summaryrefslogtreecommitdiff
path: root/include/basegfx/numeric/ftools.hxx
blob: 1e7f0a34e71cab123d36e11bff7176d281023f58 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */

#pragma once

#include <rtl/math.h>
#include <cmath>
#include <math.h>
#include <basegfx/basegfxdllapi.h>
#include <limits>
#include <algorithm>


// fTools defines

namespace basegfx
{
    /** Round double to nearest integer

        @return the nearest integer
    */
    inline sal_Int32 fround( double fVal )
    {
        if (fVal >= 0.0)
        {
            if (fVal >= std::numeric_limits<sal_Int32>::max() - .5)
                return std::numeric_limits<sal_Int32>::max();
            return static_cast<sal_Int32>(fVal + .5);
        }
        if (fVal <= std::numeric_limits<sal_Int32>::min() + .5)
            return std::numeric_limits<sal_Int32>::min();
        return static_cast<sal_Int32>(fVal - .5);
    }

    /** Round double to nearest integer

        @return the nearest 64 bit integer
    */
    inline sal_Int64 fround64( double fVal )
    {
        return fVal > 0.0 ? static_cast<sal_Int64>( fVal + .5 ) : -static_cast<sal_Int64>( -fVal + .5 );
    }

    /** Prune a small epsilon range around zero.

        Use this method e.g. for calculating scale values. There, it
        is usually advisable not to set a scaling to 0.0, because that
        yields singular transformation matrices.

        @param fVal
        An arbitrary, but finite and valid number

        @return either fVal, or a small value slightly above (when
        fVal>0) or below (when fVal<0) zero.
     */
    inline double pruneScaleValue( double fVal )
    {
        if(fVal < 0.0)
            return std::min(fVal, -0.00001);
        else
            return std::max(fVal, 0.00001);
    }

    /** Convert value from degrees to radians
     */
    template <int DegMultiple = 1> constexpr double deg2rad( double v )
    {
        // divide first, to get exact values for v being a multiple of
        // 90 degrees
        return v / (90.0 * DegMultiple) * M_PI_2;
    }

    /** Convert value radians to degrees
     */
    template <int DegMultiple = 1> constexpr double rad2deg( double v )
    {
        // divide first, to get exact values for v being a multiple of
        // pi/2
        return v / M_PI_2 * (90.0 * DegMultiple);
    }

    /** Snap v to nearest multiple of fStep, from negative and
        positive side.

        Examples:

        snapToNearestMultiple(-0.1, 0.5) = 0.0
        snapToNearestMultiple(0.1, 0.5) = 0.0
        snapToNearestMultiple(0.25, 0.5) = 0.0
        snapToNearestMultiple(0.26, 0.5) = 0.5
     */
    BASEGFX_DLLPUBLIC double snapToNearestMultiple(double v, const double fStep);

    /** Snap v to the range [0.0 .. fWidth] using modulo
     */
    BASEGFX_DLLPUBLIC double snapToZeroRange(double v, double fWidth);

    /** Snap v to the range [fLow .. fHigh] using modulo
     */
    double snapToRange(double v, double fLow, double fHigh);

    /** return fValue with the sign of fSignCarrier, thus evtl. changed
    */
    inline double copySign(double fValue, double fSignCarrier)
    {
#ifdef _WIN32
        return _copysign(fValue, fSignCarrier);
#else
        return copysign(fValue, fSignCarrier);
#endif
    }

    /** RotateFlyFrame3: Normalize to range defined by [0.0 ... fRange[, independent
        if v is positive or negative.

        Examples:

        normalizeToRange(0.5, -1.0) = 0.0
        normalizeToRange(0.5, 0.0) = 0.0
        normalizeToRange(0.5, 1.0) = 0.5
        normalizeToRange(-0.5, 1.0) = 0.5
        normalizeToRange(-0.3, 1.0) = 0.7
        normalizeToRange(-0.7, 1.0) = 0.3
        normalizeToRange(3.5, 1.0) = 0.5
        normalizeToRange(3.3, 1.0) = 0.3
        normalizeToRange(3.7, 1.0) = 0.7
        normalizeToRange(-3.5, 1.0) = 0.5
        normalizeToRange(-3.3, 1.0) = 0.7
        normalizeToRange(-3.7, 1.0) = 0.3
     */
    BASEGFX_DLLPUBLIC double normalizeToRange(double v, const double fRange);

    namespace fTools
    {
        /// Get threshold value for equalZero and friends
        inline double getSmallValue() { return 0.000000001f; }

        /// Compare against small value
        template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
        inline bool equalZero(const T& rfVal)
        {
            return (fabs(rfVal) <= getSmallValue());
        }

        /// Compare against given small value
        template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
        inline bool equalZero(const T& rfVal, const T& rfSmallValue)
        {
            return (fabs(rfVal) <= rfSmallValue);
        }

        template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
        inline bool equal(T const& rfValA, T const& rfValB)
        {
            // changed to approxEqual usage for better numerical correctness
            return rtl_math_approxEqual(rfValA, rfValB);
        }

        template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
        inline bool equal(const T& rfValA, const T& rfValB, const T& rfSmallValue)
        {
            return (fabs(rfValA - rfValB) <= rfSmallValue);
        }

        template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
        inline bool less(const T& rfValA, const T& rfValB)
        {
            return (rfValA < rfValB && !equal(rfValA, rfValB));
        }

        template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
        inline bool lessOrEqual(const T& rfValA, const T& rfValB)
        {
            return (rfValA < rfValB || equal(rfValA, rfValB));
        }

        template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
        inline bool more(const T& rfValA, const T& rfValB)
        {
            return (rfValA > rfValB && !equal(rfValA, rfValB));
        }

        template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
        inline bool moreOrEqual(const T& rfValA, const T& rfValB)
        {
            return (rfValA > rfValB || equal(rfValA, rfValB));
        }

        template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
        inline bool betweenOrEqualEither(const T& rfValA, const T& rfValB, const T& rfValC)
        {
            return (rfValA > rfValB && rfValA < rfValC) || equal(rfValA, rfValB) || equal(rfValA, rfValC);
        }
    };
} // end of namespace basegfx

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */