BT411/game/reconstructed/btinput.cpp

//===========================================================================//
// File:    btinput.cpp                                                      //
// Project: BattleTech           Brick: BattleTech LBE Application           //
// Contents: The desktop input binding engine (CONTROLS.MAP + XInput).      //
//---------------------------------------------------------------------------//
// PORT ADDITION (2026-07-18, input-remap task): the pod reads its stick /   //
// throttle / pedals / lamp buttons / keypads through the RIO serial board   //
// (L4RIO -> LBE4ControlsManager).  On a desktop none of that hardware       //
// exists; this engine maps PC keys and an XInput gamepad onto the same      //
// channels through a user-editable text file.  See btinput.hpp for the      //
// architecture and content/CONTROLS.MAP for the grammar + active profile.   //
//                                                                           //
// AUTHENTIC EMISSION CONVENTIONS (LBE4ControlsManager::ProcessRIOEvent,     //
// L4CTRL.cpp:2470-2520 -- mirrored exactly):                                //
//   button press:   buttonGroup[a].Update(value = a+1,  currentModeMask)    //
//   button release: buttonGroup[a].Update(value = -a-1, mask saved at press)//
//   keypad key:     keyboardGroup[unit].ForceUpdate('0'-'9'/'A'-'F', mask)  //
//                                                                           //
// The four pod JOYSTICK fire buttons (0x40 trigger / 0x45 pinky / 0x46      //
// thumb-low / 0x47 thumb-high) do NOT go through buttonGroup here: the      //
// bring-up fire dispatcher (mech4.cpp weapon groups) consumes them as       //
// levels, and double-driving both channels would double-fire once the       //
// streamed ChooseButton mappings are exercised.  They publish as            //
// gBTInput.fire* levels instead.                                            //
//===========================================================================//

#include <bt.hpp>
#include <btl4app.hpp>		// application (the BTL4Application global)
#include <l4ctrl.hpp>		// LBE4ControlsManager
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "btinput.hpp"

BTInputState gBTInput = {0};

//=============================================================================
// Binding model
//=============================================================================

enum BTAxisID
{
	BTAxisThrottle = 0,
	BTAxisLeftPedal,
	BTAxisRightPedal,
	BTAxisPedals,			// signed convenience alias: + = right pedal
	BTAxisJoystickX,		// the pod stick X = torso twist (Standard mode)
	BTAxisJoystickY,		// parsed + tracked; no consumer yet
	BTAxisCount
};

enum BTActionID
{
	BTActNone = 0,
	BTActViewToggle,
	BTActLookBehind,
	BTActAllStop,
	BTActModeCycle,
	BTActValve,
	BTActConfigHold,
	BTActGenerator1,
	BTActGenerator2,
	BTActGenerator3,
	BTActGenerator4,
	BTActReconnect,
	BTActCount
};

enum BTTargetKind
{
	BTTargetButton = 0,		// RIO buttonGroup address (or fire-level for 0x40..0x47)
	BTTargetAxisDeflect,	// hold the axis at <scale> while down, spring back
	BTTargetAxisRate,		// walk the axis at <scale>/second while down
	BTTargetKeypad,			// keyboardGroup[unit] key value
	BTTargetPCKey,			// keyboardGroup[KeyboardPC] character (authentic hotkeys)
	BTTargetAction			// port-side dev control
};

enum BTSourceKind
{
	BTSourceKey = 0,		// PC key (GetAsyncKeyState VK)
	BTSourcePadButton,		// XInput digital button (or trigger past 50%)
	BTSourcePadAxis			// XInput analog axis
};

struct BTBinding
{
	int		sourceKind;
	int		sourceCode;		// VK / XINPUT button bit index / pad-axis id
	int		targetKind;
	int		targetCode;		// button addr / axis id / keypad unit / char / action
	int		keypadValue;	// BTTargetKeypad only
	float	scale;			// deflect value or rate-per-second
	float	deadzone;		// pad axes
	int		invert;			// pad axes
	int		toggle;			// buttons: press latches on/off
	// runtime
	int		wasDown;		// raw source state (toggle edge detection)
	int		lastEffective;	// last emitted/latched state (edge -> emission)
	int		latched;
	int		pressMask;		// mode mask captured at press (release uses it)
};

#define BTINPUT_MAX_BINDINGS 192
static BTBinding	sBindings[BTINPUT_MAX_BINDINGS];
static int			sBindingCount = 0;
static int			sLoaded = 0;

