158 lines
6.4 KiB
Java
158 lines
6.4 KiB
Java
|
package androidx.dynamicanimation.animation;
|
||
|
|
||
|
import androidx.annotation.FloatRange;
|
||
|
import androidx.annotation.RestrictTo;
|
||
|
import androidx.dynamicanimation.animation.DynamicAnimation;
|
||
|
public final class SpringForce implements Force {
|
||
|
public static final float DAMPING_RATIO_HIGH_BOUNCY = 0.2f;
|
||
|
public static final float DAMPING_RATIO_LOW_BOUNCY = 0.75f;
|
||
|
public static final float DAMPING_RATIO_MEDIUM_BOUNCY = 0.5f;
|
||
|
public static final float DAMPING_RATIO_NO_BOUNCY = 1.0f;
|
||
|
public static final float STIFFNESS_HIGH = 10000.0f;
|
||
|
public static final float STIFFNESS_LOW = 200.0f;
|
||
|
public static final float STIFFNESS_MEDIUM = 1500.0f;
|
||
|
public static final float STIFFNESS_VERY_LOW = 50.0f;
|
||
|
private static final double UNSET = Double.MAX_VALUE;
|
||
|
private static final double VELOCITY_THRESHOLD_MULTIPLIER = 62.5d;
|
||
|
private double mDampedFreq;
|
||
|
public double mDampingRatio = 0.5d;
|
||
|
private double mFinalPosition = Double.MAX_VALUE;
|
||
|
private double mGammaMinus;
|
||
|
private double mGammaPlus;
|
||
|
private boolean mInitialized = false;
|
||
|
private final DynamicAnimation.MassState mMassState = new DynamicAnimation.MassState();
|
||
|
public double mNaturalFreq = Math.sqrt(1500.0d);
|
||
|
private double mValueThreshold;
|
||
|
private double mVelocityThreshold;
|
||
|
|
||
|
public SpringForce() {
|
||
|
}
|
||
|
|
||
|
public SpringForce(float f) {
|
||
|
this.mFinalPosition = (double) f;
|
||
|
}
|
||
|
|
||
|
private void init() {
|
||
|
if (!this.mInitialized) {
|
||
|
if (this.mFinalPosition != Double.MAX_VALUE) {
|
||
|
double d = this.mDampingRatio;
|
||
|
if (d > 1.0d) {
|
||
|
double d2 = this.mNaturalFreq;
|
||
|
this.mGammaPlus = (Math.sqrt((d * d) - 1.0d) * d2) + ((-d) * d2);
|
||
|
double d3 = this.mDampingRatio;
|
||
|
double d4 = this.mNaturalFreq;
|
||
|
this.mGammaMinus = ((-d3) * d4) - (Math.sqrt((d3 * d3) - 1.0d) * d4);
|
||
|
} else if (d >= 0.0d && d < 1.0d) {
|
||
|
this.mDampedFreq = Math.sqrt(1.0d - (d * d)) * this.mNaturalFreq;
|
||
|
}
|
||
|
this.mInitialized = true;
|
||
|
return;
|
||
|
}
|
||
|
throw new IllegalStateException("Error: Final position of the spring must be set before the animation starts");
|
||
|
}
|
||
|
}
|
||
|
|
||
|
@Override // androidx.dynamicanimation.animation.Force
|
||
|
@RestrictTo({RestrictTo.Scope.LIBRARY})
|
||
|
public float getAcceleration(float f, float f2) {
|
||
|
float finalPosition = f - getFinalPosition();
|
||
|
double d = this.mNaturalFreq;
|
||
|
return (float) (((-(d * d)) * ((double) finalPosition)) - (((d * 2.0d) * this.mDampingRatio) * ((double) f2)));
|
||
|
}
|
||
|
|
||
|
public float getDampingRatio() {
|
||
|
return (float) this.mDampingRatio;
|
||
|
}
|
||
|
|
||
|
public float getFinalPosition() {
|
||
|
return (float) this.mFinalPosition;
|
||
|
}
|
||
|
|
||
|
public float getStiffness() {
|
||
|
double d = this.mNaturalFreq;
|
||
|
return (float) (d * d);
|
||
|
}
|
||
|
|
||
|
@Override // androidx.dynamicanimation.animation.Force
|
||
|
@RestrictTo({RestrictTo.Scope.LIBRARY})
|
||
|
public boolean isAtEquilibrium(float f, float f2) {
|
||
|
