PathInterpolator

Kotlin |Java

public class PathInterpolator implements Interpolator

An interpolator that can traverse a Path that extends from Point(0, 0) to (1, 1). The x coordinate along the Path is the input value and the output is the y coordinate of the line at that point. This means that the Path must conform to a function y = f(x).

The Path must not have gaps in the x direction and must not loop back on itself such that there can be two points sharing the same x coordinate. It is alright to have a disjoint line in the vertical direction:

    Path path = new Path();
    path.lineTo(0.25f, 0.25f);
    path.moveTo(0.25f, 0.5f);
    path.lineTo(1f, 1f);

Summary

Public constructors
`PathInterpolator(@NonNull Path path)` Create an interpolator for an arbitrary `Path`.
`PathInterpolator(float controlX, float controlY)` Create an interpolator for a quadratic Bezier curve.
`PathInterpolator( @NonNull Context context, @Nullable AttributeSet attrs, @NonNull XmlPullParser parser )` Create an interpolator from XML.
`PathInterpolator( float controlX1, float controlY1, float controlX2, float controlY2 )` Create an interpolator for a cubic Bezier curve.
`PathInterpolator( @NonNull Resources res, @Nullable Resources.Theme theme, @Nullable AttributeSet attrs, @NonNull XmlPullParser parser )` Create an interpolator from XML.

Public methods
`float`	`getInterpolation(@FloatRange(from = 0, to = 1) float input)` Using the line in the Path in this interpolator that can be described as `y = f(x)`, finds the y coordinate of the line given `t` as the x coordinate.

Public constructors

PathInterpolator

public PathInterpolator(@NonNull Path path)

Create an interpolator for an arbitrary Path. The Path must begin at (0, 0) and end at (1, 1).

Parameters
`@NonNull Path path`	The `Path` to use to make the line representing the interpolator.

PathInterpolator

public PathInterpolator(float controlX, float controlY)

Create an interpolator for a quadratic Bezier curve. The end points (0, 0) and (1, 1) are assumed.

Parameters
`float controlX`	The x coordinate of the quadratic Bezier control point.
`float controlY`	The y coordinate of the quadratic Bezier control point.

PathInterpolator

public PathInterpolator(
    @NonNull Context context,
    @Nullable AttributeSet attrs,
    @NonNull XmlPullParser parser
)

Create an interpolator from XML.

Parameters
`@NonNull Context context`	The context.
`@Nullable AttributeSet attrs`	The AttributeSet for pathInterpolator.
`@NonNull XmlPullParser parser`	The XmlPullParser that was used to create the AttributeSet with `asAttributeSet`.

PathInterpolator

public PathInterpolator(
    float controlX1,
    float controlY1,
    float controlX2,
    float controlY2
)

Create an interpolator for a cubic Bezier curve. The end points (0, 0) and (1, 1) are assumed.

Parameters
`float controlX1`	The x coordinate of the first control point of the cubic Bezier.
`float controlY1`	The y coordinate of the first control point of the cubic Bezier.
`float controlX2`	The x coordinate of the second control point of the cubic Bezier.
`float controlY2`	The y coordinate of the second control point of the cubic Bezier.

PathInterpolator

public PathInterpolator(
    @NonNull Resources res,
    @Nullable Resources.Theme theme,
    @Nullable AttributeSet attrs,
    @NonNull XmlPullParser parser
)

Create an interpolator from XML.

Parameters
`@NonNull Resources res`	The resources.
`@Nullable Resources.Theme theme`	The theme.
`@Nullable AttributeSet attrs`	The AttributeSet for pathInterpolator.
`@NonNull XmlPullParser parser`	The XmlPullParser that was used to create the AttributeSet with `asAttributeSet`.

Public methods

getInterpolation

public float getInterpolation(@FloatRange(from = 0, to = 1) float input)

Using the line in the Path in this interpolator that can be described as y = f(x), finds the y coordinate of the line given t as the x coordinate. Values less than 0 will always return 0 and values greater than 1 will always return 1.

Parameters
`@FloatRange(from = 0, to = 1) float input`	Treated as the x coordinate along the line.

Returns
`float`	The y coordinate of the Path along the line where x = `t`.

See also
`getInterpolation`