ImmutableAffineTransform

public final class ImmutableAffineTransform extends AffineTransform

java.lang.Object
   ↳ androidx.ink.geometry.AffineTransform
     ↳ androidx.ink.geometry.ImmutableAffineTransform

An affine transformation in the plane. The transformation can be thought of as a 3x3 matrix:

⎡m00  m10  m20⎤
⎢m01  m11  m21⎥
⎣ 0    0    1 ⎦

Applying the transformation can be thought of as a matrix multiplication, with the to-be-transformed point represented as a column vector with an extra 1:

⎡m00  m10  m20⎤   ⎡x⎤   ⎡m00*x + m10*y + m20⎤
⎢m01  m11  m21⎥ * ⎢y⎥ = ⎢m01*x + m11*y + m21⎥
⎣ 0    0    1 ⎦   ⎣1⎦   ⎣         1         ⎦

Transformations are composed via multiplication. Multiplication is not commutative (i.e. AB != BA), and the left-hand transformation is composed "after" the right hand transformation. E.g., if you have:

val rotate = ImmutableAffineTransform.rotate(Angle.degreesToRadians(45))
val translate = ImmutableAffineTransform.translate(Vec(10, 0))

then rotate * translate first translates 10 units in the positive x-direction, then rotates 45° about the origin.

See MutableAffineTransform for mutable alternative to this class.

Summary

Nested types

Public constructors
ImmutableAffineTransform(@Size(min = 6) @NonNull float[] values)

Like the primary constructor, but accepts a FloatArray instead of individual Float values.
ImmutableAffineTransform(
    float m00,
    float m10,
    float m20,
    float m01,
    float m11,
    float m21
)

Constructs this transform with 6 float values, starting with the top left corner of the matrix and proceeding in row-major order.

Public methods
boolean
equals(Object other)

Component-wise equality operator for ImmutableAffineTransform.
int
static final @NonNull ImmutableAffineTransform
rotate(@AngleRadiansFloat float angleOfRotation)

Returns a transformation that rotates by the given angle, centered about the origin.
static final @NonNull ImmutableAffineTransform
scale(float scaleFactor)

Returns a transformation that scales in both the x- and y-direction by the given scaleFactor, centered about the origin.
static final @NonNull ImmutableAffineTransform
scale(float xScaleFactor, float yScaleFactor)

Returns a transformation that scales in both the x- and y-direction by the given pair of factors; xScaleFactor and yScaleFactor respectively, centered about the origin.
static final @NonNull ImmutableAffineTransform
scaleX(float scaleFactor)

Returns a transformation that scales in the x-direction by the given factor, centered about the origin.
static final @NonNull ImmutableAffineTransform
scaleY(float scaleFactor)

Returns a transformation that scales in the y-direction by the given factor, centered about the origin.
static final @NonNull ImmutableAffineTransform
shearX(float shearFactor)

Returns a transformation that shears in the x-direction by the given factor.
static final @NonNull ImmutableAffineTransform
shearY(float shearFactor)

Returns a transformation that shears in the y-direction by the given factor.
@NonNull String
static final @NonNull ImmutableAffineTransform

Returns a transformation that translates by the given offset vector.

Inherited methods
From androidx.ink.geometry.AffineTransform
final @NonNull ImmutableParallelogram

Returns an ImmutableParallelogram containing the result of applying the AffineTransform to box.
final @NonNull ImmutableParallelogram

Returns an ImmutableParallelogram containing the result of applying the AffineTransform to parallelogram.
final @NonNull ImmutableVec

Returns an ImmutableVec containing the result of applying the AffineTransform to point.
final @NonNull ImmutableSegment

Returns an ImmutableSegment containing the result of applying the AffineTransform to segment.
final @NonNull ImmutableTriangle

Returns an ImmutableTriangle containing the result of applying the AffineTransform to triangle.
final @NonNull MutableParallelogram
applyTransform(
    @NonNull Box box,
    @NonNull MutableParallelogram outParallelogram
)

Apply the AffineTransform to the Box and store the result in the MutableParallelogram.
final @NonNull MutableParallelogram
applyTransform(
    @NonNull Parallelogram parallelogram,
    @NonNull MutableParallelogram outParallelogram
)

