337424 - Unloaded part of image drawn as black when top of image is above visible region

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Pawel Chmielowski]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9a1) Gecko/20060509 Firefox/3.0a1
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9a1) Gecko/20060509 Firefox/3.0a1

Fix from bug 326672 and bug 336236 draws only decoded parts of image but it doesn't take into account that image in some cases will not be draw from (0,0) position. This can be spoted when image bigger then visible region is loaded and page is scrolled down.

Reproducible: Always

Comment 1

[Pawel Chmielowski]

Attachment: v1

This patch fixes this issue by decreasing clip size by region not visible on screen.

Comment 2

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Comment on attachment 221579 [details] [diff] [review]
v1

Hmm. I /think/ this is ok; thanks for the patch!  Something is niggling at me that there may need to be some scaling involved with SX/SY, but maybe not.

r=me in any case, we can fix the scaled case if it's wrong.

Comment 3

[Pawel Chmielowski]

Attachment: v2

You have right, aS{X,Y} should be scaled as well, anyway i taken deeper look at that code and simplified this code by removing source cliping entirely.

I am not 100% sure that removing memset is correct, but didn't see what can require it now, when cliping is corrected.

Comment 4

[Pawel Chmielowski]

Attachment: v3

This version correctly handles images which decodes from bottom to top, it fixes bug 339204.

Comment 5

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Comment on attachment 223352 [details] [diff] [review]
v3

Looks good; this should also fix the crash people are seeing due to the clip, but I still need to track that down (because thta crash shouldn't be there!)

Comment 6

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

checked in, thanks!