struct SF::Color

• SF::Color
• Struct
• Value
• Object

Overview

Utility struct for manipulating RGBA colors

SF::Color is a simple color struct composed of 4 components:

• Red
• Green
• Blue
• Alpha (opacity)

Each component is a public member, an unsigned integer in the range 0..255. Thus, colors can be constructed and manipulated very easily:

color = SF::Color.new(255, 0, 0) # red
color.r = 0                      # make it black
color.b = 128                    # make it dark blue

The fourth component of colors, named "alpha", represents the opacity of the color. A color with an alpha value of 255 will be fully opaque, while an alpha value of 0 will make a color fully transparent, whatever the value of the other components is.

The most common colors are already defined as static variables:

black       = SF::Color::Black
white       = SF::Color::White
red         = SF::Color::Red
green       = SF::Color::Green
blue        = SF::Color::Blue
yellow      = SF::Color::Yellow
magenta     = SF::Color::Magenta
cyan        = SF::Color::Cyan
transparent = SF::Color::Transparent

Colors can also be added and modulated (multiplied) using the overloaded operators + and *.

Defined in:

graphics/graphics.cr
graphics/obj.cr

Constant Summary

Black = new(0, 0, 0)

Black predefined color

Blue = new(0, 0, 255)

Blue predefined color

Cyan = new(0, 255, 255)

Cyan predefined color

Green = new(0, 255, 0)

Green predefined color

Magenta = new(255, 0, 255)

Magenta predefined color

Red = new(255, 0, 0)

Red predefined color

Transparent = new(0, 0, 0, 0)

Transparent (black) predefined color

White = new(255, 255, 255)

White predefined color

Yellow = new(255, 255, 0)

Yellow predefined color

Constructors

• .new(red : Int, green : Int, blue : Int, alpha : Int = 255)

  Construct the color from its 4 RGBA components

• .new(color : Int)

  Construct the color from 32-bit unsigned integer

• .new

  Default constructor

Instance Method Summary

• #!=(right : Color) : Bool

  Overload of the != operator

• #*(right : Color) : Color

  Overload of the binary * operator

• #+(right : Color) : Color

  Overload of the binary + operator

• #-(right : Color) : Color

  Overload of the binary - operator

• #==(right : Color) : Bool

  Overload of the == operator

• #a : UInt8

  Alpha (opacity) component

• #a=(a : Int)
• #b : UInt8

  Blue component

• #b=(b : Int)
• #dup : Color

  Returns a shallow copy of this object.

• #g : UInt8

  Green component

• #g=(g : Int)
• #inspect(io)
• #r : UInt8

  Red component

• #r=(r : Int)
• #to_integer : UInt32

  Retrieve the color as a 32-bit unsigned integer

Constructor Detail

Instance Method Detail