support for native keyboard input (from Chocolate Doom) (#2030)

* matching Chocolate Doom behaviour with cheat codes

* implement `ev_text` event

src/d_event.h

@@ -40,7 +40,8 @@ typedef enum evtype_e
   ev_joyb_up,
   ev_joystick,
   ev_joystick_state,
-  ev_gyro
+  ev_gyro,
+  ev_text
 } evtype_t;
 
 typedef union evdata_u

src/d_main.c

@@ -2634,6 +2634,7 @@ void D_DoomMain(void)
 
   // [FG] init graphics (video.widedelta) before HUD widgets
   I_InitGraphics();
+  I_InitKeyboard();
 
   MN_InitMenuStrings();
 

src/f_finale.c

@@ -389,7 +389,7 @@ void F_TextWrite (void)
     }
 
     c = M_ToUpper(c) - HU_FONTSTART;
-    if (c < 0 || c> HU_FONTSIZE)
+    if (c < 0 || c> HU_FONTSIZE || hu_font[c] == NULL)
     {
       cx += 4;
       continue;
@@ -618,7 +618,7 @@ void F_CastPrint (char* text)
     if (!c)
       break;
     c = M_ToUpper(c) - HU_FONTSTART;
-    if (c < 0 || c> HU_FONTSIZE)
+    if (c < 0 || c> HU_FONTSIZE || hu_font[c] == NULL)
     {
       width += 4;
       continue;
@@ -637,7 +637,7 @@ void F_CastPrint (char* text)
     if (!c)
       break;
     c = M_ToUpper(c) - HU_FONTSTART;
-    if (c < 0 || c> HU_FONTSIZE)
+    if (c < 0 || c> HU_FONTSIZE || hu_font[c] == NULL)
     {
       cx += 4;
       continue;

src/i_input.c

@@ -1,4 +1,5 @@
 //
+// Copyright(C) 2005-2014 Simon Howard
 // Copyright(C) 2023 Roman Fomin
 //
 // This program is free software; you can redistribute it and/or
@@ -606,8 +607,63 @@ void I_HandleGamepadEvent(SDL_Event *sdlevent, boolean menu)
 
 static const int scancode_translate_table[] = SCANCODE_TO_KEYS_ARRAY;
 
-static int TranslateKey(int scancode)
-{
+// If true, I_StartTextInput() has been called, and we are populating
+// the data3 field of ev_keydown events.
+
+static boolean text_input_enabled;
+
+// key tables
+// jff 5/10/98 french support removed, 
+// as it was not being used and couldn't be easily tested
+//
+
+static const char shiftxform[] =
+{
+    0,
+    1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
+    11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
+    21, 22, 23, 24, 25, 26, 27, 28, 29, 30,
+    31,
+    ' ', '!', '"', '#', '$', '%', '&',
+    '"', // shift-'
+    '(', ')', '*', '+',
+    '<', // shift-,
+    '_', // shift--
+    '>', // shift-.
+    '?', // shift-/
+    ')', // shift-0
+    '!', // shift-1
+    '@', // shift-2
+    '#', // shift-3
+    '$', // shift-4
+    '%', // shift-5
+    '^', // shift-6
+    '&', // shift-7
+    '*', // shift-8
+    '(', // shift-9
+    ':',
+    ':', // shift-;
+    '<',
+    '+', // shift-=
+    '>', '?', '@',
+    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
+    'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
+    '[', // shift-[
+    '!', // shift-backslash - OH MY GOD DOES WATCOM SUCK
+    ']', // shift-]
+    '"', '_',
+    '\'', // shift-`
+    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
+    'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
+    '{', '|', '}', '~', 127
+};
+
+static boolean vanilla_keyboard_mapping;
+
+static int TranslateKey(SDL_Keysym *sym)
+{
+    int scancode = sym->scancode;
+
     switch (scancode)
     {
         case SDL_SCANCODE_LCTRL:
@@ -636,6 +692,67 @@ static int TranslateKey(int scancode)
     }
 }
 
