEY, event->keysym.scancode);
+#else
 	if (!(event->keysym.mod & ~(KMOD_NUM | KMOD_CAPS))) {
 		key = mInputMapKey(sdlContext->bindings, SDL_BINDING_KEY, event->keysym.sym);
 	}
+#endif
 	if (key != -1) {
 		mCoreThreadInterrupt(context);
 		if (event->type == SDL_KEYDOWN) {
diff --git a/src/platform/sdl/sdl-events.h b/src/platform/sdl/sdl-events.h
index 8bdbd7c0b04..005d09b7ec0 100644
--- a/src/platform/sdl/sdl-events.h
+++ b/src/platform/sdl/sdl-events.h
@@ -27,7 +27,10 @@ CXX_GUARD_START
 
 mLOG_DECLARE_CATEGORY(SDL_EVENTS);
 
-#define SDL_BINDING_KEY 0x53444C4BU
+// SDL_BINDING_KEYCODE: Bindings for SDL_Keysym.sim (SDL < 2.0).
+#define SDL_BINDING_KEYCODE 0x53444C4BU
+// SDL_BINDING_SCANCODE: Bindings for SDL_Keysym.scancode (SDL >= 2.0).
+#define SDL_BINDING_SCANCODE 0x53444C53U
 #define SDL_BINDING_BUTTON 0x53444C42U
 
 #define MAX_PLAYERS 4