#include <stdio.h>
#include <math.h>                             
#include <fstream.h>
#include <iostream.h>
#include <stdlib.h>
#include <conio.h>
#include <process.h>
#include <dos.h>
#include <io.h>
#include <errno.h>
#include <direct.h>
extern unsigned _stklen =54321U;

int main(int)
{
int const  MAXELEM=38;     //Max number of elements
int const  FX=25,  FX2=35; //X value for first column and second column
int const  MAXX=4, CURX=3, X=0, Y=1, WIDTH=2;//Array position name definitions


//Key press definitions
int const  LEFT=75, RIGHT=77,ESCP=27,UP=72, DOWN=80,F1=59,F2=60;
int const  ENTER=13,DEL=83,  BACK=8, END=79,HOME=71,TAB=9,RTAB=15;

int        HIELEM=5,IN=0,j,jj,i,key;     //HIELEM takes on the value of the first cell
int	   mode=0,change=0;

char       imgbuff[MAXELEM+1][30]; //???
char       inbuff [MAXELEM+1][15]; //???

int        def  [MAXELEM+1][5]; //Element structure allocation
int        valid[MAXELEM+1];    //???

long int    minutes,seconds;
long double windspeed,winddirection,groundspeed,angle1,angle2,angle3,bearing,airspeed,distance,time;

double	   *values;



if((values = (double (*))malloc(((MAXELEM+1)*10))) == NULL)
		{
		printf("\nNOT ENOUGH MEMORY FOR Value BUFFER.");goto exit;
		}
values[0]=1;

textmode(C80);
textbackground(0);
clrscr();
textcolor(7);
gotoxy(1,1);
cprintf("Legs=");
textcolor(4);
gotoxy(44,1);
textbackground(7);
cprintf("WINDCALC v1.0e Credits Hit F2  ");
gotoxy(44,2);
textcolor(0);
cprintf("Arrows control cursor. Enter   ");
gotoxy(44,3);
textcolor(0);
cprintf("up to 16 legs. Spc toggles     ");
gotoxy(44,4);
textcolor(0);
cprintf("mode and converts fields.      ");
textcolor(7);
textbackground(0);
	//define first cell positions,sizeand its present cursor position.
	def[0][X]    =14;         		//starting x position
	def[0][Y]    =1;      		        //Starting y position
	def[0][WIDTH]=2;          		//Field width
	def[0][CURX]=def[0][X];	        	//Current x postion defined as its first position here
	def[0][MAXX]=def[0][X]+def[0][WIDTH]-1;	//Max x position
	gotoxy(def[0][X]-1,def[0][Y]);          //draw bracket around cell
	textcolor(15);
	putch('['); textcolor(7); putch('1');
	gotoxy(def[0][MAXX]+1,def[0][Y]);
	textcolor(15);putch(']');
	textcolor(7);
	cprintf("            (Tab/Shf-tab)");

	def[1][X]    =14;         		//starting x position
	def[1][Y]    =2;      		        //Starting y position
	def[1][WIDTH]=6;          		//Field width
	def[1][CURX]=def[1][X];	        	//Current x postion defined as its first position here
	def[1][MAXX]=def[1][X]+def[1][WIDTH]-1;	//Max x position
gotoxy(1,2);
cprintf("AirSpeed=");
	gotoxy(def[1][X]-1,def[1][Y]);          //draw bracket around cell
	textcolor(15);
	putch('[');
	gotoxy(def[1][MAXX]+1,def[1][Y]);
	putch(']');
	textcolor(7);
	cprintf("        (cruise)");

	def[2][X]    =14;         		//starting x position
	def[2][Y]    =3;      		        //Starting y position
	def[2][WIDTH]=6;          		//Field width
	def[2][CURX]=def[2][X];	        	//Current x postion defined as its first position here
	def[2][MAXX]=def[2][X]+def[2][WIDTH]-1;	//Max x position
	gotoxy(1,3);
	cprintf("WndSpd/Dir=");
	gotoxy(def[2][X]-1,def[2][Y]);          //draw bracket around cell
	textcolor(15);
	putch('[');
	gotoxy(def[2][MAXX]+1,def[2][Y]);
	putch(']');
	putch('/');

