examples/altonegen.c

   1 /*
   2  * OpenAL Tone Generator Test
   3  *
   4  * Copyright (c) 2015 by Chris Robinson <chris.kcat@gmail.com>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 /* This file contains a test for generating waveforms and plays them for a
  26  * given length of time. Intended to inspect the behavior of the mixer by
  27  * checking the output with a spectrum analyzer and oscilloscope.
  28  *
  29  * TODO: This would actually be nicer as a GUI app with buttons to start and
  30  * stop individual waveforms, include additional whitenoise and pinknoise
  31  * generators, and have the ability to hook up EFX filters and effects.
  32  */
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <assert.h>
  38 #include <math.h>
  39
  40 #include "AL/al.h"
  41 #include "AL/alc.h"
  42 #include "AL/alext.h"
  43
  44 #include "common/alhelpers.h"
  45
  46 #ifndef M_PI
  47 #define M_PI    (3.14159265358979323846)
  48 #endif
  49
  50 enum WaveType {
  51     WT_Sine,
  52     WT_Square,
  53     WT_Sawtooth,
  54     WT_Triangle,
  55     WT_Impulse,
  56 };
  57
  58 static const char *GetWaveTypeName(enum WaveType type)
  59 {
  60     switch(type)
  61     {
  62         case WT_Sine: return "sine";
  63         case WT_Square: return "square";
  64         case WT_Sawtooth: return "sawtooth";
  65         case WT_Triangle: return "triangle";
  66         case WT_Impulse: return "impulse";
  67     }
  68     return "(unknown)";
  69 }
  70
  71 static void ApplySin(ALfloat *data, ALdouble g, ALuint srate, ALuint freq)
  72 {
  73     ALdouble smps_per_cycle = (ALdouble)srate / freq;
  74     ALuint i;
  75     for(i = 0;i < srate;i++)
  76         data[i] += (ALfloat)(sin(i/smps_per_cycle * 2.0*M_PI) * g);
  77 }
  78
  79 /* Generates waveforms using additive synthesis. Each waveform is constructed
  80  * by summing one or more sine waves, up to (and excluding) nyquist.
  81  */
  82 static ALuint CreateWave(enum WaveType type, ALuint freq, ALuint srate)
  83 {
  84     ALint data_size;
  85     ALfloat *data;
  86     ALuint buffer;
  87     ALenum err;
  88     ALuint i;
  89
  90     data_size = srate * sizeof(ALfloat);
  91     data = calloc(1, data_size);
  92     if(type == WT_Sine)
  93         ApplySin(data, 1.0, srate, freq);
  94     else if(type == WT_Square)
  95         for(i = 1;freq*i < srate/2;i+=2)
  96             ApplySin(data, 4.0/M_PI * 1.0/i, srate, freq*i);
  97     else if(type == WT_Sawtooth)
  98         for(i = 1;freq*i < srate/2;i++)
  99             ApplySin(data, 2.0/M_PI * ((i&1)*2 - 1.0) / i, srate, freq*i);
 100     else if(type == WT_Triangle)
 101         for(i = 1;freq*i < srate/2;i+=2)
 102             ApplySin(data, 8.0/(M_PI*M_PI) * (1.0 - (i&2)) / (i*i), srate, freq*i);
 103     else if(type == WT_Impulse)
 104     {
 105         /* NOTE: Impulse isn't really a waveform, but it can still be useful to
 106          * test (other than resampling, the ALSOFT_DEFAULT_REVERB environment
 107          * variable can prove useful here to test the reverb response).
 108          */
 109         for(i = 0;i < srate;i++)
 110             data[i] = (i%(srate/freq)) ? 0.0f : 1.0f;
 111     }
 112
 113     /* Buffer the audio data into a new buffer object. */
 114     buffer = 0;
 115     alGenBuffers(1, &buffer);
 116     alBufferData(buffer, AL_FORMAT_MONO_FLOAT32, data, data_size, srate);
 117     free(data);
 118
 119     /* Check if an error occured, and clean up if so. */
 120     err = alGetError();
 121     if(err != AL_NO_ERROR)
 122     {
 123         fprintf(stderr, "OpenAL Error: %s\n", alGetString(err));
 124         if(alIsBuffer(buffer))
 125             alDeleteBuffers(1, &buffer);
 126         return 0;
 127     }
 128
 129     return buffer;
 130 }
 131
 132
 133 int main(int argc, char *argv[])
 134 {
 135     enum WaveType wavetype = WT_Sine;
 136     ALuint source, buffer;
 137     ALint last_pos, num_loops;
 138     ALint max_loops = 4;
 139     ALint srate = -1;
 140     ALint tone_freq = 1000;
 141     ALCint dev_rate;
 142     ALenum state;
 143     int i;
 144
 145     for(i = 1;i < argc;i++)
 146     {
 147         if(strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "--help") == 0)
 148         {
 149             fprintf(stderr, "OpenAL Tone Generator\n"
 150 "\n"
 151 "Usage: %s <options>\n"
 152 "\n"
 153 "Available options:\n"
 154 "  --help/-h                 This help text\n"
