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Bug 2708 - SDL_SetWindowShape can produce strange results
Summary: SDL_SetWindowShape can produce strange results
Status: RESOLVED FIXED
Alias: None
Product: SDL
Classification: Unclassified
Component: video (show other bugs)
Version: 2.0.3
Hardware: All Windows 7
: P2 major
Assignee: Jørgen Tjernø
QA Contact: Sam Lantinga
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-08-28 00:31 UTC by Jørgen Tjernø
Modified: 2015-05-26 16:17 UTC (History)
2 users (show)

See Also:

Attachments
Window shape bitmap (11.02 KB, image/bmp)
2014-08-28 00:31 UTC, Jørgen Tjernø 		Details
Shaped window screenshot (721 bytes, image/png)
2014-08-28 00:33 UTC, Jørgen Tjernø 		Details
Image causing SDL_SetWindowShape to render the Window shape incorectly (378.88 KB, image/bmp)
2015-04-28 23:18 UTC, Michel Courtine 		Details
View All Add an attachment (proposed patch, testcase, etc.)

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Description Jørgen Tjernø 2014-08-28 00:31:22 UTC 
Created attachment 1854 [details]
Window shape bitmap

Some SDL_Surfaces passed to SDL_SetWindowShape will produce strange results. Tested on Windows 7.

The attached window_shape.bmp can be passed to test_shape, and will produce strange artifacts.
Comment 1 Jørgen Tjernø 2014-08-28 00:33:27 UTC 
Created attachment 1855 [details]
Shaped window screenshot

Attached is a screenshot of test_shape.exe on the previously attached window_shape.bmp, running on a white background. Artifacts are obviously visible.
Comment 2 Jørgen Tjernø 2014-08-28 18:40:06 UTC 
I have a fix for this locally, I'll push it on Monday or Tuesday. The shape tree building code only works properly on power-of-two images, on other images it skips some pixels. On Windows, this turns into blank spaces, since the Windows shaping code builds up a region of all the opaque spaces.
Comment 3 Jørgen Tjernø 2014-09-02 21:16:15 UTC 
Should be fixed in https://hg.libsdl.org/SDL/rev/cd6696d55781
Comment 4 Michel Courtine 2015-04-28 23:18:49 UTC 
Created attachment 2139 [details]
Image causing SDL_SetWindowShape to render the Window shape incorectly
Comment 5 Michel Courtine 2015-04-28 23:22:33 UTC 
This bug is not fixed for me. I just attached a bmp that renders the window shape very strangely. Skipping some pixels again. If I resize it to a power of 2 resolution, the shape is rendered correctly.
Comment 6 Michel Courtine 2015-04-28 23:30:36 UTC 
I was using the prebuilt .lib & .dll from the download page (https://www.libsdl.org/download-2.0.php).
Tried rebuilding SDL from source and the issue is indeed fixed but the binaries distribution would probably need to be refreshed.
Comment 7 Jørgen Tjernø 2015-05-04 23:19:20 UTC 
This is fixed, it is just that the last release (2.0.3) came out on 2014-03-15. 2.0.4 will contains this fix.
Comment 8 Ryan C. Gordon 2015-05-26 16:17:21 UTC 
(In reply to Jørgen Tjernø from comment #7)
> This is fixed, it is just that the last release (2.0.3) came out on
> 2014-03-15. 2.0.4 will contains this fix.

(and we're working on wrapping up 2.0.4 right now.)

--ryan.