QR Codes

BGE.QrCode encodes and draws QR codes directly on a plain roScreen channel

no SceneGraph, no image asset. Handy anywhere you'd otherwise show a URL for a player to type in by hand, like connecting a controller. Ports Project Nayuki's QR Code generator via the paramount-engineering BrightScript port (both MIT-licensed; see LICENSE-THIRD-PARTY.md) to plain BrighterScript.

CODE

BGE.QrCode.draw(renderer, x, y, "https://example.com", 200)

A QR code drawn next to the controller connection URL text

renderer is any BGE.Renderer (game canvas or UI canvas); x/y are the top-left corner and width the rendered size in pixels (square). It draws black-on-white by default - pass darkRgba/lightRgba (packed RGBA) for a different look:

CODE

BGE.QrCode.draw(renderer, x, y, code, width, BGE.Colors.White, BGE.Colors.Black)

Drawing one every frame

A GameEntity/Room's onDrawEnd(gameRenderer, uiRenderer) hook runs once per frame after the normal scene draw - the natural place to draw a QR code alongside the rest of your UI. The UI renderer stays crisp regardless of game canvas scaling, so it's usually the right target for something like this.

For text that doesn't change (a connection URL, say), don't call draw() itself every frame - it re-encodes from scratch each time (segment building, version-fit search, Reed-Solomon ECC, mask-penalty scoring), wasted work for byte-identical output. Encode once and cache the result, then re-blit the already-encoded code each frame with qrDrawModules():

CODE

override sub onCreate(args as roAssociativeArray)
  m.qr = BGE.QrCode.qrEncodeText(m.game.getControllerConnectionInfo(), BGE.QrCode.EccLevel.medium)
end sub

override sub onDrawEnd(gameRenderer as BGE.Renderer, uiRenderer as BGE.Renderer)
  draw2d = uiRenderer.getDraw2d()
  uiRenderer.incrementDrawCalls(BGE.QrCode.qrDrawModules(draw2d, m.qr, 20, 20, 150))
end sub

If the text genuinely changes frame to frame, draw()'s one-call convenience is worth paying the re-encode cost for.

Encoding without drawing

BGE.QrCode.qrEncodeText(text, ecl) returns a BGE.QrCode.QrCode you can inspect module-by-module - useful if you want to draw it some other way (a Model3d texture, a custom shape, etc.) instead of draw()'s plain filled squares:

CODE

qr = BGE.QrCode.qrEncodeText("hello", BGE.QrCode.EccLevel.medium)
isDark = qr.getModule(x, y) ' x, y in [0, qr.size)

ecl is a BGE.QrCode.EccLevel (low/medium/quartile/high) - a higher level survives more damage/obstruction before becoming unreadable, at the cost of a denser (sometimes larger) code for the same text.

See examples/controller's MainRoom for a runnable example (drawing the controller connection URL as a QR code instead of - or alongside - plain text).