diff options
Diffstat (limited to 'examples/altonegen.c')
| -rw-r--r-- | examples/altonegen.c | 75 |
1 files changed, 42 insertions, 33 deletions
diff --git a/examples/altonegen.c b/examples/altonegen.c index 75db2d6b..ec7f77bb 100644 --- a/examples/altonegen.c +++ b/examples/altonegen.c @@ -79,63 +79,72 @@ static inline ALuint dither_rng(ALuint *seed) return *seed; } -static void ApplySin(ALfloat *data, ALdouble g, ALuint srate, ALuint freq) +static void ApplySin(ALfloat *data, ALuint length, ALdouble g, ALuint srate, ALuint freq) { - ALdouble smps_per_cycle = (ALdouble)srate / freq; + ALdouble cycles_per_sample = (ALdouble)freq / srate; ALuint i; - for(i = 0;i < srate;i++) + for(i = 0;i < length;i++) { ALdouble ival; - data[i] += (ALfloat)(sin(modf(i/smps_per_cycle, &ival) * 2.0*M_PI) * g); + data[i] += (ALfloat)(sin(modf(i*cycles_per_sample, &ival) * 2.0*M_PI) * g); } } /* Generates waveforms using additive synthesis. Each waveform is constructed * by summing one or more sine waves, up to (and excluding) nyquist. */ -static ALuint CreateWave(enum WaveType type, ALuint freq, ALuint srate, ALfloat gain) +static ALuint CreateWave(enum WaveType type, ALuint seconds, ALuint freq, ALuint srate, + ALfloat gain) { ALuint seed = 22222; + ALuint num_samples; ALuint data_size; ALfloat *data; ALuint buffer; ALenum err; ALuint i; - data_size = (ALuint)(srate * sizeof(ALfloat)); + if(seconds > INT_MAX / srate / sizeof(ALfloat)) + { + fprintf(stderr, "Too many seconds: %u * %u * %zu > %d\n", seconds, srate, sizeof(ALfloat), + INT_MAX); + return 0; + } + + num_samples = seconds * srate; + + data_size = (ALuint)(num_samples * sizeof(ALfloat)); data = calloc(1, data_size); switch(type) { case WT_Sine: - ApplySin(data, 1.0, srate, freq); + ApplySin(data, num_samples, 1.0, srate, freq); break; case WT_Square: for(i = 1;freq*i < srate/2;i+=2) - ApplySin(data, 4.0/M_PI * 1.0/i, srate, freq*i); + ApplySin(data, num_samples, 4.0/M_PI * 1.0/i, srate, freq*i); break; case WT_Sawtooth: for(i = 1;freq*i < srate/2;i++) - ApplySin(data, 2.0/M_PI * ((i&1)*2 - 1.0) / i, srate, freq*i); + ApplySin(data, num_samples, 2.0/M_PI * ((i&1)*2 - 1.0) / i, srate, freq*i); break; case WT_Triangle: for(i = 1;freq*i < srate/2;i+=2) - ApplySin(data, 8.0/(M_PI*M_PI) * (1.0 - (i&2)) / (i*i), srate, freq*i); + ApplySin(data, num_samples, 8.0/(M_PI*M_PI) * (1.0 - (i&2)) / (i*i), srate, freq*i); break; case WT_Impulse: /* NOTE: Impulse isn't handled using additive synthesis, and is - * instead just a non-0 sample at a given rate. This can still be - * useful to test (other than resampling, the ALSOFT_DEFAULT_REVERB - * environment variable can prove useful here to test the reverb - * response). + * instead just a non-0 sample. This can be useful to test (other + * than resampling, the ALSOFT_DEFAULT_REVERB environment variable + * can test the reverb response). */ - for(i = 0;i < srate;i++) - data[i] = (i%(srate/freq)) ? 0.0f : 1.0f; + data[0] = 1.0f; break; case WT_WhiteNoise: /* NOTE: WhiteNoise is just uniform set of uncorrelated values, and * is not influenced by the waveform frequency. */ - for(i = 0;i < srate;i++) + for(i = 0;i < num_samples;i++) { ALuint rng0 = dither_rng(&seed); ALuint rng1 = dither_rng(&seed); @@ -146,7 +155,7 @@ static ALuint CreateWave(enum WaveType type, ALuint freq, ALuint srate, ALfloat if(gain != 1.0f) { - for(i = 0;i < srate;i++) + for(i = 0;i < num_samples;i++) data[i] *= gain; } @@ -156,7 +165,7 @@ static ALuint CreateWave(enum WaveType type, ALuint freq, ALuint srate, ALfloat alBufferData(buffer, AL_FORMAT_MONO_FLOAT32, data, (ALsizei)data_size, (ALsizei)srate); free(data); - /* Check if an error occured, and clean up if so. */ + /* Check if an error occurred, and clean up if so. */ err = alGetError(); if(err != AL_NO_ERROR) { @@ -175,8 +184,8 @@ int main(int argc, char *argv[]) enum WaveType wavetype = WT_Sine; const char *appname = argv[0]; ALuint source, buffer; - ALint last_pos, num_loops; - ALint max_loops = 4; + ALint last_pos; + ALint seconds = 4; ALint srate = -1; ALint tone_freq = 1000; ALCint dev_rate; @@ -220,7 +229,9 @@ int main(int argc, char *argv[]) else if(i+1 < argc && strcmp(argv[i], "-t") == 0) { i++; - max_loops = atoi(argv[i]) - 1; + seconds = atoi(argv[i]); + if(seconds <= 0) + seconds = 4; } else if(i+1 < argc && (strcmp(argv[i], "--waveform") == 0 || strcmp(argv[i], "-w") == 0)) { @@ -281,7 +292,7 @@ int main(int argc, char *argv[]) srate = dev_rate; /* Load the sound into a buffer. */ - buffer = CreateWave(wavetype, (ALuint)tone_freq, (ALuint)srate, gain); + buffer = CreateWave(wavetype, (ALuint)seconds, (ALuint)tone_freq, (ALuint)srate, gain); if(!buffer) { CloseAL(); @@ -289,7 +300,7 @@ int main(int argc, char *argv[]) } printf("Playing %dhz %s-wave tone with %dhz sample rate and %dhz output, for %d second%s...\n", - tone_freq, GetWaveTypeName(wavetype), srate, dev_rate, max_loops+1, max_loops?"s":""); + tone_freq, GetWaveTypeName(wavetype), srate, dev_rate, seconds, (seconds!=1)?"s":""); fflush(stdout); /* Create the source to play the sound with. */ @@ -299,21 +310,19 @@ int main(int argc, char *argv[]) assert(alGetError()==AL_NO_ERROR && "Failed to setup sound source"); /* Play the sound for a while. */ - num_loops = 0; - last_pos = 0; - alSourcei(source, AL_LOOPING, (max_loops > 0) ? AL_TRUE : AL_FALSE); + last_pos = -1; alSourcePlay(source); do { ALint pos; al_nssleep(10000000); - alGetSourcei(source, AL_SAMPLE_OFFSET, &pos); alGetSourcei(source, AL_SOURCE_STATE, &state); - if(pos < last_pos && state == AL_PLAYING) + alGetSourcei(source, AL_SAMPLE_OFFSET, &pos); + pos /= srate; + + if(pos > last_pos) { - ++num_loops; - if(num_loops >= max_loops) - alSourcei(source, AL_LOOPING, AL_FALSE); - printf("%d...\n", max_loops - num_loops + 1); + last_pos = 0; + printf("%d...\n", seconds - pos); fflush(stdout); } last_pos = pos; |