BouncingParticle Class Reference

Inheritance diagram for BouncingParticle:

Public Member Functions
	BouncingParticle (SkRandom *random, SkSize stageSize, SkSize particleSize, float maxVelocity)
void	animate (double deltaNanos) override
Public Member Functions inherited from MMObject
virtual	~MMObject ()=default
virtual void	draw (SkCanvas *canvas)=0
virtual void	animate (double)=0

Protected Attributes
SkSize	fStageSize
SkSize	fSize
SkPoint	fPosition
float	fAngle
float	fVelocity
Rotater	fRotater

Detailed Description

Definition at line 664 of file MotionMarkSlide.cpp.

Constructor & Destructor Documentation

BouncingParticle()

BouncingParticle::BouncingParticle ( SkRandom *  random, SkSize  stageSize, SkSize  particleSize, float  maxVelocity  )

inline

Definition at line 666 of file MotionMarkSlide.cpp.

            : fStageSize(stageSize)
            , fSize(particleSize)
            , fPosition(random_position(random,
                                        {stageSize.fWidth - particleSize.fWidth,
                                         stageSize.fHeight - particleSize.fHeight}))
            , fAngle(random_angle(random))
            , fVelocity(random_velocity(random, maxVelocity))
            , fRotater(random_rotater(random)) {
    }

Member Function Documentation

animate()

void BouncingParticle::animate ( double  deltaNanos )

inlineoverridevirtual

Implements MMObject.

Reimplemented in BouncingTaggedImage.

Definition at line 677 of file MotionMarkSlide.cpp.

                                             {
        // TODO: consolidate and pass in millis to the Stages
        constexpr double kMillisPerNano = 0.0000001;
        fPosition += point_on_circle(fAngle, fVelocity * (deltaNanos * kMillisPerNano));
        fRotater.next(deltaNanos * kMillisPerNano);
 
        // If particle is going to move off right side
        if (fPosition.fX + fSize.width() > fStageSize.width()) {
            // If direction is East-South, go West-South.
            if (fAngle >= 0 && fAngle < SK_FloatPI / 2)
                fAngle = SK_FloatPI - fAngle;
            // If angle is East-North, go West-North.
            else if (fAngle > SK_FloatPI / 2 * 3)
                fAngle = fAngle - (fAngle - SK_FloatPI / 2 * 3) * 2;
            // Make sure the particle does not go outside the stage boundaries.
            fPosition.fX = fStageSize.width() - fSize.width();
        }
 
        // If particle is going to move off left side
        if (fPosition.fX < 0) {
            // If angle is West-South, go East-South.
            if (fAngle > SK_FloatPI / 2 && fAngle < SK_FloatPI)
                fAngle = SK_FloatPI - fAngle;
            // If angle is West-North, go East-North.
            else if (fAngle > SK_FloatPI && fAngle < SK_FloatPI / 2 * 3)
                fAngle = fAngle + (SK_FloatPI / 2 * 3 - fAngle) * 2;
            // Make sure the particle does not go outside the stage boundaries.
            fPosition.fX = 0;
        }
 
        // If particle is going to move off bottom side
        if (fPosition.fY + fSize.height() > fStageSize.height()) {
            // If direction is South, go North.
            if (fAngle > 0 && fAngle < SK_FloatPI)
                fAngle = SK_FloatPI * 2 - fAngle;
            // Make sure the particle does not go outside the stage boundaries.
            fPosition.fY = fStageSize.height() - fSize.height();
        }
 
        // If particle is going to move off top side
        if (fPosition.fY < 0) {
            // If direction is North, go South.
            if (fAngle > SK_FloatPI && fAngle < SK_FloatPI * 2)
                fAngle = fAngle - (fAngle - SK_FloatPI) * 2;
            // Make sure the particle does not go outside the stage boundaries.
            fPosition.fY = 0;
        }
    }

Member Data Documentation

fAngle

float BouncingParticle::fAngle

protected

Definition at line 730 of file MotionMarkSlide.cpp.

fPosition

SkPoint BouncingParticle::fPosition

protected

Definition at line 729 of file MotionMarkSlide.cpp.

fRotater

Rotater BouncingParticle::fRotater

protected

Definition at line 732 of file MotionMarkSlide.cpp.

fSize

SkSize BouncingParticle::fSize

protected

Definition at line 728 of file MotionMarkSlide.cpp.

fStageSize

SkSize BouncingParticle::fStageSize

protected

Definition at line 727 of file MotionMarkSlide.cpp.

fVelocity

float BouncingParticle::fVelocity

protected

Definition at line 731 of file MotionMarkSlide.cpp.

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

• third_party/skia/tools/viewer/MotionMarkSlide.cpp