Bug fixes

.gitignore

@@ -0,0 +1,3 @@
+# Misc system files
+.zshrc
+.dstore

Makefile

@@ -8,9 +8,12 @@ clean:
 UNAME := $(shell uname -s)
 
 ifeq ($(UNAME),Darwin)
-	IFLAGS := -I . -I /Library/Frameworks/SDL2.framework/Headers 
+	# Use the SDL2 installed by Homebrew (brew install sdl2). sdl2-config reports
+	# the correct include/lib paths whether SDL2 lives under /opt/homebrew (Apple
+	# Silicon) or /usr/local (Intel). Make sure sdl2-config is on PATH (see mac.md).
+	IFLAGS := -I . $(shell sdl2-config --cflags)
 	CFLAGS := -Wno-format -fsanitize=float-divide-by-zero -g -flto -DNDEBUG -fno-strict-aliasing -std=gnu99 $(IFLAGS)
-	LDFLAGS := -F /Library/Frameworks/ -framework SDL2
+	LDFLAGS := $(shell sdl2-config --libs)
 else
 	IFLAGS := -I . -I /usr/include/SDL2
 	CFLAGS := -rdynamic -g -flto -DNDEBUG -fno-strict-aliasing -O1 -std=gnu99 $(IFLAGS)

base/input.c

@@ -47,6 +47,7 @@ static int keymap[NUM_SCAN];
 // These are the only especially encoded keys the game uses.
 #define SPECIAL_KEY_LIST \
     KEY_MAP(SDL_SCANCODE_F1,         59) \
+    KEY_MAP(SDL_SCANCODE_F2,         60) \
     KEY_MAP(SDL_SCANCODE_UP,         72) \
     KEY_MAP(SDL_SCANCODE_LEFT,       75) \
     KEY_MAP(SDL_SCANCODE_DOWN,       80) \
@@ -64,6 +65,15 @@ static const int special_keycodes[] = { SPECIAL_KEY_LIST };
 
 static const int NUM_SPECIAL = sizeof(special_keys) / sizeof(special_keys[0]);
 
+// Keys travel through the circular buffer as plain SDL scancodes, but the
+// modifier state (shift / caps lock) that was active when the key was pressed
+// is lost by the time the game thread decodes them. We preserve it by packing
+// the modifier flags into high bits of the buffered value (scancodes are < 512,
+// so bits 16/17 are free). keydecode() unpacks them to produce capitals.
+#define KEYCODE_SCAN_MASK 0x1FF
+#define KEYCODE_SHIFT_BIT (1 << 16)
+#define KEYCODE_CAPS_BIT  (1 << 17)
+
 #include "include/base/input_proto.h"
 
 void input_init()
@@ -200,11 +210,18 @@ static void process_key_event(const SDL_Event *e)
 
     if (e->type == SDL_KEYDOWN)
     {
+        // Modifier keys (shift, ctrl, alt, caps lock, ...) are not characters.
+        // Don't buffer them as keypresses - their state is read separately and
+        // folded into the keys they modify. (Previously these leaked through and
+        // decoded to junk: shift, caps lock, etc. appeared as stray letters.)
+        if (is_modifier(scancode))
+            return;
+
         if (keymap[scancode] == 0)
         {
             // immediate keypress this frame
             keymap[scancode] = frames;
-            pushkey(scancode);
+            pushkey(encode_key(scancode, e->key.keysym.mod));
         }
     }
     else if (e->type == SDL_KEYUP)
@@ -229,7 +246,7 @@ static void keyscan()
         // Do a repeat if held down for half a second or more
         // at a rate of 20 presses per second (every 3 frames)
         if ((delta >= 30 && (delta % 3) == 0))
-            pushkey(i);
+            pushkey(encode_key(i, SDL_GetModState()));
     }
 }
 
@@ -246,9 +263,16 @@ void get_mouse(int *x, int *y)
     *y = r;
 }
 
-// Used by the TP emulation layer to decode a scancode 
-int keydecode(int scancode, int *special)
+// Used by the TP emulation layer to decode a buffered key into the code the
+// game expects. The argument carries the scancode in its low bits plus the
+// shift/caps modifier flags (see encode_key).
+int keydecode(int code, int *special)
 {
+    int scancode = code & KEYCODE_SCAN_MASK;
+    int shift    = (code & KEYCODE_SHIFT_BIT) != 0;
+    int caps     = (code & KEYCODE_CAPS_BIT) != 0;
+
+    // Special navigation / function keys map to fixed DOS-style codes.
     int si = find_special(scancode);
 
     if (si != -1)
@@ -258,7 +282,46 @@ int keydecode(int scancode, int *special)
     }
 