// characters/VKs claimed by key bindings (legacy keyboard-feed suppression)
static unsigned char	sSuppressChar[256];		// WM_CHAR values
static unsigned char	sSuppressKeyUp[256];	// WM_KEYUP/-SYSKEYUP values (VK aliases)

static int sInputLog = -1;
#define BTINPUT_LOG(x) \
	do { if (sInputLog < 0) sInputLog = getenv("BT_INPUT_LOG") ? 1 : 0; \
	     if (sInputLog) { DEBUG_STREAM << "[input] " << x << "\n" << std::flush; } } while (0)

//=============================================================================
// Name tables
//=============================================================================

struct BTName { const char *name; int code; };

static const BTName sKeyNames[] =
{
	{"Space", ' '}, {"Enter", 0x0D}, {"Tab", 0x09}, {"Escape", 0x1B},
	{"Shift", 0x10}, {"Ctrl", 0x11}, {"Alt", 0x12},
	{"LShift", 0xA0}, {"RShift", 0xA1}, {"LCtrl", 0xA2}, {"RCtrl", 0xA3},
	{"Up", 0x26}, {"Down", 0x28}, {"Left", 0x25}, {"Right", 0x27},
	{"PageUp", 0x21}, {"PageDown", 0x22}, {"End", 0x23}, {"Home", 0x24},
	{"Insert", 0x2D}, {"Delete", 0x2E}, {"Back", 0x08},
	{"NumPad0", 0x60}, {"NumPad1", 0x61}, {"NumPad2", 0x62},
	{"NumPad3", 0x63}, {"NumPad4", 0x64}, {"NumPad5", 0x65},
	{"NumPad6", 0x66}, {"NumPad7", 0x67}, {"NumPad8", 0x68},
	{"NumPad9", 0x69}, {"Multiply", 0x6A}, {"Add", 0x6B},
	{"Subtract", 0x6D}, {"Decimal", 0x6E}, {"Divide", 0x6F},
	{"OemMinus", 0xBD}, {"Oemplus", 0xBB}, {"Oemcomma", 0xBC},
	{"OemPeriod", 0xBE}, {"OemQuestion", 0xBF}, {"OemTilde", 0xC0},
	{"OemOpenBrackets", 0xDB}, {"OemPipe", 0xDC}, {"OemCloseBrackets", 0xDD},
	{"OemSemicolon", 0xBA}, {"OemQuotes", 0xDE},
	{0, 0}
};

// XInput wButtons bit positions (XINPUT_GAMEPAD_* values are single bits)
static const BTName sPadButtonNames[] =
{
	{"DPadUp", 0x0001}, {"DPadDown", 0x0002},
	{"DPadLeft", 0x0004}, {"DPadRight", 0x0008},
	{"Start", 0x0010}, {"Back", 0x0020},
	{"LeftThumb", 0x0040}, {"RightThumb", 0x0080},
	{"LeftShoulder", 0x0100}, {"RightShoulder", 0x0200},
	{"A", 0x1000}, {"B", 0x2000}, {"X", 0x4000}, {"Y", 0x8000},
	// analog triggers usable as digital buttons (>= 50% = pressed);
	// out-of-band codes above the 16-bit button mask
	{"LeftTrigger", 0x10000}, {"RightTrigger", 0x20000},
	{0, 0}
};

enum { BTPadLX = 0, BTPadLY, BTPadRX, BTPadRY, BTPadLT, BTPadRT, BTPadAxisCount };
static const BTName sPadAxisNames[] =
{
	{"LeftStickX", BTPadLX}, {"LeftStickY", BTPadLY},
	{"RightStickX", BTPadRX}, {"RightStickY", BTPadRY},
	{"LeftTrigger", BTPadLT}, {"RightTrigger", BTPadRT},
	{0, 0}
};

static const BTName sAxisNames[] =
{
	{"Throttle", BTAxisThrottle},
	{"LeftPedal", BTAxisLeftPedal}, {"RightPedal", BTAxisRightPedal},
	{"Pedals", BTAxisPedals},
	{"JoystickX", BTAxisJoystickX}, {"JoystickY", BTAxisJoystickY},
	{0, 0}
};

static const BTName sActionNames[] =
{
	{"ViewToggle", BTActViewToggle}, {"LookBehind", BTActLookBehind},
	{"AllStop", BTActAllStop}, {"ModeCycle", BTActModeCycle},
	{"Valve", BTActValve}, {"ConfigHold", BTActConfigHold},
	{"Generator1", BTActGenerator1}, {"Generator2", BTActGenerator2},
	{"Generator3", BTActGenerator3}, {"Generator4", BTActGenerator4},
	{"Reconnect", BTActReconnect},
	{0, 0}
};