Apply the AffineTransform to the Parallelogram and store the result in the MutableParallelogram.
final @NonNull MutableVec

Apply the AffineTransform to the Vec and store the result in the MutableVec.
final @NonNull MutableSegment
applyTransform(
    @NonNull Segment segment,
    @NonNull MutableSegment outSegment
)

Apply the AffineTransform to the Segment and store the result in the MutableSegment.
final @NonNull MutableTriangle
applyTransform(
    @NonNull Triangle triangle,
    @NonNull MutableTriangle outTriangle
)

Apply the AffineTransform to the Triangle and store the result in the MutableTriangle.
final @NonNull ImmutableAffineTransform

Returns the inverse of the AffineTransform.
final @NonNull MutableAffineTransform

Populates outAffineTransform with the inverse of this AffineTransform.
final @Size(min = 6) @NonNull float[]
getValues(@Size(min = 6) @NonNull float[] outArray)

Populates the first 6 elements of outArray with the values of this transform, starting with the top left corner of the matrix and proceeding in row-major order.
final boolean
isAlmostEqual(
    @NonNull AffineTransform other,
    @FloatRange(from = 0.0) float tolerance
)

Compares this AffineTransform with other, and returns true if each component of the transform matrix is within tolerance of the corresponding component of other.

Public constructors

ImmutableAffineTransform

Added in 1.0.0-alpha06
public ImmutableAffineTransform(@Size(min = 6) @NonNull float[] values)

Like the primary constructor, but accepts a FloatArray instead of individual Float values.

ImmutableAffineTransform

Added in 1.0.0-alpha06
public ImmutableAffineTransform(
    float m00,
    float m10,
    float m20,
    float m01,
    float m11,
    float m21
)

Constructs this transform with 6 float values, starting with the top left corner of the matrix and proceeding in row-major order. Prefer to create this object with functions that apply specific transform operations, such as scale or translate, rather than directly passing in the actual numeric values of this transform. This constructor is useful for when the values are needed to be provided all at once, for example for serialization. To access these values in the same order as they are passed in here, use AffineTransform.getValues. To construct this object using an array as input, there is another public constructor for that.

Public methods

equals

public boolean equals(Object other)

Component-wise equality operator for ImmutableAffineTransform.

Due to the propagation floating point precision errors, operations that may be equivalent over the real numbers are not always equivalent for floats, and might return false for equals in some cases.

hashCode

public int hashCode()

rotate

Added in 1.0.0-alpha06
public static final @NonNull ImmutableAffineTransform rotate(@AngleRadiansFloat float angleOfRotation)

Returns a transformation that rotates by the given angle, centered about the origin.

scale

Added in 1.0.0-alpha06
public static final @NonNull ImmutableAffineTransform scale(float scaleFactor)

Returns a transformation that scales in both the x- and y-direction by the given scaleFactor, centered about the origin.

scale

Added in 1.0.0-alpha06
public static final @NonNull ImmutableAffineTransform scale(float xScaleFactor, float yScaleFactor)

Returns a transformation that scales in both the x- and y-direction by the given pair of factors; xScaleFactor and yScaleFactor respectively, centered about the origin.

scaleX

Added in 1.0.0-alpha06
public static final @NonNull ImmutableAffineTransform scaleX(float scaleFactor)

Returns a transformation that scales in the x-direction by the given factor, centered about the origin.

scaleY

Added in 1.0.0-alpha06
public static final @NonNull ImmutableAffineTransform scaleY(float scaleFactor)

Returns a transformation that scales in the y-direction by the given factor, centered about the origin.

shearX

Added in 1.0.0-alpha06
public static final @NonNull ImmutableAffineTransform shearX(float shearFactor)

Returns a transformation that shears in the x-direction by the given factor.

shearY

Added in 1.0.0-alpha06
public static final @NonNull ImmutableAffineTransform shearY(float shearFactor)

Returns a transformation that shears in the y-direction by the given factor.

toString

public @NonNull String toString()

translate

Added in 1.0.0-alpha06
public static final @NonNull ImmutableAffineTransform translate(@NonNull Vec offset)

Returns a transformation that translates by the given offset vector.