Smooth finalizing, rewinding, and a bit more crash safety

* Smooth finalizing of song when loop is disabled (old ugly hack has been removed :wink:)
* Added an ability to reset song position to begin (very helpful when song reaches the end)
* Avoided possible crashes on attempt to fetch sample data without opening of MIDI file

1 files changed, 53 insertions, 224 deletions

diff --git a/src/adlmidi.cpp b/src/adlmidi.cpp
index 79c1422..11b7c9b 100644
--- a/src/adlmidi.cpp
+++ b/src/adlmidi.cpp
@@ -23,52 +23,47 @@
 
 #include "adlmidi_private.hpp"
 
-#ifdef ADLMIDI_buildAsApp
-#define SDL_MAIN_HANDLED
-#include <SDL2/SDL.h>
-#endif
-
 static const unsigned MaxCards = 100;
 
 /*---------------------------EXPORTS---------------------------*/
 
 ADLMIDI_EXPORT struct ADL_MIDIPlayer *adl_init(long sample_rate)
 {
-    ADL_MIDIPlayer *_device;
-    _device = (ADL_MIDIPlayer *)malloc(sizeof(ADL_MIDIPlayer));
-    _device->PCM_RATE = static_cast<unsigned long>(sample_rate);
-    _device->AdlBank    = 0;
-    _device->NumFourOps = 7;
-    _device->NumCards   = 2;
-    _device->HighTremoloMode   = 0;
-    _device->HighVibratoMode   = 0;
-    _device->AdlPercussionMode = 0;
-    _device->LogarithmicVolumes = 0;
-    _device->QuitFlag = 0;
-    _device->SkipForward = 0;
-    _device->QuitWithoutLooping = 0;
-    _device->ScaleModulators = 0;
-    _device->delay = 0.0;
-    _device->carry = 0.0;
-    _device->mindelay = 1.0 / (double)_device->PCM_RATE;
-    _device->maxdelay = 512.0 / (double)_device->PCM_RATE;
-    _device->stored_samples = 0;
-    _device->backup_samples_size = 0;
+    ADL_MIDIPlayer *midi_device;
+    midi_device = (ADL_MIDIPlayer *)malloc(sizeof(ADL_MIDIPlayer));
+    midi_device->PCM_RATE = static_cast<unsigned long>(sample_rate);
+    midi_device->AdlBank    = 0;
+    midi_device->NumFourOps = 7;
+    midi_device->NumCards   = 2;
+    midi_device->HighTremoloMode   = 0;
+    midi_device->HighVibratoMode   = 0;
+    midi_device->AdlPercussionMode = 0;
+    midi_device->LogarithmicVolumes = 0;
+    midi_device->SkipForward = 0;
+    midi_device->QuitWithoutLooping = 0;
+    midi_device->ScaleModulators = 0;
+    midi_device->delay = 0.0;
+    midi_device->carry = 0.0;
+    midi_device->mindelay = 1.0 / (double)midi_device->PCM_RATE;
+    midi_device->maxdelay = 512.0 / (double)midi_device->PCM_RATE;
+    midi_device->stored_samples = 0;
+    midi_device->backup_samples_size = 0;
+
     MIDIplay *player = new MIDIplay;
-    _device->adl_midiPlayer = player;
-    player->config = _device;
-    player->opl._parent = _device;
-    player->opl.NumCards = _device->NumCards;
-    player->opl.AdlBank = _device->AdlBank;
-    player->opl.NumFourOps = _device->NumFourOps;
-    player->opl.LogarithmicVolumes = (bool)_device->LogarithmicVolumes;
-    player->opl.HighTremoloMode = (bool)_device->HighTremoloMode;
-    player->opl.HighVibratoMode = (bool)_device->HighVibratoMode;
-    player->opl.AdlPercussionMode = (bool)_device->AdlPercussionMode;
-    player->opl.ScaleModulators = (bool)_device->ScaleModulators;
+    midi_device->adl_midiPlayer = player;
+    player->config = midi_device;
+    player->opl._parent = midi_device;
+    player->opl.NumCards = midi_device->NumCards;
+    player->opl.AdlBank = midi_device->AdlBank;
+    player->opl.NumFourOps = midi_device->NumFourOps;
+    player->opl.LogarithmicVolumes = (bool)midi_device->LogarithmicVolumes;
+    player->opl.HighTremoloMode = (bool)midi_device->HighTremoloMode;
+    player->opl.HighVibratoMode = (bool)midi_device->HighVibratoMode;
+    player->opl.AdlPercussionMode = (bool)midi_device->AdlPercussionMode;
+    player->opl.ScaleModulators = (bool)midi_device->ScaleModulators;
     player->ChooseDevice("none");
-    adlRefreshNumCards(_device);
-    return _device;
+    adlRefreshNumCards(midi_device);
+    return midi_device;
 }
 
 ADLMIDI_EXPORT int adl_setNumCards(ADL_MIDIPlayer *device, int numCards)
@@ -92,6 +87,12 @@ ADLMIDI_EXPORT int adl_setNumCards(ADL_MIDIPlayer *device, int numCards)
 
