Workaround bug in ftoa.

1 files changed, 22 insertions, 310 deletions

diff --git a/source/fitz/ftoa.c b/source/fitz/ftoa.c
index 355f0879..92ee9edf 100644
--- a/source/fitz/ftoa.c
+++ b/source/fitz/ftoa.c
@@ -1,178 +1,5 @@
-/* The authors of this software are Rob Pike and Ken Thompson.
- * Copyright (c) 2002 by Lucent Technologies.
- * Permission to use, copy, modify, and distribute this software for any
- * purpose without fee is hereby granted, provided that this entire notice
- * is included in all copies of any software which is or includes a copy
- * or modification of this software and in all copies of the supporting
- * documentation for such software.
- * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
- * WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY
- * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
- * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
- */
-
 #include "mupdf/fitz.h"
 
-#include <stdio.h>
-#include <math.h>
-#include <float.h>
-#include <string.h>
-#include <stdlib.h>
-#include <errno.h>
-
-#ifndef INFINITY
-#define INFINITY (DBL_MAX+DBL_MAX)
-#endif
-#ifndef NAN
-#define NAN (INFINITY-INFINITY)
-#endif
-
-#ifndef DEFINED_ULONG
-#define DEFINED_ULONG
-typedef unsigned long ulong;
-#endif
-
-enum { NSIGNIF	= 9 };
-
-/*
- * first few powers of 10
- */
-static float pows10[] =
-{
-	1e0f,	1e1f,	1e2f,	1e3f,	1e4f,	1e5f,	1e6f,	1e7f,	1e8f,	1e9f,
-	1e10f,	1e11f,	1e12f,	1e13f,	1e14f,	1e15f,	1e16f,	1e17f,	1e18f,	1e19f,
-	1e20f,	1e21f,	1e22f,	1e23f,	1e24f,	1e25f,	1e26f,	1e27f,	1e28f,	1e29f,
-	1e30f,	1e31f,	1e32f,	1e33f,	1e34f,	1e35f,	1e36f,	1e37f,	1e38f
-};
-#define	npows10 ((int)(sizeof(pows10)/sizeof(pows10[0])))
-#define	pow10(x) fmtpow10(x)
-
-static float
-pow10(int n)
-{
-	float d;
-	int neg;
-
-	neg = 0;
-	if(n < 0){
-		neg = 1;
-		n = -n;
-	}
-
-	if(n < npows10)
-		d = pows10[n];
-	else{
-		d = pows10[npows10-1];
-		for(;;){
-			n -= npows10 - 1;
-			if(n < npows10){
-				d *= pows10[n];
-				break;
-			}
-			d *= pows10[npows10 - 1];
-		}
-	}
-	if(neg)
-		return 1./d;
-	return d;
-}
-
-/*
- * add 1 to the decimal integer string a of length n.
- * if 99999 overflows into 10000, return 1 to tell caller
- * to move the virtual decimal point.
- */
-static int
-xadd1(char *a, int n)
-{
-	char *b;
-	int c;
-
-	if(n < 0 || n > NSIGNIF)
-		return 0;
-	for(b = a+n-1; b >= a; b--) {
-		c = *b + 1;
-		if(c <= '9') {
-			*b = c;
-			return 0;
-		}
-		*b = '0';
-	}
-	/*
-	 * need to overflow adding digit.
-	 * shift number down and insert 1 at beginning.
-	 * decimal is known to be 0s or we wouldn't
-	 * have gotten this far. (e.g., 99999+1 => 00000)
-	 */
-	a[0] = '1';
-	return 1;
-}
-
-/*
- * subtract 1 from the decimal integer string a.
- * if 10000 underflows into 09999, make it 99999
- * and return 1 to tell caller to move the virtual
- * decimal point. this way, xsub1 is inverse of xadd1.
- */
-static int
-xsub1(char *a, int n)
-{
-	char *b;
-	int c;
-
-	if(n < 0 || n > NSIGNIF)
-		return 0;
-	for(b = a+n-1; b >= a; b--) {
-		c = *b - 1;
-		if(c >= '0') {
-			if(c == '0' && b == a) {
-				/*
-				 * just zeroed the top digit; shift everyone up.
-				 * decimal is known to be 9s or we wouldn't
-				 * have gotten this far. (e.g., 10000-1 => 09999)
-				 */
-				*b = '9';
-				return 1;
-			}
-			*b = c;
-			return 0;
-		}
-		*b = '9';
-	}
-	/*
-	 * can't get here. the number a is always normalized
-	 * so that it has a nonzero first digit.
-	 */
-	return 0;
-}
-
-/*
- * format exponent like sprintf(p, "e%+d", e)
- */
-static void
-fmtexp(char *p, int e)
-{
-	char se[9];
-	int i;
-
-	*p++ = 'e';
-	if(e < 0) {
-		*p++ = '-';
-		e = -e;
-	} else
-		*p++ = '+';
-	i = 0;
-	while(e) {
-		se[i++] = e % 10 + '0';
-		e /= 10;
-	}
-	while(i < 1)
-		se[i++] = '0';
-	while(i > 0)
-		*p++ = se[--i];
-	*p++ = '\0';
-}
-
 /*
  * compute decimal integer m, exp such that:
  *	f = m*10^exp
@@ -182,149 +9,34 @@ fmtexp(char *p, int e)
 void
 fz_ftoa(float f, char *s, int *exp, int *neg, int *ns)
 {
-	int c, d, e2, e, ee, i, ndigit, oerrno;
-	char tmp[NSIGNIF+10];
-	float g;
-
-	oerrno = errno; /* in case strtod smashes errno */
-
-	/*
-	 * make f non-negative.
-	 */
-	*neg = 0;
-	if(f < 0) {
-		f = -f;
-		*neg = 1;
-	}
-
-	/*
-	 * must handle zero specially.
-	 */
-	if(f == 0){
-		*exp = 0;
-		s[0] = '0';
-		s[1] = '\0';
-		*ns = 1;
-		return;
-	}
-
-	/*
-	 * find g,e such that f = g*10^e.
-	 * guess 10-exponent using 2-exponent, then fine tune.
-	 */
-	frexpf(f, &e2);
-	e = (int)(e2 * .301029995664f);
-	g = f * pow10(-e);
-	while(g < 1) {
-		e--;
-		g = f * pow10(-e);
-	}
-	while(g >= 10) {
-		e++;
-		g = f * pow10(-e);
-	}
-
-	/*
-	 * convert NSIGNIF digits as a first approximation.
-	 */
-	for(i=0; i<NSIGNIF; i++) {
-		d = (int)g;
-		s[i] = d+'0';
-		g = (g-d) * 10;
-	}
-	s[i] = 0;
-
-	/*
-	 * adjust e because s is 314159... not 3.14159...
-	 */
-	e -= NSIGNIF-1;
-	fmtexp(s+NSIGNIF, e);
-
-	/*
-	 * adjust conversion until strtod(s) == f exactly.
-	 */
-	for(i=0; i<10; i++) {
-		g = fz_strtod(s, NULL);
-		if(f > g) {
-			if(xadd1(s, NSIGNIF)) {
-				/* gained a digit */
-				e--;
-				fmtexp(s+NSIGNIF, e);
-			}
-			continue;
-		}
-		if(f < g) {
-			if(xsub1(s, NSIGNIF)) {
-				/* lost a digit */
-				e++;
-				fmtexp(s+NSIGNIF, e);
-			}
-			continue;
-		}
-		break;
-	}
-
-	/*
-	 * play with the decimal to try to simplify.
-	 */
+	char buf[40], *p = buf;
+	int i;
 