     *special = 0;
-    return (int) SDL_GetKeyFromScancode((SDL_Scancode) scancode);
+
+    // Letters: apply shift / caps lock so the player can type capitals.
+    // shift XOR caps -> uppercase, just like a real keyboard.
+    if (scancode >= SDL_SCANCODE_A && scancode <= SDL_SCANCODE_Z)
+    {
+        int c = 'a' + (scancode - SDL_SCANCODE_A);
+        if (shift ^ caps)
+            c -= 32;
+        return c;
+    }
+
+    // Numeric keypad: map to the digits the DOS game expects, regardless of
+    // Num Lock, so numpad 7/9 throw grenades and 8/4/6/2 steer the ejected
+    // pilot the way they did on the original.
+    switch (scancode)
+    {
+        case SDL_SCANCODE_KP_0:      return '0';
+        case SDL_SCANCODE_KP_1:      return '1';
+        case SDL_SCANCODE_KP_2:      return '2';
+        case SDL_SCANCODE_KP_3:      return '3';
+        case SDL_SCANCODE_KP_4:      return '4';
+        case SDL_SCANCODE_KP_5:      return '5';
+        case SDL_SCANCODE_KP_6:      return '6';
+        case SDL_SCANCODE_KP_7:      return '7';
+        case SDL_SCANCODE_KP_8:      return '8';
+        case SDL_SCANCODE_KP_9:      return '9';
+        case SDL_SCANCODE_KP_ENTER:  return 13;
+        case SDL_SCANCODE_KP_PERIOD: return '.';
+    }
+
+    // Everything else: the plain ASCII value (digits, space, enter, esc,
+    // backspace, punctuation). SDL keycodes above 255 are non-character keys
+    // (unused F-keys, etc.); drop them instead of truncating into bogus
+    // letters the way the old code did.
+    int k = (int) SDL_GetKeyFromScancode((SDL_Scancode) scancode);
+
+    if (k > 255)
+        return 0;
+
+    return k;
 }
 
 // Used by keydecode to detect a special key
@@ -272,3 +335,43 @@ static int find_special(int code)
 
     return -1;
 }
+
+// True for keys that are modifiers rather than characters. These are tracked
+// via their modifier state and must not be buffered as keypresses themselves.
+static int is_modifier(int scancode)
+{
+    switch (scancode)
+    {
+        case SDL_SCANCODE_LCTRL:
+        case SDL_SCANCODE_RCTRL:
+        case SDL_SCANCODE_LSHIFT:
+        case SDL_SCANCODE_RSHIFT:
+        case SDL_SCANCODE_LALT:
+        case SDL_SCANCODE_RALT:
+        case SDL_SCANCODE_LGUI:
+        case SDL_SCANCODE_RGUI:
+        case SDL_SCANCODE_CAPSLOCK:
+        case SDL_SCANCODE_NUMLOCKCLEAR:
+        case SDL_SCANCODE_SCROLLLOCK:
+        case SDL_SCANCODE_MODE:
+            return 1;
+        default:
+            return 0;
+    }
+}
+
+// Pack a scancode together with the shift/caps state active when it was
+// pressed, so keydecode (which runs later, on the game thread) can produce
+// the right character. Scancodes are < 512, so the high bits are free.
+static int encode_key(int scancode, unsigned mod)
+{
+    int v = scancode & KEYCODE_SCAN_MASK;
+
+    if (mod & KMOD_SHIFT)
+        v |= KEYCODE_SHIFT_BIT;
+
+    if (mod & KMOD_CAPS)
+        v |= KEYCODE_CAPS_BIT;
+
+    return v;
+}

game/chopper2.c

@@ -213,6 +213,7 @@ int16_t pict2[1+12];
 int16_t pict3[1+45]; // { parachute }
 int16_t pblank[1+12];
 bool mainquit;
+bool tomenu; // { set by ESC: abandon current screen/mission and return to the main menu }
 
