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alpha()

Gets the alpha (transparency) value of a color.

alpha() extracts the alpha value from a color object, an array of color components, or a CSS color string.

Examples

alpha example 1

require("L5")

function setup()
  size(100, 100)

  background(200)

  -- Create a color object.
  c = color(0, 126, 255, 102)

  -- Draw the left rectangle.
  noStroke()
  fill(c)
  rect(15, 15, 35, 70)

  -- Set 'alphaValue' to 102.
  alphaValue = alpha(c)

  -- Draw the right rectangle.
  fill(alphaValue)
  rect(50, 15, 35, 70)

  describe('Two rectangles. The left one is light blue and the right one is charcoal gray.')
end

alpha example 2

require("L5")

function setup()
  size(100, 100)

  background(200)

  -- Create a color array.
  local c = {0, 126, 255, 102}

  -- Draw the left rectangle.
  noStroke()
  fill(c)
  rect(15, 15, 35, 70)

  -- Set 'alphaValue' to 102.
  local alphaValue = alpha(c)

  -- Draw the left rectangle.
  fill(alphaValue)
  rect(50, 15, 35, 70)

  describe('Two rectangles. The left one is light blue and the right one is charcoal gray.')
end

Syntax

alpha(color)

Parameters

Parameter
color Color/Number/String.

This reference page contains content adapted from p5.js and Processing by p5.js Contributors and Processing Foundation, licensed under CC BY-NC-SA 4.0.