fix canvas clearRect size calculation (#8328)

Co-authored-by: Marcel Samyn <marcel.samyn@lab900.com>

diff --git a/src/helpers/helpers.canvas.js b/src/helpers/helpers.canvas.js
index 064c5e9c4afaaa9357dbb315a83a53eb80ab3ef1..25fcfc4bf82e5a98726d6f920cec4ba83006ee23 100644 (file)
--- a/src/helpers/helpers.canvas.js
+++ b/src/helpers/helpers.canvas.js
@@ -113,7 +113,13 @@ export function _alignPixel(chart, pixel, width) {
  */
 export function clearCanvas(canvas, ctx) {
        ctx = ctx || canvas.getContext('2d');
+
+       ctx.save();
+       // canvas.width and canvas.height do not consider the canvas transform,
+       // while clearRect does
+       ctx.resetTransform();
        ctx.clearRect(0, 0, canvas.width, canvas.height);
+       ctx.restore();
 }
 
 export function drawPoint(ctx, options, x, y) {