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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 | 75a95f82bc1f |
children | 6d2e1961661a |
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This is the porting of 1.2.0 version of SDL (the latest stable one) to AmigaOS/68k. All the bugs known of the past version have been corrected. And I've added all the new SDL features. This version of SDL needs Cybergraphx V3 (r69+) or CyberGraphX V4 and AHI v3+. Probably it works also with P96 or CGXAga, but it's untested. This version is available as linked library for SAS/C and GCC, only 68k this time, a powerup (ppcemu compatible) and a morphos version will be ready quite soon (i hope). Implemented: - 8/16/24/32bit video modes, both fullscreen and windowed. - Hardware surfaces. - CGX blitting acceleration. - CGX colorkey blitting acceleration. - AHI audio (8/16 bit, with any audio format), always uses unit 0 for now. - Thread support (maybe not 100% compatible with other implementations) - Semaphores - Window resizing and backdrop windows (NEW) - Joystick/Joypad support. To do: - CDRom audio playing support - OpenGL (A guy was working on it but I've lost his tracks :( ) The SAS/C library is distributed with debug info attached, to strip debug info simply add STRIPDEBUG argument to the linker. NOTE: SDL includes debug output using kprintf, to disable it add to your project a function like this: void kprintf(char *a,...) { } Otherwise you can redirect the debug to a console window with sushi, sashimi or similar tools (the default output is the internal serial port). For info, support, bugfix and other feel free to mail me: Gabriele Greco (gabriele.greco@aruba.it) You can find also a small SDL Amiga page at: http://ggreco.interfree.it/sdl.html