-	/*
-	 * bump last few digits up to 9 if we can
-	 */
-	for(i=NSIGNIF-1; i>=NSIGNIF-3; i--) {
-		c = s[i];
-		if(c != '9') {
-			s[i] = '9';
-			g = fz_strtod(s, NULL);
-			if(g != f) {
-				s[i] = c;
-				break;
-			}
-		}
+	for (i = 0; i < 10; ++i)
+	{
+		sprintf(buf, "%.*e", i, f);
+		if (fz_atof(buf) == f)
+			break;
 	}
 
-	/*
-	 * add 1 in hopes of turning 9s to 0s
-	 */
-	if(s[NSIGNIF-1] == '9') {
-		strcpy(tmp, s);
-		ee = e;
-		if(xadd1(tmp, NSIGNIF)) {
-			ee--;
-			fmtexp(tmp+NSIGNIF, ee);
-		}
-		g = fz_strtod(tmp, NULL);
-		if(g == f) {
-			strcpy(s, tmp);
-			e = ee;
-		}
+	if (*p == '-')
+	{
+		*neg = 1;
+		++p;
 	}
+	else
+		*neg = 0;
 
-	/*
-	 * bump last few digits down to 0 as we can.
-	 */
-	for(i=NSIGNIF-1; i>=NSIGNIF-3; i--) {
-		c = s[i];
-		if(c != '0') {
-			s[i] = '0';
-			g = fz_strtod(s, NULL);
-			if(g != f) {
-				s[i] = c;
-				break;
-			}
+	*ns = 0;
+	while (*p && *p != 'e')
+	{
+		if (*p >= '0' && *p <= '9')
+		{
+			*ns += 1;
+			*s++ = *p;
 		}
+		++p;
 	}
 
-	/*
-	 * remove trailing zeros.
-	 */
-	ndigit = NSIGNIF;
-	while(ndigit > 1 && s[ndigit-1] == '0'){
-		e++;
-		--ndigit;
-	}
-	s[ndigit] = 0;
-	*exp = e;
-	*ns = ndigit;
-	errno = oerrno;
+	*exp = fz_atoi(p+1) - (*ns) + 1;
 }