DirectInput to CEGUI utf32

This function converts DirectInput's scan codes into a utf32 character value compatible with the injectChar() function. It converts both simple characters as well as characters composed of a dead key as well as a single character. The value of zero is returned if a character could not be converted.

CEGUI::utf32 keycodeToUTF32( unsigned int scanCode) { CEGUI::utf32 utf = 0;

BYTE keyboardState[256]; unsigned char ucBuffer[3]; static WCHAR deadKey = '\0';

// Retrieve the keyboard layout in order to perform the necessary convertions HKL hklKeyboardLayout = GetKeyboardLayout(0); // 0 means current thread // This seemingly cannot fail // If this value is cached then the application must respond to WM_INPUTLANGCHANGE

// Retrieve the keyboard state // Handles CAPS-lock and SHIFT states if (GetKeyboardState(keyboardState) == FALSE) return utf;

/* 0. Convert virtual-key code into a scan code

      1. Convert scan code into a virtual-key code

Does not distinguish between left- and right-hand keys.

      2. Convert virtual-key code into an unshifted character value

in the low order word of the return value. Dead keys (diacritics) are indicated by setting the top bit of the return value.

      3. Windows NT/2000/XP: Convert scan code into a virtual-key

Distinguishes between left- and right-hand keys.*/ UINT virtualKey = MapVirtualKeyEx(scanCode, 3, hklKeyboardLayout); if (virtualKey == 0) // No translation possible return utf;

   /* Parameter 5:

0. No menu is active 1. A menu is active

      Return values:

Negative. Returned a dead key 0. No translation available 1. A translation exists 2. Dead-key could not be combined with character */ int ascii = ToAsciiEx(virtualKey, scanCode, keyboardState, (LPWORD) ucBuffer, 0, hklKeyboardLayout); if(deadKey != '\0' && ascii == 1) { // A dead key is stored and we have just converted a character key // Combine the two into a single character WCHAR wcBuffer[3]; WCHAR out[3]; wcBuffer[0] = ucBuffer[0]; wcBuffer[1] = deadKey; wcBuffer[2] = '\0'; if( FoldStringW(MAP_PRECOMPOSED, (LPWSTR) wcBuffer, 3, (LPWSTR) out, 3) ) utf = out[0]; else { // FoldStringW failed DWORD dw = GetLastError(); switch(dw) { case ERROR_INSUFFICIENT_BUFFER: case ERROR_INVALID_FLAGS: case ERROR_INVALID_PARAMETER: break; } } deadKey = '\0'; } else if (ascii == 1) { // We have a single character utf = ucBuffer[0]; deadKey = '\0'; } else { // Convert a non-combining diacritical mark into a combining diacritical mark // Combining versions range from 0x300 to 0x36F; only 5 (for French) have been mapped below // http://www.fileformat.info/info/unicode/block/combining_diacritical_marks/images.htm switch(ucBuffer[0]) { case 0x5E: // Circumflex accent: â deadKey = 0x302; break; case 0x60: // Grave accent: à deadKey = 0x300; break; case 0xA8: // Diaeresis: ü deadKey = 0x308; break; case 0xB4: // Acute accent: é deadKey = 0x301; break; case 0xB8: // Cedilla: ç deadKey = 0x327; break; default: deadKey = ucBuffer[0]; } }

return utf; }