/* 07/11/2001: initial version 0.1 */
/* 15/11/2001: bug reported by "jpa" corrected: display buffer was too short */

/********** INCLUDES ***********/
#include <rex/rex.h>
#include <stdlib.h>
#include <message.h>
#include <math.h>
#include <float.h>

// # include <eurocalc.h>
/****** BEGINNING of manually included <eurocalc.h> ******/

/********** DISPLAY POSITIONS & SIZES***********/
#define	DISP_X		25
#define DISP1_Y		8
#define DISP2_Y		28
#define DISP_W		130
#define DISP_H		20

#define DISPRES_X	DISP_X+5
#define DISPRES_Y1	DISP1_Y+5
#define DISPRES_Y2	DISP2_Y+5
#define DISPRES_W	DISP_W-6
#define	DISPRES_H	DISP_H-6

#define DISPLAY_MAXLEN	7

/********** KEYPAD POSITIONS & SIZES ***********/
#define KEYX0 30          /* pos of left edge of keypad */
#define KEYY0 52          /* pos of upper edge of keypad */
#define KEYXW 24          /* width of each key */
#define KEYYW 17          /* height of each key */


/********** KEYPAD DEF. ***********/
#define KEYID_0		0x50		// 0
#define KEYID_1		0x51		// 1
#define KEYID_2		0x52		// 2
#define KEYID_3		0x53		// 3
#define KEYID_4		0x54		// 4
#define KEYID_5		0x55		// 5
#define KEYID_6		0x56		// 6
#define KEYID_7		0x57		// 7
#define KEYID_8		0x58		// 8
#define KEYID_9		0x59		// 9
#define KEYID_DOT	0x5A		// .
#define KEYID_OPP	0x5B		// +/-
#define KEYID_EQ	0x5C		// =
#define KEYID_ADD	0x5D		// +
#define KEYID_SUB	0x5E		// -
#define KEYID_MUL	0x5F		// x
#define KEYID_DIV	0x60		// /
#define KEYID_CLR	0x61		// C; Clear
#define KEYID_AC	0x62		// AC; All Clear
#define KEYID_MOD	0x63		// MODE; change mode 
#define KEYID_CUR	0x64		// Currency; change currency
#define KEYID_OFF	0x65		// OFF


/********** CURRENCIES MODES ***********/
#define	MODE_EUR	-1	//special euro mode
#define	MODE_BEF	0
#define	MODE_DEM	1
#define	MODE_ESP	2
#define	MODE_FRF	3
#define	MODE_IEP	4
#define	MODE_ITL	5
#define	MODE_LUF	6
#define	MODE_NLG	7
#define	MODE_ATS	8
#define	MODE_PTE	9
#define	MODE_FIM	10
#define	MODE_GRD	11


/********** CURRENCIES LABELS ***********/
const char curr_names [] = {
'B','E','F',					//BEF
'D','E','M',					//DEM
'E','S','P',					//ESP
'F','R','F',					//FRF
'I','E','P',					//IEP
'I','T','L',					//ITL
'L','U','F',					//LUF
'N','L','G',					//NLG
'A','T','S',					//ATS
'P','T','E',					//PTE
'F','I','M',					//FIM
'G','R','D'};					//GRD


/********** EURO sign BITMAP ***********/
const char i_euro[] = {6, 9,
	0x3c,
	0x44,
	0x80,
	0xf8,
	0x80,
	0xf0,
	0x80,
	0x84,
	0x78
};

/********** GLOBAL VARS ***********/
/* REM: don't initialize here */
float 		res1, res2, res_tmp;
unsigned char	mMode, mModeLoc;
unsigned char   dispreset, dotted;
char	operation;
char cdisplay[DISPLAY_MAXLEN+1];
unsigned char pos;
unsigned char i;		//"for loops" generic integer

char cur[4];	//string for currencies label
float rates[12];	//array of european fixed change rates