static int
	LookupName(const BTName *table, const char *token)
{
	for (int i = 0; table[i].name != 0; ++i)
	{
		if (_stricmp(table[i].name, token) == 0)
		{
			return table[i].code;
		}
	}
	return -1;
}

static int
	ParseKeyName(const char *token)
{
	// single letter / digit-row Dn / function keys / named specials
	if (token[1] == '\0' && isalpha((unsigned char)token[0]))
	{
		return toupper((unsigned char)token[0]);		// VK == 'A'..'Z'
	}
	if ((token[0] == 'D' || token[0] == 'd')
		&& isdigit((unsigned char)token[1]) && token[2] == '\0')
	{
		return '0' + (token[1] - '0');					// VK == '0'..'9'
	}
	if ((token[0] == 'F' || token[0] == 'f') && isdigit((unsigned char)token[1]))
	{
		int n = atoi(token + 1);
		if (n >= 1 && n <= 12)
		{
			return 0x70 + n - 1;						// VK_F1..VK_F12
		}
	}
	return LookupName(sKeyNames, token);
}

//=============================================================================
// The compiled-in default profile: WASD CLASSIC -- byte-identical to
// content/CONTROLS.MAP as shipped.  Deleting the file restores exactly this.
//=============================================================================

static const char *sDefaultProfile =
	"key W     axis Throttle rate 0.7\n"
	"key S     axis Throttle rate -0.7\n"
	"key Up    axis Throttle rate 0.7\n"
	"key Down  axis Throttle rate -0.7\n"
	"key A     axis LeftPedal deflect 1\n"
	"key D     axis RightPedal deflect 1\n"
	"key Left  axis LeftPedal deflect 1\n"
	"key Right axis RightPedal deflect 1\n"
	"key Q     axis JoystickX deflect -1\n"
	"key E     axis JoystickX deflect 1\n"
	"key X     action AllStop\n"
	"key D1    button 0x40\n"
	"key Space button 0x40\n"
	"key D2    button 0x46\n"
	"key D3    button 0x47\n"
	"key Ctrl  button 0x47\n"
	"key D4    button 0x45\n"
	"key G     action ConfigHold\n"
	"key C     action Valve\n"
	"key M     action ModeCycle\n"
	"key V     action ViewToggle\n"
	"key B     action LookBehind\n"
	"key F5    action Generator1\n"
	"key F6    action Generator2\n"
	"key F7    action Generator3\n"
	"key F8    action Generator4\n"
	"key F9    action Reconnect\n"
	"padaxis LeftStickX   axis Pedals deadzone 0.24\n"
	"padaxis RightStickX  axis JoystickX deadzone 0.24\n"
	"padaxis RightStickY  axis Throttle rate 0.75 deadzone 0.24\n"
	"pad RightTrigger  button 0x40\n"
	"pad LeftTrigger   button 0x47\n"
	"pad RightShoulder button 0x46\n"
	"pad LeftShoulder  button 0x45\n"
	"pad DPadUp    button 0x42\n"
	"pad DPadDown  button 0x41\n"
	"pad DPadLeft  button 0x44\n"
	"pad DPadRight button 0x43\n"
	"pad B     action AllStop\n"
	"pad Y     action ViewToggle\n"
	"pad X     action LookBehind\n"
	"pad Start action ModeCycle\n"
	"pad Back  action Valve\n";

//=============================================================================
// Parser
//=============================================================================

static void
	RegisterKeySuppression(int vk)
{
	// WM_KEYUP/-SYSKEYUP deliver the raw VK as the key value (the engine
	// keyboard feed, L4CTRL.cpp:1506) -- suppress it; this is what aliased
	// F5's key-up (0x74) to the 't' pilot-select hotkey, and letter key-ups
	// (uppercase) to developer fake events.
	if (vk >= 0 && vk < 256)
	{
		sSuppressKeyUp[vk] = 1;
	}
	// WM_CHAR delivers typed characters: suppress both cases of a letter,
	// the digit itself, space, and the base punctuation of the Oem keys.
	if (vk >= 'A' && vk <= 'Z')
	{
		sSuppressChar[tolower(vk)] = 1;
		sSuppressChar[vk] = 1;
	}
	else if (vk >= '0' && vk <= '9')
	{
		sSuppressChar[vk] = 1;
	}
	else if (vk == ' ')
	{
		sSuppressChar[' '] = 1;
	}
	else
	{
		static const struct { int vk; char ch; } oem[] =
		{
			{0xBD, '-'}, {0xBB, '='}, {0xBC, ','}, {0xBE, '.'},
			{0xBF, '/'}, {0xC0, '`'}, {0xDB, '['}, {0xDC, '\\'},
			{0xDD, ']'}, {0xBA, ';'}, {0xDE, '\''}, {0x0D, '\r'},
			{0x09, '\t'}, {0x08, '\b'},
		};
		for (int i = 0; i < (int)(sizeof(oem) / sizeof(oem[0])); ++i)
		{
			if (oem[i].vk == vk)
			{
				sSuppressChar[(unsigned char)oem[i].ch] = 1;
			}
		}
	}
}

