diff options
Diffstat (limited to 'Xcode-iOS/Demos/src/mixer.c')
| -rw-r--r-- | Xcode-iOS/Demos/src/mixer.c | 344 |
1 files changed, 0 insertions, 344 deletions
diff --git a/Xcode-iOS/Demos/src/mixer.c b/Xcode-iOS/Demos/src/mixer.c deleted file mode 100644 index 14945ad33..000000000 --- a/Xcode-iOS/Demos/src/mixer.c +++ /dev/null @@ -1,344 +0,0 @@ -/* - * mixer.c - * written by Holmes Futrell - * use however you want - */ - -#include "SDL.h" -#include "common.h" - -#define NUM_CHANNELS 8 /* max number of sounds we can play at once */ -#define NUM_DRUMS 4 /* number of drums in our set */ - -static struct -{ - SDL_Rect rect; /* where the button is drawn */ - SDL_Color upColor; /* color when button is not active */ - SDL_Color downColor; /* color when button is active */ - int isPressed; /* is the button being pressed ? */ - int touchIndex; /* what mouse (touch) index pressed the button ? */ -} buttons[NUM_DRUMS]; - -struct sound -{ - Uint8 *buffer; /* audio buffer for sound file */ - Uint32 length; /* length of the buffer (in bytes) */ -}; - -/* this array holds the audio for the drum noises */ -static struct sound drums[NUM_DRUMS]; - -/* function declarations */ -void handleMouseButtonDown(SDL_Event * event); -void handleMouseButtonUp(SDL_Event * event); -int playSound(struct sound *); -void initializeButtons(SDL_Renderer *); -void audioCallback(void *userdata, Uint8 * stream, int len); -void loadSound(const char *file, struct sound *s); - -struct -{ - /* channel array holds information about currently playing sounds */ - struct - { - Uint8 *position; /* what is the current position in the buffer of this sound ? */ - Uint32 remaining; /* how many bytes remaining before we're done playing the sound ? */ - Uint32 timestamp; /* when did this sound start playing ? */ - } channels[NUM_CHANNELS]; - SDL_AudioSpec outputSpec; /* what audio format are we using for output? */ - int numSoundsPlaying; /* how many sounds are currently playing */ -} mixer; - -/* sets up the buttons (color, position, state) */ -void -initializeButtons(SDL_Renderer *renderer) -{ - int i; - int spacing = 10; /* gap between drum buttons */ - SDL_Rect buttonRect; /* keeps track of where to position drum */ - SDL_Color upColor = { 86, 86, 140, 255 }; /* color of drum when not pressed */ - SDL_Color downColor = { 191, 191, 221, 255 }; /* color of drum when pressed */ - int renderW, renderH; - - SDL_RenderGetLogicalSize(renderer, &renderW, &renderH); - - buttonRect.x = spacing; - buttonRect.y = spacing; - buttonRect.w = renderW - 2 * spacing; - buttonRect.h = (renderH - (NUM_DRUMS + 1) * spacing) / NUM_DRUMS; - - /* setup each button */ - for (i = 0; i < NUM_DRUMS; i++) { - - buttons[i].rect = buttonRect; - buttons[i].isPressed = 0; - buttons[i].upColor = upColor; - buttons[i].downColor = downColor; - - buttonRect.y += spacing + buttonRect.h; /* setup y coordinate for next drum */ - - } -} - -/* - loads a wav file (stored in 'file'), converts it to the mixer's output format, - and stores the resulting buffer and length in the sound structure - */ -void -loadSound(const char *file, struct sound *s) -{ - SDL_AudioSpec spec; /* the audio format of the .wav file */ - SDL_AudioCVT cvt; /* used to convert .wav to output format when formats differ */ - int result; - if (SDL_LoadWAV(file, &spec, &s->buffer, &s->length) == NULL) { - fatalError("could not load .wav"); - } - /* build the audio converter */ - result = SDL_BuildAudioCVT(&cvt, spec.format, spec.channels, spec.freq, - mixer.outputSpec.format, - mixer.outputSpec.channels, - mixer.outputSpec.freq); - if (result == -1) { - fatalError("could not build audio CVT"); - } else if (result != 0) { - /* - this happens when the .wav format differs from the output format. - we convert the .wav buffer here - */ - cvt.buf = (Uint8 *) SDL_malloc(s->length * cvt.len_mult); /* allocate conversion buffer */ - cvt.len = s->length; /* set conversion buffer length */ - SDL_memcpy(cvt.buf, s->buffer, s->length); /* copy sound to conversion buffer */ - if (SDL_ConvertAudio(&cvt) == -1) { /* convert the sound */ - fatalError("could not convert .wav"); - } - SDL_free(s->buffer); /* free the original (unconverted) buffer */ - s->buffer = cvt.buf; /* point sound buffer to converted buffer */ - s->length = cvt.len_cvt; /* set sound buffer's new length */ - } -} - -/* called from main event loop */ -void -handleMouseButtonDown(SDL_Event * event) -{ - - int x, y, mouseIndex, i, drumIndex; - - mouseIndex = 0; - drumIndex = -1; - - SDL_GetMouseState(&x, &y); - /* check if we hit any of the drum buttons */ - for (i = 0; i < NUM_DRUMS; i++) { - if (x >= buttons[i].rect.x - && x < buttons[i].rect.x + buttons[i].rect.w - && y >= buttons[i].rect.y - && y < buttons[i].rect.y + buttons[i].rect.h) { - drumIndex = i; - break; - } - } - if (drumIndex != -1) { - /* if we hit a button */ - buttons[drumIndex].touchIndex = mouseIndex; - buttons[drumIndex].isPressed = 1; - playSound(&drums[drumIndex]); - } - -} - -/* called from main event loop */ -void -handleMouseButtonUp(SDL_Event * event) -{ - int i; - int mouseIndex = 0; - /* check if this should cause any of the buttons to become unpressed */ - for (i = 0; i < NUM_DRUMS; i++) { - if (buttons[i].touchIndex == mouseIndex) { - buttons[i].isPressed = 0; - } - } -} - -/* draws buttons to screen */ -void -render(SDL_Renderer *renderer) -{ - int i; - SDL_SetRenderDrawColor(renderer, 50, 50, 50, 255); - SDL_RenderClear(renderer); /* draw background (gray) */ - /* draw the drum buttons */ - for (i = 0; i < NUM_DRUMS; i++) { - SDL_Color color = - buttons[i].isPressed ? buttons[i].downColor : buttons[i].upColor; - SDL_SetRenderDrawColor(renderer, color.r, color.g, color.b, color.a); - SDL_RenderFillRect(renderer, &buttons[i].rect); - } - /* update the screen */ - SDL_RenderPresent(renderer); -} - -/* - finds a sound channel in the mixer for a sound - and sets it up to start playing -*/ -int -playSound(struct sound *s) -{ - /* - find an empty channel to play on. - if no channel is available, use oldest channel - */ - int i; - int selected_channel = -1; - int oldest_channel = 0; - - if (mixer.numSoundsPlaying == 0) { - /* we're playing a sound now, so start audio callback back up */ - SDL_PauseAudio(0); - } - - /* find a sound channel to play the sound on */ - for (i = 0; i < NUM_CHANNELS; i++) { - if (mixer.channels[i].position == NULL) { - /* if no sound on this channel, select it */ - selected_channel = i; - break; - } - /* if this channel's sound is older than the oldest so far, set it to oldest */ - if (mixer.channels[i].timestamp < - mixer.channels[oldest_channel].timestamp) - oldest_channel = i; - } - - /* no empty channels, take the oldest one */ - if (selected_channel == -1) - selected_channel = oldest_channel; - else - mixer.numSoundsPlaying++; - - /* point channel data to wav data */ - mixer.channels[selected_channel].position = s->buffer; - mixer.channels[selected_channel].remaining = s->length; - mixer.channels[selected_channel].timestamp = SDL_GetTicks(); - - return selected_channel; -} - -/* - Called from SDL's audio system. Supplies sound input with data by mixing together all - currently playing sound effects. -*/ -void -audioCallback(void *userdata, Uint8 * stream, int len) -{ - int i; - int copy_amt; - SDL_memset(stream, mixer.outputSpec.silence, len); /* initialize buffer to silence */ - /* for each channel, mix in whatever is playing on that channel */ - for (i = 0; i < NUM_CHANNELS; i++) { - if (mixer.channels[i].position == NULL) { - /* if no sound is playing on this channel */ - continue; /* nothing to do for this channel */ - } - - /* copy len bytes to the buffer, unless we have fewer than len bytes remaining */ - copy_amt = - mixer.channels[i].remaining < - len ? mixer.channels[i].remaining : len; - - /* mix this sound effect with the output */ - SDL_MixAudioFormat(stream, mixer.channels[i].position, - mixer.outputSpec.format, copy_amt, SDL_MIX_MAXVOLUME); - - /* update buffer position in sound effect and the number of bytes left */ - mixer.channels[i].position += copy_amt; - mixer.channels[i].remaining -= copy_amt; - - /* did we finish playing the sound effect ? */ - if (mixer.channels[i].remaining == 0) { - mixer.channels[i].position = NULL; /* indicates no sound playing on channel anymore */ - mixer.numSoundsPlaying--; - if (mixer.numSoundsPlaying == 0) { - /* if no sounds left playing, pause audio callback */ - SDL_PauseAudio(1); - } - } - } -} - -int -main(int argc, char *argv[]) -{ - int done; /* has user tried to quit ? */ - SDL_Window *window; /* main window */ - SDL_Renderer *renderer; - SDL_Event event; - int i; - int width; - int height; - - if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0) { - fatalError("could not initialize SDL"); - } - window = SDL_CreateWindow(NULL, 0, 0, 320, 480, SDL_WINDOW_BORDERLESS | SDL_WINDOW_ALLOW_HIGHDPI); - renderer = SDL_CreateRenderer(window, 0, 0); - - SDL_GetWindowSize(window, &width, &height); - SDL_RenderSetLogicalSize(renderer, width, height); - - /* initialize the mixer */ - SDL_memset(&mixer, 0, sizeof(mixer)); - /* setup output format */ - mixer.outputSpec.freq = 44100; - mixer.outputSpec.format = AUDIO_S16LSB; - mixer.outputSpec.channels = 2; - mixer.outputSpec.samples = 256; - mixer.outputSpec.callback = audioCallback; - mixer.outputSpec.userdata = NULL; - - /* open audio for output */ - if (SDL_OpenAudio(&mixer.outputSpec, NULL) != 0) { - fatalError("Opening audio failed"); - } - - /* load our drum noises */ - loadSound("ds_kick_big_amb.wav", &drums[3]); - loadSound("ds_brush_snare.wav", &drums[2]); - loadSound("ds_loose_skin_mute.wav", &drums[1]); - loadSound("ds_china.wav", &drums[0]); - - /* setup positions, colors, and state of buttons */ - initializeButtons(renderer); - - /* enter main loop */ - done = 0; - while (!done) { - while (SDL_PollEvent(&event)) { - switch (event.type) { - case SDL_MOUSEBUTTONDOWN: - handleMouseButtonDown(&event); - break; - case SDL_MOUSEBUTTONUP: - handleMouseButtonUp(&event); - break; - case SDL_QUIT: - done = 1; - break; - } - } - render(renderer); /* draw buttons */ - - SDL_Delay(1); - } - - /* cleanup code, let's free up those sound buffers */ - for (i = 0; i < NUM_DRUMS; i++) { - SDL_free(drums[i].buffer); - } - /* let SDL do its exit code */ - SDL_Quit(); - - return 0; -} |