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Bug 755 - SDL_DisplayFormatAlpha() crashes
Summary: SDL_DisplayFormatAlpha() crashes
Status: RESOLVED INVALID
Alias: None
Product: SDL
Classification: Unclassified
Component: video (show other bugs)
Version: 1.2.13
Hardware: x86 Linux
: P2 major
Assignee: Ryan C. Gordon
QA Contact: Sam Lantinga
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2009-06-15 15:36 UTC by Sjors Gielen
Modified: 2009-06-15 16:13 UTC (History)
0 users

See Also:

Attachments
Testcase (1.74 KB, text/x-csrc)
2009-06-15 15:38 UTC, Sjors Gielen 		Details
Sample file with which this bug occurs (8.27 KB, image/x-ms-bmp)
2009-06-15 15:39 UTC, Sjors Gielen 		Details
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Description Sjors Gielen 2009-06-15 15:36:17 UTC 
I am using SDL_DisplayFormatAlpha() on a surface just previously loaded from a BMP file. I will attach the test case and the BMP image I am using. It is 8 bpp. What I was trying to do in my main application, was set the alpha color key to 0, because that's the color of the "background" which I want transparent. Then I called SDL_DisplayFormatAlpha to get a nice 32-bpp image with alpha value which I could use to blit over my screen.
However, I noticed SDL_DisplayFormatAlpha kept crashing so I wrote a test case. The segfault has been confirmed by two other people.
Comment 1 Sjors Gielen 2009-06-15 15:38:49 UTC 
Created attachment 330 [details]
Testcase
Comment 2 Sjors Gielen 2009-06-15 15:39:23 UTC 
Created attachment 331 [details]
Sample file with which this bug occurs
Comment 3 Sjors Gielen 2009-06-15 16:13:03 UTC 
Oops, this is caused by not calling SDL_SetVideoMode(). Added a note on this to the docwiki so it doesn't bite others... http://www.libsdl.org/cgi/docwiki.cgi/SDL_DisplayFormatAlpha