 ADLMIDI_EXPORT int adl_setBank(ADL_MIDIPlayer *device, int bank)
 {
+    #ifdef DISABLE_EMBEDDED_BANKS
+    ADL_UNUSED(device);
+    ADL_UNUSED(bank);
+    ADLMIDI_ErrorString = "This build of libADLMIDI has no embedded banks. Please load bank by using of adl_openBankFile() or adl_openBankData() functions instead of adl_setBank()";
+    return -1;
+    #else
     const uint32_t NumBanks = static_cast<uint32_t>(maxAdlBanks());
     int32_t bankno = bank;
 
@@ -99,7 +100,8 @@ ADLMIDI_EXPORT int adl_setBank(ADL_MIDIPlayer *device, int bank)
         bankno = 0;
 
     device->AdlBank = static_cast<uint32_t>(bankno);
-    reinterpret_cast<MIDIplay *>(device->adl_midiPlayer)->opl.AdlBank = device->AdlBank;
+    MIDIplay *play = reinterpret_cast<MIDIplay *>(device->adl_midiPlayer);
+    play->opl.AdlBank = device->AdlBank;
 
     if(device->AdlBank >= NumBanks)
     {
@@ -110,6 +112,7 @@ ADLMIDI_EXPORT int adl_setBank(ADL_MIDIPlayer *device, int bank)
     }
 
     return adlRefreshNumCards(device);
+    #endif
 }
 
 ADLMIDI_EXPORT int adl_getBanksCount()
@@ -317,6 +320,14 @@ ADLMIDI_EXPORT void adl_reset(ADL_MIDIPlayer *device)
     reinterpret_cast<MIDIplay *>(device->adl_midiPlayer)->opl.Reset();
 }
 
+ADLMIDI_EXPORT void adl_positionRewind(struct ADL_MIDIPlayer *device)
+{
+    if(!device)
+        return;
+    reinterpret_cast<MIDIplay *>(device->adl_midiPlayer)->rewind();
+}
+
+
 #ifdef ADLMIDI_USE_DOSBOX_OPL
 
 #define ADLMIDI_CLAMP(V, MIN, MAX) std::max(std::min(V, (MAX)), (MIN))
@@ -393,9 +404,6 @@ ADLMIDI_EXPORT int adl_play(ADL_MIDIPlayer *device, int sampleCount, short *out)
     if(sampleCount < 0)
         return 0;
 
-    if(device->QuitFlag)
-        return 0;
-
     ssize_t gotten_len = 0;
     ssize_t n_periodCountStereo = 512;
     //ssize_t n_periodCountPhys = n_periodCountStereo * 2;
@@ -446,6 +454,9 @@ ADLMIDI_EXPORT int adl_play(ADL_MIDIPlayer *device, int sampleCount, short *out)
                 out_buf.resize(1024 /*n_samples * 2*/);
                 MIDIplay *player = reinterpret_cast<MIDIplay *>(device->adl_midiPlayer);
 
+                if((player->atEnd) && (device->delay <= 0.0))
+                    break;//Stop to fetch samples at reaching of song end with disabled loop
+
                 ssize_t in_generatedStereo = (n_periodCountStereo > 512) ? 512 : n_periodCountStereo;
                 ssize_t in_generatedPhys = in_generatedStereo * 2;
 
@@ -500,185 +511,3 @@ ADLMIDI_EXPORT int adl_play(ADL_MIDIPlayer *device, int sampleCount, short *out)
 
