Colours
A colour is a 3-byte array of the form 0xRRGGBB. For example, full red would be 0xff0000. In general,
wherever a colour is expected, either a pre-defined colour from this module can be used, or a
custom 3-byte array.
Built-in named colours
Any colour from the list below can used used either by referencing the value directly (.gg.colour.Crimson),
or by referring to it as a symbol (`crimson). If referring to the colour as a symbol, case does not matter.
Colour palettes
There are a number of built-in colour palettes available, as well as functions for generating gradients for use as colour scales.
See .gg.colour.brewer for a set of colour palettes which can be used to generate gradient or be used as
categorical colour scales.
The default categorical colour scale uses the .gg.colour.cat10 colour palette, which provides 10 distinct
colours. .gg.colour.cat20 is based on the same colours, but presented as dark-light pairs.
.gg.colour.brewer
Return the brewer palette for the given name and colour count. Each available palette comes in
a number of sets defined by the number of colours returned. For example, for a 6-value palette
from yellow to green, run .gg.colour.brewer[`YlGn;6]. All available brewer palettes and
their set options are visible below.
Parameters:
| Name | Type | Description |
|---|---|---|
| palette | symbol | palette name (see example below) |
| n | long | colour count (see example below) |
Returns:
| Type | Description |
|---|---|
| byte[][] | list of colours |
.gg.colour.cat10
10 distinct colours. The colours are displayed below.
.gg.colour.cat20
20 distinct colours (10 colours in lightness pairs). The colours are displayed below.
.gg.colour.gradient
Given a range of numeric values, and a value within that range, return a colour corresponding to the colour along a gradient.
Parameters:
| Name | Type | Description |
|---|---|---|
| values_ | number[] | number | scalar within the source range min and max |
| min_ | number | source range min |
| max_ | number | source range max |
| color1 | byte[] | low colour on the gradient |
| color2 | byte[] | high colour on the gradient |
Returns:
| Type | Description |
|---|---|
| byte[] | resulting colour along the gradient |
Example:
.gg.colour.gradient[til 5; 0; 10; .gg.colour.Red; .gg.colour.Blue]
//=> 16711680 15073306 13369395 11731021 10027110i
.gg.colour.rgbFromHSL
Return an RGB colour (0xRRGGBB) from an HSL colour
Parameter:
| Name | Type | Description |
|---|---|---|
| hsl | float[] |
Returns:
| Type | Description |
|---|---|
| byte[] |
Example:
0x0070cd ~ .gg.colour.rgbFromHSL .gg.colour.hsl 0x0070cd