// Device pixel ratio helpers. Clamped to 2 to keep canvases under iOS 15 GPU
// process limits (research 01 §canvas).

const MAX_DPR = 2;
const MAX_BACKING_WIDTH = 2048;

export function getDpr(): number {
  if (typeof window === 'undefined') return 1;
  const dpr = window.devicePixelRatio ?? 1;
  return Math.min(Math.max(dpr, 1), MAX_DPR);
}

export function backingWidth(cssWidth: number, dpr = getDpr()): number {
  return Math.min(Math.round(cssWidth * dpr), MAX_BACKING_WIDTH);
}

export function backingHeight(cssHeight: number, dpr = getDpr()): number {
  return Math.round(cssHeight * dpr);
}