/* * 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 "../private/SkFloatingPoint.h" #undef SK_SCALAR_IS_FLOAT #define SK_SCALAR_IS_FLOAT 1 typedef float SkScalar; #define SK_Scalar1 1.0f #define SK_ScalarHalf 0.5f #define SK_ScalarSqrt2 1.41421356f #define SK_ScalarPI 3.14159265f #define SK_ScalarTanPIOver8 0.414213562f #define SK_ScalarRoot2Over2 0.707106781f #define SK_ScalarMax 3.402823466e+38f #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_floor((x) + 0.5f) #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) #define SK_ScalarMin (-SK_ScalarMax) 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_float_isfinite(a) && sk_float_isfinite(b); } static inline bool SkScalarsAreFinite(const SkScalar array[], int count) { SkScalar prod = 0; for (int i = 0; i < count; ++i) { prod *= array[i]; } // At this point, prod will either be NaN or 0 return prod == 0; // if prod is NaN, this check will return false } /** * Variant of SkScalarRoundToInt, that performs the rounding step (adding 0.5) explicitly using * double, to avoid possibly losing the low bit(s) of the answer before calling floor(). * * This routine will likely be slower than SkScalarRoundToInt(), and should only be used when the * extra precision is known to be valuable. * * In particular, this catches the following case: * SkScalar x = 0.49999997; * int ix = SkScalarRoundToInt(x); * SkASSERT(0 == ix); // <--- fails * ix = SkDScalarRoundToInt(x); * SkASSERT(0 == ix); // <--- succeeds */ static inline int SkDScalarRoundToInt(SkScalar x) { double xx = x; xx += 0.5; return (int)floor(xx); } /** Returns the fractional part of the scalar. */ static inline SkScalar SkScalarFraction(SkScalar x) { return x - SkScalarTruncToScalar(x); } static inline SkScalar SkScalarClampMax(SkScalar x, SkScalar max) { x = SkTMin(x, max); x = SkTMax<SkScalar>(x, 0); return x; } static inline SkScalar SkScalarPin(SkScalar x, SkScalar min, SkScalar max) { return SkTPin(x, min, max); } SkScalar SkScalarSinCos(SkScalar radians, SkScalar* cosValue); 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 SkScalar SkMaxScalar(SkScalar a, SkScalar b) { return a > b ? a : b; } static inline SkScalar SkMinScalar(SkScalar a, SkScalar b) { return a < b ? a : b; } 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; } /** 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