MutableAffineTransform

kotlin.Any
   ↳ androidx.ink.geometry.AffineTransform
     ↳ androidx.ink.geometry.MutableAffineTransform

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 ImmutableAffineTransform for an immutable alternative to this class.

Summary

Public constructors

Constructs an identity MutableAffineTransform:
android

Public functions
open operator Boolean
equals(other: Any?)

Component-wise equality operator for MutableAffineTransform.
android
open Int
android
MutableAffineTransform

Fills this MutableAffineTransform with the same values contained in input.
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MutableAffineTransform

Fills this MutableAffineTransform with an identity transformation, which maps a point to itself, i.e. it leaves it unchanged.
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MutableAffineTransform

Fills this MutableAffineTransform with a transformation that rotates by the given angle, centered about the origin.
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MutableAffineTransform
populateFromScale(scaleFactor: Float)

Fills this MutableAffineTransform with a transformation that scales in both the x and y direction by the given scaleFactor, centered about the origin.
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MutableAffineTransform
populateFromScale(xScaleFactor: Float, yScaleFactor: Float)

Fills this MutableAffineTransform with 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.
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MutableAffineTransform
populateFromScaleX(scaleFactor: Float)

Fills this MutableAffineTransform with a transformation that scales in the x-direction by the given factor, centered about the origin.
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MutableAffineTransform
populateFromScaleY(scaleFactor: Float)

Fills this MutableAffineTransform with a transformation that scales in the y-direction by the given factor, centered about the origin.
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MutableAffineTransform
populateFromShearX(shearFactor: Float)

Fills this MutableAffineTransform with a transformation that shears in the x-direction by the given factor.
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MutableAffineTransform
populateFromShearY(shearFactor: Float)

Fills this MutableAffineTransform with a transformation that shears in the y-direction by the given factor.
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MutableAffineTransform

Fills this MutableAffineTransform with a transformation that translates by the given offset vector.
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Unit
setValues(values: @Size(min = 6) FloatArray)

Like setValues, but accepts a FloatArray instead of individual float values.
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Unit
setValues(m00: Float, m10: Float, m20: Float, m01: Float, m11: Float, m21: Float)

Populates this transform with the given values, starting with the top left corner of the matrix and proceeding in row-major order.
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open String
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Extension functions
MutableAffineTransform

Fills this MutableAffineTransform with the values from matrix.
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MutableAffineTransform

Fills this MutableAffineTransform with the values from matrix.
android

Inherited functions
From androidx.ink.geometry.AffineTransform
ImmutableParallelogram

Returns an ImmutableParallelogram containing the result of applying the AffineTransform to box.
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ImmutableParallelogram
applyTransform(parallelogram: Parallelogram)

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

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

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

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

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

Apply the AffineTransform to the Parallelogram and store the result in the MutableParallelogram.
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MutableVec
applyTransform(point: Vec, outVec: MutableVec)

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

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

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

Returns the inverse of the AffineTransform.
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MutableAffineTransform

Populates outAffineTransform with the inverse of this AffineTransform.
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@Size(min = 6) FloatArray
getValues(outArray: @Size(min = 6) FloatArray)

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.
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Boolean
isAlmostEqual(
    other: AffineTransform,
    tolerance: @FloatRange(from = 0.0) Float
)

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

Public constructors

MutableAffineTransform

android
Added in 1.0.0-alpha06
MutableAffineTransform()

Constructs an identity MutableAffineTransform:

⎡1  0  0⎤
⎢0  1  0⎥
⎣0  0  1⎦

This is useful when pre-allocating a scratch instance to be filled later.

Public functions

equals

android 
open operator fun equals(other: Any?): Boolean

Component-wise equality operator for MutableAffineTransform.

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

android 
open fun hashCode(): Int

populateFrom

android
Added in 1.0.0-alpha06
fun populateFrom(input: AffineTransform): MutableAffineTransform

Fills this MutableAffineTransform with the same values contained in input.

Returns the modified instance to allow chaining calls.

Returns
MutableAffineTransform

this

populateFromIdentity

android
Added in 1.0.0-alpha06
fun populateFromIdentity(): MutableAffineTransform

Fills this MutableAffineTransform with an identity transformation, which maps a point to itself, i.e. it leaves it unchanged.

