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Most SDL functions used to indicate success or failure using an int return code. These functions have been changed to return SDL_bool. Here is a coccinelle patch to change code that previously compared the return value to 0 and changes it to a boolean test: @ bool_return_type @ identifier func =~ "^(SDL_AddEventWatch|SDL_AddHintCallback|SDL_AddSurfaceAlternateImage|SDL_AddVulkanRenderSemaphores|SDL_BindAudioStream|SDL_BindAudioStreams|SDL_BlitSurface|SDL_BlitSurface9Grid|SDL_BlitSurfaceScaled|SDL_BlitSurfaceTiled|SDL_BlitSurfaceTiledWithScale|SDL_BlitSurfaceUnchecked|SDL_BlitSurfaceUncheckedScaled|SDL_CaptureMouse|SDL_ClearAudioStream|SDL_ClearClipboardData|SDL_ClearComposition|SDL_ClearError|SDL_ClearProperty|SDL_ClearSurface|SDL_CloseIO|SDL_CloseStorage|SDL_ConvertAudioSamples|SDL_ConvertEventToRenderCoordinates|SDL_ConvertPixels|SDL_ConvertPixelsAndColorspace|SDL_CopyFile|SDL_CopyProperties|SDL_CopyStorageFile|SDL_CreateDirectory|SDL_CreateStorageDirectory|SDL_CreateWindowAndRenderer|SDL_DateTimeToTime|SDL_DestroyWindowSurface|SDL_DetachVirtualJoystick|SDL_DisableScreenSaver|SDL_EnableScreenSaver|SDL_EnumerateDirectory|SDL_EnumerateProperties|SDL_EnumerateStorageDirectory|SDL_FillSurfaceRect|SDL_FillSurfaceRects|SDL_FlashWindow|SDL_FlipSurface|SDL_FlushAudioStream|SDL_FlushRenderer|SDL_GL_DestroyContext|SDL_GL_GetAttribute|SDL_GL_GetSwapInterval|SDL_GL_LoadLibrary|SDL_GL_MakeCurrent|SDL_GL_SetAttribute|SDL_GL_SetSwapInterval|SDL_GL_SwapWindow|SDL_GetAudioDeviceFormat|SDL_GetAudioStreamFormat|SDL_GetCameraFormat|SDL_GetClosestFullscreenDisplayMode|SDL_GetCurrentRenderOutputSize|SDL_GetCurrentTime|SDL_GetDXGIOutputInfo|SDL_GetDateTimeLocalePreferences|SDL_GetDisplayBounds|SDL_GetDisplayUsableBounds|SDL_GetGDKDefaultUser|SDL_GetGDKTaskQueue|SDL_GetGamepadSensorData|SDL_GetGamepadTouchpadFinger|SDL_GetHapticEffectStatus|SDL_GetJoystickBall|SDL_GetMasksForPixelFormat|SDL_GetPathInfo|SDL_GetRectUnion|SDL_GetRectUnionFloat|SDL_GetRenderClipRect|SDL_GetRenderColorScale|SDL_GetRenderDrawBlendMode|SDL_GetRenderDrawColor|SDL_GetRenderDrawColorFloat|SDL_GetRenderLogicalPresentation|SDL_GetRenderLogicalPresentationRect|SDL_GetRenderOutputSize|SDL_GetRenderSafeArea|SDL_GetRenderScale|SDL_GetRenderVSync|SDL_GetRenderViewport|SDL_GetSensorData|SDL_GetStorageFileSize|SDL_GetStoragePathInfo|SDL_GetSurfaceAlphaMod|SDL_GetSurfaceBlendMode|SDL_GetSurfaceClipRect|SDL_GetSurfaceColorKey|SDL_GetSurfaceColorMod|SDL_GetTextInputArea|SDL_GetTextureAlphaMod|SDL_GetTextureAlphaModFloat|SDL_GetTextureBlendMode|SDL_GetTextureColorMod|SDL_GetTextureColorModFloat|SDL_GetTextureScaleMode|SDL_GetTextureSize|SDL_GetWindowAspectRatio|SDL_GetWindowBordersSize|SDL_GetWindowMaximumSize|SDL_GetWindowMinimumSize|SDL_GetWindowPosition|SDL_GetWindowRelativeMouseMode|SDL_GetWindowSafeArea|SDL_GetWindowSize|SDL_GetWindowSizeInPixels|SDL_GetWindowSurfaceVSync|SDL_HideCursor|SDL_HideWindow|SDL_Init|SDL_InitHapticRumble|SDL_InitSubSystem|SDL_LoadWAV|SDL_LoadWAV_IO|SDL_LockAudioStream|SDL_LockProperties|SDL_LockSurface|SDL_LockTexture|SDL_LockTextureToSurface|SDL_MaximizeWindow|SDL_MinimizeWindow|SDL_MixAudio|SDL_OpenURL|SDL_OutOfMemory|SDL_PauseAudioDevice|SDL_PauseAudioStreamDevice|SDL_PauseHaptic|SDL_PlayHapticRumble|SDL_PremultiplyAlpha|SDL_PremultiplySurfaceAlpha|SDL_PushEvent|SDL_PutAudioStreamData|SDL_RaiseWindow|SDL_ReadStorageFile|SDL_ReadSurfacePixel|SDL_ReadSurfacePixelFloat|SDL_RegisterApp|SDL_ReloadGamepadMappings|SDL_RemovePath|SDL_RemoveStoragePath|SDL_RemoveTimer|SDL_RenamePath|SDL_RenameStoragePath|SDL_RenderClear|SDL_RenderCoordinatesFromWindow|SDL_RenderCoordinatesToWindow|SDL_RenderFillRect|SDL_RenderFillRects|SDL_RenderGeometry|SDL_RenderGeometryRaw|SDL_RenderLine|SDL_RenderLines|SDL_RenderPoint|SDL_RenderPoints|SDL_RenderPresent|SDL_RenderRect|SDL_RenderRects|SDL_RenderTexture|SDL_RenderTexture9Grid|SDL_RenderTextureRotated|SDL_RenderTextureTiled|SDL_RequestAndroidPermission|SDL_RestoreWindow|SDL_ResumeAudioDevice|SDL_ResumeAudioStreamDevice|SDL_ResumeHaptic|SDL_RumbleGamepad|SDL_RumbleGamepadTriggers|SDL_RumbleJoystick|SDL_RumbleJoystickTriggers|SDL_RunHapticEffect|SDL_SaveBMP|SDL_SaveBMP_IO|SDL_SendAndroidMessage|SDL_SendGamepadEffect|SDL_SendJoystickEffect|SDL_SendJoystickVirtualSensorData|SDL_SetAppMetadata|SDL_SetAppMetadataProperty|SDL_SetAudioDeviceGain|SDL_SetAudioPostmixCallback|SDL_SetAudioStreamFormat|SDL_SetAudioStreamFrequencyRatio|SDL_SetAudioStreamGain|SDL_SetAudioStreamGetCallback|SDL_SetAudioStreamInputChannelMap|SDL_SetAudioStreamOutputChannelMap|SDL_SetAudioStreamPutCallback|SDL_SetBooleanProperty|SDL_SetClipboardData|SDL_SetClipboardText|SDL_SetCursor|SDL_SetFloatProperty|SDL_SetGamepadLED|SDL_SetGamepadMapping|SDL_SetGamepadPlayerIndex|SDL_SetGamepadSensorEnabled|SDL_SetHapticAutocenter|SDL_SetHapticGain|SDL_SetJoystickLED|SDL_SetJoystickPlayerIndex|SDL_SetJoystickVirtualAxis|SDL_SetJoystickVirtualBall|SDL_SetJoystickVirtualButton|SDL_SetJoystickVirtualHat|SDL_SetJoystickVirtualTouchpad|SDL_SetLinuxThreadPriority|SDL_SetLinuxThreadPriorityAndPolicy|SDL_SetLogPriorityPrefix|SDL_SetMemoryFunctions|SDL_SetNumberProperty|SDL_SetPaletteColors|SDL_SetPointerProperty|SDL_SetPointerPropertyWithCleanup|SDL_SetPrimarySelectionText|SDL_SetRenderClipRect|SDL_SetRenderColorScale|SDL_SetRenderDrawBlendMode|SDL_SetRenderDrawColor|SDL_SetRenderDrawColorFloat|SDL_SetRenderLogicalPresentation|SDL_SetRenderScale|SDL_SetRenderTarget|SDL_SetRenderVSync|SDL_SetRenderViewport|SDL_SetScancodeName|SDL_SetStringProperty|SDL_SetSurfaceAlphaMod|SDL_SetSurfaceBlendMode|SDL_SetSurfaceColorKey|SDL_SetSurfaceColorMod|SDL_SetSurfaceColorspace|SDL_SetSurfacePalette|SDL_SetSurfaceRLE|SDL_SetTLS|SDL_SetTextInputArea|SDL_SetTextureAlphaMod|SDL_SetTextureAlphaModFloat|SDL_SetTextureBlendMode|SDL_SetTextureColorMod|SDL_SetTextureColorModFloat|SDL_SetTextureScaleMode|SDL_SetThreadPriority|SDL_SetWindowAlwaysOnTop|SDL_SetWindowAspectRatio|SDL_SetWindowBordered|SDL_SetWindowFocusable|SDL_SetWindowFullscreen|SDL_SetWindowFullscreenMode|SDL_SetWindowHitTest|SDL_SetWindowIcon|SDL_SetWindowKeyboardGrab|SDL_SetWindowMaximumSize|SDL_SetWindowMinimumSize|SDL_SetWindowModalFor|SDL_SetWindowMouseGrab|SDL_SetWindowMouseRect|SDL_SetWindowOpacity|SDL_SetWindowPosition|SDL_SetWindowRelativeMouseMode|SDL_SetWindowResizable|SDL_SetWindowShape|SDL_SetWindowSize|SDL_SetWindowSurfaceVSync|SDL_SetWindowTitle|SDL_SetiOSAnimationCallback|SDL_ShowAndroidToast|SDL_ShowCursor|SDL_ShowMessageBox|SDL_ShowSimpleMessageBox|SDL_ShowWindow|SDL_ShowWindowSystemMenu|SDL_StartTextInput|SDL_StartTextInputWithProperties|SDL_StopHapticEffect|SDL_StopHapticEffects|SDL_StopHapticRumble|SDL_StopTextInput|SDL_SyncWindow|SDL_TimeToDateTime|SDL_TryLockMutex|SDL_TryLockRWLockForReading|SDL_TryLockRWLockForWriting|SDL_TryWaitSemaphore|SDL_UnlockAudioStream|SDL_UpdateHapticEffect|SDL_UpdateNVTexture|SDL_UpdateTexture|SDL_UpdateWindowSurface|SDL_UpdateWindowSurfaceRects|SDL_UpdateYUVTexture|SDL_Vulkan_CreateSurface|SDL_Vulkan_LoadLibrary|SDL_WaitConditionTimeout|SDL_WaitSemaphoreTimeout|SDL_WarpMouseGlobal|SDL_WriteStorageFile|SDL_WriteSurfacePixel|SDL_WriteSurfacePixelFloat)$"; @@ ( func( ... ) - == 0 | - func( + !func( ... ) - < 0 | - func( + !func( ... ) - != 0 | - func( + !func( ... ) - == -1 )
111 lines
4.9 KiB
C
111 lines
4.9 KiB
C
/*
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* This example code creates an simple audio stream for playing sound, and
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* generates a sine wave sound effect for it to play as time goes on. Unlike
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* the previous example, this uses a callback to generate sound.
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*
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* This might be the path of least resistance if you're moving an SDL2
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* program's audio code to SDL3.
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*
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* This code is public domain. Feel free to use it for any purpose!
