/*---------------------------------------------------------------------------------
	$Id$

	Touch screen control for the ARM7

	Copyright (C) 2005
		Michael Noland (joat)
		Jason Rogers (dovoto)
		Dave Murphy (WinterMute)

	This software is provided 'as-is', without any express or implied
	warranty.  In no event will the authors be held liable for any
	damages arising from the use of this software.

	Permission is granted to anyone to use this software for any
	purpose, including commercial applications, and to alter it and
	redistribute it freely, subject to the following restrictions:

	1.	The origin of this software must not be misrepresented; you
			must not claim that you wrote the original software. If you use
			this software in a product, an acknowledgment in the product
			documentation would be appreciated but is not required.
	2.	Altered source versions must be plainly marked as such, and
			must not be misrepresented as being the original software.
	3.	This notice may not be removed or altered from any source
			distribution.

---------------------------------------------------------------------------------*/

#include <nds/jtypes.h>
#include <nds/system.h>
#include <nds/arm7/touch.h>
#include <nds/interrupts.h>

#include <stdlib.h>

static u8 last_time_touched = 0;

static u8 range_counter_1 = 0;
static u8 range_counter_2 = 0;
static u8 range = 20;
static u8 min_range = 20;

//---------------------------------------------------------------------------------
u8 CheckStylus(void){
//---------------------------------------------------------------------------------

	SerialWaitBusy();

	REG_SPICNT = SPI_ENABLE | SPI_BAUD_2MHz | SPI_DEVICE_TOUCH | SPI_CONTINUOUS; //0x8A01;
	REG_SPIDATA = TSC_MEASURE_TEMP1;

	SerialWaitBusy();

	REG_SPIDATA = 0;

	SerialWaitBusy();

	REG_SPICNT = SPI_ENABLE | SPI_BAUD_2MHz | SPI_DEVICE_TOUCH;// 0x8201;
	REG_SPIDATA = 0;

	SerialWaitBusy();

	if(last_time_touched == 1){
		if( !(REG_KEYXY & 0x40) )
			return 1;
		else{
			REG_SPICNT = SPI_ENABLE | SPI_BAUD_2MHz | SPI_DEVICE_TOUCH | SPI_CONTINUOUS;
			REG_SPIDATA = TSC_MEASURE_TEMP1;

			SerialWaitBusy();

			REG_SPIDATA = 0;

			SerialWaitBusy();

			REG_SPICNT = SPI_ENABLE | SPI_BAUD_2MHz | SPI_DEVICE_TOUCH;
			REG_SPIDATA = 0;

			SerialWaitBusy();

			return !(REG_KEYXY & 0x40) ? 2 : 0;
		}
	}else{
		return !(REG_KEYXY & 0x40) ? 1 : 0;
	}
}

//---------------------------------------------------------------------------------
uint16 touchRead(uint32 command) {
//---------------------------------------------------------------------------------
	uint16 result, result2;

	uint32 oldIME = REG_IME;

	REG_IME = 0;

	SerialWaitBusy();

	// Write the command and wait for it to complete
	REG_SPICNT = SPI_ENABLE | SPI_BAUD_2MHz | SPI_DEVICE_TOUCH | SPI_CONTINUOUS; //0x8A01;
	REG_SPIDATA = command;
	SerialWaitBusy();

	// Write the second command and clock in part of the data
	REG_SPIDATA = 0;
	SerialWaitBusy();
	result = REG_SPIDATA;

	// Clock in the rest of the data (last transfer)
	REG_SPICNT = SPI_ENABLE | 0x201;
	REG_SPIDATA = 0;
	SerialWaitBusy();

	result2 = REG_SPIDATA >>3;

	REG_IME = oldIME;

	// Return the result
	return ((result & 0x7F) << 5) | result2;
}


//---------------------------------------------------------------------------------
uint32 touchReadTemperature(int * t1, int * t2) {
//---------------------------------------------------------------------------------
	*t1 = touchRead(TSC_MEASURE_TEMP1);
	*t2 = touchRead(TSC_MEASURE_TEMP2);
	return 8490 * (*t2 - *t1) - 273*4096;
}


static bool touchInit = false;
static s32 xscale, yscale;
static s32 xoffset, yoffset;

//---------------------------------------------------------------------------------
int16 readTouchValue(uint32 command, int16 *dist_max, u8 *err){
//---------------------------------------------------------------------------------
	int16 values[5];
	int32 aux1, aux2, aux3, dist, dist2, result = 0;
	u8 i, j, k;

	*err = 1;

	SerialWaitBusy();

	REG_SPICNT = SPI_ENABLE | SPI_BAUD_2MHz | SPI_DEVICE_TOUCH | SPI_CONTINUOUS;
	REG_SPIDATA = command;

	SerialWaitBusy();

	for(i=0; i<5; i++){
		REG_SPIDATA = 0;
		SerialWaitBusy();

		aux1 = REG_SPIDATA;
		aux1 = aux1 & 0xFF;
		aux1 = aux1 << 16;
		aux1 = aux1 >> 8;

		values[4-i] = aux1;

		REG_SPIDATA = command;
		SerialWaitBusy();

		aux1 = REG_SPIDATA;
		aux1 = aux1 & 0xFF;
		aux1 = aux1 << 16;

		aux1 = values[4-i] | (aux1 >> 16);
		values[4-i] = ((aux1 & 0x7FF8) >> 3);
	}

	REG_SPICNT = SPI_ENABLE | SPI_BAUD_2MHz | SPI_DEVICE_TOUCH;
	REG_SPIDATA = 0;
	SerialWaitBusy();

	dist = 0;
	for(i=0; i<4; i++){
		aux1 = values[i];

		for(j=i+1; j<5; j++){
			aux2 = values[j];
			aux2 = abs(aux1 - aux2);
			if(aux2>dist) dist = aux2;
		}
	}

