From c51c359b7601f4f071444a4579d1678b5aac7d06 Mon Sep 17 00:00:00 2001
From: Jan Breuer <jan.breuer@jaybee.cz>
Date: 周一, 09 11月 2015 23:30:07 +0800
Subject: [PATCH] Custom double to string conversion routine
---
libscpi/src/utils.c | 175 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 175 insertions(+), 0 deletions(-)
diff --git a/libscpi/src/utils.c b/libscpi/src/utils.c
index 1e26e17..f69428d 100644
--- a/libscpi/src/utils.c
+++ b/libscpi/src/utils.c
@@ -40,6 +40,7 @@
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
+#include <math.h>
#include "utils_private.h"
#include "scpi/utils.h"
@@ -753,3 +754,177 @@
}
#endif
+// Floating point to string conversion routines
+//
+// Copyright (C) 2002 Michael Ringgaard. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions
+// are met:
+//
+// 1. Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright
+// notice, this list of conditions and the following disclaimer in the
+// documentation and/or other materials provided with the distribution.
+// 3. Neither the name of the project nor the names of its contributors
+// may be used to endorse or promote products derived from this software
+// without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+// SUCH DAMAGE.
+
+static char *scpi_ecvt(double arg, int ndigits, int *decpt, int *sign, char *buf, size_t bufsize) {
+ int r2;
+ double fi, fj;
+ char *p, *p1;
+
+ if (ndigits < 0) ndigits = 0;
+ if (ndigits >= (int) (bufsize - 1)) ndigits = bufsize - 2;
+ r2 = 0;
+ *sign = 0;
+ p = &buf[0];
+ if (arg < 0) {
+ *sign = 1;
+ arg = -arg;
+ }
+ arg = modf(arg, &fi);
+ p1 = &buf[bufsize];
+
+ if (fi != 0) {
+ p1 = &buf[bufsize];
+ while (fi != 0) {
+ fj = modf(fi / 10, &fi);
+ *--p1 = (int) ((fj + .03) * 10) + '0';
+ r2++;
+ }
+ while (p1 < &buf[bufsize]) *p++ = *p1++;
+ } else if (arg > 0) {
+ while ((fj = arg * 10) < 1) {
+ arg = fj;
+ r2--;
+ }
+ }
+ p1 = &buf[ndigits];
+ *decpt = r2;
+ if (p1 < &buf[0]) {
+ buf[0] = '\0';
+ return buf;
+ }
+ while (p <= p1 && p < &buf[bufsize]) {
+ arg *= 10;
+ arg = modf(arg, &fj);
+ *p++ = (int) fj + '0';
+ }
+ if (p1 >= &buf[bufsize]) {
+ buf[bufsize - 1] = '\0';
+ return buf;
+ }
+ p = p1;
+ *p1 += 5;
+ while (*p1 > '9') {
+ *p1 = '0';
+ if (p1 > buf) {
+ ++*--p1;
+ } else {
+ *p1 = '1';
+ (*decpt)++;
+ }
+ }
+ *p = '\0';
+ return buf;
+}
+
+#define SCPI_DTOSTRE_BUFFER_SIZE 310
+
+char * SCPI_dtostre(double __val, char * __s, size_t __ssize, unsigned char __prec, unsigned char __flags) {
+ char buffer[SCPI_DTOSTRE_BUFFER_SIZE];
+
+ int sign = signbit(__val);
+ char * s = buffer;
+ int decpt;
+ if (sign) {
+ __val = -__val;
+ s[0] = '-';
+ s++;
+ } else if (!isnan(__val)) {
+ if (SCPI_DTOSTRE_PLUS_SIGN & __flags) {
+ s[0] = '+';
+ s++;
+ } else if (SCPI_DTOSTRE_ALWAYS_SIGN & __flags) {
+ s[0] = ' ';
+ s++;
+ }
+ }
+
+ if (!isfinite(__val)) {
+ if (isnan(__val)) {
+ strcpy(s, (__flags & SCPI_DTOSTRE_UPPERCASE) ? "NAN" : "nan");
+ } else {
+ strcpy(s, (__flags & SCPI_DTOSTRE_UPPERCASE) ? "INF" : "inf");
+ }
+ strncpy(__s, buffer, __ssize);
+ return __s;
+ }
+
+ scpi_ecvt(__val, __prec, &decpt, &sign, s, SCPI_DTOSTRE_BUFFER_SIZE - 1);
+ if (decpt > 1 && decpt <= __prec) {
+ memmove(s + decpt + 1, s + decpt, __prec + 1 - decpt);
+ s[decpt] = '.';
+ decpt = 0;
+ } else if (decpt > -4 && decpt <= 0) {
+ decpt = -decpt + 1;
+ memmove(s + decpt + 1, s, __prec + 1);
+ memset(s, '0', decpt + 1);
+ s[1] = '.';
+ decpt = 0;
+ } else {
+ memmove(s + 2, s + 1, __prec + 1);
+ s[1] = '.';
+ decpt--;
+ }
+
+ s = &s[__prec];
+ while (s[0] == '0') {
+ s[0] = 0;
+ s--;
+ }
+ if (s[0] == '.') {
+ s[0] = 0;
+ s--;
+ }
+
+ if (decpt != 0) {
+ s++;
+ s[0] = 'e';
+ s++;
+ if (decpt != 0) {
+ if (decpt > 0) {
+ s[0] = '+';
+ }
+ if (decpt < 0) {
+ s[0] = '-';
+ decpt = -decpt;
+ }
+ s++;
+ }
+ UInt32ToStrBaseSign(decpt, s, 5, 10, 0);
+ if (s[1] == 0) {
+ s[2] = s[1];
+ s[1] = s[0];
+ s[0] = '0';
+ }
+ }
+
+ strncpy(__s, buffer, __ssize);
+ return __s;
+}
--
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