diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/include/core/SkScalar.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gfx/skia/trunk/include/core/SkScalar.h Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,234 @@ +/* + * 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 "SkFixed.h" +#include "SkFloatingPoint.h" + +//#define SK_SUPPORT_DEPRECATED_SCALARROUND + +typedef float SkScalar; + +/** SK_Scalar1 is defined to be 1.0 represented as an SkScalar +*/ +#define SK_Scalar1 (1.0f) +/** SK_Scalar1 is defined to be 1/2 represented as an SkScalar +*/ +#define SK_ScalarHalf (0.5f) +/** SK_ScalarInfinity is defined to be infinity as an SkScalar +*/ +#define SK_ScalarInfinity SK_FloatInfinity +/** SK_ScalarNegativeInfinity is defined to be negative infinity as an SkScalar +*/ +#define SK_ScalarNegativeInfinity SK_FloatNegativeInfinity +/** SK_ScalarMax is defined to be the largest value representable as an SkScalar +*/ +#define SK_ScalarMax (3.402823466e+38f) +/** SK_ScalarMin is defined to be the smallest value representable as an SkScalar +*/ +#define SK_ScalarMin (-SK_ScalarMax) +/** SK_ScalarNaN is defined to be 'Not a Number' as an SkScalar +*/ +#define SK_ScalarNaN SK_FloatNaN +/** SkScalarIsNaN(n) returns true if argument is not a number +*/ +static inline bool SkScalarIsNaN(float x) { return x != x; } + +/** Returns true if x is not NaN and not infinite */ +static inline bool SkScalarIsFinite(float x) { + // We rely on the following behavior of infinities and nans + // 0 * finite --> 0 + // 0 * infinity --> NaN + // 0 * NaN --> NaN + float prod = x * 0; + // At this point, prod will either be NaN or 0 + // Therefore we can return (prod == prod) or (0 == prod). + return prod == prod; +} + +/** SkIntToScalar(n) returns its integer argument as an SkScalar +*/ +#define SkIntToScalar(n) ((float)(n)) +/** SkFixedToScalar(n) returns its SkFixed argument as an SkScalar +*/ +#define SkFixedToScalar(x) SkFixedToFloat(x) +/** SkScalarToFixed(n) returns its SkScalar argument as an SkFixed +*/ +#define SkScalarToFixed(x) SkFloatToFixed(x) + +#define SkScalarToFloat(n) (n) +#ifndef SK_SCALAR_TO_FLOAT_EXCLUDED +#define SkFloatToScalar(n) (n) +#endif + +#define SkScalarToDouble(n) (double)(n) +#define SkDoubleToScalar(n) (float)(n) + +/** SkScalarFraction(x) returns the signed fractional part of the argument +*/ +#define SkScalarFraction(x) sk_float_mod(x, 1.0f) + +#define SkScalarFloorToScalar(x) sk_float_floor(x) +#define SkScalarCeilToScalar(x) sk_float_ceil(x) +#define SkScalarRoundToScalar(x) sk_float_floor((x) + 0.5f) + +#define SkScalarFloorToInt(x) sk_float_floor2int(x) +#define SkScalarCeilToInt(x) sk_float_ceil2int(x) +#define SkScalarRoundToInt(x) sk_float_round2int(x) +#define SkScalarTruncToInt(x) static_cast(x) + +/** Returns the absolute value of the specified SkScalar +*/ +#define SkScalarAbs(x) sk_float_abs(x) +/** Return x with the sign of y + */ +#define SkScalarCopySign(x, y) sk_float_copysign(x, y) +/** Returns the value pinned between 0 and max inclusive +*/ +inline SkScalar SkScalarClampMax(SkScalar x, SkScalar max) { + return x < 0 ? 0 : x > max ? max : x; +} +/** Returns the value pinned between min and max inclusive +*/ +inline SkScalar SkScalarPin(SkScalar x, SkScalar min, SkScalar max) { + return x < min ? min : x > max ? max : x; +} +/** Returns the specified SkScalar squared (x*x) +*/ +inline SkScalar SkScalarSquare(SkScalar x) { return x * x; } +/** Returns the product of two SkScalars +*/ +#define SkScalarMul(a, b) ((float)(a) * (b)) +/** Returns the product of two SkScalars plus a third SkScalar +*/ +#define SkScalarMulAdd(a, b, c) ((float)(a) * (b) + (c)) +/** Returns the quotient of two SkScalars (a/b) +*/ +#define SkScalarDiv(a, b) ((float)(a) / (b)) +/** Returns the mod of two SkScalars (a mod b) +*/ +#define SkScalarMod(x,y) sk_float_mod(x,y) +/** Returns the product of the first two arguments, divided by the third argument +*/ +#define SkScalarMulDiv(a, b, c) ((float)(a) * (b) / (c)) +/** Returns the multiplicative inverse of the SkScalar (1/x) +*/ +#define SkScalarInvert(x) (SK_Scalar1 / (x)) +#define SkScalarFastInvert(x) (SK_Scalar1 / (x)) +/** Returns the square root of the SkScalar +*/ +#define SkScalarSqrt(x) sk_float_sqrt(x) +/** Returns b to the e +*/ +#define SkScalarPow(b, e) sk_float_pow(b, e) +/** Returns the average of two SkScalars (a+b)/2 +*/ +#define SkScalarAve(a, b) (((a) + (b)) * 0.5f) +/** Returns one half of the specified SkScalar +*/ +#define SkScalarHalf(a) ((a) * 0.5f) + +#define SK_ScalarSqrt2 1.41421356f +#define SK_ScalarPI 3.14159265f +#define SK_ScalarTanPIOver8 0.414213562f +#define SK_ScalarRoot2Over2 0.707106781f + +#define SkDegreesToRadians(degrees) ((degrees) * (SK_ScalarPI / 180)) +#define SkRadiansToDegrees(radians) ((radians) * (180 / SK_ScalarPI)) +float SkScalarSinCos(SkScalar radians, SkScalar* cosValue); +#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) + +inline SkScalar SkMaxScalar(SkScalar a, SkScalar b) { return a > b ? a : b; } +inline SkScalar SkMinScalar(SkScalar a, SkScalar b) { return a < b ? a : b; } + +static inline bool SkScalarIsInt(SkScalar x) { + return x == (float)(int)x; +} + +// DEPRECATED : use ToInt or ToScalar variant +#ifdef SK_SUPPORT_DEPRECATED_SCALARROUND +# define SkScalarFloor(x) SkScalarFloorToInt(x) +# define SkScalarCeil(x) SkScalarCeilToInt(x) +# define SkScalarRound(x) SkScalarRoundToInt(x) +#endif + +/** + * 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; +} + +/** 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 was inspired by a desire + to change the multiplier for thickness in fakeBold; therefore it 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), and if key is the value of a repeated scalar in + keys, the first one will be used. However, that may change if a binary + search is 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