forked from Elron_dev/elbear_arduino_bsp
92 lines
2.4 KiB
C
92 lines
2.4 KiB
C
/*
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dtostrf - Emulation for dtostrf function from avr-libc
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Copyright (c) 2013 Arduino. All rights reserved.
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Written by Cristian Maglie <c.maglie@arduino.cc>
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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char *dtostrf (double val, signed char width, unsigned char prec, char *sout) {
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//Commented code is the original version
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/*char fmt[20];
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sprintf(fmt, "%%%d.%df", width, prec);
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sprintf(sout, fmt, val);
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return sout;*/
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// Handle negative numbers
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unsigned int negative = 0;
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if (val < 0.0)
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{
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negative = 1;
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val = -val;
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}
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// Round correctly so that print(1.999, 2) prints as "2.00"
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double rounding = 0.5;
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for (int i=0; i<prec; ++i)
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rounding /= 10.0;
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val += rounding;
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// Extract the integer part of the number
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unsigned long int_part = (unsigned long)val;
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double remainder = val - (double)int_part;
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if(negative)
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int_part = -int_part;
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// Extract digits from the remainder
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unsigned long dec_part = 0;
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double decade = 1.0;
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for(int i=0; i < prec; i++)
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decade *= 10.0;
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remainder *= decade;
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dec_part = (int)remainder;
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sprintf(sout, "%ld.%ld", int_part, dec_part);
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// Handle minimum field width of the output string
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// width is signed value, negative for left adjustment.
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// Range -128,127
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char fmt[129] = "";
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unsigned int w = width;
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if (width < 0) {
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negative = 1;
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w = -width;
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} else {
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negative = 0;
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}
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if(strlen(sout) < w) {
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memset(fmt, ' ', 128);
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fmt[w-strlen(sout)] = '\0';
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if(negative == 0) {
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char *tmp = strdup(sout);
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strcpy(sout,fmt);
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strcat(sout, tmp);
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free(tmp);
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} else {
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// left adjustment
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strcat(sout, fmt);
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}
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}
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return sout;
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}
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