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Diffstat (limited to 'gfx/skia/skia/include/core/SkScalar.h')
| -rw-r--r-- | gfx/skia/skia/include/core/SkScalar.h | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/gfx/skia/skia/include/core/SkScalar.h b/gfx/skia/skia/include/core/SkScalar.h new file mode 100644 index 0000000000..f3e11b34c2 --- /dev/null +++ b/gfx/skia/skia/include/core/SkScalar.h @@ -0,0 +1,173 @@ +/* + * Copyright 2006 The Android Open Source Project + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#ifndef SkScalar_DEFINED +#define SkScalar_DEFINED + +#include "include/private/base/SkAssert.h" +#include "include/private/base/SkFloatingPoint.h" + +typedef float SkScalar; + +#define SK_Scalar1 1.0f +#define SK_ScalarHalf 0.5f +#define SK_ScalarSqrt2 SK_FloatSqrt2 +#define SK_ScalarPI SK_FloatPI +#define SK_ScalarTanPIOver8 0.414213562f +#define SK_ScalarRoot2Over2 0.707106781f +#define SK_ScalarMax 3.402823466e+38f +#define SK_ScalarMin (-SK_ScalarMax) +#define SK_ScalarInfinity SK_FloatInfinity +#define SK_ScalarNegativeInfinity SK_FloatNegativeInfinity +#define SK_ScalarNaN SK_FloatNaN + +#define SkScalarFloorToScalar(x) sk_float_floor(x) +#define SkScalarCeilToScalar(x) sk_float_ceil(x) +#define SkScalarRoundToScalar(x) sk_float_round(x) +#define SkScalarTruncToScalar(x) sk_float_trunc(x) + +#define SkScalarFloorToInt(x) sk_float_floor2int(x) +#define SkScalarCeilToInt(x) sk_float_ceil2int(x) +#define SkScalarRoundToInt(x) sk_float_round2int(x) + +#define SkScalarAbs(x) sk_float_abs(x) +#define SkScalarCopySign(x, y) sk_float_copysign(x, y) +#define SkScalarMod(x, y) sk_float_mod(x,y) +#define SkScalarSqrt(x) sk_float_sqrt(x) +#define SkScalarPow(b, e) sk_float_pow(b, e) + +#define SkScalarSin(radians) (float)sk_float_sin(radians) +#define SkScalarCos(radians) (float)sk_float_cos(radians) +#define SkScalarTan(radians) (float)sk_float_tan(radians) +#define SkScalarASin(val) (float)sk_float_asin(val) +#define SkScalarACos(val) (float)sk_float_acos(val) +#define SkScalarATan2(y, x) (float)sk_float_atan2(y,x) +#define SkScalarExp(x) (float)sk_float_exp(x) +#define SkScalarLog(x) (float)sk_float_log(x) +#define SkScalarLog2(x) (float)sk_float_log2(x) + +////////////////////////////////////////////////////////////////////////////////////////////////// + +#define SkIntToScalar(x) static_cast<SkScalar>(x) +#define SkIntToFloat(x) static_cast<float>(x) +#define SkScalarTruncToInt(x) sk_float_saturate2int(x) + +#define SkScalarToFloat(x) static_cast<float>(x) +#define SkFloatToScalar(x) static_cast<SkScalar>(x) +#define SkScalarToDouble(x) static_cast<double>(x) +#define SkDoubleToScalar(x) sk_double_to_float(x) + +static inline bool SkScalarIsNaN(SkScalar x) { return x != x; } + +/** Returns true if x is not NaN and not infinite + */ +static inline bool SkScalarIsFinite(SkScalar x) { return sk_float_isfinite(x); } + +static inline bool SkScalarsAreFinite(SkScalar a, SkScalar b) { + return sk_floats_are_finite(a, b); +} + +static inline bool SkScalarsAreFinite(const SkScalar array[], int count) { + return sk_floats_are_finite(array, count); +} + +/** Returns the fractional part of the scalar. */ +static inline SkScalar SkScalarFraction(SkScalar x) { + return x - SkScalarTruncToScalar(x); +} + +static inline SkScalar SkScalarSquare(SkScalar x) { return x * x; } + +#define SkScalarInvert(x) sk_ieee_float_divide_TODO_IS_DIVIDE_BY_ZERO_SAFE_HERE(SK_Scalar1, (x)) +#define SkScalarAve(a, b) (((a) + (b)) * SK_ScalarHalf) +#define SkScalarHalf(a) ((a) * SK_ScalarHalf) + +#define SkDegreesToRadians(degrees) ((degrees) * (SK_ScalarPI / 180)) +#define SkRadiansToDegrees(radians) ((radians) * (180 / SK_ScalarPI)) + +static inline bool SkScalarIsInt(SkScalar x) { + return x == SkScalarFloorToScalar(x); +} + +/** + * Returns -1 || 0 || 1 depending on the sign of value: + * -1 if x < 0 + * 0 if x == 0 + * 1 if x > 0 + */ +static inline int SkScalarSignAsInt(SkScalar x) { + return x < 0 ? -1 : (x > 0); +} + +// Scalar result version of above +static inline SkScalar SkScalarSignAsScalar(SkScalar x) { + return x < 0 ? -SK_Scalar1 : ((x > 0) ? SK_Scalar1 : 0); +} + +#define SK_ScalarNearlyZero (SK_Scalar1 / (1 << 12)) + +static inline bool SkScalarNearlyZero(SkScalar x, + SkScalar tolerance = SK_ScalarNearlyZero) { + SkASSERT(tolerance >= 0); + return SkScalarAbs(x) <= tolerance; +} + +static inline bool SkScalarNearlyEqual(SkScalar x, SkScalar y, + SkScalar tolerance = SK_ScalarNearlyZero) { + SkASSERT(tolerance >= 0); + return SkScalarAbs(x-y) <= tolerance; +} + +#define SK_ScalarSinCosNearlyZero (SK_Scalar1 / (1 << 16)) + +static inline float SkScalarSinSnapToZero(SkScalar radians) { + float v = SkScalarSin(radians); + return SkScalarNearlyZero(v, SK_ScalarSinCosNearlyZero) ? 0.0f : v; +} + +static inline float SkScalarCosSnapToZero(SkScalar radians) { + float v = SkScalarCos(radians); + return SkScalarNearlyZero(v, SK_ScalarSinCosNearlyZero) ? 0.0f : v; +} + +/** Linearly interpolate between A and B, based on t. + If t is 0, return A + If t is 1, return B + else interpolate. + t must be [0..SK_Scalar1] +*/ +static inline SkScalar SkScalarInterp(SkScalar A, SkScalar B, SkScalar t) { + SkASSERT(t >= 0 && t <= SK_Scalar1); + return A + (B - A) * t; +} + +/** Interpolate along the function described by (keys[length], values[length]) + for the passed searchKey. SearchKeys outside the range keys[0]-keys[Length] + clamp to the min or max value. This function assumes the number of pairs + (length) will be small and a linear search is used. + + Repeated keys are allowed for discontinuous functions (so long as keys is + monotonically increasing). If key is the value of a repeated scalar in + keys the first one will be used. +*/ +SkScalar SkScalarInterpFunc(SkScalar searchKey, const SkScalar keys[], + const SkScalar values[], int length); + +/* + * Helper to compare an array of scalars. + */ +static inline bool SkScalarsEqual(const SkScalar a[], const SkScalar b[], int n) { + SkASSERT(n >= 0); + for (int i = 0; i < n; ++i) { + if (a[i] != b[i]) { + return false; + } + } + return true; +} + +#endif |