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Avoid to have a factor too close to 2 when downscaling image

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It's a workaround for bug 1820511: it only affects Firefox on Windows
using the D2D backend.
This commit is contained in:
Calixte Denizet 2023-03-06 16:21:37 +01:00
parent 076fdbf6df
commit 1617ee6c3f
2 changed files with 19 additions and 4 deletions
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9
src/core/image_resizer.js
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@ -184,8 +184,13 @@ class ImageResizer {
for (const step of steps) {
const prevWidth = newWidth;
const prevHeight = newHeight;
newWidth = Math.floor(newWidth / step);
newHeight = Math.floor(newHeight / step);
// See bug 1820511 (Windows specific bug).
// TODO: once the above bug is fixed we could revert to:
// newWidth = Math.floor(newWidth / 2);
newWidth = Math.floor(newWidth / step) - 1;
newHeight = Math.floor(newHeight / step) - 1;
const canvas = new OffscreenCanvas(newWidth, newHeight);
const ctx = canvas.getContext("2d");
ctx.drawImage(

14
src/display/canvas.js
View File

@ -1313,11 +1313,21 @@ class CanvasGraphics {
let newWidth = paintWidth,
newHeight = paintHeight;
if (widthScale > 2 && paintWidth > 1) {
newWidth = Math.ceil(paintWidth / 2);
// See bug 1820511 (Windows specific bug).
// TODO: once the above bug is fixed we could revert to:
// newWidth = Math.ceil(paintWidth / 2);
newWidth =
paintWidth >= 16384
? Math.floor(paintWidth / 2) - 1 || 1
: Math.ceil(paintWidth / 2);
widthScale /= paintWidth / newWidth;
}
if (heightScale > 2 && paintHeight > 1) {
newHeight = Math.ceil(paintHeight / 2);
// TODO: see the comment above.
newHeight =
paintHeight >= 16384
? Math.floor(paintHeight / 2) - 1 || 1
: Math.ceil(paintHeight) / 2;
heightScale /= paintHeight / newHeight;
}
tmpCanvas = this.cachedCanvases.getCanvas(