PixelMap

Artifact: androidx.compose.ui:ui-graphics

Added in 1.0.0

Cmn
```
class PixelMap
```

Result of a pixel read operation. This contains the ImageBitmap pixel information represented as a 1 dimensional array of values that supports queries of pixel values based on the 2 dimensional coordinates of the corresponding ImageBitmap this was obtained from

import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.ImageBitmap
import androidx.compose.ui.graphics.PixelMap

val imageBitmap = createImageBitmap()

val buffer = IntArray(20 * 10)
imageBitmap.readPixels(buffer = buffer, startX = 8, startY = 9, width = 20, height = 10)

val pixelmap = PixelMap(buffer = buffer, width = 20, height = 10, stride = 20, bufferOffset = 0)

// create a histogram to count the number of occurrences of a color within the specified
// subsection of the provided ImageBitmap
val histogram = HashMap<Color, Int>()
for (x in 0 until pixelmap.width) {
    for (y in 0 until pixelmap.height) {
        val color = pixelmap[x, y]
        val colorCount = histogram[color] ?: 0
        histogram[color] = (colorCount + 1)
    }
}

See also
`readPixels`
`toPixelMap`

Summary

Public constructors
`PixelMap( buffer: IntArray, width: Int, height: Int, bufferOffset: Int, stride: Int )`	Cmn

Public functions
`operator Color`	`get(x: @IntRange(from = 0) Int, y: @IntRange(from = 0) Int)` Obtain the color of the pixel at the given coordinate.	Cmn

Public properties
`IntArray`	`buffer` IntArray where pixel information is stored as an ARGB value packed into an Int	Cmn
`Int`	`bufferOffset` first index in the buffer where pixel information for the `ImageBitmap` is stored	Cmn
`Int`	`height` Height of the subsection of the `ImageBitmap` this buffer represents	Cmn
`Int`	`stride` Number of entries to skip between rows	Cmn
`Int`	`width` Width of the subsection of the `ImageBitmap` this buffer represents	Cmn

Public constructors

PixelMap

Cmn

Added in 1.0.0

PixelMap(
    buffer: IntArray,
    width: Int,
    height: Int,
    bufferOffset: Int,
    stride: Int
)

Parameters
`buffer: IntArray`	IntArray where pixel information is stored as an ARGB value packed into an Int
`width: Int`	Width of the subsection of the `ImageBitmap` this buffer represents
`height: Int`	Height of the subsection of the `ImageBitmap` this buffer represents
`bufferOffset: Int`	first index in the buffer where pixel information for the `ImageBitmap` is stored
`stride: Int`	Number of entries to skip between rows

Public functions

get

Cmn

Added in 1.0.0

operator fun get(x: @IntRange(from = 0) Int, y: @IntRange(from = 0) Int): Color

Obtain the color of the pixel at the given coordinate.

Parameters
`x: @IntRange(from = 0) Int`	the horizontal pixel coordinate, minimum 1
`y: @IntRange(from = 0) Int`	the vertical pixel coordinate, minimum 1

Public properties

buffer

Cmn

Added in 1.0.0

val buffer: IntArray

IntArray where pixel information is stored as an ARGB value packed into an Int

bufferOffset

Cmn

Added in 1.0.0

val bufferOffset: Int

first index in the buffer where pixel information for the ImageBitmap is stored

height

Cmn

Added in 1.0.0

val height: Int

Height of the subsection of the ImageBitmap this buffer represents

stride

Cmn

Added in 1.0.0

val stride: Int

Number of entries to skip between rows

width

Cmn

Added in 1.0.0

val width: Int

Width of the subsection of the ImageBitmap this buffer represents