SkScalar.h File Reference

#include "include/private/SkFloatingPoint.h"

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Macros
#define	SK_SCALAR_IS_FLOAT   1
#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)
#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))
#define	SK_ScalarNearlyZero   (SK_Scalar1 / (1 << 12))

Typedefs
typedef float	SkScalar

Functions
static bool	SkScalarIsNaN (SkScalar x)
static bool	SkScalarIsFinite (SkScalar x)
	Returns true if x is not NaN and not infinite. More...
static bool	SkScalarsAreFinite (SkScalar a, SkScalar b)
static bool	SkScalarsAreFinite (const SkScalar array[], int count)
static int	SkDScalarRoundToInt (SkScalar x)
	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(). More...
static SkScalar	SkScalarFraction (SkScalar x)
	Returns the fractional part of the scalar. More...
static SkScalar	SkScalarSquare (SkScalar x)
static bool	SkScalarIsInt (SkScalar x)
static int	SkScalarSignAsInt (SkScalar x)
	Returns -1 || 0 || 1 depending on the sign of value: -1 if x < 0 0 if x == 0 1 if x > 0. More...
static SkScalar	SkScalarSignAsScalar (SkScalar x)
static bool	SkScalarNearlyZero (SkScalar x, SkScalar tolerance=SK_ScalarNearlyZero)
static bool	SkScalarNearlyEqual (SkScalar x, SkScalar y, SkScalar tolerance=SK_ScalarNearlyZero)
static float	SkScalarSinSnapToZero (SkScalar radians)
static float	SkScalarCosSnapToZero (SkScalar radians)
static SkScalar	SkScalarInterp (SkScalar A, SkScalar B, SkScalar t)
	Linearly interpolate between A and B, based on t. More...
SkScalar	SkScalarInterpFunc (SkScalar searchKey, const SkScalar keys[], const SkScalar values[], int length)
	Interpolate along the function described by (keys[length], values[length]) for the passed searchKey. More...
static bool	SkScalarsEqual (const SkScalar a[], const SkScalar b[], int n)

Macro Definition Documentation

SK_Scalar1

#define SK_Scalar1   1.0f

SK_SCALAR_IS_FLOAT

#define SK_SCALAR_IS_FLOAT   1

SK_ScalarHalf

#define SK_ScalarHalf   0.5f

SK_ScalarInfinity

#define SK_ScalarInfinity   SK_FloatInfinity

SK_ScalarMax

#define SK_ScalarMax   3.402823466e+38f

SK_ScalarMin

#define SK_ScalarMin   (-SK_ScalarMax)

SK_ScalarNaN

#define SK_ScalarNaN   SK_FloatNaN

SK_ScalarNearlyZero

#define SK_ScalarNearlyZero   (SK_Scalar1 / (1 << 12))

SK_ScalarNegativeInfinity

#define SK_ScalarNegativeInfinity   SK_FloatNegativeInfinity

SK_ScalarPI

#define SK_ScalarPI   SK_FloatPI

SK_ScalarRoot2Over2

#define SK_ScalarRoot2Over2   0.707106781f

SK_ScalarSqrt2

#define SK_ScalarSqrt2   SK_FloatSqrt2

SK_ScalarTanPIOver8

#define SK_ScalarTanPIOver8   0.414213562f

SkDegreesToRadians

#define SkDegreesToRadians

(

degrees

)

((degrees) * (SK_ScalarPI / 180))

SkDoubleToScalar

#define SkDoubleToScalar

(

x

)

sk_double_to_float(x)

SkFloatToScalar

#define SkFloatToScalar

(

x

)

static_cast<SkScalar>(x)

SkIntToFloat

#define SkIntToFloat

(

x

)

static_cast<float>(x)

SkIntToScalar

#define SkIntToScalar

(

x

)

static_cast<SkScalar>(x)

SkRadiansToDegrees

#define SkRadiansToDegrees

(

radians

)

((radians) * (180 / SK_ScalarPI))

SkScalarAbs

#define SkScalarAbs

(

x

)

sk_float_abs(x)

SkScalarACos

#define SkScalarACos

(

val

)

(float)sk_float_acos(val)

SkScalarASin

#define SkScalarASin

(

val

)

(float)sk_float_asin(val)

SkScalarATan2

#define SkScalarATan2	(		y,
			x
	)		(float)sk_float_atan2(y,x)

SkScalarAve

#define SkScalarAve	(		a,
			b
	)		(((a) + (b)) * SK_ScalarHalf)

SkScalarCeilToInt

#define SkScalarCeilToInt

(

x

)

sk_float_ceil2int(x)

SkScalarCeilToScalar

#define SkScalarCeilToScalar

(

x

)

sk_float_ceil(x)

