1194719 - Copying with drawImage causes a blurry canvas on Nexus 7

Status: ASSIGNED

(Core :: Graphics: Canvas2D, defect)

Description

[Samuel]

Attachment: Very simple page which illustrates the error

User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.15 Safari/537.36
Firefox for Android

Steps to reproduce:

1. Firefox 40 running on Nexus 7 with Android 5.1.1
2. Use canvasContext.drawImage to copy content from the canvas to the same canvas


Actual results:

The resulting image in the canvas is blurry. The more times you do the copy, the blurrier it gets.


Expected results:

It should not get blurry.

Comment 1

[Samuel]

Setting the following property will work around the issue:

canvasContext.mozImageSmoothingEnabled = false;

Comment 2

[Jamie Nicol [:jnicol]]

I can reproduce this on both my 2013 Nexus 7 (Adreno 320) and my Nexus 5 (Adreno 330).
This issue does not affect my Nexus 6 (Adreno 420) or my Galaxy S6 (Mali-T760).

Comment 3

[Jamie Nicol [:jnicol]]

This is only an issue when using SkiaGL for canvas, and drawing with the skia filter mode set to SkPaint::kLow_FilterLevel or SkPaint::kMedium_FilterLevel. kNone_FilterLevel and kHigh_FilterLevel render correctly. Not sure yet what's going on internally in skia (and the driver) that's causing this.