1054196 - drawImage on canvas is extremely slow.

Status: RESOLVED WORKSFORME

(Core :: Graphics: Canvas2D, defect)

Description

[vincent_booman]

User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0 (Beta/Release)
Build ID: 20140716183446

Steps to reproduce:

I performed a basic canvas.drawImage to render a small portion of a 2048x2048 spritesheet.


Actual results:

The framerate dropped instantly to around 10 frames per second.


Expected results:

The framedrop should not have happened. It runs just fine on Firefox 30 and other browsers.

Comment 1

[vincent_booman]

I've tested this on a Samsung Galaxy Tab 4, a Samsung Galaxy Note and a Galaxy S 2.

Comment 2

[James Willcox (:snorp) ([e-mail]) (he/him)]

Hi, are you able to attach a small testcase? And just to be clear, the performance was good in 30 but regressed in 31?

Comment 3

[Kevin Brosnan [Ex-Mozilla]]

Reporter can you answer James's question?

Comment 4

[vincent_booman]

Attachment: testcase.rar

This rar contains a simple html page with a canvas that displays a plain image and an FPS counter.

Comment 5

[vincent_booman]

You are correct, the performance was just fine in Firefox 30.

Comment 6

[James Willcox (:snorp) ([e-mail]) (he/him)]

Thanks for the reply, Vincent.

I get about 20fps on this test in 31, but on 32 and higher I consistently get 60fps. I would like to find out what regressed in 31 and also what fixed it in 32. I imagine we got a busted Skia update, or something.