window

The window package brings OSL's original graphical model to compiled programs: you open a real desktop window and draw into it every frame using OSL's rendering commands (the "draw cursor", shapes, text, icons and 3D). This is the same drawing model that powered originOS apps.

Migration: renderer plumbing such as batch*, icn*, drawIconCached, and executeIconCommands is now internal. Use the stable drawing commands and methods such as line, rect, window.Icon, and window.Text.

import "std:window"

Program structure

A windowed program has two parts:

1. Setup - top-level statements that run once. Configure the window and load assets here.

2. The main loop - everything after the mainloop: label runs once per frame. This is where you read input and draw.

import "std:window"

window.setTitle("Hello OSL")
window.setColor("#ffffff")
window.show()
window.resize(800, 450)

number x = 0

mainloop:

x += 1
goto x window.top - 40
centext "hello world" 10 : c#000

mainloop: is a bare label - it has no parentheses and no body brackets. Everything below it is the per-frame loop, and it keeps running until the window closes.

Window properties & methods

Read the window's size and edges as properties (no parentheses):

window.width      window.height
window.left       window.right
window.top        window.bottom

Control the window with methods:

Method	Purpose
window.setTitle(title)	Set the title bar text.
window.setColor(hex)	Set the background colour.
window.show() / window.hide()	Show or hide the window.
window.resize(w, h)	Resize the window.
window.setResizable(bool)	Allow or block user resizing.
window.fullscreen() / window.isFullscreen()	Toggle / query fullscreen.
window.minimise()	Minimise.
window.close()	Close the window and stop the program.
window.on(event, handler)	Listen for window events.

Drawing

Inside the loop you draw with rendering commands. They operate on a moving "draw cursor":

goto x y                 // move the draw cursor
change_x n   change_y n  // move it relatively
c "#ff0000"              // set the draw colour
icon iconString size     // draw an ICN icon
image url w h            // draw an image
text "hello" 10          // draw text from the cursor
centext "hello" 10       // draw text centred on the cursor

Many commands accept an inline modifier after a colon - for example : c#000 sets the colour just for that element:

centext "Score: " ++ score 10 : c#000

The rendering commands, modifiers, clipping operations, and input globals are documented on this page because they are part of std:window, not the core language.

Input

Keyboard keys are queried by name:

if "space".isKeyDown() (
  jump = true
)
move_left  = "a".isKeyDown()
move_right = "d".isKeyDown()

The window package also exposes per-frame global variables you can read directly in the loop:

Global	Meaning
mouse_x, mouse_y	Mouse position.
x_position, y_position	The current draw-cursor position.
direction	The draw cursor's heading (for pen/turtle drawing).
timer	A steadily increasing timer, handy for timing events.

A complete example

import "std:window"

object player = { x: 0, y: 0 }

window.setColor("#fff")
window.setTitle("Move me")
window.show()
window.resize(800, 450)

mainloop:

if "a".isKeyDown() (
  player.x -= 4
)
if "d".isKeyDown() (
  player.x += 4
)
if "w".isKeyDown() (
  player.y += 4
)
if "s".isKeyDown() (
  player.y -= 4
)

goto player.x.toNum() player.y.toNum()
icon "c #000 square 0 0 20 20" 2

goto 0 window.top - 30
centext "use WASD" 10 : c#000

Companion packages

• win-buttons - add clickable buttons to a window (import "std:win-buttons").

• sound - play audio in a windowed app.

Heads-up: the window package depends on native graphics libraries, so the first compile pulls in extra dependencies. Server and CLI programs don't need any of this.

Complete API reference

window

Method	Returns	Notes
window.on(name: any, callback: any)	void
window.emit(name: any, ...args: any)	void
window.show()	void
window.Create()	void
window.Goto(x: any, y: any)	void
window.hide()	void
window.resize(width: any, height: any)	void
window.close()	void	Closes the resource.
window.minimise()	void	Minimizes the current native window.
window.fullscreen()	void	Toggles fullscreen on the current native window.
window.isFullscreen()	boolean	Reports whether the current native window is fullscreen.
window.color()	string
window.setColor(col: any)	void	Sets color.
window.setTitle(title: any)	void	Sets title.
window.keyPressed(key: string)	boolean
window.setResizable(resizable: boolean)	void	Sets resizable.
window.setDragbox(box: any)	void	Sets dragbox.
window.dragbox()	array

Window values

Method	Returns	Notes
value.Run(loop: function)	void	Runs the window loop callback until the window closes.
value.width()	number
value.height()	number
value.left()	number
value.right()	number
value.top()	number
value.bottom()	number
value.SetTitle(title: string)	void	Sets title.
value.resize(width: any, height: any)	void
value.setResizable(resizable: boolean)	void	Sets resizable.
value.Clear(col: color.Color)	void
value.Update()	void
value.KeyPressed(key: string)	boolean

winRender values

Method	Returns	Notes
value.Hex(hex: any)	color.RGBA
value.Color(col: any)	void
value.Goto(x: any, y: any)	void
value.Loc(a: any, b: any, c: any, d: any)	void
value.toScreen(x: number, y: number)	pixel.Vec	Converts to screen.
value.drawColor()	color.Color
value.Effect(name: any, value: any)	void	Sets an effect; transparency is clamped when rendered.
value.penSize()	number
value.beginElement()	void
value.updateLast(minX: number, minY: number, maxX: number, maxY: number)	void
value.checkClick()	void
value.LineTo(endX: number, endY: number)	void
value.Rect(...args: any)	void
value.Icon(icon: any, size: number)	void
value.Text(text: string, size: any)	void
value.Centext(text: string, size: any)	void
value.SetThickness(thickness: number)	void	Sets thickness.
value.Change(offsetX: number, offsetY: number)	void
value.Direction(dirFloat: number)	void
value.Turnright(angle: number)	void
value.Turnleft(angle: number)	void
value.Pointat(x: number, y: number)	void
value.Image(key: string, w: any, h: any)	void
window.off(name: any, callback: any)	boolean	Removes one event callback without disturbing other listeners.

Notes

• Prefer import "std:window"; the older import "osl/window" spelling remains supported.

Behavior and limits

Empty colors and invalid image data return failure values instead of panicking. PNG and JPEG data use Go's image decoders. A failed asynchronous image load releases its queue slot. Icon commands split on whitespace and reject operations with the wrong number of numeric arguments.