/****** END of manually included <eurocalc.h> ******/


////////////////////////// C PROG Starts here//////////////////////////
/* COMPILED with REXDX                                               */
/* with -lm & -doublestr options                                     */
/** [zcc +rex -lm -doublestr -create-app -oeurocalc.bin eurocalc.c] **/
/*********************************************************************/

///// set Display to 0
DisplayRaz()
{
	pos = 0;
	cdisplay[0] = '0';
	cdisplay[1] = '\0';
}


///// set All to 0
Raz()
{
	DisplayRaz();
	res2 = 0;
	res_tmp = 0;
	dotted = 0;
	dispreset = 1;
        operation = ' ';
}


///// change local currency string
// ATTN: cur[4] must be set to 0 (cf. initialize);
change_cur(MLoc)
unsigned char MLoc;
{	
	for (i=0; i<3; i++)
		cur[i] = curr_names[3*MLoc+i];
}


ClearScreen()
{
	DsDisplayBlockClear(0, 0, 240, 120);
}


/*** Display Results ***/
DisplayRes()
{
	char cRes[15];
	unsigned char precision;

	res2 = atof(cdisplay);

	/******* conversion *******/
	if (mMode == MODE_EUR)
		res1 = res2 / rates[mModeLoc];
	else
		res1 = res2 * rates[mModeLoc];

	/***** Display numbers ****/
	precision = 2;
	if (!dotted) precision = 0;

	DsDisplayBlockClear(DISPRES_X,DISPRES_Y1,DISPRES_W,DISPRES_H);
	DsDisplayBlockClear(DISPRES_X,DISPRES_Y2,DISPRES_W,DISPRES_H);
	ftoa(res1,2,cRes);
	DsPrintf(DISPRES_X,DISPRES_Y1,16,cRes);

	DsPrintf(DISPRES_X,DISPRES_Y2,16,cdisplay);

	/***** Display currencies ****/
	if (mMode==MODE_EUR)
	{
	  DsDisplayBitmapDraw(125,DISPRES_Y1, i_euro , 0);
	  DsPrintf(120,DISPRES_Y2,16,cur);
	}
	else
	{
	  DsDisplayBitmapDraw(125,DISPRES_Y2, i_euro , 0);
	  DsPrintf(120,DISPRES_Y1,16,cur);
	}
}


///// initialize all (screen, button events, rates, default values...)
///// and draw screen
initialize()
{
	DsEventClear();

	ClearScreen();

	/* Draw Display 1 */
	DsDisplayBlock(DISP_X, DISP1_Y, DISP_W, DISP_H, 0);

	/* Draw Display 2 */
	DsDisplayBlock(DISP_X, DISP2_Y, DISP_W, DISP_H, 0);

	/* deco */
	for (i=DISP1_Y; i<DISP2_Y+DISP_H; i=i+2)
	{
	   DsDisplayLine(0,i,DISP_X,0,0xff);
	   DsDisplayLine(DISP_X+DISP_W,i,240-DISP_X-DISP_W,0,0xff);
	}