+
+// Get the localized version of the key press. This takes into account the
+// keyboard layout, but does not apply any changes due to modifiers, (eg.
+// shift-, alt-, etc.)
+
+static int GetLocalizedKey(SDL_Keysym *sym)
+{
+    // When using Vanilla mapping, we just base everything off the scancode
+    // and always pretend the user is using a US layout keyboard.
+    if (vanilla_keyboard_mapping)
+    {
+        return TranslateKey(sym);
+    }
+    else
+    {
+        int result = sym->sym;
+
+        if (result < 0 || result >= 128)
+        {
+            result = 0;
+        }
+
+        return result;
+    }
+}
+
+static int GetTypedChar(SDL_Keysym *sym)
+{
+    int result = TranslateKey(sym);
+
+    // If shift is held down, apply the original uppercase
+    // translation table used under DOS.
+    if ((SDL_GetModState() & KMOD_SHIFT) != 0 && result >= 0
+        && result < arrlen(shiftxform))
+    {
+        result = shiftxform[result];
+    }
+
+    return result;
+}
+
+void I_StartTextInput(void)
+{
+    text_input_enabled = true;
+
+    if (!vanilla_keyboard_mapping)
+    {
+        SDL_StartTextInput();
+    }
+}
+
+void I_StopTextInput(void)
+{
+    text_input_enabled = false;
+
+    if (!vanilla_keyboard_mapping)
+    {
+        SDL_StopTextInput();
+    }
+}
+
 static void UpdateMouseButtonState(unsigned int button, boolean on,
                                    unsigned int dclick)
 {
@@ -782,31 +899,67 @@ void I_HandleKeyboardEvent(SDL_Event *sdlevent)
     {
         case SDL_KEYDOWN:
             event.type = ev_keydown;
-            event.data1.i = TranslateKey(sdlevent->key.keysym.scancode);
+            event.data1.i = TranslateKey(&sdlevent->key.keysym);
+            event.data2.i = GetLocalizedKey(&sdlevent->key.keysym);
 
             if (event.data1.i != 0)
             {
                 D_PostEvent(&event);
             }
+
+            if (text_input_enabled && vanilla_keyboard_mapping)
+            {
+                event.type = ev_text;
+                event.data1.i = GetTypedChar(&sdlevent->key.keysym);
+
+                if (event.data1.i != 0)
+                {
+                    D_PostEvent(&event);
+                }
+            }
             break;
 
         case SDL_KEYUP:
             event.type = ev_keyup;
-            event.data1.i = TranslateKey(sdlevent->key.keysym.scancode);
+            event.data1.i = TranslateKey(&sdlevent->key.keysym);
 
-            // data2/data3 are initialized to zero for ev_keyup.
-            // For ev_keydown it's the shifted Unicode character
-            // that was typed, but if something wants to detect
-            // key releases it should do so based on data1
+            // data2 is initialized to zero for ev_keyup. For ev_keydown it's
+            // the shifted Unicode character that was typed, but if something
+            // wants to detect key releases it should do so based on data1
             // (key ID), not the printable char.
 
+            event.data2.i = 0;
+
             if (event.data1.i != 0)
             {
                 D_PostEvent(&event);
             }
             break;
 
+        case SDL_TEXTINPUT:
+            // SDL_TEXTINPUT are fired only after SDL_StartTextInput().
+            if (strlen(sdlevent->text.text) == 1
+                && (sdlevent->text.text[0] & 0x80) == 0)
+            {
+                event.type = ev_text;
+                event.data1.i = sdlevent->text.text[0];
+                D_PostEvent(&event);
+            }
+            break;
+
         default:
             break;
     }
 }
+
+void I_InitKeyboard(void)
+{
+    // On desktop platforms, SDL_StartTextInput() is implicitly called on SDL
+    // window creation
+    SDL_StopTextInput();
+}
+
+void I_BindKeyboardVariables(void)
+{
+    BIND_BOOL(vanilla_keyboard_mapping, false, "Vanilla keyboard mapping");
+}

src/i_input.h

@@ -45,4 +45,9 @@ void I_HandleGamepadEvent(SDL_Event *sdlevent, boolean menu);
 void I_HandleKeyboardEvent(SDL_Event *sdlevent);
 void I_HandleMouseEvent(SDL_Event *sdlevent);
 
+void I_InitKeyboard(void);
+void I_StartTextInput(void);
+void I_StopTextInput(void);
+void I_BindKeyboardVariables(void);
+
 #endif

src/i_video.c

@@ -471,6 +471,7 @@ static void ProcessEvent(SDL_Event *ev)
             // deliberate fall-though
 
         case SDL_KEYUP:
+        case SDL_TEXTINPUT:
             I_HandleKeyboardEvent(ev);
             break;
 

src/m_cheat.c

@@ -1310,7 +1310,7 @@ boolean M_CheatResponder(event_t *ev)
   if (strictmode && demorecording)
     return false;
 
