1/*
2 * Copyright 2006 The Android Open Source Project
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef SkScalar_DEFINED
9#define SkScalar_DEFINED
10
11#include "include/private/base/SkAssert.h"
12#include "include/private/base/SkFloatingPoint.h"
13
14typedef float SkScalar;
15
16#define SK_Scalar1 1.0f
17#define SK_ScalarHalf 0.5f
18#define SK_ScalarSqrt2 SK_FloatSqrt2
19#define SK_ScalarPI SK_FloatPI
20#define SK_ScalarTanPIOver8 0.414213562f
21#define SK_ScalarRoot2Over2 0.707106781f
22#define SK_ScalarMax 3.402823466e+38f
23#define SK_ScalarMin (-SK_ScalarMax)
24#define SK_ScalarInfinity SK_FloatInfinity
25#define SK_ScalarNegativeInfinity SK_FloatNegativeInfinity
26#define SK_ScalarNaN SK_FloatNaN
27
28#define SkScalarFloorToScalar(x) sk_float_floor(x)
29#define SkScalarCeilToScalar(x) sk_float_ceil(x)
30#define SkScalarRoundToScalar(x) sk_float_round(x)
31#define SkScalarTruncToScalar(x) sk_float_trunc(x)
32
33#define SkScalarFloorToInt(x) sk_float_floor2int(x)
34#define SkScalarCeilToInt(x) sk_float_ceil2int(x)
35#define SkScalarRoundToInt(x) sk_float_round2int(x)
36
37#define SkScalarAbs(x) sk_float_abs(x)
38#define SkScalarCopySign(x, y) sk_float_copysign(x, y)
39#define SkScalarMod(x, y) sk_float_mod(x,y)
40#define SkScalarSqrt(x) sk_float_sqrt(x)
41#define SkScalarPow(b, e) sk_float_pow(b, e)
42
43#define SkScalarSin(radians) (float)sk_float_sin(radians)
44#define SkScalarCos(radians) (float)sk_float_cos(radians)
45#define SkScalarTan(radians) (float)sk_float_tan(radians)
46#define SkScalarASin(val) (float)sk_float_asin(val)
47#define SkScalarACos(val) (float)sk_float_acos(val)
48#define SkScalarATan2(y, x) (float)sk_float_atan2(y,x)
49#define SkScalarExp(x) (float)sk_float_exp(x)
50#define SkScalarLog(x) (float)sk_float_log(x)
51#define SkScalarLog2(x) (float)sk_float_log2(x)
52
53//////////////////////////////////////////////////////////////////////////////////////////////////
54
55#define SkIntToScalar(x) static_cast<SkScalar>(x)
56#define SkIntToFloat(x) static_cast<float>(x)
57#define SkScalarTruncToInt(x) sk_float_saturate2int(x)
58
59#define SkScalarToFloat(x) static_cast<float>(x)
60#define SkFloatToScalar(x) static_cast<SkScalar>(x)
61#define SkScalarToDouble(x) static_cast<double>(x)
62#define SkDoubleToScalar(x) sk_double_to_float(x)
63
64static inline bool SkScalarIsNaN(SkScalar x) { return x != x; }
65
66/** Returns true if x is not NaN and not infinite
67 */
68static inline bool SkScalarIsFinite(SkScalar x) { return sk_float_isfinite(x); }
69
70static inline bool SkScalarsAreFinite(SkScalar a, SkScalar b) {
71 return sk_floats_are_finite(a, b);
72}
73
74static inline bool SkScalarsAreFinite(const SkScalar array[], int count) {
75 return sk_floats_are_finite(array, count);
76}
77
78/** Returns the fractional part of the scalar. */
79static inline SkScalar SkScalarFraction(SkScalar x) {
80 return x - SkScalarTruncToScalar(x);
81}
82
83static inline SkScalar SkScalarSquare(SkScalar x) { return x * x; }
84
85#define SkScalarInvert(x) (SK_Scalar1 / (x))
86#define SkScalarAve(a, b) (((a) + (b)) * SK_ScalarHalf)
87#define SkScalarHalf(a) ((a) * SK_ScalarHalf)
88
89#define SkDegreesToRadians(degrees) ((degrees) * (SK_ScalarPI / 180))
90#define SkRadiansToDegrees(radians) ((radians) * (180 / SK_ScalarPI))
91
92static inline bool SkScalarIsInt(SkScalar x) {
93 return x == SkScalarFloorToScalar(x);
94}
95
96/**
97 * Returns -1 || 0 || 1 depending on the sign of value:
98 * -1 if x < 0
99 * 0 if x == 0
100 * 1 if x > 0
101 */
102static inline int SkScalarSignAsInt(SkScalar x) {
103 return x < 0 ? -1 : (x > 0);
104}
105
106// Scalar result version of above
107static inline SkScalar SkScalarSignAsScalar(SkScalar x) {
108 return x < 0 ? -SK_Scalar1 : ((x > 0) ? SK_Scalar1 : 0);
109}
110
111#define SK_ScalarNearlyZero (SK_Scalar1 / (1 << 12))
112
113static inline bool SkScalarNearlyZero(SkScalar x,
114 SkScalar tolerance = SK_ScalarNearlyZero) {
115 SkASSERT(tolerance >= 0);
116 return SkScalarAbs(x) <= tolerance;
117}
118
119static inline bool SkScalarNearlyEqual(SkScalar x, SkScalar y,
120 SkScalar tolerance = SK_ScalarNearlyZero) {
121 SkASSERT(tolerance >= 0);
122 return SkScalarAbs(x-y) <= tolerance;
123}
124
125#define SK_ScalarSinCosNearlyZero (SK_Scalar1 / (1 << 16))
126
127static inline float SkScalarSinSnapToZero(SkScalar radians) {
128 float v = SkScalarSin(radians);
129 return SkScalarNearlyZero(x: v, SK_ScalarSinCosNearlyZero) ? 0.0f : v;
130}
131
132static inline float SkScalarCosSnapToZero(SkScalar radians) {
133 float v = SkScalarCos(radians);
134 return SkScalarNearlyZero(x: v, SK_ScalarSinCosNearlyZero) ? 0.0f : v;
135}
136
137/** Linearly interpolate between A and B, based on t.
138 If t is 0, return A
139 If t is 1, return B
140 else interpolate.
141 t must be [0..SK_Scalar1]
142*/
143static inline SkScalar SkScalarInterp(SkScalar A, SkScalar B, SkScalar t) {
144 SkASSERT(t >= 0 && t <= SK_Scalar1);
145 return A + (B - A) * t;
146}
147
148/** Interpolate along the function described by (keys[length], values[length])
149 for the passed searchKey. SearchKeys outside the range keys[0]-keys[Length]
150 clamp to the min or max value. This function assumes the number of pairs
151 (length) will be small and a linear search is used.
152
153 Repeated keys are allowed for discontinuous functions (so long as keys is
154 monotonically increasing). If key is the value of a repeated scalar in
155 keys the first one will be used.
156*/
157SkScalar SkScalarInterpFunc(SkScalar searchKey, const SkScalar keys[],
158 const SkScalar values[], int length);
159
160/*
161 * Helper to compare an array of scalars.
162 */
163static inline bool SkScalarsEqual(const SkScalar a[], const SkScalar b[], int n) {
164 SkASSERT(n >= 0);
165 for (int i = 0; i < n; ++i) {
166 if (a[i] != b[i]) {
167 return false;
168 }
169 }
170 return true;
171}
172
173#endif
174

source code of flutter_engine/third_party/skia/include/core/SkScalar.h