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*/
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#define SDL_MAIN_USE_CALLBACKS 1 /* use the callbacks instead of main() */
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#include <SDL3/SDL.h>
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#include <SDL3/SDL_main.h>
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/* We will use this renderer to draw into this window every frame. */
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static SDL_Window *window = NULL;
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static SDL_Renderer *renderer = NULL;
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static SDL_AudioStream *stream = NULL;
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static int total_samples_generated = 0;
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/* this function will be called (usually in a background thread) when the audio stream is consuming data. */
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static void SDLCALL FeedTheAudioStreamMore(void *userdata, SDL_AudioStream *astream, int additional_amount, int total_amount)
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{
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/* total_amount is how much data the audio stream is eating right now, additional_amount is how much more it needs
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than what it currently has queued (which might be zero!). You can supply any amount of data here; it will take what
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it needs and use the extra later. If you don't give it enough, it will take everything and then feed silence to the
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hardware for the rest. Ideally, though, we always give it what it needs and no extra, so we aren't buffering more
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than necessary. */
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additional_amount /= sizeof (float); /* convert from bytes to samples */
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while (additional_amount > 0) {
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float samples[128]; /* this will feed 128 samples each iteration until we have enough. */
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const int total = SDL_min(additional_amount, SDL_arraysize(samples));
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int i;
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for (i = 0; i < total; i++) {
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/* You don't have to care about this math; we're just generating a simple sine wave as we go.
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https://en.wikipedia.org/wiki/Sine_wave */
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const float time = total_samples_generated / 8000.0f;
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const int sine_freq = 500; /* run the wave at 500Hz */
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samples[i] = SDL_sinf(6.283185f * sine_freq * time);
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total_samples_generated++;
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}
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/* feed the new data to the stream. It will queue at the end, and trickle out as the hardware needs more data. */
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SDL_PutAudioStreamData(astream, samples, total * sizeof (float));
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additional_amount -= total; /* subtract what we've just fed the stream. */
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}
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}
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/* This function runs once at startup. */
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SDL_AppResult SDL_AppInit(void **appstate, int argc, char *argv[])
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{
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SDL_AudioSpec spec;
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if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO)) {
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SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Couldn't initialize SDL!", SDL_GetError(), NULL);
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return SDL_APP_FAILURE;
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}
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/* we don't _need_ a window for audio-only things but it's good policy to have one. */
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if (!SDL_CreateWindowAndRenderer("examples/audio/simple-playback-callback", 640, 480, 0, &window, &renderer)) {
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SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Couldn't create window/renderer!", SDL_GetError(), NULL);
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return SDL_APP_FAILURE;
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}
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/* We're just playing a single thing here, so we'll use the simplified option.
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We are always going to feed audio in as mono, float32 data at 8000Hz.
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The stream will convert it to whatever the hardware wants on the other side. */
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spec.channels = 1;
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spec.format = SDL_AUDIO_F32;
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spec.freq = 8000;
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stream = SDL_OpenAudioDeviceStream(SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK, &spec, FeedTheAudioStreamMore, NULL);
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if (!stream) {
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SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Couldn't create audio stream!", SDL_GetError(), window);
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return SDL_APP_FAILURE;
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}
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/* SDL_OpenAudioDeviceStream starts the device paused. You have to tell it to start! */
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SDL_ResumeAudioStreamDevice(stream);
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return SDL_APP_CONTINUE; /* carry on with the program! */
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}
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/* This function runs when a new event (mouse input, keypresses, etc) occurs. */
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SDL_AppResult SDL_AppEvent(void *appstate, const SDL_Event *event)
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{
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if (event->type == SDL_EVENT_QUIT) {
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return SDL_APP_SUCCESS; /* end the program, reporting success to the OS. */
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}
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return SDL_APP_CONTINUE; /* carry on with the program! */
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}
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/* This function runs once per frame, and is the heart of the program. */
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SDL_AppResult SDL_AppIterate(void *appstate)
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{
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/* we're not doing anything with the renderer, so just blank it out. */
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SDL_RenderClear(renderer);
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SDL_RenderPresent(renderer);
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/* all the work of feeding the audio stream is happening in a callback in a background thread. */
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return SDL_APP_CONTINUE; /* carry on with the program! */
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}
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/* This function runs once at shutdown. */
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void SDL_AppQuit(void *appstate)
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{
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/* SDL will clean up the window/renderer for us. */
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}
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