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mouseDragged()

A function that's called when the mouse moves while a button is pressed.

Declaring the function mouseDragged() sets a code block to run automatically when the user clicks and drags the mouse:

function mouseDragged() 
  -- Code to run.
end

The mouse system variables, such as mouseX and mouseY, will be updated with their most recent value when mouseDragged() is called by L5:

function mouseDragged() 
  if mouseX < 50 then
    -- Code to run if the mouse is on the left.
  end

  if mouseY > 50 then
    -- Code to run if the mouse is near the bottom.
  end
end

Examples

mouseDragged example 1

local value = 0

function setup()
  size(100, 100)

  describe(
    'A gray square with a black square at its center. The inner square becomes lighter as the user drags the mouse.'
  )
end

function draw()
  background(200)

  -- Style the square.
  fill(value)

  -- Draw the square.
  square(25, 25, 50)
end

function mouseDragged()
  -- Update the grayscale value.
  value = value + 5

  -- Reset the grayscale value.
  if value > 255 then
    value = 0
  end
end

Syntax

mouseDragged()