basegfx::utils::KeyStopLerp Class Reference

Lerp in a vector of key stops. More...

#include <keystoplerp.hxx>

Public Types
typedef std::pair< std::ptrdiff_t, double >	ResultType

Public Member Functions
	KeyStopLerp (std::vector< double > &&rKeyStops)
	Create lerper with given vector of stops. More...
	KeyStopLerp (const css::uno::Sequence< double > &rKeyStops)
	Create lerper with given sequence of stops. More...
ResultType	lerp (double fAlpha) const
	Find two nearest bucket index & interpolate. More...

Private Attributes
std::vector< double >	maKeyStops
std::ptrdiff_t	mnLastIndex

Detailed Description

Lerp in a vector of key stops.

This class holds a key stop vector and provides the functionality to lerp inside it. Useful e.g. for multi-stop gradients, or the SMIL key time activity.

For those, given a global [0,1] lerp alpha, one need to find the suitable bucket index from key stop vector, and then calculate the relative alpha between the two buckets found.

Definition at line 42 of file keystoplerp.hxx.

Member Typedef Documentation

ResultType

typedef std::pair<std::ptrdiff_t,double> basegfx::utils::KeyStopLerp::ResultType

Definition at line 45 of file keystoplerp.hxx.

Constructor & Destructor Documentation

KeyStopLerp() [1/2]

basegfx::utils::KeyStopLerp::KeyStopLerp ( std::vector< double > &&  rKeyStops )

explicit

Create lerper with given vector of stops.

Parameters

rKeyStops

Vector of stops, must contain at least two elements (though preferably more, otherwise you probably don't need key stop lerping in the first place). All elements must be of monotonically increasing value.

Definition at line 45 of file keystoplerp.cxx.

References maKeyStops, and validateInput().

KeyStopLerp() [2/2]

basegfx::utils::KeyStopLerp::KeyStopLerp ( const css::uno::Sequence< double > &  rKeyStops )

explicit

Create lerper with given sequence of stops.

Parameters

rKeyStops

Sequence of stops, must contain at least two elements (though preferably more, otherwise you probably don't need key stop lerping in the first place). All elements must be of monotonically increasing value.

Member Function Documentation

lerp()

KeyStopLerp::ResultType basegfx::utils::KeyStopLerp::lerp

(

double

fAlpha

)

const

Find two nearest bucket index & interpolate.

Parameters

fAlpha

Find bucket index i, with keyStops[i] < fAlpha <= keyStops[i+1]. Return new alpha value in [0,1), proportional to fAlpha's position between keyStops[i] and keyStops[i+1]

Definition at line 59 of file keystoplerp.cxx.

References maKeyStops, and mnLastIndex.

Member Data Documentation

maKeyStops

std::vector<double> basegfx::utils::KeyStopLerp::maKeyStops

private

Definition at line 80 of file keystoplerp.hxx.

Referenced by KeyStopLerp(), and lerp().

mnLastIndex

std::ptrdiff_t basegfx::utils::KeyStopLerp::mnLastIndex

mutableprivate

Definition at line 81 of file keystoplerp.hxx.

Referenced by lerp().

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The documentation for this class was generated from the following files:

• keystoplerp.hxx
• keystoplerp.cxx