Renamed audio stream callback and moved the userdata parameter first

In general SDL API callbacks are called with the userdata paramter first, to mimic C++ method call convention

include/SDL3/SDL_audio.h

@@ -910,12 +910,12 @@ extern DECLSPEC int SDLCALL SDL_UnlockAudioStream(SDL_AudioStream *stream);
  * manage the lock explicitly.
  *
  * \param stream The SDL audio stream associated with this callback.
- * \param approx_request The _approximate_ amout of data, in bytes, that is requested.
+ * \param approx_amount The _approximate_ amount of data, in bytes, that is requested or available.
  *                       This might be slightly overestimated due to buffering or
- *                       resampling, and may change from call to call anyhow.
+ *                       resampling, and may change from call to call.
  * \param userdata An opaque pointer provided by the app for their personal use.
  */
-typedef void (SDLCALL *SDL_AudioStreamRequestCallback)(SDL_AudioStream *stream, int approx_request, void *userdata);
+typedef void (SDLCALL *SDL_AudioStreamCallback)(void *userdata, SDL_AudioStream *stream, int approx_amount);
 
 /**
  * Set a callback that runs when data is requested from an audio stream.
@@ -960,7 +960,7 @@ typedef void (SDLCALL *SDL_AudioStreamRequestCallback)(SDL_AudioStream *stream,
  *
  * \sa SDL_SetAudioStreamPutCallback
  */
-extern DECLSPEC int SDLCALL SDL_SetAudioStreamGetCallback(SDL_AudioStream *stream, SDL_AudioStreamRequestCallback callback, void *userdata);
+extern DECLSPEC int SDLCALL SDL_SetAudioStreamGetCallback(SDL_AudioStream *stream, SDL_AudioStreamCallback callback, void *userdata);
 
 /**
  * Set a callback that runs when data is added to an audio stream.
@@ -1008,7 +1008,7 @@ extern DECLSPEC int SDLCALL SDL_SetAudioStreamGetCallback(SDL_AudioStream *strea
  *
  * \sa SDL_SetAudioStreamGetCallback
  */
-extern DECLSPEC int SDLCALL SDL_SetAudioStreamPutCallback(SDL_AudioStream *stream, SDL_AudioStreamRequestCallback callback, void *userdata);
+extern DECLSPEC int SDLCALL SDL_SetAudioStreamPutCallback(SDL_AudioStream *stream, SDL_AudioStreamCallback callback, void *userdata);
 
 
 /**
@@ -1080,7 +1080,7 @@ extern DECLSPEC void SDLCALL SDL_DestroyAudioStream(SDL_AudioStream *stream);
  *
  * \since This function is available since SDL 3.0.0.
  */
-extern DECLSPEC SDL_AudioStream *SDLCALL SDL_OpenAudioDeviceStream(SDL_AudioDeviceID devid, const SDL_AudioSpec *spec, SDL_AudioStreamRequestCallback callback, void *userdata);
+extern DECLSPEC SDL_AudioStream *SDLCALL SDL_OpenAudioDeviceStream(SDL_AudioDeviceID devid, const SDL_AudioSpec *spec, SDL_AudioStreamCallback callback, void *userdata);
 
 /**
  * Load the audio data of a WAVE file into memory.

src/audio/SDL_audio.c

@@ -1511,7 +1511,7 @@ SDL_AudioDeviceID SDL_GetAudioStreamDevice(SDL_AudioStream *stream)
     return retval;
 }
 
-SDL_AudioStream *SDL_OpenAudioDeviceStream(SDL_AudioDeviceID devid, const SDL_AudioSpec *spec, SDL_AudioStreamRequestCallback callback, void *userdata)
+SDL_AudioStream *SDL_OpenAudioDeviceStream(SDL_AudioDeviceID devid, const SDL_AudioSpec *spec, SDL_AudioStreamCallback callback, void *userdata)
 {
     SDL_AudioDeviceID logdevid = SDL_OpenAudioDevice(devid, spec);
     if (!logdevid) {

src/audio/SDL_audiocvt.c

@@ -777,7 +777,7 @@ SDL_AudioStream *SDL_CreateAudioStream(const SDL_AudioSpec *src_spec, const SDL_
     return retval;
 }
 
-int SDL_SetAudioStreamGetCallback(SDL_AudioStream *stream, SDL_AudioStreamRequestCallback callback, void *userdata)
+int SDL_SetAudioStreamGetCallback(SDL_AudioStream *stream, SDL_AudioStreamCallback callback, void *userdata)
 {
     if (!stream) {
         return SDL_InvalidParamError("stream");
@@ -789,7 +789,7 @@ int SDL_SetAudioStreamGetCallback(SDL_AudioStream *stream, SDL_AudioStreamReques
     return 0;
 }
 
-int SDL_SetAudioStreamPutCallback(SDL_AudioStream *stream, SDL_AudioStreamRequestCallback callback, void *userdata)
+int SDL_SetAudioStreamPutCallback(SDL_AudioStream *stream, SDL_AudioStreamCallback callback, void *userdata)
 {
     if (!stream) {
         return SDL_InvalidParamError("stream");
@@ -894,7 +894,7 @@ int SDL_PutAudioStreamData(SDL_AudioStream *stream, const void *buf, int len)
     if (stream->put_callback) {
         const int newavail = SDL_GetAudioStreamAvailable(stream) - prev_available;
         if (newavail > 0) {   // don't call the callback if we can't actually offer new data (still filling future buffer, only added 1 frame but downsampling needs more to produce new sound, etc).
-            stream->put_callback(stream, newavail, stream->put_callback_userdata);
+            stream->put_callback(stream->put_callback_userdata, stream, newavail);
         }
     }
 
