How to center an image when scaling?

Question

JavaScript

How to correctly center the image when scaling, otherwise it is somehow not very centered. Most likely there is a school geometry course, but I just can’t remember how to do something.

function renderImage(canvas, scale) { 
 const context = canvas.getContext('2d');
 const canvasSize = canvas.clientWidth;
 const centerSize = canvasSize/2;
 canvas.width = canvasSize;
 canvas.height = canvasSize;
   
 const scaleKoef = (10 + scale) / 10;
 const scaleSize = canvasSize / scaleKoef;
 
  // Центрируем изображение
 const centerX = (image.width * scaleKoef / 2 - centerSize) ;
 const centerY = (image.height * scaleKoef / 2 - centerSize) ;
 
 context.drawImage(
  image, 
  centerX, centerY, scaleSize, scaleSize,
  0, 0, canvasSize, canvasSize
 );
}

Answer 1

So ?