	def[3][X]    =23;         		//starting x position
	def[3][Y]    =3;      		        //Starting y position
	def[3][WIDTH]=3;          		//Field width
	def[3][CURX]=def[3][X];	        	//Current x postion defined as its first position here
	def[3][MAXX]=def[3][X]+def[3][WIDTH]-1;	//Max x position
	gotoxy(def[3][X]-1,def[3][Y]);          //draw bracket around cell
	putch('[');
	gotoxy(def[3][MAXX]+1,def[3][Y]);
	putch(']');
	textcolor(7);
	cprintf("  (Wind Out Of)");


	def[4][X]    =14;         		//starting x position
	def[4][Y]    =4;      		        //Starting y position
	def[4][WIDTH]=8;          		//Field width
	def[4][CURX]=def[4][X];	        	//Current x postion defined as its first position here
	def[4][MAXX]=def[4][X]+def[4][WIDTH]-1;	//Max x position
	gotoxy(1,4);
	cprintf("Mode=");
	gotoxy(def[4][X]-1,def[4][Y]);          //draw bracket around cell
	textcolor(15);
	putch('[');
	textcolor(7);
	cprintf("STATUTE");
	gotoxy(def[4][MAXX]+1,def[4][Y]);
	textcolor(15);
	putch(']');
	textcolor(7);
	cprintf("      (S or N)");
gotoxy(1,5);
textcolor(4);
textbackground(0);
cprintf("------------------------------------------------------------------------------");
gotoxy(1,6);
textcolor(15);
textbackground(0);
cprintf("                        BEARING   DISTANCE");
//Define each cell as to postion and width ect for future printing
textcolor(15);
 gotoxy(50,6);
 cprintf("Heading,   GS,  Time(min,sec)");
textcolor(7);
for (i=5;i <= MAXELEM; i=i+2)                   //Loop to define each input cell.
	{
	values[i]=0;                            //Init data holder for each cell
	values[i+1]=0;
	def[i][X]    =FX;                       //starting x position for column 1 of cell i
	def[i][Y]    =5+(i-1)/2;      		//Starting y position (row) of cell i
	def[i][WIDTH]=7;          		//Field width (width of cell i)
	def[i][CURX] =def[i][X];	        //Current x postion (remember last curser pos)
	def[i][MAXX] =def[i][X]+def[i][WIDTH]-1;//Max x position definition

	//Column two defs
	def[i+1][X]    =FX2;                    //starting x position for column 2
	def[i+1][Y]    =5+(i-1)/2;              //Starting y position (row)
	def[i+1][WIDTH]=7;
	def[i+1][CURX] =def[i+1][X];       		//Current x postion
	def[i+1][MAXX] =def[i+1][X]+def[i+1][WIDTH]-1;  //Max x position

	}


redef:
for (i=5;i <= MAXELEM; i=i+2)           //Erase brackets from old cells that have
	{                               //been undefined

	gotoxy(def[i][X]-7,def[i][Y]);   //Erase Leg markers too
	cprintf("       ");
	gotoxy(def[i][X]-1,def[i][Y]);
	putch(' ');
	gotoxy(def[i][MAXX]+1,def[i][Y]);
	putch(' ');


	gotoxy(def[i+1][X]-1,def[i+1][Y]);
	putch(' ');
	gotoxy(def[i+1][MAXX]+1,def[i+1][Y]);
	putch(' ');
	}


j=1;
for (i=5;i <= HIELEM; i=i+2)
	{
	gotoxy(def[i][X]-7,def[i][Y]);
	textcolor(7);
	cprintf("Leg%0d=",j++);
	gotoxy(def[i][X]-1,def[i][Y]);
	textcolor(15);
	putch('[');
	gotoxy(def[i][MAXX]+1,def[i][Y]);
	putch(']');


	gotoxy(def[i+1][X]-1,def[i+1][Y]);
	putch('[');
	gotoxy(def[i+1][MAXX]+1,def[i+1][Y]);
	putch(']');
	}