	*dist_max = dist;

	for(i=0; i<3; i++){
		aux1 = values[i];

		for(j=i+1; j<4; j++){
			aux2 = values[j];
			dist = abs(aux1 - aux2);

			if( dist <= range ){
				for(k=j+1; k<5; k++){
					aux3 = values[k];
					dist2 = abs(aux1 - aux3);

					if( dist2 <= range ){
						result = aux2 + (aux1 << 1);
						result = result + aux3;
						result = result >> 2;
						result = result & (~7);

						*err = 0;

						break;
					}
				}
			}
		}
	}

	if((*err) == 1){
		result = values[0] + values[4];
		result = result >> 1;
		result = result & (~7);
	}

	return (result & 0xFFF);
}

//---------------------------------------------------------------------------------
void UpdateRange(uint8 *this_range, int16 last_dist_max, u8 data_error, u8 tsc_touched){
//---------------------------------------------------------------------------------
	//range_counter_1 = counter_0x380A98C
	//range_counter_2 = counter_0x380A990
	//Initial values:
	// range = 20
	// min_range = 20

	if(tsc_touched != 0){
		if( data_error == 0){
			range_counter_2 = 0;

			if( last_dist_max >= ((*this_range) >> 1)){
				range_counter_1 = 0;
			}else{
				range_counter_1++;

				if(range_counter_1 >= 4){
					range_counter_1 = 0;

					if((*this_range) > min_range){
						(*this_range)--;
						range_counter_2 = 3;
					}
				}
			}
		}else{
			range_counter_1 = 0;
			range_counter_2++;

			if(range_counter_2 >= 4){

				range_counter_2 = 0;

				if((*this_range) < 35){  //0x23 = 35
					*this_range = (*this_range) + 1;
				}
			}
		}
	}else{
		range_counter_2 = 0;
		range_counter_1 = 0;
	}
}

//---------------------------------------------------------------------------------
// reading pixel position:
//---------------------------------------------------------------------------------
touchPosition touchReadXY() {
//---------------------------------------------------------------------------------

	int16 dist_max_y, dist_max_x, dist_max;
	u8 error, error_where, first_check, i;

	touchPosition touchPos = { 0, 0, 0, 0, 0, 0 };

	if ( !touchInit ) {

		xscale = ((PersonalData->calX2px - PersonalData->calX1px) << 19) / ((PersonalData->calX2) - (PersonalData->calX1));
		yscale = ((PersonalData->calY2px - PersonalData->calY1px) << 19) / ((PersonalData->calY2) - (PersonalData->calY1));

		xoffset = ((PersonalData->calX1 + PersonalData->calX2) * xscale  - ((PersonalData->calX1px + PersonalData->calX2px) << 19) ) / 2;
		yoffset = ((PersonalData->calY1 + PersonalData->calY2) * yscale  - ((PersonalData->calY1px + PersonalData->calY2px) << 19) ) / 2;
		touchInit = true;
	}

	uint32 oldIME = REG_IME;

	REG_IME = 0;

	first_check = CheckStylus();
	if(first_check != 0){
		error_where = 0;

		touchPos.z1 =  readTouchValue(TSC_MEASURE_Z1 | 1, &dist_max, &error);
		touchPos.z2 =  readTouchValue(TSC_MEASURE_Z2 | 1, &dist_max, &error);

		touchPos.x = readTouchValue(TSC_MEASURE_X | 1, &dist_max_x, &error);
		if(error==1) error_where += 1;

		touchPos.y = readTouchValue(TSC_MEASURE_Y | 1, &dist_max_y, &error);
		if(error==1) error_where += 2;

		REG_SPICNT = SPI_ENABLE | SPI_BAUD_2MHz | SPI_DEVICE_TOUCH | SPI_CONTINUOUS;
		for(i=0; i<12; i++){
			REG_SPIDATA = 0;

			SerialWaitBusy();
		}

		REG_SPICNT = SPI_ENABLE | SPI_BAUD_2MHz | SPI_DEVICE_TOUCH;
		REG_SPIDATA = 0;

		SerialWaitBusy();

		if(first_check == 2) error_where = 3;

		switch( CheckStylus() ){
		case 0:
			last_time_touched = 0;
			break;
		case 1:
			last_time_touched = 1;

			if(dist_max_x > dist_max_y)
				dist_max = dist_max_x;
			else
				dist_max = dist_max_y;

			break;
		case 2:
			last_time_touched = 0;
			error_where = 3;

			break;
		}

		s16 px = ( touchPos.x * xscale - xoffset + xscale/2 ) >>19;
		s16 py = ( touchPos.y * yscale - yoffset + yscale/2 ) >>19;

		if ( px < 0) px = 0;
		if ( py < 0) py = 0;
		if ( px > (SCREEN_WIDTH -1)) px = SCREEN_WIDTH -1;
		if ( py > (SCREEN_HEIGHT -1)) py = SCREEN_HEIGHT -1;

		touchPos.px = px;
		touchPos.py = py;


	}else{
		error_where = 3;
		touchPos.x = 0;
		touchPos.y = 0;
		last_time_touched = 0;
	}

	UpdateRange(&range, dist_max, error_where, last_time_touched);

	REG_IME = oldIME;


	return touchPos;

}