SkScalarCopySign

#define SkScalarCopySign	(		x,
			y
	)		sk_float_copysign(x, y)

SkScalarCos

#define SkScalarCos

(

radians

)

(float)sk_float_cos(radians)

SkScalarExp

#define SkScalarExp

(

x

)

(float)sk_float_exp(x)

SkScalarFloorToInt

#define SkScalarFloorToInt

(

x

)

sk_float_floor2int(x)

SkScalarFloorToScalar

#define SkScalarFloorToScalar

(

x

)

sk_float_floor(x)

SkScalarHalf

#define SkScalarHalf

(

a

)

((a) * SK_ScalarHalf)

SkScalarInvert

#define SkScalarInvert

(

x

)

sk_ieee_float_divide_TODO_IS_DIVIDE_BY_ZERO_SAFE_HERE(SK_Scalar1, (x))

SkScalarLog

#define SkScalarLog

(

x

)

(float)sk_float_log(x)

SkScalarLog2

#define SkScalarLog2

(

x

)

(float)sk_float_log2(x)

SkScalarMod

#define SkScalarMod	(		x,
			y
	)		sk_float_mod(x,y)

SkScalarPow

#define SkScalarPow	(		b,
			e
	)		sk_float_pow(b, e)

SkScalarRoundToInt

#define SkScalarRoundToInt

(

x

)

sk_float_round2int(x)

SkScalarRoundToScalar

#define SkScalarRoundToScalar

(

x

)

sk_float_floor((x) + 0.5f)

SkScalarSin

#define SkScalarSin

(

radians

)

(float)sk_float_sin(radians)

SkScalarSqrt

#define SkScalarSqrt

(

x

)

sk_float_sqrt(x)

SkScalarTan

#define SkScalarTan

(

radians

)

(float)sk_float_tan(radians)

SkScalarToDouble

#define SkScalarToDouble

(

x

)

static_cast<double>(x)

SkScalarToFloat

#define SkScalarToFloat

(

x

)

static_cast<float>(x)

SkScalarTruncToInt

#define SkScalarTruncToInt

(

x

)

sk_float_saturate2int(x)

SkScalarTruncToScalar

#define SkScalarTruncToScalar

(

x

)

sk_float_trunc(x)

Typedef Documentation

SkScalar

typedef float SkScalar

Function Documentation

SkDScalarRoundToInt()

static int SkDScalarRoundToInt ( SkScalar  x )

inlinestatic

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

SkScalarCosSnapToZero()

static float SkScalarCosSnapToZero ( SkScalar  radians )

inlinestatic

SkScalarFraction()

static SkScalar SkScalarFraction ( SkScalar  x )

inlinestatic

Returns the fractional part of the scalar.

SkScalarInterp()

static SkScalar SkScalarInterp ( SkScalar  A, SkScalar  B, SkScalar  t  )

inlinestatic

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]

SkScalarInterpFunc()

SkScalar SkScalarInterpFunc	(	SkScalar	searchKey,
		const SkScalar	keys[],
		const SkScalar	values[],
		int	length
	)

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.

SkScalarIsFinite()

static bool SkScalarIsFinite ( SkScalar  x )

inlinestatic

Returns true if x is not NaN and not infinite.

SkScalarIsInt()

static bool SkScalarIsInt ( SkScalar  x )

inlinestatic

SkScalarIsNaN()

static bool SkScalarIsNaN ( SkScalar  x )

inlinestatic

SkScalarNearlyEqual()

static bool SkScalarNearlyEqual ( SkScalar  x, SkScalar  y, SkScalar  tolerance = SK_ScalarNearlyZero  )

inlinestatic

SkScalarNearlyZero()

static bool SkScalarNearlyZero ( SkScalar  x, SkScalar  tolerance = SK_ScalarNearlyZero  )

inlinestatic

SkScalarsAreFinite() [1/2]

static bool SkScalarsAreFinite ( const SkScalar  array[], int  count  )

inlinestatic

SkScalarsAreFinite() [2/2]

static bool SkScalarsAreFinite ( SkScalar  a, SkScalar  b  )

inlinestatic

SkScalarsEqual()

static bool SkScalarsEqual ( const SkScalar  a[], const SkScalar  b[], int  n  )

inlinestatic

SkScalarSignAsInt()

static int SkScalarSignAsInt ( SkScalar  x )

inlinestatic

Returns -1 || 0 || 1 depending on the sign of value: -1 if x < 0 0 if x == 0 1 if x > 0.

SkScalarSignAsScalar()

static SkScalar SkScalarSignAsScalar ( SkScalar  x )

inlinestatic

SkScalarSinSnapToZero()

static float SkScalarSinSnapToZero ( SkScalar  radians )

inlinestatic

SkScalarSquare()

static SkScalar SkScalarSquare ( SkScalar  x )

inlinestatic