Merge pull request #432 from majenkotech/fix-dtostrf

Rewrite dtostrf to use snprintf with float formatting

pic32/cores/pic32/WProgram.h

@@ -5,6 +5,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
+#include "stdlib_noniso.h"
 
 #include <pins_arduino.h>
 

pic32/cores/pic32/WString.cpp

@@ -23,24 +23,6 @@
 
 #include <stdio.h>
 
-/*********************************************/
-/*  Utilities                                */
-/*********************************************/
-
-char *dtostrf(double __val, signed char __width, unsigned char __prec, char *__s) {
-    int i = (int)__val;
-    double trunc = __val - (float)i;
-    if (trunc < 0) {
-        trunc = 0 - trunc;
-    }
-    for (int q = 0; q < __prec; q++) {
-        trunc *= 10.0;
-    }
-    unsigned int dec = (int)trunc;
-    snprintf(__s, __width, "%d.%d", i, dec);
-    return __s;
-}
-
 /*********************************************/
 /*  Constructors                             */
 /*********************************************/

pic32/cores/pic32/WString.h

@@ -24,6 +24,7 @@
 #ifdef __cplusplus
 
 #include <stdlib.h>
+#include "stdlib_noniso.h"
 #include <string.h>
 #include <ctype.h>
 
@@ -39,10 +40,6 @@
 class __FlashStringHelper;
 #define F(string_literal) (reinterpret_cast<const __FlashStringHelper *>(string_literal))
 
-
-extern char *dtostrf(double __val, signed char __width, unsigned char __prec, char *__s);
-
-
 // An inherited class for holding the result of a concatenation.  These
 // result objects are assumed to be writable by subsequent concatenations.
 class StringSumHelper;

pic32/cores/pic32/noniso.c

@@ -0,0 +1,169 @@
+/*
+ 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"
+
+#if _NEED_REVERSE
+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;
+    }
+}
+#endif
+
+#ifdef _NEED_LTOA
+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;
+}
+#endif
+
+#ifdef _NEED_ULTOA
+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;
+}
+#endif
+
+#ifdef _NEED_DTOSTRF
+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;
+}
+#endif

pic32/cores/pic32/stdlib_noniso.h

@@ -0,0 +1,65 @@
+/* 
+  stdlib_noniso.h - 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
+*/
+
+#ifndef STDLIB_NONISO_H
+#define STDLIB_NONISO_H
+
+//#define _NEED_REVERSE
+//#define _NEED_LTOA
+//#define _NEED_ULTOA
+#define _NEED_DTOSTRF
+
+#ifdef __cplusplus
+extern "C"{
+#endif
+
+int atoi(const char *s);
+
+long atol(const char* s);
+
+double atof(const char* s);
+
+char* itoa (int val, char *s, int radix);
+
+#ifdef _NEED_LTOA
+char* ltoa (long val, char *s, int radix);
+#endif
+
+char* utoa (unsigned int val, char *s, int radix);
+
+#ifdef _NEED_ULTOA
+char* ultoa (unsigned long val, char *s, int radix);
+#endif
+
+#ifdef _NEED_DTOSTRF
+char* dtostrf (double val, signed char width, unsigned char prec, char *s);
+#endif
+
+#ifdef _NEED_REVERSE
+void reverse(char* begin, char* end);
+#endif
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+
+#endif