/*
   ds48 - Nintendo DS ZX Spectrum emulator.

   Copyright (C) 2007  Ian Cowburn <ianc@noddybox.co.uk>
   
   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; either version 2
   of the License, or (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  
   $Id$

   This code is based on the example templates for ndslib
*/

#include <nds.h>
#include <stdlib.h>

//---------------------------------------------------------------------------------
void startSound(int sampleRate, const void* data, u32 bytes, u8 channel, u8 vol,  u8 pan, u8 format) {
//---------------------------------------------------------------------------------
	SCHANNEL_TIMER(channel)  = SOUND_FREQ(sampleRate);
	SCHANNEL_SOURCE(channel) = (u32)data;
	SCHANNEL_LENGTH(channel) = bytes >> 2 ;
	SCHANNEL_CR(channel)     = SCHANNEL_ENABLE | SOUND_ONE_SHOT | SOUND_VOL(vol) | SOUND_PAN(pan) | (format==1?SOUND_8BIT:SOUND_16BIT);
}


//---------------------------------------------------------------------------------
s32 getFreeSoundChannel() {
//---------------------------------------------------------------------------------
	int i;
	for (i=0; i<16; i++) {
		if ( (SCHANNEL_CR(i) & SCHANNEL_ENABLE) == 0 ) return i;
	}
	return -1;
}

int vcount;
touchPosition first,tempPos;

//---------------------------------------------------------------------------------
void VcountHandler() {
//---------------------------------------------------------------------------------
	static int lastbut = -1;
	
	uint16 but=0, x=0, y=0, xpx=0, ypx=0, z1=0, z2=0;

	but = REG_KEYXY;

	if (!( (but ^ lastbut) & (1<<6))) {
 
		tempPos = touchReadXY();

		if ( tempPos.x == 0 || tempPos.y == 0 ) {
			but |= (1 <<6);
			lastbut = but;
		} else {
			x = tempPos.x;
			y = tempPos.y;
			xpx = tempPos.px;
			ypx = tempPos.py;
			z1 = tempPos.z1;
			z2 = tempPos.z2;
		}
		
	} else {
		lastbut = but;
		but |= (1 <<6);
	}

	if ( vcount == 80 ) {
		first = tempPos;
	} else {
		if (	abs( xpx - first.px) > 10 || abs( ypx - first.py) > 10 ||
				(but & ( 1<<6)) ) {

			but |= (1 <<6);
			lastbut = but;

		} else { 	
			IPC->mailBusy = 1;
			IPC->touchX			= x;
			IPC->touchY			= y;
			IPC->touchXpx		= xpx;
			IPC->touchYpx		= ypx;
			IPC->touchZ1		= z1;
			IPC->touchZ2		= z2;
			IPC->mailBusy = 0;
		}
	}
	IPC->buttons		= but;
	vcount ^= (80 ^ 130);
	SetYtrigger(vcount);

}

//---------------------------------------------------------------------------------
void VblankHandler(void) {
//---------------------------------------------------------------------------------

	u32 i;


	//sound code  :)
	TransferSound *snd = IPC->soundData;
	IPC->soundData = 0;

	if (0 != snd) {

		for (i=0; i<snd->count; i++) {
			s32 chan = getFreeSoundChannel();

			if (chan >= 0) {
				startSound(snd->data[i].rate, snd->data[i].data, snd->data[i].len, chan, snd->data[i].vol, snd->data[i].pan, snd->data[i].format);
			}
		}
	}

}

//---------------------------------------------------------------------------------
int main(int argc, char ** argv) {
//---------------------------------------------------------------------------------

	// Reset the clock if needed
	rtcReset();

	//enable sound
	powerON(POWER_SOUND);
	SOUND_CR = SOUND_ENABLE | SOUND_VOL(0x7F);
	IPC->soundData = 0;

	irqInit();
	irqSet(IRQ_VBLANK, VblankHandler);
	SetYtrigger(80);
	vcount = 80;
	irqSet(IRQ_VCOUNT, VcountHandler);
	irqEnable(IRQ_VBLANK | IRQ_VCOUNT);

	// Keep the ARM7 idle
	while (1) swiWaitForVBlank();
}