Returns the modified instance to allow chaining calls.

Returns
MutableAffineTransform

this

populateFromRotation

android
Added in 1.0.0-alpha06
fun populateFromRotation(angleOfRotation: @AngleRadiansFloat Float): MutableAffineTransform

Fills this MutableAffineTransform with a transformation that rotates by the given angle, centered about the origin.

Returns the modified instance to allow chaining calls.

Returns
MutableAffineTransform

this

populateFromScale

android
Added in 1.0.0-alpha06
fun populateFromScale(scaleFactor: Float): MutableAffineTransform

Fills this MutableAffineTransform with a transformation that scales in both the x and y direction by the given scaleFactor, centered about the origin.

Returns the modified instance to allow chaining calls.

Returns
MutableAffineTransform

this

populateFromScale

android
Added in 1.0.0-alpha06
fun populateFromScale(xScaleFactor: Float, yScaleFactor: Float): MutableAffineTransform

Fills this MutableAffineTransform with 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.

Returns the modified instance to allow chaining calls.

Returns
MutableAffineTransform

this

populateFromScaleX

android
Added in 1.0.0-alpha06
fun populateFromScaleX(scaleFactor: Float): MutableAffineTransform

Fills this MutableAffineTransform with a transformation that scales in the x-direction by the given factor, centered about the origin.

Returns the modified instance to allow chaining calls.

Returns
MutableAffineTransform

this

populateFromScaleY

android
Added in 1.0.0-alpha06
fun populateFromScaleY(scaleFactor: Float): MutableAffineTransform

Fills this MutableAffineTransform with a transformation that scales in the y-direction by the given factor, centered about the origin.

Returns the modified instance to allow chaining calls.

Returns
MutableAffineTransform

this

populateFromShearX

android
Added in 1.0.0-alpha06
fun populateFromShearX(shearFactor: Float): MutableAffineTransform

Fills this MutableAffineTransform with a transformation that shears in the x-direction by the given factor.

Returns the modified instance to allow chaining calls.

Returns
MutableAffineTransform

this

populateFromShearY

android
Added in 1.0.0-alpha06
fun populateFromShearY(shearFactor: Float): MutableAffineTransform

Fills this MutableAffineTransform with a transformation that shears in the y-direction by the given factor.

Returns the modified instance to allow chaining calls.

Returns
MutableAffineTransform

this

populateFromTranslate

android
Added in 1.0.0-alpha06
fun populateFromTranslate(offset: Vec): MutableAffineTransform

Fills this MutableAffineTransform with a transformation that translates by the given offset vector.

Returns the modified instance to allow chaining calls.

Returns
MutableAffineTransform

this

setValues

android
Added in 1.0.0-alpha06
fun setValues(values: @Size(min = 6) FloatArray): Unit

Like setValues, but accepts a FloatArray instead of individual float values.

setValues

android
Added in 1.0.0-alpha06
fun setValues(m00: Float, m10: Float, m20: Float, m01: Float, m11: Float, m21: Float): Unit

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

Prefer to modify this object with functions that apply specific transform operations, such as populateFromScale or populateFromRotate, rather than directly setting the actual numeric values of this transform. This function is useful for when the values are needed to be provided in bulk, for example for serialization.

To access these values in the same order as they are set here, use AffineTransform.getValues.

toString

android 
open fun toString(): String

Extension functions

populateFrom

android 
fun MutableAffineTransform.populateFrom(matrix: Matrix): MutableAffineTransform

Fills this MutableAffineTransform with the values from matrix.

If matrix is not an affine transform, throws IllegalArgumentException instead.

Leaves matrix unchanged. Returns this modified instance to allow chaining calls.

Returns
MutableAffineTransform

this
Throws
kotlin.IllegalArgumentException

if matrix is not an affine transform.

populateFrom

android 
fun MutableAffineTransform.populateFrom(matrix: Matrix): MutableAffineTransform

Fills this MutableAffineTransform with the values from matrix.

If matrix is not an affine transform, throws IllegalArgumentException instead.

Leaves the input matrix unchanged. Returns the modified instance to allow chaining calls.

Returns
MutableAffineTransform

this
Throws
kotlin.IllegalArgumentException

if matrix is not a 2D affine transform.