#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <stdlib.h>


#define FLOAT_VALUE 560.0





#define TRUE    1
#define FALSE    0

void F2b(float UserFloat, int format);
uint8_t Byte1, Byte2, Byte3, Byte4, be;
FILE* destFile;


void main (int argc, char **argv)
{
double val;
val = atof(argv[2]);
F2b(val,0);
char buf[50];
destFile = fopen(argv[1], "wb");
sprintf (buf,"asm\(\"\\t psect eeprom_data,class=EEDATA\");\n");
fwrite(buf, 1, strlen(buf), destFile);
sprintf (buf,"asm\(\"\\t DB 0x%2.2X, 0x%2.2X, 0x%2.2X\");\n",Byte1,Byte2,Byte3);
fwrite(buf, 1, strlen(buf), destFile);
fclose(destFile);
}


//derived from http://www.piclist.com/techref/microchip/math/fpconvert.htm

void F2b(float UserFloat, int format)
{

    double x, z;
    unsigned long mantissa=0;
    int e, k;
    char *endstr, sign;

    endstr = "\0";      // used by strtod function

    // remember sign and keep positive
    if (UserFloat < 0)
    {
        sign = 1;
        UserFloat *= -1;
    }
    else sign = 0;

    // what format are we using?
    switch (format) {

    case 0 :    // Hitech 24bit

        if (UserFloat == 0.0)
        {
            e = -127;
            Byte1 = 0;
            Byte2 = 0;
            Byte3 = 0;
            Byte4 = 0;
            mantissa = 1.0;
        }
        else
        {
            z = log(UserFloat) / log(2.0);
            e = (int)(z);
            if ((double)e > z)
                e --;
            be = e + 127;

            x = UserFloat / pow(2.0, (double)e);

            for (k=0; k>-15; k--)
            {
                if (x >= pow(2.0, k))
                {
                    mantissa++;     // set bit
                    x -= pow(2.0, k);   // update remainder
                }
                mantissa = mantissa << 1;
            }

            // fill byte values
            if (sign) Byte1 = 0x80;
            else Byte1 = 0;
            Byte1 += (be & 0xFE) >> 1;
            Byte2 = (be & 0x01) << 7;
            Byte2 += ((int)mantissa & 0x7F00) >> 8;
            Byte3 = (int)mantissa & 0xFF;
            Byte4 = 0;
        }

        break;

    case 1 :    // IEEE754 32Bit

        if (UserFloat == 0.0)
        {
            e = -127;
            Byte1 = 0;
            Byte2 = 0;
            Byte3 = 0;
            Byte4 = 0;
            mantissa = 1.0;
        }
        else
        {
            z = log(UserFloat) / log(2.0);
            e = (int)(z);
            if ((double)e > z)
            e --;
            be = e + 127;

            x = UserFloat / pow(2.0, (double)e);

            for (k=0; k>-23; k--)
            {
                if (x >= pow(2.0, k))
                {
                    mantissa++;     // set bit
                    x -= pow(2.0, k);   // update remainder
                }
                mantissa = mantissa << 1;
            }

            // fill byte values
            if (sign) Byte1 = 0x80;
            else Byte1 = 0;
            Byte1 += (be & 0xFE) >> 1;
            Byte2 = (be & 0x01) << 7;
            Byte2 += ((int)mantissa & 0x7F0000) >> 16;
            Byte3 = ((int)mantissa & 0xFF00) >> 8;
            Byte4 = (int)mantissa & 0xFF;
        }

        break;

    case 2 :    // Microchip 32Bit

        if (UserFloat == 0.0)
        {
            e = -127;
            Byte1 = 0;
            Byte2 = 0;
            Byte3 = 0;
            Byte4 = 0;
            mantissa = 1.0;
        }
        else
        {
            z = log(UserFloat) / log(2.0);
            e = (int)(z);
            if ((double)e > z)
                e --;
            be = e + 127;

            x = UserFloat / pow(2.0, (double)e);

            for (k=0; k>-23; k--)
            {
                if (x >= pow(2.0, k))
                {
                    mantissa++;     // set bit
                    x -= pow(2.0, k);   // update remainder
                }
                mantissa = mantissa << 1;
            }

            // fill byte values
            Byte1 = be;
            if (sign) Byte2 = 0x80;
            else Byte2 = 0;
            Byte2 += ((int)mantissa & 0x7F0000) >> 16;
            Byte3 = ((int)mantissa & 0xFF00) >> 8;
            Byte4 = (int)mantissa & 0xFF;
        }

        break;

    case 3 :    // Microchip 24Bit

        if (UserFloat == 0.0)
        {
            e = -127;
            Byte1 = 0;
            Byte2 = 0;
            Byte3 = 0;
            Byte4 = 0;
            mantissa = 1.0;
        }
        else
        {
            z = log(UserFloat) / log(2.0);
            e = (int)(z);
            if ((double)e > z)
                e --;
            be = e + 127;

            x = UserFloat / pow(2.0, (double)e);

            for (k=0; k>-15; k--)
            {
                if (x >= pow(2.0, k))
                {
                    mantissa++;     // set bit
                    x -= pow(2.0, k);   // update remainder
                }
                mantissa = mantissa << 1;
            }

            // fill byte values
            Byte1 = be;
            if (sign) Byte2 = 0x80;
            else Byte2 = 0;
            Byte2 += ((int)mantissa & 0x7F00) >> 8;
            Byte3 = (int)mantissa & 0xFF;
            Byte4 = 0;
        }

        break;
    }
}