static int
	ParseLine(char *line, int line_number)
{
	// strip comments + tokenize
	char *hash = strchr(line, '#');
	if (hash != 0)
	{
		*hash = '\0';
	}
	char *tokens[8];
	int token_count = 0;
	for (char *t = strtok(line, " \t\r\n");
		 t != 0 && token_count < 8;
		 t = strtok(0, " \t\r\n"))
	{
		tokens[token_count++] = t;
	}
	if (token_count == 0)
	{
		return 1;										// blank / comment
	}
	if (token_count < 3 || sBindingCount >= BTINPUT_MAX_BINDINGS)
	{
		BTINPUT_LOG("CONTROLS.MAP line " << line_number << ": malformed (ignored)");
		return 0;
	}

	BTBinding b;
	memset(&b, 0, sizeof(b));

	// ---- source ----
	int arg = 2;										// first token after <verb> <source>
	if (_stricmp(tokens[0], "key") == 0)
	{
		b.sourceKind = BTSourceKey;
		b.sourceCode = ParseKeyName(tokens[1]);
	}
	else if (_stricmp(tokens[0], "pad") == 0)
	{
		b.sourceKind = BTSourcePadButton;
		b.sourceCode = LookupName(sPadButtonNames, tokens[1]);
	}
	else if (_stricmp(tokens[0], "padaxis") == 0)
	{
		b.sourceKind = BTSourcePadAxis;
		b.sourceCode = LookupName(sPadAxisNames, tokens[1]);
	}
	else
	{
		BTINPUT_LOG("CONTROLS.MAP line " << line_number << ": unknown verb '"
			<< tokens[0] << "'");
		return 0;
	}
	if (b.sourceCode < 0)
	{
		BTINPUT_LOG("CONTROLS.MAP line " << line_number << ": unknown source '"
			<< tokens[1] << "'");
		return 0;
	}

