Mercurial > sdl-ios-xcode
view README.Epoc @ 1544:ab1e4c41ab71
Fixed bug #33
Mike Frysinger wrote:
> with libsdl-1.2.9, some games (like bomberclone) started
> segfaulting in Gentoo
[...snip...]
> the last change in the last hunk:
[...snip...]
> if i change the statement to read:
> (table[which].blit_features & GetBlitFeatures()) == GetBlitFeatures()
> bomberclone no longer segfaults on my box
Alex Volkov wrote:
> The test "(table[which].blit_features & GetBlitFeatures()) ==
> table[which].blit_features)" is correct, and the previous
> "(table[which].cpu_mmx == SDL_HasMMX())" was actually broken.
I think there is potentially a slightly different cause of the above problem.
During the introduction of the Altivec code, the blit_table struct field
'alpha' got changed from a straightforward enum to a bitmask, which makes
perfect sense by itself. However, now the table driven blitter selection code
in SDL_CalculateBlitN() can choose the wrong blitters when searching for a
NO_ALPHA blitter because of the following code:
int a_need = 0;
...
(a_need & table[which].alpha) == a_need &&
When searching through the normal_blit_2[] table, a SET_ALPHA blitter (like
Blit_RGB565_ARGB8888) can now be selected instead of a NO_ALPHA one, causing
alpha channel bits to appear in a non-alpha destination surface. I suppose this
could theoretically be an indirect cause of the segfault mentioned above.
I *think* this can be fixed by changing to
int a_need = NO_ALPHA;
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Wed, 15 Mar 2006 15:47:49 +0000 |
parents | 74a8f672f2f8 |
children |
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============================================================================== Using the Simple DirectMedia Layer with EPOC/SymbianOS 6.0 ============================================================================== ============================================================================== I. Building the Simple DirectMedia Layer libraries: You can get Symbian SDK from: http://www.symbian.com. First create "Epoc" directory under SDL main directory and unpack EpocBuildFiles.zip in it. To build the librarys goto "epoc" directory and type: bldmake bldfiles abld makefile vc6 (for creating Microsoft Visual C++ makefiles) abld build wins udeb (building for wins emulator) abld build armi urel (building for real device) ============================================================================== II. Building the Simple DirectMedia Layer programs: Building SDL test programs is easy once you have built the libraries: abld test build wins udeb abld test build armi urel Supported real screen resolutions 320 x 200 x 8 bit 320 x 200 x 12 bit 640 x 200 x 8 bit 640 x 200 x 12 bit Supported "emulated" screen resolutions 640 x 400 x 8 bit 640 x 400 x 12 bit 640 x 480 x 8 bit 640 x 480 x 12 bit "Emulated" resolutions are implemented by by shrinking the screen vertically i.e. only every second scanline is drawn. This is mainly ment to be used for testing quick ports of programs. Using faked resolutions is a waste of memory and cpu power! ============================================================================== III. Running test programs Copy executable to the device and run it from the File manager. The Esc key quits demo programs. In Crystal, Exe programs do not appear in task list nor in Extras :-(. Test programs are tested in Nokia 9210 Communicator. Special keys used in SDL: The Caps lock key enables or disables the virtual cursor. Function keys are mapped as follows: F1=chr+q, F2=chr+w,..., F8=chr+i, F9=chr+a,..., F12=chr+d. ============================================================================== IV. Enjoy! :) If you have a project you'd like me to know about, or want to ask questions, go ahead and join the SDL developer's mailing list by sending e-mail to: sdl-request@libsdl.org and put "subscribe" into the subject of the message. Or alternatively you can use the web interface: http://www.libsdl.org/mailman/listinfo/sdl You can find more info about Epoc version of SDL from Hannu Viitala's homepage http://www.mbnet.fi/~haviital ==============================================================================