 // { starting }
 
@@ -267,6 +268,17 @@ void ToggleMouse();
 #include "title.h"
 #include "terrain.h"
 
+// ESC during a mission abandons it and returns to the main menu (rather than
+// quitting the program). quit ends the mission loop; firstgo=0 makes the next
+// TitleScreen show the menu again; tomenu tells the outer loop to skip the
+// post-mission results/save and go straight back to the menu.
+void ReturnToMenu()
+{
+    tomenu = true;
+    firstgo = 0;
+    quit = true;
+}
+
 void GraphicStartUp()
 {
     int16_t gm;
@@ -296,6 +308,7 @@ void ResetVars()
     }
 
   quit = false;
+  tomenu = false;
   x = 25;
   mfall = 0;
 
@@ -677,7 +690,7 @@ void Input()
              writeln_u16_str(ammo," ");
          }
               break; 
-     case 27:  Shutdown(); break;
+     case 27:  ReturnToMenu(); break;
      case 'e': case 'E': case 60:
           dostatus();
           ammo = 10;
@@ -1431,7 +1444,7 @@ void ManCheck()  // ( man in air (not soldier) )
                     writeln_u16_str(ammo," ");
                 }
                 break;
-            case 27 : Shutdown(); break;
+            case 27 : ReturnToMenu(); break;
             case 'p':case 'P' : Pause(); break;
             case 's':case 'S' : Speeds(); break;
             case 't':case 'T' : ToggleMouse(); break;
@@ -1523,7 +1536,7 @@ void Input2() // ( after eject )
                       man.time = -120;
                   }
                   break;
-        case 27 : Shutdown(); break;
+        case 27 : ReturnToMenu(); break;
         case 'p':case 'P' : Pause(); break;
         case 's':case 'S' : Speeds(); break;
         case 't':case 'T' : ToggleMouse(); break;
@@ -2207,6 +2220,8 @@ void Start()
     ResetVars();
     TitleScreen(&level,&pilnum,&pilot,&free_);
 
+    if (tomenu) return; // ESC at the title/roster/difficulty screen -> back to menu
+
     InitMouse();
     ResetVars2();
 
@@ -2228,6 +2243,8 @@ void Start()
         }
     }
 
+    if (tomenu) return; // ESC during mission selection -> back to menu
+
     MissionSet();
 
     if (step == 5) // { start at NorthCape Base }
@@ -2277,25 +2294,39 @@ void* gamecode(void *arg)
 
     do {
         Start();
+
+        // ESC at the title/roster/difficulty screen: no mission was set up,
+        // so there's nothing to tear down - just loop back to the menu.
+        if (tomenu)
+        {
+            keyhit = '@';
+            continue;
+        }
+
         gettime(&time1,&time22,&time3,&time4);
         Main();
         CalcTime();
         nosound();
         for (loop = 1; loop <= MaxHoles; loop++) // (* free memory of screen save *)
             freemem(hole.image[loop],hole.size[loop]);
-        delay (2000);
-        if (pl.yv == -32) pl.alive = true;
-        if (free_ == false) MissionResults (&pilot,onscreen,CalcDif,man.cond,mis,time2,time_,building,deheli,
-                cruise.alive,tank.alive,pl.alive,cruise.xv,step,damage,totalejects,level,HitTotal);
-        else
-            if ((man.cond < 1) && (onscreen == 3) && (x < 50) && (y > 133) && (time2 < 5)) 
-                Practice3();
-            else
-                if ((deheli[1]) && (man.cond > 0)) Practice1();
-                else Practice2();
-        if (free_ == false)
+
+        // ESC mid-mission abandons it: skip the stats/save and return to menu.
+        if (!tomenu)
         {
-            Save(&pilot, pilnum);
+            delay (2000);
+            if (pl.yv == -32) pl.alive = true;
+            if (free_ == false) MissionResults (&pilot,onscreen,CalcDif,man.cond,mis,time2,time_,building,deheli,
+                    cruise.alive,tank.alive,pl.alive,cruise.xv,step,damage,totalejects,level,HitTotal);
+            else
+                if ((man.cond < 1) && (onscreen == 3) && (x < 50) && (y > 133) && (time2 < 5))
+                    Practice3();
+                else
+                    if ((deheli[1]) && (man.cond > 0)) Practice1();
+                    else Practice2();
+            if (free_ == false)
+            {
+                Save(&pilot, pilnum);
+            }
         }
 
         keyhit = '@';

game/missions.h

@@ -435,7 +435,10 @@ void StatsScreen(pilottype *pilot,
         outtextxyp(200,145,pilot->rank);
         outtextxy (30,155,"total damage in (mil.)");
 
