chromium/third_party/skia/src/utils/SkFloatToDecimal.cpp

/*
 * Copyright 2017 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "src/utils/SkFloatToDecimal.h"

#include "include/core/SkTypes.h"

#include <cfloat>
#include <cmath>

#ifdef SK_DEBUG
#include <limits.h>
#endif

// returns `value * pow(base, e)`, assuming `e` is positive.
static double pow_by_squaring(double value, double base, int e) { … }

// Return pow(10.0, e), optimized for common cases.
static double pow10(int e) { … }

/** Write a string into output, including a terminating '\0' (for
    unit testing).  Return strlen(output) (for SkWStream::write) The
    resulting string will be in the form /[-]?([0-9]*.)?[0-9]+/ and
    sscanf(output, "%f", &x) will return the original value iff the
    value is finite. This function accepts all possible input values.

    Motivation: "PDF does not support [numbers] in exponential format
    (such as 6.02e23)."  Otherwise, this function would rely on a
    sprintf-type function from the standard library. */
unsigned SkFloatToDecimal(float value, char output[kMaximumSkFloatToDecimalLength]) { … }