	// ---- target ----
	if (_stricmp(tokens[arg], "button") == 0 && arg + 1 < token_count)
	{
		b.targetKind = BTTargetButton;
		b.targetCode = (int)strtol(tokens[arg + 1], 0, 0);
		if (b.targetCode < 0 || b.targetCode > 0x47)
		{
			BTINPUT_LOG("CONTROLS.MAP line " << line_number
				<< ": button address out of range (0x00-0x47)");
			return 0;
		}
		arg += 2;
		if (arg < token_count && _stricmp(tokens[arg], "toggle") == 0)
		{
			b.toggle = 1;
			++arg;
		}
	}
	else if (_stricmp(tokens[arg], "axis") == 0 && arg + 1 < token_count)
	{
		int axis = LookupName(sAxisNames, tokens[arg + 1]);
		if (axis < 0)
		{
			BTINPUT_LOG("CONTROLS.MAP line " << line_number << ": unknown axis '"
				<< tokens[arg + 1] << "'");
			return 0;
		}
		b.targetCode = axis;
		arg += 2;
		b.targetKind = BTTargetAxisDeflect;
		b.scale = 1.0f;
		b.deadzone = 0.0f;
		while (arg < token_count)
		{
			if (_stricmp(tokens[arg], "deflect") == 0 && arg + 1 < token_count)
			{
				b.targetKind = BTTargetAxisDeflect;
				b.scale = (float)atof(tokens[arg + 1]);
				arg += 2;
			}
			else if (_stricmp(tokens[arg], "rate") == 0 && arg + 1 < token_count)
			{
				b.targetKind = BTTargetAxisRate;
				b.scale = (float)atof(tokens[arg + 1]);
				arg += 2;
			}
			else if (_stricmp(tokens[arg], "deadzone") == 0 && arg + 1 < token_count)
			{
				b.deadzone = (float)atof(tokens[arg + 1]);
				arg += 2;
			}
			else if (_stricmp(tokens[arg], "invert") == 0)
			{
				b.invert = 1;
				++arg;
			}
			else
			{
				BTINPUT_LOG("CONTROLS.MAP line " << line_number
					<< ": unknown axis option '" << tokens[arg] << "'");
				return 0;
			}
		}
	}
	else if (_stricmp(tokens[arg], "keypad") == 0 && arg + 2 < token_count)
	{
		b.targetKind = BTTargetKeypad;
		if (_stricmp(tokens[arg + 1], "pilot") == 0)
		{
			b.targetCode = LBE4ControlsManager::KeyboardPilot;
		}
		else if (_stricmp(tokens[arg + 1], "external") == 0)
		{
			b.targetCode = LBE4ControlsManager::KeyboardExternal;
		}
		else
		{
			BTINPUT_LOG("CONTROLS.MAP line " << line_number
				<< ": keypad unit must be pilot|external");
			return 0;
		}
		// the RIO converts keypad units 0-15 to '0'-'9','A'-'F'
		// (L4CTRL.cpp:2526); accept the same range
		int v = (int)strtol(tokens[arg + 2], 0, 0);
		if (v < 0 || v > 15)
		{
			BTINPUT_LOG("CONTROLS.MAP line " << line_number
				<< ": keypad value must be 0-15");
			return 0;
		}
		b.keypadValue = (v <= 9) ? ('0' + v) : ('A' + v - 10);
		arg += 3;
	}
	else if (_stricmp(tokens[arg], "pckey") == 0 && arg + 1 < token_count)
	{
		// send an authentic PC-keyboard hotkey character (the 1995
		// KeypressMessageHandler dispatcher: '+'/'-' zoom, presets, ...)
		b.targetKind = BTTargetPCKey;
		b.targetCode = (tokens[arg + 1][1] == '\0')
			? (unsigned char)tokens[arg + 1][0]
			: (int)strtol(tokens[arg + 1], 0, 0);
		arg += 2;
	}
	else if (_stricmp(tokens[arg], "action") == 0 && arg + 1 < token_count)
	{
		b.targetKind = BTTargetAction;
		b.targetCode = LookupName(sActionNames, tokens[arg + 1]);
		if (b.targetCode < 0)
		{
			BTINPUT_LOG("CONTROLS.MAP line " << line_number << ": unknown action '"
				<< tokens[arg + 1] << "'");
			return 0;
		}
		arg += 2;
	}
	else
	{
		BTINPUT_LOG("CONTROLS.MAP line " << line_number << ": unknown target '"
			<< tokens[arg] << "'");
		return 0;
	}

	if (b.sourceKind == BTSourceKey)
	{
		RegisterKeySuppression(b.sourceCode);
	}
	sBindings[sBindingCount++] = b;
	return 1;
}

static void
	LoadBindings()
{
	sLoaded = 1;
	sBindingCount = 0;
	memset(sSuppressChar, 0, sizeof(sSuppressChar));
	memset(sSuppressKeyUp, 0, sizeof(sSuppressKeyUp));

	char *text = 0;
	FILE *f = fopen("CONTROLS.MAP", "rb");				// cwd == content/
	if (f != 0)
	{
		fseek(f, 0, SEEK_END);
		long len = ftell(f);
		fseek(f, 0, SEEK_SET);
		if (len > 0 && len < 256 * 1024)
		{
			text = (char *)malloc((size_t)len + 1);
			if (text != 0)
			{
				fread(text, 1, (size_t)len, f);
				text[len] = '\0';
			}
		}
		fclose(f);
	}

	const char *source = text != 0 ? text : sDefaultProfile;
	char *work = _strdup(source);
	int line_number = 0;
	// strtok is used inside ParseLine, so split lines manually first
	for (char *line = work, *next = 0; line != 0; line = next)
	{
		next = strchr(line, '\n');
		if (next != 0)
		{
			*next++ = '\0';
		}
		++line_number;
		ParseLine(line, line_number);
	}
	free(work);

	BTINPUT_LOG("loaded " << sBindingCount << " binding(s) from "
		<< (text != 0 ? "CONTROLS.MAP" : "built-in WASD-classic defaults"));
	if (text != 0)
	{
		free(text);
	}
}

//=============================================================================
// Device polling
//=============================================================================