	/* Draw Keys */
	DsDialogTextButton(KEYX0+KEYXW*0, KEYY0+KEYYW*3,KEYXW, KEYYW, KEYID_0, "0");
	DsDialogTextButton(KEYX0+KEYXW*0, KEYY0+KEYYW*2,KEYXW, KEYYW, KEYID_1, "1");
	DsDialogTextButton(KEYX0+KEYXW*1, KEYY0+KEYYW*2,KEYXW, KEYYW, KEYID_2, "2");
	DsDialogTextButton(KEYX0+KEYXW*2, KEYY0+KEYYW*2,KEYXW, KEYYW, KEYID_3, "3");
	DsDialogTextButton(KEYX0+KEYXW*0, KEYY0+KEYYW*1,KEYXW, KEYYW, KEYID_4, "4");
	DsDialogTextButton(KEYX0+KEYXW*1, KEYY0+KEYYW*1,KEYXW, KEYYW, KEYID_5, "5");
	DsDialogTextButton(KEYX0+KEYXW*2, KEYY0+KEYYW*1,KEYXW, KEYYW, KEYID_6, "6");
	DsDialogTextButton(KEYX0+KEYXW*0, KEYY0+KEYYW*0,KEYXW, KEYYW, KEYID_7, "7");
	DsDialogTextButton(KEYX0+KEYXW*1, KEYY0+KEYYW*0,KEYXW, KEYYW, KEYID_8, "8");
	DsDialogTextButton(KEYX0+KEYXW*2, KEYY0+KEYYW*0,KEYXW, KEYYW, KEYID_9, "9");
	DsDialogTextButton(KEYX0+KEYXW*1, KEYY0+KEYYW*3,KEYXW, KEYYW, KEYID_DOT, ".");
	DsDialogTextButton(KEYX0+KEYXW*2, KEYY0+KEYYW*3,KEYXW, KEYYW, KEYID_OPP, "+/-");
	DsDialogTextButton(KEYX0+KEYXW*3, KEYY0+KEYYW*0,KEYXW, KEYYW, KEYID_ADD, "+");
	DsDialogTextButton(KEYX0+KEYXW*3, KEYY0+KEYYW*1,KEYXW, KEYYW, KEYID_SUB, "-");
	DsDialogTextButton(KEYX0+KEYXW*3, KEYY0+KEYYW*2,KEYXW, KEYYW, KEYID_MUL, "x");
	DsDialogTextButton(KEYX0+KEYXW*3, KEYY0+KEYYW*3,KEYXW, KEYYW, KEYID_DIV, "/");
	DsDialogTextButton(KEYX0+KEYXW*4, KEYY0+KEYYW*0,KEYXW, KEYYW, KEYID_CLR, "C");
	DsDialogTextButton(KEYX0+KEYXW*4, KEYY0+KEYYW*1,KEYXW, KEYYW, KEYID_AC, "AC");
	DsDialogTextButton(KEYX0+KEYXW*4, KEYY0+KEYYW*2,KEYXW, KEYYW*2, KEYID_EQ, " ");
	DsPrintf(KEYX0+KEYXW*4+8,KEYY0+KEYYW*2+12,16,"=");	// for centering "=" on key

	DsDialogTextButton(175, KEYY0+KEYYW*2,60, KEYYW, KEYID_CUR, "Currency");
	DsDialogTextButton(175, KEYY0+KEYYW*3,60, KEYYW, KEYID_MOD, "MODE");
	DsDialogTextButton(190, 60 ,30, KEYYW, KEYID_OFF, "OFF");


	Raz();  // set all to 0	


	// EURO FIXED CHANGE RATES (1 EURO costs... //
	rates[MODE_BEF] = 40.3399;	//BEF
	rates[MODE_DEM] = 1.95583;	//DEM
	rates[MODE_ESP] = 166.386;	//ESP
	rates[MODE_FRF] = 6.55957;	//FRF
	rates[MODE_IEP] = 0.787564;	//IEP
	rates[MODE_ITL] = 1936.27;	//ITL
	rates[MODE_LUF] = 40.3399;	//LUF
	rates[MODE_NLG] = 2.20371;	//NLG
	rates[MODE_ATS] = 13.7603;	//ATS
	rates[MODE_PTE] = 200.482;	//PTE
	rates[MODE_FIM] = 5.94573;	//FIM
	rates[MODE_GRD] = 340.750;	//GRD

	// set default (starting) mode
	mMode = MODE_FRF;
// you could also set default mode to EURO mode with: mMode=MODE_EUR;
	
	//set default (starting) local currency
	mModeLoc = MODE_FRF;

	//initialize local currency string
	cur[4] = '\0';
	change_cur(mModeLoc);
	DisplayRes();
}