     return static_cast<int>(gotten_len);
 }
-
-#ifdef ADLMIDI_buildAsApp
-static std::deque<short> AudioBuffer;
-static MutexType AudioBuffer_lock;
-
-static void SDL_AudioCallbackX(void *, Uint8 *stream, int len)
-{
-    SDL_LockAudio();
-    short *target = (short *) stream;
-    AudioBuffer_lock.Lock();
-    /*if(len != AudioBuffer.size())
-        fprintf(stderr, "len=%d stereo samples, AudioBuffer has %u stereo samples",
-            len/4, (unsigned) AudioBuffer.size()/2);*/
-    unsigned ate = len / 2; // number of shorts
-
-    if(ate > AudioBuffer.size()) ate = AudioBuffer.size();
-
-    for(unsigned a = 0; a < ate; ++a)
-        target[a] = AudioBuffer[a];
-
-    AudioBuffer.erase(AudioBuffer.begin(), AudioBuffer.begin() + ate);
-    AudioBuffer_lock.Unlock();
-    SDL_UnlockAudio();
-}
-
-int main(int argc, char **argv)
-{
-    if(argc < 2 || std::string(argv[1]) == "--help" || std::string(argv[1]) == "-h")
-    {
-        std::printf(
-            "Usage: adlmidi <midifilename> [ <options> ] [ <banknumber> [ <numcards> [ <numfourops>] ] ]\n"
-            " -p Enables adlib percussion instrument mode\n"
-            " -t Enables tremolo amplification mode\n"
-            " -v Enables vibrato amplification mode\n"
-            " -s Enables scaling of modulator volumes\n"
-            " -nl Quit without looping\n"
-            " -w Write WAV file rather than playing\n"
-        );
-
-        for(unsigned a = 0; a < sizeof(banknames) / sizeof(*banknames); ++a)
-            std::printf("%10s%2u = %s\n",
-                        a ? "" : "Banks:",
-                        a,
-                        banknames[a]);
-
-        std::printf(
-            "     Use banks 2-5 to play Descent \"q\" soundtracks.\n"
-            "     Look up the relevant bank number from descent.sng.\n"
-            "\n"
-            "     The fourth parameter can be used to specify the number\n"
-            "     of four-op channels to use. Each four-op channel eats\n"
-            "     the room of two regular channels. Use as many as required.\n"
-            "     The Doom & Hexen sets require one or two, while\n"
-            "     Miles four-op set requires the maximum of numcards*6.\n"
-            "\n"
-        );
-        return 0;
-    }
-
-    //const unsigned MaxSamplesAtTime = 512; // 512=dbopl limitation
-    // How long is SDL buffer, in seconds?
-    // The smaller the value, the more often SDL_AudioCallBack()
-    // is called.
-    const double AudioBufferLength = 0.08;
-    // How much do WE buffer, in seconds? The smaller the value,
-    // the more prone to sound chopping we are.
-    const double OurHeadRoomLength = 0.1;
-    // The lag between visual content and audio content equals
-    // the sum of these two buffers.
-    SDL_AudioSpec spec;
-    SDL_AudioSpec obtained;
-    spec.freq     = 44100;
-    spec.format   = AUDIO_S16SYS;
-    spec.channels = 2;
-    spec.samples  = spec.freq * AudioBufferLength;
-    spec.callback = SDL_AudioCallbackX;
-
-    // Set up SDL
-    if(SDL_OpenAudio(&spec, &obtained) < 0)
-    {
-        std::fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError());
-        //return 1;
-    }
-
-    if(spec.samples != obtained.samples)
-        std::fprintf(stderr, "Wanted (samples=%u,rate=%u,channels=%u); obtained (samples=%u,rate=%u,channels=%u)\n",
-                     spec.samples,    spec.freq,    spec.channels,
-                     obtained.samples, obtained.freq, obtained.channels);
-
-    ADL_MIDIPlayer *myDevice;
-    myDevice = adl_init(44100);
-
-    if(myDevice == NULL)
-    {
-        std::fprintf(stderr, "Failed to init MIDI device!\n");
-        return 1;
-    }
-
-    while(argc > 2)
-    {
-        bool had_option = false;
-
-        if(!std::strcmp("-p", argv[2]))
-            adl_setPercMode(myDevice, 1);
-        else if(!std::strcmp("-v", argv[2]))
-            adl_setHVibrato(myDevice, 1);
-        else if(!std::strcmp("-t", argv[2]))
-            adl_setHTremolo(myDevice, 1);
-        else if(!std::strcmp("-nl", argv[2]))
-            adl_setLoopEnabled(myDevice, 0);
-        else if(!std::strcmp("-s", argv[2]))
-            adl_setScaleModulators(myDevice, 1);
-        else break;
-
-        std::copy(argv + (had_option ? 4 : 3), argv + argc,
-                  argv + 2);
-        argc -= (had_option ? 2 : 1);
-    }
-
-    if(argc >= 3)
-    {
-        int bankno = std::atoi(argv[2]);
-
-        if(adl_setBank(myDevice, bankno) != 0)
-        {
-            std::fprintf(stderr, "%s", adl_errorString());
-            return 0;
-        }
-    }
-
-    if(argc >= 4)
-    {
-        if(adl_setNumCards(myDevice, std::atoi(argv[3])) != 0)
-        {
-            std::fprintf(stderr, "%s\n", adl_errorString());
-            return 0;
-        }
-    }
-
-    if(argc >= 5)
-    {
-        if(adl_setNumFourOpsChn(myDevice, std::atoi(argv[4])) != 0)
-        {
-            std::fprintf(stderr, "%s\n", adl_errorString());
-            return 0;
-        }
-    }
-
-    if(adl_openFile(myDevice, argv[1]) != 0)
-    {
-        std::fprintf(stderr, "%s\n", adl_errorString());
-        return 2;
-    }
-
-    SDL_PauseAudio(0);
-
-    while(1)
-    {
-        int buff[4096];
-        unsigned long gotten = adl_play(myDevice, 4096, buff);
-
-        if(gotten <= 0) break;
-
-        AudioBuffer_lock.Lock();
-        size_t pos = AudioBuffer.size();
-        AudioBuffer.resize(pos + gotten);
-
-        for(unsigned long p = 0; p < gotten; ++p)
-            AudioBuffer[pos + p] = buff[p];
-
-        AudioBuffer_lock.Unlock();
-        const SDL_AudioSpec &spec_ = obtained;
-
-        while(AudioBuffer.size() > spec_.samples + (spec_.freq * 2) * OurHeadRoomLength)
-            SDL_Delay(1);
-    }
-
-    adl_close(myDevice);
-    SDL_CloseAudio();
-    return 0;
-}
-#endif