// -- keyboard (dynamic, same pattern as the old shim: WndProc key messages
//    are consumed by the engine keyboard reader, so poll async state) --
typedef short (__stdcall *BTAsyncFn)(int);
typedef void *(__stdcall *BTFgFn)(void);
typedef unsigned long (__stdcall *BTWtpFn)(void *, unsigned long *);
typedef unsigned long (__stdcall *BTPidFn)(void);
static BTAsyncFn	sAsync = 0;
static BTFgFn		sFg = 0;
static BTWtpFn		sWtp = 0;
static BTPidFn		sPid = 0;

// -- XInput (dynamic: xinput1_4.dll on Win8+, xinput9_1_0.dll everywhere) --
struct BTXInputGamepad
{
	unsigned short	wButtons;
	unsigned char	bLeftTrigger;
	unsigned char	bRightTrigger;
	short			sThumbLX;
	short			sThumbLY;
	short			sThumbRX;
	short			sThumbRY;
};
struct BTXInputStateRaw
{
	unsigned long	dwPacketNumber;
	BTXInputGamepad	Gamepad;
};
typedef unsigned long (__stdcall *BTXInputGetStateFn)(unsigned long, BTXInputStateRaw *);
static BTXInputGetStateFn	sXInputGetState = 0;
static int					sXInputTried = 0;
static int					sPadConnected = 0;
static unsigned long		sPadRecheckAt = 0;			// GetTickCount throttle

static void
	InitDevices()
{
	HMODULE u = GetModuleHandleA("user32.dll");
	HMODULE k = GetModuleHandleA("kernel32.dll");
	if (u != 0 && k != 0)
	{
		sAsync = (BTAsyncFn)GetProcAddress(u, "GetAsyncKeyState");
		sFg    = (BTFgFn)GetProcAddress(u, "GetForegroundWindow");
		sWtp   = (BTWtpFn)GetProcAddress(u, "GetWindowThreadProcessId");
		sPid   = (BTPidFn)GetProcAddress(k, "GetCurrentProcessId");
	}
	if (!sXInputTried)
	{
		sXInputTried = 1;
		static const char *dlls[] =
			{ "xinput1_4.dll", "xinput1_3.dll", "xinput9_1_0.dll" };
		for (int i = 0; i < 3 && sXInputGetState == 0; ++i)
		{
			HMODULE x = LoadLibraryA(dlls[i]);
			if (x != 0)
			{
				sXInputGetState =
					(BTXInputGetStateFn)GetProcAddress(x, "XInputGetState");
				if (sXInputGetState != 0)
				{
					BTINPUT_LOG("XInput via " << dlls[i]);
				}
			}
		}
	}
}

static float
	PadAxisValue(const BTXInputGamepad &pad, int axis)
{
	switch (axis)
	{
	case BTPadLX:	return pad.sThumbLX / 32767.0f;
	case BTPadLY:	return pad.sThumbLY / 32767.0f;
	case BTPadRX:	return pad.sThumbRX / 32767.0f;
	case BTPadRY:	return pad.sThumbRY / 32767.0f;
	case BTPadLT:	return pad.bLeftTrigger / 255.0f;
	case BTPadRT:	return pad.bRightTrigger / 255.0f;
	}
	return 0.0f;
}

//=============================================================================
// Emission (the authentic RIO event mirror)
//=============================================================================

static void
	EmitButton(BTBinding &b, int down)
{
	LBE4ControlsManager *controls =
		(LBE4ControlsManager *)application->GetControlsManager();
	if (controls == 0)
	{
		return;
	}
	int addr = b.targetCode;
	// the four pod joystick fire buttons feed the bring-up fire channels
	// as LEVELS (see file banner); handled in the poll aggregation.
	if (addr >= 0x40 && addr <= 0x47 && addr != 0x41 && addr != 0x42
		&& addr != 0x43 && addr != 0x44)
	{
		return;
	}
	if (down)
	{
		ControlsButton value = (ControlsButton)(addr + 1);
		b.pressMask = application->GetModeManager()->GetModeMask();
		controls->buttonGroup[addr].Update(&value, b.pressMask);
		BTINPUT_LOG("button 0x" << std::hex << addr << std::dec << " PRESS");
	}
	else
	{
		ControlsButton value = (ControlsButton)(-addr - 1);
		controls->buttonGroup[addr].Update(&value, b.pressMask);
		BTINPUT_LOG("button 0x" << std::hex << addr << std::dec << " release");
	}
}

