Module turtle::color[−][src]

Color types and constants

When setting a color, you can use a variety of different color names. This module contains many of the most common colors that you might want to use. There is an even more comprehensive list in the extended module. Any of the color names listed in this module or in the extended module can be used as a color. You only need to reference the color::extended module if you want to use a specific color constant from that module.

You can refer to a color by using its color name as a string literal. For example:

// This will set the turtle's pen color to BLACK
turtle.set_pen_color("black");
// This is the same as the previous line
turtle.set_pen_color(color::BLACK);
// You can use any of the supported color names (including the ones from extended)
turtle.set_pen_color("deep lilac");

You can also use hexadecimal color strings to get any color you want (even ones that aren't listed here).

turtle.set_pen_color("#3366ff");
turtle.set_pen_color("#36f");

Each color's constant name is in uppercase in the list below. The color name you should use to refer to it is in lower case next to the constant.

For your convenience, there are two static variables COLORS and COLOR_NAMES which contain the values of all the color constants and each of their names as strings. These static variables only contain the colors from this module. The extended module has its own static COLOR and COLOR_NAMES variables.

Random Colors

You can also generate random colors. Here's an example:

use turtle::{random, Color};
turtle.set_pen_color(random::<Color>().opaque());

The syntax used in random::<Color>() is referred to as "turbofish" syntax. See that documentation for more information.

Notice that you need to explicitly call the opaque() method on the color in order to make sure that the color has an alpha value of 1.0. By default, when you generate a random color, it's alpha value will be random as well.

See the examples directory on GitHub for more information.

Creating a Color from Values

Usually, you won't need to initialize a color this way since the above methods are quite convenient. However, in some situations it may be necessary to create a color with specific red, green, and blue values. The following example illustrates how to do that.

use turtle::Color;
let my_color = Color {red: 255.0, green: 55.0, blue: 11.0, alpha: 1.0};

Note that when creating a color this way, we do not check if the values of each property are within their valid ranges.

Another ergonomic syntax can also be used when passing a color to a method that supports any type that implements Into<Color>.

// A solid color with alpha = 1.0
// Syntax is [red, green, blue] and doesn't require explicitly writing the field names
turtle.set_pen_color([133.0, 23.0, 96.0]);
turtle.set_fill_color([133.0, 23.0, 96.0]);
turtle.drawing_mut().set_background_color([133.0, 23.0, 96.0]);
// This is a little easier to type than the equivalent:
turtle.drawing_mut().set_background_color(Color {red: 133.0, green: 23.0, blue: 96.0, alpha: 1.0});

// Add an additional element to the array to specify the alpha
// Syntax is [red, green, blue, alpha]
turtle.set_pen_color([133.0, 23.0, 96.0, 0.5]);
turtle.set_fill_color([133.0, 23.0, 96.0, 0.5]);
turtle.drawing_mut().set_background_color([133.0, 23.0, 96.0, 0.5]);
// This is a little easier to type than the equivalent:
turtle.drawing_mut().set_background_color(Color {red: 133.0, green: 23.0, blue: 96.0, alpha: 0.5});

When creating a color this way, we will check whether or not the color is valid and provide an error message to let you know what happened.

// Color values must only go up to 255.0
turtle.set_pen_color([133.0, 256.0, 96.0]); // This will panic with an error message

There are also constructor methods available for Color that allow you to create a new color using provided values. These are:

rgb(red, green, blue): Create from the given red, green, and blue values with an alpha value of 1.0
rgba(red, green, blue, alpha): Similar to rgb but also accepts an alpha value
hsl(hue, saturation, lightness): Create from the given hue, saturation, and lightness values with an alpha of 1.0
hsla(hue, saturation, lightness, alpha): Similar to hsl but also accepts an alpha value

These methods provide a concise syntax for creating a new Color. If the values passed in are invalid, the program will exit with an error that lets you know what happened. See the documentation for each method (linked above) to see which values are correct for each parameter.

use turtle::Color;

// These are equivalent
let white_manual = Color { red: 255.0, green: 255.0, blue: 255.0, alpha: 1.0 };
let white_rgb = Color::rgb(255.0, 255.0, 255.0);
let white_rgba = Color::rgba(255.0, 255.0, 255.0, 1.0);
let white_hsl = Color::hsl(0.0, 0.0, 1.0);
let white_hsla = Color::hsla(0.0, 0.0, 1.0, 1.0);

assert_eq!(white_manual, white_rgb);
assert_eq!(white_rgb, white_rgba);
assert_eq!(white_rgba, white_hsl);
assert_eq!(white_hsl, white_hsla);

So, you can incorporate these constructors into your turtle code along with other methods of color creation if you like:

// Set the pen color to blue
turtle.set_pen_color(Color::rgb(0.0, 130.0, 200.0));

// And the same color can be set for the fill color via the array syntax.
turtle.set_fill_color([0.0, 130.0, 200.0]);

// Then, we can set the background to black
turtle.drawing_mut().set_background_color("black");

BEIGE	beige
BLACK	black
BLUE	blue
BROWN	brown
CORAL	coral
CYAN	cyan
GREEN	green
GREY	grey
LAVENDER	lavender
LIME	lime
MAGENTA	magenta
MAROON	maroon
MINT	mint
NAVY	navy
OLIVE	olive
ORANGE	orange
PINK	pink
PURPLE	purple
RED	red
TEAL	teal
TRANSPARENT	transparent
WHITE	white
YELLOW	yellow

Statics

COLORS	A list of all of the colors
COLOR_NAMES	A list of all of the color names

Module turtle::color[−][src]

Random Colors

Creating a Color from Values

Modules

Structs

Constants

Statics