Color

<init>

Color(value: ULong)

The Color class contains color information to be used while painting in Canvas. Color supports ColorSpaces with 3 components, plus one for alpha.

Creating

Color can be created with one of these methods:

    // from 4 separate [Float] components. Alpha and ColorSpace are optional
    val rgbaWhiteFloat = Color(red = 1f, green = 1f, blue = 1f, alpha = 1f,
        ColorSpace.get(ColorSpaces.Srgb))

    // from a 32-bit SRGB color integer
    val fromIntWhite = Color(android.graphics.Color.WHITE)
    val fromLongBlue = Color(0xFF0000FF)

    // from SRGB integer component values. Alpha is optional
    val rgbaWhiteInt = Color(red = 0xFF, green = 0xFF, blue = 0xFF, alpha = 0xFF)

Representation

A Color always defines a color using 4 components packed in a single 64 bit long value. One of these components is always alpha while the other three components depend on the color space's color model. The most common color model is the RGB model in which the components represent red, green, and blue values.

Component ranges: the ranges defined in the tables below indicate the ranges that can be encoded in a color long. They do not represent the actual ranges as they may differ per color space. For instance, the RGB components of a color in the Display P3 color space use the [0..1] range. Please refer to the documentation of the various color spaces to find their respective ranges.

Alpha range: while alpha is encoded in a color long using a 10 bit integer (thus using a range of [0..1023]), it is converted to and from [0..1] float values when decoding and encoding color longs.

sRGB color space: for compatibility reasons and ease of use, Color encoded sRGB colors do not use the same encoding as other color longs.

| Component | Name        | Size    | Range                 |
|-----------|-------------|---------|-----------------------|
| [RGB][ColorSpace.Model.Rgb] color model |
| R         | Red         | 16 bits | `[-65504.0, 65504.0]` |
| G         | Green       | 16 bits | `[-65504.0, 65504.0]` |
| B         | Blue        | 16 bits | `[-65504.0, 65504.0]` |
| A         | Alpha       | 10 bits | `[0..1023]`           |
|           | Color space | 6 bits  | `[0..63]`             |
| [SRGB][ColorSpaces.Srgb] color space |
| R         | Red         | 8 bits  | `[0..255]`            |
| G         | Green       | 8 bits  | `[0..255]`            |
| B         | Blue        | 8 bits  | `[0..255]`            |
| A         | Alpha       | 8 bits  | `[0..255]`            |
| X         | Unused      | 32 bits | `[0]`                 |
| [XYZ][ColorSpace.Model.Xyz] color model |
| X         | X           | 16 bits | `[-65504.0, 65504.0]` |
| Y         | Y           | 16 bits | `[-65504.0, 65504.0]` |
| Z         | Z           | 16 bits | `[-65504.0, 65504.0]` |
| A         | Alpha       | 10 bits | `[0..1023]`           |
|           | Color space | 6 bits  | `[0..63]`             |
| [Lab][ColorSpace.Model.Lab] color model |
| L         | L           | 16 bits | `[-65504.0, 65504.0]` |
| a         | a           | 16 bits | `[-65504.0, 65504.0]` |
| b         | b           | 16 bits | `[-65504.0, 65504.0]` |
| A         | Alpha       | 10 bits | `[0..1023]`           |
|           | Color space | 6 bits  | `[0..63]`             |

The components in this table are listed in encoding order (see below), which is why color longs in the RGB model are called RGBA colors (even if this doesn't quite hold for the special case of sRGB colors).

The color encoding relies on half-precision float values (fp16). If you wish to know more about the limitations of half-precision float values, please refer to the documentation of the Float16 class.

The values returned by these methods depend on the color space encoded in the color long. The values are however typically in the [0..1] range for RGB colors. Please refer to the documentation of the various color spaces for the exact ranges.

component1

@Stable operator fun component1(): Float

component2

@Stable operator fun component2(): Float

component3

@Stable operator fun component3(): Float

component4

@Stable operator fun component4(): Float

component5

@Stable operator fun component5(): ColorSpace

convert

fun convert(colorSpace: ColorSpace): Color

Converts this color from its color space to the specified color space. The conversion is done using the default rendering intent as specified by ColorSpace.connect.

copy

@Stable fun copy(
    alpha: Float = this.alpha, 
    red: Float = this.red, 
    green: Float = this.green, 
    blue: Float = this.blue
): Color

Copies the existing color, changing only the provided values. The ColorSpace of the returned Color is the same as this colorSpace.

toString

fun toString(): String

Returns a string representation of the object. This method returns a string equal to the value of:

    "Color($r, $g, $b, $a, ${colorSpace.name})"

For instance, the string representation of opaque black in the sRGB color space is equal to the following value:

    Color(0.0, 0.0, 0.0, 1.0, sRGB IEC61966-2.1)

alpha

@Stable val alpha: Float

Returns the value of the alpha component in the range [0..1].