return ((double) Math.abs(f2)) < this.mVelocityThreshold && ((double) Math.abs(f - getFinalPosition())) < this.mValueThreshold;
|
||
|
}
|
||
|
|
||
|
public SpringForce setDampingRatio(@FloatRange(from = 0.0d) float f) {
|
||
|
if (f >= 0.0f) {
|
||
|
this.mDampingRatio = (double) f;
|
||
|
this.mInitialized = false;
|
||
|
return this;
|
||
|
}
|
||
|
throw new IllegalArgumentException("Damping ratio must be non-negative");
|
||
|
}
|
||
|
|
||
|
public SpringForce setFinalPosition(float f) {
|
||
|
this.mFinalPosition = (double) f;
|
||
|
return this;
|
||
|
}
|
||
|
|
||
|
public SpringForce setStiffness(@FloatRange(from = 0.0d, fromInclusive = false) float f) {
|
||
|
if (f > 0.0f) {
|
||
|
this.mNaturalFreq = Math.sqrt((double) f);
|
||
|
this.mInitialized = false;
|
||
|
return this;
|
||
|
}
|
||
|
throw new IllegalArgumentException("Spring stiffness constant must be positive.");
|
||
|
}
|
||
|
|
||
|
public void setValueThreshold(double d) {
|
||
|
double abs = Math.abs(d);
|
||
|
this.mValueThreshold = abs;
|
||
|
this.mVelocityThreshold = abs * 62.5d;
|
||
|
}
|
||
|
|
||
|
public DynamicAnimation.MassState updateValues(double d, double d2, long j) {
|
||
|
double d3;
|
||
|
double d4;
|
||
|
init();
|
||
|
double d5 = ((double) j) / 1000.0d;
|
||
|
double d6 = d - this.mFinalPosition;
|
||
|
double d7 = this.mDampingRatio;
|
||
|
if (d7 > 1.0d) {
|
||
|
double d8 = this.mGammaMinus;
|
||
|
double d9 = this.mGammaPlus;
|
||
|
double d10 = d6 - (((d8 * d6) - d2) / (d8 - d9));
|
||
|
double d11 = ((d6 * d8) - d2) / (d8 - d9);
|
||
|
d3 = (Math.pow(2.718281828459045d, this.mGammaPlus * d5) * d11) + (Math.pow(2.718281828459045d, d8 * d5) * d10);
|
||
|
double d12 = this.mGammaMinus;
|
||
|
double pow = Math.pow(2.718281828459045d, d12 * d5) * d10 * d12;
|
||
|
double d13 = this.mGammaPlus;
|
||
|
d4 = (Math.pow(2.718281828459045d, d13 * d5) * d11 * d13) + pow;
|
||
|
} else if (d7 == 1.0d) {
|
||
|
double d14 = this.mNaturalFreq;
|
||
|
double d15 = (d14 * d6) + d2;
|
||
|
double d16 = (d15 * d5) + d6;
|
||
|
double pow2 = Math.pow(2.718281828459045d, (-d14) * d5) * d16;
|
||
|
double pow3 = Math.pow(2.718281828459045d, (-this.mNaturalFreq) * d5) * d16;
|
||
|
double d17 = this.mNaturalFreq;
|
||
|
d4 = (Math.pow(2.718281828459045d, (-d17) * d5) * d15) + (pow3 * (-d17));
|
||
|
d3 = pow2;
|
||
|
} else {
|
||
|
double d18 = 1.0d / this.mDampedFreq;
|
||
|
double d19 = this.mNaturalFreq;
|
||
|
double d20 = ((d7 * d19 * d6) + d2) * d18;
|
||
|
double sin = ((Math.sin(this.mDampedFreq * d5) * d20) + (Math.cos(this.mDampedFreq * d5) * d6)) * Math.pow(2.718281828459045d, (-d7) * d19 * d5);
|
||
|
double d21 = this.mNaturalFreq;
|
||
|
double d22 = this.mDampingRatio;
|
||
|
double d23 = (-d21) * sin * d22;
|
||
|
double pow4 = Math.pow(2.718281828459045d, (-d22) * d21 * d5);
|
||
|
double d24 = this.mDampedFreq;
|
||
|
double d25 = (-d24) * d6;
|
||
|
double d26 = this.mDampedFreq;
|
||
|
d4 = (((Math.cos(d26 * d5) * d20 * d26) + (Math.sin(d24 * d5) * d25)) * pow4) + d23;
|
||
|
d3 = sin;
|
||
|
}
|
||
|
DynamicAnimation.MassState massState = this.mMassState;
|
||
|
massState.mValue = (float) (d3 + this.mFinalPosition);
|
||
|
massState.mVelocity = (float) d4;
|
||
|
return massState;
|
||
|
}
|
||
|
}
|