Clarify documentation for audio callback migration

main
Sam Lantinga 2023-11-02 22:32:25 -07:00
parent 6cf84e2c5b
commit 14980b25a8
1 changed files with 15 additions and 5 deletions

View File

@ -62,7 +62,7 @@ In SDL2, you might have done something like this to play audio...
```c
void SDLCALL MyAudioCallback(void *userdata, Uint8 * stream, int len)
{
/* calculate a little more audio here, maybe using `userdata`, write it to `stream` */
/* Calculate a little more audio here, maybe using `userdata`, write it to `stream` */
}
/* ...somewhere near startup... */
@ -81,15 +81,25 @@ In SDL2, you might have done something like this to play audio...
...in SDL3, you can do this...
```c
void SDLCALL MyAudioCallback(SDL_AudioStream *stream, int len, void *userdata)
void SDLCALL MyAudioCallback3(void *userdata, SDL_AudioStream *stream, int additional_amount, int total_amount)
{
/* calculate a little more audio here, maybe using `userdata`, write it to `stream` */
SDL_PutAudioStreamData(stream, newdata, len);
/* Calculate a little more audio here, maybe using `userdata`, write it to `stream`
*
* If you want to reuse the original callback, you could do something like this:
*/
if (additional_amount > 0) {
Uint16 *data = SDL_stack_alloc(Uint16, additional_amount / sizeof(Uint16));
if (data) {
MyAudioCallback(userdata, data, additional_amount);
SDL_PutAudioStreamData(stream, data, additional_amount);
SDL_stack_free(data);
}
}
}
/* ...somewhere near startup... */
const SDL_AudioSpec spec = { SDL_AUDIO_S16, 2, 44100 };
SDL_AudioStream *stream = SDL_OpenAudioDeviceStream(SDL_AUDIO_DEVICE_DEFAULT_OUTPUT, &spec, MyAudioCallback, &my_audio_callback_user_data);
SDL_AudioStream *stream = SDL_OpenAudioDeviceStream(SDL_AUDIO_DEVICE_DEFAULT_OUTPUT, &spec, MyAudioCallback3, &my_audio_callback_user_data);
SDL_ResumeAudioDevice(SDL_GetAudioStreamDevice(stream));
```