ret:	while(1)
	{
		{
		textbackground(0);
		textcolor(15);
		gotoxy(def[IN][CURX],def[IN][Y]);
		key=getch();
		gotoxy(1,8);
		cprintf ("F1 to Calculate");
		gotoxy(1,9);
		cprintf("F2 for Credits  ");
		gotoxy(1,10);
		cprintf("ESC to QUIT");
		textcolor(7);
		if((key > 47 && key < 58 || (key == 110) || (key == 78) || (key==32)) && (IN == 4) && (mode==0))
			{
			gotoxy(def[IN][X],def[IN][Y]);
			textcolor(7);
			cprintf("NAUTICAL");
			mode=1;
			change=1;
			}
		else if((key > 47 && key < 58 || (key == 83) || (key == 115) || (key==32))&& (IN == 4) && (mode==1))
			{
			gotoxy(def[IN][X],def[IN][Y]);
			textcolor(7);
			cprintf("STATUTE ");
			mode=0;
			change=1;
			}

		else if(key == LEFT)
			{
			if(def[IN][CURX]-1 >= def[IN][X])
				{
				gotoxy(def[IN][--def[IN][CURX]], def[IN][Y]);
				}
			else
				{
				gotoxy(def[IN][X],def[IN][Y]);
				}
			}

		else if(key == RIGHT)
			{
			if(def[IN][CURX]+1 <= def[IN][MAXX])
				{
				gotoxy(def[IN][++def[IN][CURX]], def[IN][Y]);
				}
			else
				{
				gotoxy(def[IN][MAXX],def[IN][Y]);
				}
			}
		else if(key == UP || key == RTAB)
			{
			if(IN-1 >= 0)
				{
				gotoxy(def[--IN][CURX],def[IN][Y]);
				}
			else
				{
				gotoxy(def[0][CURX],def[0][Y]);
				}
			}
		else if(key == DOWN || key == TAB || key == ENTER)
			{
			if(IN+1 <= HIELEM)
				{
				gotoxy(def[++IN][CURX],def[IN][Y]);
				}
			else
				{
				gotoxy(def[HIELEM][CURX],def[HIELEM][Y]);
				}
			}
		else if(key == HOME)
			{
			gotoxy((def[0][CURX]=def[0][X]),def[0][Y]);
			IN=0;
			}
		else if(key == END)
			{
			gotoxy(def[HIELEM][X],def[HIELEM][Y]);
			IN=HIELEM;
			}

		else if((key == DEL || key == BACK) && (IN != 4))
			{
			puttext(def[IN][X],def[IN][Y],def[IN][MAXX],def[IN][Y]," \a \a \a \a \a \a \a"); //Clear the field
			gotoxy((def[IN][CURX]=def[IN][X]),def[IN][Y]);
			values[IN]=0;
			}



		else if(key > 47 && key < 58 || (key == 46) || (key==32))
			{
			if(def[IN][CURX] <= def[IN][MAXX])
				{
				gotoxy(def[IN][CURX]++,def[IN][Y]);//Be sure we're at the correct position for writing the next character
				putch(key);
				if(def[IN][CURX] > def[IN][MAXX])
					{
					def[IN][CURX]--; //Don't allow write past MAXX
					}

				}

			}
		else if (key == ESCP)
			{
			textbackground(0);
			textcolor(7);
			clrscr();
			goto exit;
			}
	  }


for(i=0;i<=HIELEM; i++)
     {
     gettext(def[i][X],def[i][Y],def[i][MAXX],def[i][Y],&imgbuff[i]);
     for(j=0; j<def[i][WIDTH]; j++)
		{
		inbuff[i][j]=imgbuff[i][j*2]; //Pack field info
		}
	inbuff[i][j]=NULL;

     if(sscanf(inbuff[i],"%lf",&values[i]) <= 0)  //Scan all fields and determine if valid
	{
	valid[i]=0;
	}
     else if(change && i != 0){              //Change mode from nautical to statute
			if(i == 1)      {    //airspeed change
					for(jj=0;jj<=15;jj++)      //Erase old fields
						{
						gotoxy(50,jj+7);
						cprintf("                             ");
						}