static void
	EmitKeypad(BTBinding &b)
{
	LBE4ControlsManager *controls =
		(LBE4ControlsManager *)application->GetControlsManager();
	if (controls == 0)
	{
		return;
	}
	ControlsKey key = (ControlsKey)b.keypadValue;
	controls->keyboardGroup[b.targetCode].ForceUpdate(
		&key, application->GetModeManager()->GetModeMask());
	BTINPUT_LOG("keypad unit " << b.targetCode << " key '"
		<< (char)b.keypadValue << "'");
}

static void
	EmitPCKey(BTBinding &b)
{
	LBE4ControlsManager *controls =
		(LBE4ControlsManager *)application->GetControlsManager();
	if (controls == 0)
	{
		return;
	}
	ControlsKey key = (ControlsKey)b.targetCode;
	controls->keyboardGroup[LBE4ControlsManager::KeyboardPC].ForceUpdate(
		&key, application->GetModeManager()->GetModeMask());
	BTINPUT_LOG("pckey 0x" << std::hex << b.targetCode << std::dec);
}

//=============================================================================
// The per-frame poll
//=============================================================================

void
	BTInputPoll(float /*dt*/)
{
	if (!sLoaded)
	{
		LoadBindings();
		InitDevices();
	}

	// foreground-focus guard (BT_KEY_NOFOCUS=1 for automation harnesses)
	int focused = 0;
	if (sFg != 0 && sWtp != 0 && sPid != 0)
	{
		void *fg = sFg();
		unsigned long fg_pid = 0;
		if (fg != 0)
		{
			sWtp(fg, &fg_pid);
		}
		focused = (fg_pid == sPid());
	}
	static int sNoFocus = -1;
	if (sNoFocus < 0)
	{
		const char *nf = getenv("BT_KEY_NOFOCUS");
		sNoFocus = (nf != 0 && *nf == '1') ? 1 : 0;
	}
	if (sNoFocus)
	{
		focused = 1;
	}

	// pad state (rate-limit reconnect probing: XInputGetState on an EMPTY
	// slot is expensive, ~ms -- probe disconnected pads at 1 Hz only)
	BTXInputGamepad pad;
	memset(&pad, 0, sizeof(pad));
	if (sXInputGetState != 0)
	{
		unsigned long now = GetTickCount();
		if (sPadConnected || now >= sPadRecheckAt)
		{
			BTXInputStateRaw raw;
			memset(&raw, 0, sizeof(raw));
			if (sXInputGetState(0, &raw) == 0)			// ERROR_SUCCESS
			{
				if (!sPadConnected)
				{
					BTINPUT_LOG("gamepad CONNECTED");
				}
				sPadConnected = 1;
				pad = raw.Gamepad;
			}
			else
			{
				if (sPadConnected)
				{
					BTINPUT_LOG("gamepad disconnected");
				}
				sPadConnected = 0;
				sPadRecheckAt = now + 1000;
			}
		}
	}

	// ---- aggregate the frame ----
	BTInputState next;
	memset(&next, 0, sizeof(next));
	float axisDeflect[BTAxisCount] = {0};
	int   axisActive[BTAxisCount] = {0};
	int   axisAbsolute[BTAxisCount] = {0};
	float axisRate[BTAxisCount] = {0};

	for (int i = 0; i < sBindingCount; ++i)
	{
		BTBinding &b = sBindings[i];

		// -- source value --
		int down = 0;
		float analog = 0.0f;
		if (b.sourceKind == BTSourceKey)
		{
			down = (focused && sAsync != 0
				&& (sAsync(b.sourceCode) & 0x8000)) ? 1 : 0;
			analog = (float)down;
		}
		else if (b.sourceKind == BTSourcePadButton)
		{
			if (!sPadConnected)
			{
				down = 0;
			}
			else if (b.sourceCode == 0x10000)
			{
				down = pad.bLeftTrigger >= 128;
			}
			else if (b.sourceCode == 0x20000)
			{
				down = pad.bRightTrigger >= 128;
			}
			else
			{
				down = (pad.wButtons & b.sourceCode) ? 1 : 0;
			}
			analog = (float)down;
		}
		else // BTSourcePadAxis
		{
			analog = sPadConnected ? PadAxisValue(pad, b.sourceCode) : 0.0f;
			if (b.invert)
			{
				analog = -analog;
			}
			if (analog > -b.deadzone && analog < b.deadzone)
			{
				analog = 0.0f;
			}
			else if (b.deadzone > 0.0f && b.deadzone < 1.0f)
			{
				// rescale so the deadzone edge is 0 (no jump)
				float sign = analog < 0.0f ? -1.0f : 1.0f;
				analog = sign * ((analog * sign - b.deadzone)
								 / (1.0f - b.deadzone));
			}
			down = analog != 0.0f;
		}

