Variables

Store and change values with variables.

Creating Variables

Use let to create a variable:

fn setup() {
  size(300, 200)
}

fn draw() {
  background(rgb(30, 30, 40))

  let x = 150
  let y = 100
  let size = 60

  fill(coral)
  circle(x, y, size)
}

Changing Variables

Variables declared outside functions persist between frames:

let x = 0

fn setup() {
  size(300, 200)
}

fn draw() {
  background(rgb(30, 30, 40))

  // Move right each frame
  x = x + 2

  // Wrap around
  if x > 320 {
    x = -20
  }

  fill(coral)
  circle(x, 100, 30)
}

Math Operations

Use standard math operators:

+ add
- subtract
* multiply
/ divide
% remainder (modulo)

fn setup() {
  size(300, 200)
}

fn draw() {
  background(rgb(30, 30, 40))

  let a = 10
  let b = 3

  fill(white)
  text("10 + 3 = " + (a + b), 20, 40)
  text("10 - 3 = " + (a - b), 20, 70)
  text("10 * 3 = " + (a * b), 20, 100)
  text("10 / 3 = " + (a / b), 20, 130)
  text("10 % 3 = " + (a % b), 20, 160)
}

Built-in Variables

Bloom provides useful built-in variables:

width - Canvas width
height - Canvas height
frame - Current frame number
mouseX - Mouse X position
mouseY - Mouse Y position

fn setup() {
  size(300, 200)
}

fn draw() {
  background(rgb(30, 30, 40))

  // Center using width/height
  let cx = width / 2
  let cy = height / 2

  // Pulse size with frame
  let size = 30 + sin(frame * 0.1) * 15

  fill(coral)
  circle(cx, cy, size)
}

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