Cover and contain math functions

cover-contain-math.js

function cover(imgWidth, imgHeight, containerWidth, containerHeight){
  let wRatio = containerWidth / imgWidth;
  let hRatio = containerHeight / imgHeight;

  let coverRatio = Math.max(wRatio, hRatio);

  return [imgWidth * coverRatio, imgHeight * coverRatio];
}

function contain(imgWidth, imgHeight, containerWidth, containerHeight){
  let wRatio = containerWidth / imgWidth;
  let hRatio = containerHeight / imgHeight;

  let containRatio = Math.min(wRatio, hRatio);

  return [imgWidth * containRatio, imgHeight * containRatio];
}