/*
 *   keyboard.c
 *
 *   This file is part of Emu48
 *
 *   Copyright (C) 1995 Sebastien Carlier
 *
 */
#include "pch.h"
#include "Emu48.h"
#include "io.h"								// I/O definitions

static WORD Keyboard_GetIR(VOID)
{
	WORD r = 0;
	
	if (Chipset.out==0) return 0;
	if (Chipset.out&0x001) r|=Chipset.Keyboard_Row[0];
	if (Chipset.out&0x002) r|=Chipset.Keyboard_Row[1];
	if (Chipset.out&0x004) r|=Chipset.Keyboard_Row[2];
	if (Chipset.out&0x008) r|=Chipset.Keyboard_Row[3];
	if (Chipset.out&0x010) r|=Chipset.Keyboard_Row[4];
	if (Chipset.out&0x020) r|=Chipset.Keyboard_Row[5];
	if (Chipset.out&0x040) r|=Chipset.Keyboard_Row[6];
	if (Chipset.out&0x080) r|=Chipset.Keyboard_Row[7];
	if (Chipset.out&0x100) r|=Chipset.Keyboard_Row[8];
	return r;
}

VOID ScanKeyboard(BOOL bReset)
{
	// bReset = TRUE  -> Reset Chipset.in interrupt state register
	//          FALSE -> generate interrupt only for new pressed keys

	EnterCriticalSection(&csKeyLock);		// synchronize
	{
		BOOL bKbdInt;

		WORD wOldIn = Chipset.in;			// save old Chipset.in state

		UpdateKdnBit();						// update KDN bit
		Chipset.dwKdnCycles = (DWORD) (Chipset.cycles & 0xFFFFFFFF);

		// update keyboard only if timer is running
		if (Chipset.IORam[TIMER2_CTRL]&RUN)	// timer running
			Chipset.in = Keyboard_GetIR();	// update Chipset.in register
		else								// timer stopped, no keyboard update
			Chipset.in &= 0x1FF;			// IR[0:8], old keystate without ON key
		Chipset.in |= Chipset.IR15X;		// add ON key

		// interrrupt for any new pressed keys ?
		bKbdInt = (Chipset.in && (wOldIn & 0x1FF) == 0) || Chipset.IR15X || bReset;

		// update keyboard interrupt pending flag when 1ms keyboard scan is disabled
		Chipset.intd = Chipset.intd || (bKbdInt && !Chipset.intk);

		// keyboard interrupt enabled
		bKbdInt = bKbdInt && (Chipset.intk || Chipset.IR15X != 0) && Chipset.inte;

		if (Chipset.in != 0)				// any key pressed
		{
			if (bKbdInt)					// interrupt enabled
			{
				Chipset.SoftInt = TRUE;		// interrupt request
				bInterrupt = TRUE;			// exit emulation loop
			}

			if (Chipset.Shutdn)				// cpu sleeping
			{
				Chipset.bShutdnWake = TRUE;	// wake up from SHUTDN mode
				SetEvent(hEventShutdn);		// wake up emulation thread
			}
		}
		else
		{
			Chipset.intd = FALSE;			// no keyboard interrupt pending
		}
	}
	LeaveCriticalSection(&csKeyLock);

	return;
}

VOID KeyboardEvent(BOOL bPress, UINT out, UINT in)
{
	if (nState != SM_RUN)					// not in running state
		return;								// ignore key
	if (in == 0x8000)						// ON key ?
	{
		Chipset.IR15X = bPress?0x8000:0x0000; // refresh special ON key flag
	}
	else
	{
		_ASSERT(out < sizeof(Chipset.Keyboard_Row) / sizeof(Chipset.Keyboard_Row[0]));
		if (bPress)							// key pressed 
			Chipset.Keyboard_Row[out] |= in; // set key marker in keyboard row
		else
			Chipset.Keyboard_Row[out] &= (~in); // clear key marker in keyboard row
	}
	ScanKeyboard(FALSE);					// update Chipset.in register
	bKeySlow = FALSE;						// break key slow down
	Sleep(50);								// hold key state for a definite time
	return;
}