-  if (ev->type == ev_keydown && M_FindCheats(ev->data1.i))
+  if (ev->type == ev_keydown && M_FindCheats(ev->data2.i))
     return true;
 
   if (WS_Override())

src/m_config.c

@@ -37,6 +37,7 @@
 #include "i_flickstick.h"
 #include "i_gamepad.h"
 #include "i_gyro.h"
+#include "i_input.h"
 #include "i_oalequalizer.h"
 #include "i_printf.h"
 #include "i_rumble.h"
@@ -49,8 +50,8 @@
 #include "m_input.h"
 #include "m_io.h"
 #include "m_misc.h"
-#include "mn_menu.h"
 #include "mn_internal.h"
+#include "mn_menu.h"
 #include "r_main.h"
 #include "s_sound.h"
 #include "st_stuff.h"
@@ -126,6 +127,7 @@ void M_InitConfig(void)
     G_BindGameInputVariables();
     G_BindMouseVariables();
 
+    I_BindKeyboardVariables();
     I_BindGamepadVariables();
     I_BindRumbleVariables();
     I_BindFlickStickVariables();

src/mn_menu.c

@@ -32,6 +32,7 @@
 #include "d_event.h"
 #include "d_main.h"
 #include "doomdef.h"
+#include "doomkeys.h"
 #include "doomstat.h"
 #include "doomtype.h"
 #include "dstrings.h"
@@ -1409,6 +1410,9 @@ static void M_SaveSelect(int choice)
     // we are going to be intercepting all chars
     saveStringEnter = 1;
 
+    // We need to turn on text input:
+    I_StartTextInput();
+
     saveSlot = choice;
     strcpy(saveOldString, savegamestrings[choice]);
     // [FG] override savegame name if it already starts with a map identifier
@@ -2926,6 +2930,9 @@ boolean M_Responder(event_t *ev)
             ch = ev->data1.i;
             break;
 
+        case ev_text:
+            break;
+
         case ev_keyup:
             return false;
 
@@ -3003,7 +3010,7 @@ boolean M_Responder(event_t *ev)
 
     if (saveStringEnter)
     {
-        if (action == MENU_BACKSPACE) // phares 3/7/98
+        if (ch == KEY_BACKSPACE) // phares 3/7/98
         {
             if (saveCharIndex > 0)
             {
@@ -3019,28 +3026,32 @@ boolean M_Responder(event_t *ev)
                 savegamestrings[saveSlot][saveCharIndex] = 0;
             }
         }
-        else if (action == MENU_ESCAPE) // phares 3/7/98
+        else if (ch == KEY_ESCAPE) // phares 3/7/98
         {
+            I_StopTextInput();
             saveStringEnter = 0;
             strcpy(&savegamestrings[saveSlot][0], saveOldString);
         }
-        else if (action == MENU_ENTER) // phares 3/7/98
+        else if (ch == KEY_ENTER) // phares 3/7/98
         {
+            I_StopTextInput();
             saveStringEnter = 0;
             if (savegamestrings[saveSlot][0])
             {
                 M_DoSave(saveSlot);
             }
         }
-        else
+        else if (ev->type == ev_text)
         {
-            ch = M_ToUpper(ch);
+            int txt = ev->data1.i;
+
+            txt = M_ToUpper(txt);
 
-            if (ch >= 32 && ch <= 127 && saveCharIndex < SAVESTRINGSIZE - 1
+            if (txt >= ' ' && txt <= '_' && saveCharIndex < SAVESTRINGSIZE - 1
                 && MN_StringWidth(savegamestrings[saveSlot])
                        < (SAVESTRINGSIZE - 2) * 8)
             {
-                savegamestrings[saveSlot][saveCharIndex++] = ch;
+                savegamestrings[saveSlot][saveCharIndex++] = txt;
                 savegamestrings[saveSlot][saveCharIndex] = 0;
             }
             saveStringEnter = 2; // [FG] save string modified
@@ -3612,7 +3623,7 @@ static void WriteText(int x, int y, const char *string)
         }
 
         c = M_ToUpper(c) - HU_FONTSTART;
-        if (c < 0 || c >= HU_FONTSIZE)
+        if (c < 0 || c >= HU_FONTSIZE || hu_font[c] == NULL)
         {
             cx += 4;
             continue;