					if(mode){
						values[i]/=1.1516;
						sprintf(inbuff[i],"%5.2lf",values[i]);
						for(j=0; j<def[i][WIDTH]; j++)
							{
							imgbuff[i][j*2]=inbuff[i][j]; //Pack field info
							}
						puttext(def[i][X],def[i][Y],def[i][MAXX],def[i][Y],&imgbuff[i]);
						}
					else    {
						values[i]*=1.1516;
						sprintf(inbuff[i],"%5.2lf",values[i]);
						for(j=0; j<def[i][WIDTH]; j++)
							{
							imgbuff[i][j*2]=inbuff[i][j]; //Pack field info
							}
						puttext(def[i][X],def[i][Y],def[i][MAXX],def[i][Y],&imgbuff[i]);
						}
					}
			if(i%2 == 0)
					{      //Distance Change
					if(mode){
						values[i]/=1.1516;
						sprintf(inbuff[i],"%5.2lf",values[i]);
						for(j=0; j<def[i][WIDTH]; j++)
							{
							imgbuff[i][j*2]=inbuff[i][j]; //Pack field info
							}
						puttext(def[i][X],def[i][Y],def[i][MAXX],def[i][Y],&imgbuff[i]);
						}
					else    {
						values[i]*=1.1516;
						sprintf(inbuff[i],"%5.2lf",values[i]);
						for(j=0; j<def[i][WIDTH]; j++)
							{
							imgbuff[i][j*2]=inbuff[i][j]; //Pack field info
							}
						puttext(def[i][X],def[i][Y],def[i][MAXX],def[i][Y],&imgbuff[i]);
						}

					}
		    }
     else
	{
	valid[i]=1;
	if(values[0] < 1 || values[0] > (MAXELEM/2) - 3) //Check for invalid number of chosen legs
		{
		valid[0]=0; //Special case...clear the input field
		puttext(def[0][X],def[0][Y],def[0][MAXX],def[0][Y]," \a \a \a \a \a \a \a"); //Clear the field
		gotoxy((def[0][CURX]=def[0][X]),def[0][Y]);
		}
	}
     }
  change=0;						  //If new breakpoints number is
  if(valid[0] == 1 && (4+int(values[0])*2 != HIELEM) &&   //valid and not the same as before
    (values[0] >=1 && values[0] <=(MAXELEM/2)-3))         //and between 2 and MAXELEM/2 then OK to change
	{
	HIELEM=4+int(values[0])*2;
	goto redef;
	}

	if(key == F2)
	{
textcolor(4);
gotoxy(44,1);
textbackground(7);
cprintf("      WINDCALC v1.0e           ");
gotoxy(44,2);
textcolor(0);
cprintf("Freeware Written by Todd Snyder");
gotoxy(44,3);
textcolor(0);
cprintf("For more info go to            ");
gotoxy(44,4);
textcolor(0);
cprintf("www.homefires.us/flight      ");
textcolor(7);
textbackground(0);
	}
	if (key == F1)
		{
	textcolor(4);
	gotoxy(44,1);
	textbackground(7);
	cprintf("WINDCALC v1.0e Credits Hit F2  ");
	gotoxy(44,2);
	textcolor(0);
	cprintf("Arrows control cursor. Enter   ");
	gotoxy(44,3);
	textcolor(0);
	cprintf("up to 16 legs. Spc toggles     ");
	gotoxy(44,4);
	textcolor(0);
	cprintf("mode and converts fields.      ");
	textcolor(7);
	textbackground(0);

