Mercurial > sdl-ios-xcode
view docs/man3/SDL_LoadWAV.3 @ 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 | e5bc29de3f0a |
children | 546f7c1eb755 |
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.TH "SDL_LoadWAV" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference" .SH "NAME" SDL_LoadWAV\- Load a WAVE file .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBSDL_AudioSpec *\fBSDL_LoadWAV\fP\fR(\fBconst char *file, SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len\fR); .SH "DESCRIPTION" .PP \fBSDL_LoadWAV\fP This function loads a WAVE \fBfile\fR into memory\&. .PP If this function succeeds, it returns the given \fI\fBSDL_AudioSpec\fP\fR, filled with the audio data format of the wave data, and sets \fBaudio_buf\fR to a \fBmalloc\fP\&'d buffer containing the audio data, and sets \fBaudio_len\fR to the length of that audio buffer, in bytes\&. You need to free the audio buffer with \fI\fBSDL_FreeWAV\fP\fR when you are done with it\&. .PP This function returns \fBNULL\fP and sets the SDL error message if the wave file cannot be opened, uses an unknown data format, or is corrupt\&. Currently raw, MS-ADPCM and IMA-ADPCM WAVE files are supported\&. .SH "EXAMPLE" .PP .nf \f(CWSDL_AudioSpec wav_spec; Uint32 wav_length; Uint8 *wav_buffer; /* Load the WAV */ if( SDL_LoadWAV("test\&.wav", &wav_spec, &wav_buffer, &wav_length) == NULL ){ fprintf(stderr, "Could not open test\&.wav: %s ", SDL_GetError()); exit(-1); } \&. \&. \&. /* Do stuff with the WAV */ \&. \&. /* Free It */ SDL_FreeWAV(wav_buffer);\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_AudioSpec\fR\fR, \fI\fBSDL_OpenAudio\fP\fR, \fI\fBSDL_FreeWAV\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:58