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- /*
- * 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/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 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_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_floats_are_finite(a, b);
- }
- static inline bool SkScalarsAreFinite(const SkScalar array[], int count) {
- return sk_floats_are_finite(array, count);
- }
- /**
- * 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);
- }
- 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;
- }
- static inline float SkScalarSinSnapToZero(SkScalar radians) {
- float v = SkScalarSin(radians);
- return SkScalarNearlyZero(v) ? 0.0f : v;
- }
- static inline float SkScalarCosSnapToZero(SkScalar radians) {
- float v = SkScalarCos(radians);
- return SkScalarNearlyZero(v) ? 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 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
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