ColorMatrix

Class

Common

value class ColorMatrix(
    val values: FloatArray =
        floatArrayOf(1f, 0f, 0f, 0f, 0f, 0f, 1f, 0f, 0f, 0f, 0f, 0f, 1f, 0f, 0f, 0f, 0f, 0f, 1f, 0f)
)

4x5 matrix for transforming the color and alpha components of a source. The matrix can be passed as single array, and is treated as follows:

 ` a, b, c, d, e,  f, g, h, i, j,  k, l, m, n, o,  p, q, r, s, t `

When applied to a color R, G, B, A, the resulting color is computed as:

That resulting color R', G', B', A' then has each channel clamped to the 0 to 255 range.

The sample ColorMatrix below inverts incoming colors by scaling each channel by -1, and then shifting the result up by 255 to remain in the standard color space.

``` -1, 0, 0, 0, 255, 0, -1, 0, 0, 255, 0, 0, -1, 0, 255, 0, 0, 0, 1, 0


This is often used as input for `ColorFilter.colorMatrix` and applied at draw time through
`Paint.colorFilter`


## Functions

```kotlin
inline operator fun get(row: Int, column: Int) = values[(row * 5) + column]

Obtain an instance of the matrix value at the given row and column. ColorMatrix follows row major order in regards to the positions of matrix values within the flattened array. That is, content order goes from left to right then top to bottom as opposed to column major order.

Parameters


row	Row index to query the ColorMatrix value. Range is from 0 to 3 as `ColorMatrix` is represented as a 4 x 5 matrix
column	Column index to query the ColorMatrix value. Range is from 0 to 4 as `ColorMatrix` is represented as a 4 x 5 matrix

inline operator fun set(row: Int, column: Int, v: Float)

Set the matrix value at the given row and column. ColorMatrix follows row major order in regards to the positions of matrix values within the flattened array. That is, content order goes from left to right then top to bottom as opposed to column major order.

Parameters


row	Row index to query the ColorMatrix value. Range is from 0 to 3 as `ColorMatrix` is represented as a 4 x 5 matrix
column	Column index to query the ColorMatrix value. Range is from 0 to 4 as `ColorMatrix` is represented as a 4 x 5 matrix
v	value to update at the given `row` and `column`

inline fun reset()

Set this colormatrix to identity:

` 1 0 0 0 0   - red vector
0 1 0 0 0   - green vector
0 0 1 0 0   - blue vector
0 0 0 1 0 ` - alpha vector

fun set(src: ColorMatrix)

Assign the src colormatrix into this matrix, copying all of its values.

operator fun timesAssign(colorMatrix: ColorMatrix)

Multiply this matrix by colorMatrix and assign the result to this matrix.

fun setToSaturation(sat: Float)

Set the matrix to affect the saturation of colors.

Parameters


sat	A value of 0 maps the color to gray-scale. 1 is identity.

fun setToScale(redScale: Float, greenScale: Float, blueScale: Float, alphaScale: Float)

Create a ColorMatrix with the corresponding scale parameters for the red, green, blue and alpha axes

Parameters


redScale	Desired scale parameter for the red channel
greenScale	Desired scale parameter for the green channel
blueScale	Desired scale parameter for the blue channel
alphaScale	Desired scale parameter for the alpha channel

fun setToRotateRed(degrees: Float)

Rotate by degrees along the red color axis

fun setToRotateGreen(degrees: Float)

Rotate by degrees along the green color axis

fun setToRotateBlue(degrees: Float)

Rotate by degrees along the blue color axis

fun convertRgbToYuv()

Set the matrix to convert RGB to YUV

fun convertYuvToRgb()

Set the matrix to convert from YUV to RGB