-        sprintf(damge, " $%4.1f", damage);
+        // Lifetime total: pilot->dmg was just updated above (this mission's
+        // damage added to the running total). Print that, not this mission's
+        // damage alone.
+        sprintf(damge, " $%4.1f", pilot->dmg);
         outtextxyp(200,155,damge);
     }
 

game/title.h

@@ -27,7 +27,7 @@ void EasyWait()
    outtextxy (100,185,"press any key");
 
    key = readkey();
-   if (key == 27) Shutdown();
+   (void) key; // any key (including ESC) just returns to the menu via the caller
 }
 
 // Print out the game instructions.
@@ -52,9 +52,9 @@ void Instruct()
    outtextxy (5,127,"  \"P\"              -  pause");
    outtextxy (5,137,"  \"S\"              -  toggle game speed");
    outtextxy (5,147,"  \"X\"              -  toggle sound");
-   outtextxy (5,157,"  Esc              -  quit game");
+   outtextxy (5,157,"  Esc              -  return to main menu");
    outtextxy (5,167,"  \"A\"              -  toggle auto-eject");
-   outtextxy (5,177,"  home , PgUp keys -  throws grenades (when ejected)");
+   outtextxy (5,177,"  7/9 keys (or home/PgUp) - throw grenades (ejected)");
    EasyWait();
    cleardevice();
    settextstyle (2,0,4);
@@ -95,7 +95,7 @@ void Instruct()
    outtextxy (5,130," To exit helicopter without ejecting : land");
    outtextxy (5,140,"then press \"E\". To enter the helicopter : walk");
    outtextxy (5,150,"into it.");
-   outtextxy (5,170," Caps-Lock should be off.  Good Luck!");
+   outtextxy (5,170," Use Shift for capital letters.  Good Luck!");
    outtextxy (5,160," Gear must be UP for auto-eject to work.");
    EasyWait();
 }
@@ -398,7 +398,7 @@ void Roster(int16_t *pilnum, struct pilottype *pil)
 
    if (t_keyhit == 72) dec(pilnum);
    else if (t_keyhit == 80) inc(pilnum);
-   else if (t_keyhit == 27) Shutdown();
+   else if (t_keyhit == 27) { tomenu = true; firstgo = 0; return; } // ESC -> main menu
    else if (t_keyhit == 59)           // { enter name }
    {
        struct pilottype *with = &t_pilot[*pilnum];
@@ -491,7 +491,7 @@ void SelectDifficulty(char *level)
         outtextxy (50,100,"  2) AVERAGE (75 bombs)");
         outtextxy (50,115,"  3) COMMANDO (50 bombs)");
         *level = readkey();
-        if (*level == 27) Shutdown();
+        if (*level == 27) { tomenu = true; firstgo = 0; return; } // ESC -> main menu
     } while (!(in(*level,'1','3')));
 
 }
@@ -556,6 +556,7 @@ void TitleScreen(char *level, int16_t *pilnum, struct pilottype *pil, bool *isfr
     if (*isfree == false)
     {
         Roster(pilnum, pil);
+        if (tomenu) return; // ESC at the roster -> back to the menu
         SelectDifficulty(level);
     }
 }
@@ -579,6 +580,7 @@ void Mission(const char** scene, int16_t *mis)
 
     do {
         dif = readkey();
+        if (dif == 27) { tomenu = true; firstgo = 0; return; } // ESC -> main menu
     } while (!in(dif, '1', '4'));
 
     MissionSetUp();  // { draw box on screen }

include/base/input_proto.h

@@ -16,3 +16,5 @@ static void keyscan(void);
 void get_mouse(int *x, int *y);
 int keydecode(int scancode, int *special);
 static int find_special(int code);
+static int is_modifier(int scancode);
+static int encode_key(int scancode, unsigned mod);