Set usescancodes=true when non-US keyboards are detected (Linux/MacOS builds)

CHANGELOG

@@ -42,6 +42,8 @@ Next
     allocated block position. (maxpat78)
   - Enhanced Dynamic and Differencing VHD support #4273 (maxpat78)
   - Imported IBM Music Feature Card support from DOSBox Staging. (Allofich)
+  - Set usescancodes=true when non-US keyboards are detected. (Linux / MacOS 
+    builds) (maron2000)
   - Fix day of week detection (INT 21h 0x2Ah). (maron2000)
   - Refine KEYB and CHCP command (maron2000)
 2023.05.01

include/keymap.h

@@ -10,7 +10,7 @@ enum {
     DKM_DEU,            // German keyboard layout (one concerned user, in issue tracker)
     DKM_JPN_PC98,       // Japanese PC98 keyboard layout (for PC-98 emulation)
     DKM_JPN,            // Japanese keyboard layout (one concerned user, in issue tracker, with suggestion for mapping Ro)
-
+    DKM_NON_US,         // A non-US keyboard
     DKM_MAX
 };
 

src/gui/sdl_mapper.cpp

@@ -67,6 +67,10 @@
 
 #include <output/output_ttf.h>
 
+#if defined(MACOSX)
+#include <Carbon/Carbon.h> 
+#endif
+
 #define BMOD_Mod1               0x0001
 #define BMOD_Mod2               0x0002
 #define BMOD_Mod3               0x0004
@@ -999,7 +1003,7 @@ static SDLKey sdlkey_map[MAX_SCANCODES] = { // Convert hardware scancode (XKB =
     SDLK_WORLD_14, //0x64 Henkan
     SDLK_WORLD_15, //0x65 Hiragana/Katakana
     SDLK_WORLD_13, //0x66 Muhenkan
-    Z,Z,Z,Z, //0x67-0x6a
+    Z,SDLK_KP_ENTER,SDLK_RCTRL,SDLK_KP_DIVIDE, //0x67-0x6a
     Z, //SDLK_PRINTSCREEN, //0x6b
     SDLK_RALT,  //0x6c
     Z, //0x6d unknown
@@ -1159,6 +1163,8 @@ static SDLKey sdlkey_map[MAX_SCANCODES] = {
 
 #undef Z
 
+unsigned int Linux_GetKeyboardLayout(void); // defined in sdlmain_linux.cpp
+
 #if !defined(C_SDL2)
 void setScanCode(Section_prop * section) {
 	usescancodes = -1;
@@ -1179,7 +1185,37 @@ void setScanCode(Section_prop * section) {
             LOG_MSG("SDL_mapper: non-US keyboard detected, set usescancodes=true");
         }
     }
-#endif // defined(WIN32)
+#elif defined(__linux__)
+    else {
+        if(Linux_GetKeyboardLayout() == DKM_US) { /* Locale ID: en-us */
+            usescancodes = 0;
+            LOG_MSG("SDL_mapper: US keyboard detected, set usescancodes=false");
+        }
+        else {
+            usescancodes = 1;
+            LOG_MSG("SDL_mapper: non-US keyboard detected, set usescancodes=true");
+        }
+    }
+#elif defined(MACOSX)
+    else {
+        char layout[128];
+        memset(layout, '\0', sizeof(layout));
+        TISInputSourceRef source = TISCopyCurrentKeyboardInputSource();
+        // get input source id - kTISPropertyInputSourceID
+        // get layout name - kTISPropertyLocalizedName
+        CFStringRef layoutID = CFStringRef(TISGetInputSourceProperty(source, kTISPropertyInputSourceID));
+        CFStringGetCString(layoutID, layout, sizeof(layout), kCFStringEncodingUTF8);
+        //LOG_MSG("SDL_mapper: %s\n", layout);
+        if(!strcasecmp(layout, "com.apple.keylayout.US")) { /* US keyboard layout */
+            usescancodes = 0;
+            LOG_MSG("SDL_mapper: US keyboard detected, set usescancodes=false");
+        }
+        else {
+            usescancodes = 1;
+            LOG_MSG("SDL_mapper: non-US keyboard detected, set usescancodes=true");
+        }    
+    }
+#endif //defined(MACOSX)
 }
 void loadScanCode();
 const char* DOS_GetLoadedLayout(void);

src/gui/sdlmain_linux.cpp

@@ -240,7 +240,7 @@ void Linux_JPXKBFix(void) {
 }
 
 unsigned int Linux_GetKeyboardLayout(void) {
-    unsigned int ret = DKM_US;
+    unsigned int ret = DKM_NON_US; // a non-US keyboard
 
     SDL_SysWMinfo wminfo;
     memset(&wminfo,0,sizeof(wminfo));