	if(values[1] < .1 || values[1] > 1000)   //Airspeed
		{
		valid[1]=0; //Special case...clear the input field
		//puttext(def[1][X],def[1][Y],def[1][MAXX],def[1][Y]," \a \a \a \a \a \a \a"); //Clear the field
		//gotoxy((def[1][CURX]=def[1][X]),def[1][Y]);
		//IN=1;
		}
	if(values[2] < .1 || values[2] > 1000)     //windspeed
		{
		valid[2]=0; //Special case...clear the input field
		//puttext(def[2][X],def[2][Y],def[2][MAXX],def[2][Y]," \a \a \a \a \a \a \a"); //Clear the field
		//gotoxy((def[2][CURX]=def[2][X]),def[2][Y]);
		//IN=2;
		}
	if(values[3] < 0 || values[3] > 359.999)     //wind direction
		{
		valid[3]=0; //Special case...clear the input field
		//puttext(def[3][X],def[3][Y],def[3][MAXX],def[3][Y]," \a \a \a \a \a \a \a"); //Clear the field
		//gotoxy((def[3][CURX]=def[3][X]),def[3][Y]);
		//IN=3;
		}


 for(i=5;i<=HIELEM; i=i+2)
	{
	if(values[i] < 0 || values[i] > 359.999)
		{
		valid[i]=0; //Special case...clear the input field
		//puttext(def[i][X],def[i][Y],def[i][MAXX],def[i][Y]," \a \a \a \a \a \a \a"); //Clear the field
		//gotoxy((def[i][CURX]=def[i][X]),def[i][Y]);
		//IN=i;
		}
	if(values[i+1] < .1 || values[i+1] > 1000)
		{
		valid[i+1]=0; //Special case...clear the input field
		//puttext(def[i+1][X],def[i+1][Y],def[i+1][MAXX],def[i+1][Y]," \a \a \a \a \a \a \a"); //Clear the field
		//gotoxy((def[i+1][CURX]=def[i+1][X]),def[i+1][Y]);
		//IN=i+1;
		}

	 }
 for (i=1; i<=HIELEM; i++)   //Check for any bad data and move curser to it
	{
	if(valid[i] != 1 && i != 4)
		{
		IN=i;
		goto redef;
		}
	}

 airspeed=values[1];
 windspeed=values[2];
 winddirection=values[3];
 winddirection+=180;
 if(winddirection > 360) {winddirection-=360;}
 textcolor(15);
 gotoxy(50,6);
 cprintf("Heading,   GS , Time(min,sec)");
 for(i=0;i<=15;i++)      //Erase old fields
	{
	gotoxy(50,i+8);
	cprintf("                             ");
	}

 j=7;
 for(i=5;i<=HIELEM;i=i+2)
	{
	 distance=values[i+1];
	 bearing=values[i]; //Bearing
	 angle1=winddirection-bearing;
	 if(angle1<0) {angle1+=360;}
	 if( (fabsl(angle1-180) < .00001))
		{
		angle2=0;
		groundspeed=airspeed-windspeed;
		if(groundspeed <.0001) {groundspeed=.0001;}
		time=60*(distance/groundspeed);
		minutes=(time);
		seconds=(time-minutes)*60;

		}
	 else if(fabsl(angle1) < .0001)
		{
		angle2=0;
		groundspeed=airspeed+windspeed;
		if(groundspeed <.0001) {groundspeed=.0001;}
		time=60*(distance/groundspeed);
		minutes=(time);
		seconds=(time-minutes)*60;
		}

	 else
		{
	 angle1/=57.2958;//convert to radians
	 angle2=asinl( (windspeed*sinl(angle1))/airspeed);
	 angle3=3.141593-(angle1+angle2);
	 groundspeed=(airspeed*sinl(angle3))/sinl(angle1);
	 if(groundspeed <.0001) {groundspeed=.0001;}
	 angle1*=57.2958;
	 angle2*=57.2958;
	 angle3*=57.2958;
		}
	 if(angle2 > bearing) {angle2-=360;} //No negative headings..LOL
	 time=60*(distance/groundspeed);
	 minutes=(time);
	 seconds=(time-minutes)*60;
	 textcolor(7);
	 gotoxy(50,j++);

	 if(minutes > 9999)
		{
	 cprintf("%5.1Lf,   %5.1Lf,   NEVER  ",bearing-angle2,groundspeed);
		}
	 else{
	 cprintf("%5.1Lf,   %5.1Lf, %4ldm,%2lds",bearing-angle2,groundspeed,minutes,seconds);
	     }
	 }

		}

  }
exit:
free(values);
return(1);
}