		// toggle latch: a PRESS edge flips the held state
		if (b.toggle && b.sourceKind != BTSourcePadAxis)
		{
			if (down && !b.wasDown)
			{
				b.latched = !b.latched;
			}
			b.wasDown = down;
			down = b.latched;
			analog = (float)down;
		}

		// -- apply to target --
		switch (b.targetKind)
		{
		case BTTargetButton:
		{
			int addr = b.targetCode;
			if (down != b.lastEffective)
			{
				EmitButton(b, down);
			}
			b.lastEffective = down;
			// fire-button levels (0x40/45/46/47) aggregate every frame
			if (down)
			{
				if (addr == 0x40) next.fireTrigger = 1;
				if (addr == 0x45) next.firePinky = 1;
				if (addr == 0x46) next.fireThumbLow = 1;
				if (addr == 0x47) next.fireThumbHigh = 1;
			}
			break;
		}
		case BTTargetAxisDeflect:
			if (down)
			{
				axisDeflect[b.targetCode] += analog * b.scale;
				axisActive[b.targetCode] = 1;
				if (b.sourceKind == BTSourcePadAxis)
				{
					axisAbsolute[b.targetCode] = 1;
				}
			}
			break;
		case BTTargetAxisRate:
			if (down)
			{
				axisRate[b.targetCode] += analog * b.scale;
			}
			break;
		case BTTargetKeypad:
			if (down && !b.lastEffective)
			{
				EmitKeypad(b);
			}
			b.lastEffective = down;
			break;
		case BTTargetPCKey:
			if (down && !b.lastEffective)
			{
				EmitPCKey(b);
			}
			b.lastEffective = down;
			break;
		case BTTargetAction:
			if (down)
			{
				switch (b.targetCode)
				{
				case BTActViewToggle:	next.viewToggle = 1; break;
				case BTActLookBehind:	next.lookBehind = 1; break;
				case BTActAllStop:		next.allStop = 1; break;
				case BTActModeCycle:	next.modeCycle = 1; break;
				case BTActValve:		next.valve = 1; break;
				case BTActConfigHold:	next.configHold = 1; break;
				case BTActGenerator1:	next.genSel = 4; break;
				case BTActGenerator2:	next.genSel = 5; break;
				case BTActGenerator3:	next.genSel = 6; break;
				case BTActGenerator4:	next.genSel = 7; break;
				case BTActReconnect:	next.genSel = 8; break;
				}
			}
			break;
		}
	}

	// ---- fold the axis aliases + publish ----
	// Pedals (signed alias): + = right pedal (turn right)
	float turn = (axisDeflect[BTAxisRightPedal] - axisDeflect[BTAxisLeftPedal])
				 + axisDeflect[BTAxisPedals];
	int turn_active = axisActive[BTAxisRightPedal] || axisActive[BTAxisLeftPedal]
				 || axisActive[BTAxisPedals];
	int turn_abs = axisAbsolute[BTAxisPedals]
				 || axisAbsolute[BTAxisLeftPedal] || axisAbsolute[BTAxisRightPedal];

	if (turn > 1.0f) turn = 1.0f;
	if (turn < -1.0f) turn = -1.0f;
	float twist = axisDeflect[BTAxisJoystickX];
	if (twist > 1.0f) twist = 1.0f;
	if (twist < -1.0f) twist = -1.0f;

	next.turnTarget = turn;
	next.turnActive = turn_active;
	next.turnAbsolute = turn_abs;
	next.twistTarget = twist;
	next.twistActive = axisActive[BTAxisJoystickX];
	next.twistAbsolute = axisAbsolute[BTAxisJoystickX];
	next.leverRate = axisRate[BTAxisThrottle];

	gBTInput = next;
}

//=============================================================================
// Legacy keyboard-feed suppression (called from L4CTRL.cpp:1506 block)
//=============================================================================

extern "C" int
	BTInputSuppressKey(unsigned int key_value, int is_char)
{
	if (!sLoaded)
	{
		LoadBindings();		// the feed can run before the first poll
		InitDevices();
	}
	if (key_value > 255)
	{
		return 0;			// ALT_BIT-tagged values etc. -- never claimed
	}
	return is_char ? sSuppressChar[key_value] : sSuppressKeyUp[key_value];
}