 155 "  -t <seconds>              Time to play a tone (default 5 seconds)\n"
 156 "  --waveform/-w <type>      Waveform type: sine (default), square, sawtooth,\n"
 157 "                                triangle, impulse\n"
 158 "  --freq/-f <hz>            Tone frequency (default 1000 hz)\n"
 159 "  --srate/-s <sample rate>  Sampling rate (default output rate)\n",
 160                 argv[0]
 161             );
 162             return 1;
 163         }
 164         else if(i+1 < argc && strcmp(argv[i], "-t") == 0)
 165         {
 166             i++;
 167             max_loops = atoi(argv[i]) - 1;
 168         }
 169         else if(i+1 < argc && (strcmp(argv[i], "--waveform") == 0 || strcmp(argv[i], "-w") == 0))
 170         {
 171             i++;
 172             if(strcmp(argv[i], "sine") == 0)
 173                 wavetype = WT_Sine;
 174             else if(strcmp(argv[i], "square") == 0)
 175                 wavetype = WT_Square;
 176             else if(strcmp(argv[i], "sawtooth") == 0)
 177                 wavetype = WT_Sawtooth;
 178             else if(strcmp(argv[i], "triangle") == 0)
 179                 wavetype = WT_Triangle;
 180             else if(strcmp(argv[i], "impulse") == 0)
 181                 wavetype = WT_Impulse;
 182             else
 183                 fprintf(stderr, "Unhandled waveform: %s\n", argv[i]);
 184         }
 185         else if(i+1 < argc && (strcmp(argv[i], "--freq") == 0 || strcmp(argv[i], "-f") == 0))
 186         {
 187             i++;
 188             tone_freq = atoi(argv[i]);
 189             if(tone_freq < 1)
 190             {
 191                 fprintf(stderr, "Invalid tone frequency: %s (min: 1hz)\n", argv[i]);
 192                 tone_freq = 1;
 193             }
 194         }
 195         else if(i+1 < argc && (strcmp(argv[i], "--srate") == 0 || strcmp(argv[i], "-s") == 0))
 196         {
 197             i++;
 198             srate = atoi(argv[i]);
 199             if(srate < 40)
 200             {
 201                 fprintf(stderr, "Invalid sample rate: %s (min: 40hz)\n", argv[i]);
 202                 srate = 40;
 203             }
 204         }
 205     }
 206
 207     InitAL();
 208
 209     if(!alIsExtensionPresent("AL_EXT_FLOAT32"))
 210     {
 211         fprintf(stderr, "Required AL_EXT_FLOAT32 extension not supported on this device!\n");
 212         CloseAL();
 213         return 1;
 214     }
 215
 216     {
 217         ALCdevice *device = alcGetContextsDevice(alcGetCurrentContext());
 218         alcGetIntegerv(device, ALC_FREQUENCY, 1, &dev_rate);
 219         assert(alcGetError(device)==ALC_NO_ERROR && "Failed to get device sample rate");
 220     }
 221     if(srate < 0)
 222         srate = dev_rate;
 223
 224     /* Load the sound into a buffer. */
 225     buffer = CreateWave(wavetype, tone_freq, srate);
 226     if(!buffer)
 227     {
 228         CloseAL();
 229         return 1;
 230     }
 231
 232     printf("Playing %dhz %s-wave tone with %dhz sample rate and %dhz output, for %d second%s...\n",
 233            tone_freq, GetWaveTypeName(wavetype), srate, dev_rate, max_loops+1, max_loops?"s":"");
 234     fflush(stdout);
 235
 236     /* Create the source to play the sound with. */
 237     source = 0;
 238     alGenSources(1, &source);
 239     alSourcei(source, AL_BUFFER, buffer);
 240     assert(alGetError()==AL_NO_ERROR && "Failed to setup sound source");
 241
 242     /* Play the sound for a while. */
 243     num_loops = 0;
 244     last_pos = 0;
 245     alSourcei(source, AL_LOOPING, (max_loops > 0) ? AL_TRUE : AL_FALSE);
 246     alSourcePlay(source);
 247     do {
 248         ALint pos;
 249         al_nssleep(10000000);
 250         alGetSourcei(source, AL_SAMPLE_OFFSET, &pos);
 251         alGetSourcei(source, AL_SOURCE_STATE, &state);
 252         if(pos < last_pos && state == AL_PLAYING)
 253         {
 254             ++num_loops;
 255             if(num_loops >= max_loops)
 256                 alSourcei(source, AL_LOOPING, AL_FALSE);
 257             printf("%d...\n", max_loops - num_loops + 1);
 258             fflush(stdout);
 259         }
 260         last_pos = pos;
 261     } while(alGetError() == AL_NO_ERROR && state == AL_PLAYING);
 262
 263     /* All done. Delete resources, and close OpenAL. */
 264     alDeleteSources(1, &source);
 265     alDeleteBuffers(1, &buffer);
 266
 267     /* Close up OpenAL. */
 268     CloseAL();
 269
 270     return 0;
 271 }