@@ -948,7 +948,7 @@ static void UpdateStreamHistoryBuffer(SDL_AudioStream* stream, Uint8* input_buff
         SDL_assert(padding_bytes <= history_bytes);
         SDL_memcpy(left_padding, history_buffer + history_bytes - padding_bytes, padding_bytes);
     }
-    
+
     // Update the history buffer using the new input data
     if (input_bytes >= history_bytes) {
         SDL_memcpy(history_buffer, input_buffer + (input_bytes - history_bytes), history_bytes);
@@ -1056,7 +1056,7 @@ static int GetAudioStreamDataInternal(SDL_AudioStream *stream, void *buf, int le
     //
     // ResampleAudio also requires an additional buffer if it can't write straight to the output:
     //   resample_frame_size * output_frames
-    // 
+    //
     // Note, ConvertAudio requires (num_frames * max_sample_frame_size) of scratch space
     const int work_buffer_frames = input_frames + (resampler_padding_frames * 2);
     int work_buffer_capacity = work_buffer_frames * max_sample_frame_size;
@@ -1121,7 +1121,7 @@ static int GetAudioStreamDataInternal(SDL_AudioStream *stream, void *buf, int le
         SDL_assert(stream->flushed);
         SDL_memset(right_padding + right_padding_bytes, SDL_GetSilenceValueForFormat(src_format), padding_bytes - right_padding_bytes);
     }
-    
+
     SDL_assert(work_buffer_frames == input_frames + (resampler_padding_frames * 2));
 
     // Resampling! get the work buffer to float32 format, etc, in-place.
@@ -1186,7 +1186,7 @@ int SDL_GetAudioStreamData(SDL_AudioStream *stream, void *voidbuf, int len)
         const int already_have = SDL_GetAudioStreamAvailable(stream);
         approx_request -= SDL_min(approx_request, already_have);  // we definitely have this much output already packed in.
         if (approx_request > 0) {  // don't call the callback if we can satisfy this request with existing data.
-            stream->get_callback(stream, approx_request, stream->get_callback_userdata);
+            stream->get_callback(stream->get_callback_userdata, stream, approx_request);
         }
     }
 

src/audio/SDL_sysaudio.h

@@ -159,9 +159,9 @@ struct SDL_AudioStream
     SDL_DataQueue *queue;
     SDL_Mutex *lock;  // this is just a copy of `queue`'s mutex. We share a lock.
 
-    SDL_AudioStreamRequestCallback get_callback;
+    SDL_AudioStreamCallback get_callback;
     void *get_callback_userdata;
-    SDL_AudioStreamRequestCallback put_callback;
+    SDL_AudioStreamCallback put_callback;
     void *put_callback_userdata;
 
     Uint8 *work_buffer;    // used for scratch space during data conversion/resampling.

src/dynapi/SDL_dynapi_procs.h

@@ -943,10 +943,10 @@ SDL_DYNAPI_PROC(int,SDL_FlushAudioStream,(SDL_AudioStream *a),(a),return)
 SDL_DYNAPI_PROC(int,SDL_ClearAudioStream,(SDL_AudioStream *a),(a),return)
 SDL_DYNAPI_PROC(int,SDL_LockAudioStream,(SDL_AudioStream *a),(a),return)
 SDL_DYNAPI_PROC(int,SDL_UnlockAudioStream,(SDL_AudioStream *a),(a),return)
-SDL_DYNAPI_PROC(int,SDL_SetAudioStreamGetCallback,(SDL_AudioStream *a, SDL_AudioStreamRequestCallback b, void *c),(a,b,c),return)
-SDL_DYNAPI_PROC(int,SDL_SetAudioStreamPutCallback,(SDL_AudioStream *a, SDL_AudioStreamRequestCallback b, void *c),(a,b,c),return)
+SDL_DYNAPI_PROC(int,SDL_SetAudioStreamGetCallback,(SDL_AudioStream *a, SDL_AudioStreamCallback b, void *c),(a,b,c),return)
+SDL_DYNAPI_PROC(int,SDL_SetAudioStreamPutCallback,(SDL_AudioStream *a, SDL_AudioStreamCallback b, void *c),(a,b,c),return)
 SDL_DYNAPI_PROC(void,SDL_DestroyAudioStream,(SDL_AudioStream *a),(a),)
-SDL_DYNAPI_PROC(SDL_AudioStream*,SDL_OpenAudioDeviceStream,(SDL_AudioDeviceID a, const SDL_AudioSpec *b, SDL_AudioStreamRequestCallback c, void *d),(a,b,c,d),return)
+SDL_DYNAPI_PROC(SDL_AudioStream*,SDL_OpenAudioDeviceStream,(SDL_AudioDeviceID a, const SDL_AudioSpec *b, SDL_AudioStreamCallback c, void *d),(a,b,c,d),return)
 SDL_DYNAPI_PROC(int,SDL_LoadWAV_RW,(SDL_RWops *a, SDL_bool b, SDL_AudioSpec *c, Uint8 **d, Uint32 *e),(a,b,c,d,e),return)
 SDL_DYNAPI_PROC(int,SDL_MixAudioFormat,(Uint8 *a, const Uint8 *b, SDL_AudioFormat c, Uint32 d, int e),(a,b,c,d,e),return)
 SDL_DYNAPI_PROC(int,SDL_ConvertAudioSamples,(const SDL_AudioSpec *a, const Uint8 *b, int c, const SDL_AudioSpec *d, Uint8 **e, int *f),(a,b,c,d,e,f),return)