///// called when operator pressed
PressOperat(oper)
char	oper;
{
	char	cOp[2];


    if (!dispreset)		// op. choosen and second number OK
    {
	dispreset = 1;		// next Digit Key => new number
	
	switch (operation) {  //previous op.
		case ' ':
			res_tmp = res2;
			break;
		case '+':
			res_tmp = res_tmp + res2;
			break;
		case '-':
			res_tmp = res_tmp - res2;
			break;
		case 'x':
			res_tmp = res_tmp * res2;
			break;
		case '/':
			res_tmp = res_tmp / res2;
			break;
	}

	ftoa(res_tmp,2,cdisplay);
	DisplayRes();
   }

	// display new operation "oper"
//	if (oper=='=') oper = ' ';
	operation = oper;
	cOp[0] = operation;
	cOp[1] = '\0';
	DsDisplayBlockClear(145, DISPRES_Y2, 8, 11);
	DsPrintf(145,DISPRES_Y2,16,cOp);
}



///// called when digit pressed
PressNum(bCode)
unsigned char bCode;
{
	unsigned char num_in;


	// maxlen: can not add digit
	if (pos==DISPLAY_MAXLEN)
	  return;


	// if display reset must be done
	if (dispreset)
	{
		// reset display
		dispreset = 0;
		res2 = 0;
		dotted = 0;
		DisplayRaz();
	}


	if (bCode==KEYID_DOT)
	{

				if (!dotted)
				{
				  dotted = 1;
				  if (cdisplay[0]=='0')
				    pos++;
				  cdisplay[pos] = '.';
				  pos++;
				  cdisplay[pos] = '\0';
				}
	}
	else
	{
	// add digit to display
	cdisplay[pos] = '0' + bCode - KEYID_0;
	pos++;
	cdisplay[pos] = '\0';
	}

	//display
	DisplayRes();
}


/**********************************************/
/**********************************************/
main()
{
	MSG  msg;
        char flag;

	initialize();

	flag = 1;
	while(flag) {
		DsEventMessageGet(&msg);
		switch (msg.message) {
		case MSG_DS_CLOSE:
			flag = 0;
			break;
		case MSG_DS_KEY_DOWN:
			if (msg.sCode==KEY_TOP_C) flag = 0;
			break;
		case MSG_DS_PAINT:
			break;
		case MSG_DS_COMMAND:
			if (KEYID_0<=msg.bCode && msg.bCode<KEYID_OPP)
			  PressNum(msg.bCode);

			switch (msg.bCode) {

			   case KEYID_OPP:		// [+/-]
				if (cdisplay[0]=='-')
				{
				  // remove '-'
                                  for (i=0; i<DISPLAY_MAXLEN; i++)
                                     cdisplay[i] = cdisplay[i+1];
				  pos--;
				}
				else
				{
				  // add '-' before number
				  for (i=DISPLAY_MAXLEN; i>0; i--)
				     cdisplay[i] = cdisplay[i-1];
				  cdisplay[0] = '-';
				  pos++;
				}
				DisplayRes();
				break;

			   case KEYID_ADD:		// [+]
				PressOperat('+');
				break;

			   case KEYID_SUB:		// [-]
				PressOperat('-');
				break;

			   case KEYID_MUL:		// [x]
				PressOperat('x');
				break;

			   case KEYID_DIV:		// [/]
				PressOperat('/');
				break;

			   case KEYID_EQ:		// [=]
				PressOperat(' ');
				break;

			   case KEYID_CUR:		// [cur]
				  mModeLoc ++;
				  if (mModeLoc > MODE_GRD)
				    mModeLoc = MODE_BEF;
				  if (mMode > MODE_EUR)
				    mMode = mModeLoc;
				  change_cur(mModeLoc);
				DisplayRes();
				break;

			   case KEYID_AC:		// [AC]
				Raz();
				DisplayRes();
				break;

			   case KEYID_MOD:		// [MODE]
				// change mode: Local currency <=> EURO
				if (mMode==MODE_EUR)
				  mMode = mModeLoc;   //change to local mode
				else
				  mMode = MODE_EUR;   //change to euro mode
				DisplayRes();
				break;

			   case KEYID_CLR:		// [C]
				if (pos > 1)
				{
				   pos--;
				   cdisplay[pos] = '\0';
				}
				else DisplayRaz();
				DisplayRes();
				break;

			   case KEYID_OFF:		// [OFF]
				flag = 0;
				break;
			}
			break;
		}
	}
	ClearScreen();
	DsAddinTerminate();
}