arduino-esp32/cores/esp32/stdlib_noniso.c

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/*
core_esp8266_noniso.c - nonstandard (but usefull) conversion functions
Copyright (c) 2014 Ivan Grokhotkov. All rights reserved.
This file is part of the esp8266 core for Arduino environment.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Modified 03 April 2015 by Markus Sattler
*/
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <stdint.h>
#include <math.h>
#include "stdlib_noniso.h"
#include "esp_system.h"
#if !CONFIG_DSP_ANSI && !CONFIG_DSP_OPTIMIZED
void reverse(char* begin, char* end) {
char *is = begin;
char *ie = end - 1;
while(is < ie) {
char tmp = *ie;
*ie = *is;
*is = tmp;
++is;
--ie;
}
}
#else
void reverse(char* begin, char* end);
#endif
char* ltoa(long value, char* result, int base) {
if(base < 2 || base > 16) {
*result = 0;
return result;
}
char* out = result;
long quotient = abs(value);
do {
const long tmp = quotient / base;
*out = "0123456789abcdef"[quotient - (tmp * base)];
++out;
quotient = tmp;
} while(quotient);
// Apply negative sign
if(value < 0)
*out++ = '-';
reverse(result, out);
*out = 0;
return result;
}
char* ultoa(unsigned long value, char* result, int base) {
if(base < 2 || base > 16) {
*result = 0;
return result;
}
char* out = result;
unsigned long quotient = value;
do {
const unsigned long tmp = quotient / base;
*out = "0123456789abcdef"[quotient - (tmp * base)];
++out;
quotient = tmp;
} while(quotient);
reverse(result, out);
*out = 0;
return result;
}
char * dtostrf(double number, signed char width, unsigned char prec, char *s) {
bool negative = false;
if (isnan(number)) {
strcpy(s, "nan");
return s;
}
if (isinf(number)) {
strcpy(s, "inf");
return s;
}
char* out = s;
int fillme = width; // how many cells to fill for the integer part
if (prec > 0) {
fillme -= (prec+1);
}
// Handle negative numbers
if (number < 0.0) {
negative = true;
fillme--;
number = -number;
}
// Round correctly so that print(1.999, 2) prints as "2.00"
// I optimized out most of the divisions
double rounding = 2.0;
for (uint8_t i = 0; i < prec; ++i)
rounding *= 10.0;
rounding = 1.0 / rounding;
number += rounding;
// Figure out how big our number really is
double tenpow = 1.0;
int digitcount = 1;
while (number >= 10.0 * tenpow) {
tenpow *= 10.0;
digitcount++;
}
number /= tenpow;
fillme -= digitcount;
// Pad unused cells with spaces
while (fillme-- > 0) {
*out++ = ' ';
}
// Handle negative sign
if (negative) *out++ = '-';
// Print the digits, and if necessary, the decimal point
digitcount += prec;
int8_t digit = 0;
while (digitcount-- > 0) {
digit = (int8_t)number;
if (digit > 9) digit = 9; // insurance
*out++ = (char)('0' | digit);
if ((digitcount == prec) && (prec > 0)) {
*out++ = '.';
}
number -= digit;
number *= 10.0;
}
// make sure the string is terminated
*out = 0;
return s;
}