build system revision
[vg.git] / vg_audio.c
diff --git a/vg_audio.c b/vg_audio.c
new file mode 100644 (file)
index 0000000..1611a62
--- /dev/null
@@ -0,0 +1,1212 @@
+#include "vg_audio.h"
+#include "vg_audio_dsp.h"
+#include "vg_platform.h"
+#include "vg_io.h"
+#include "vg_m.h"
+#include "vg_console.h"
+#include "vg_profiler.h"
+#include "vg_audio_synth_bird.h"
+#include "vg_vorbis.h"
+#include <string.h>
+
+struct vg_audio_system vg_audio = 
+{ 
+   .external_global_volume = 1.0f, 
+   .dsp_enabled = 1 
+};
+
+static struct vg_profile 
+   _vg_prof_audio_decode = {.mode = k_profile_mode_accum,
+                            .name = "[T2] audio_decode()"},
+   _vg_prof_audio_mix    = {.mode = k_profile_mode_accum,
+                            .name = "[T2] audio_mix()"},
+   _vg_prof_dsp          = {.mode = k_profile_mode_accum,
+                            .name = "[T2] dsp_process()"},
+   vg_prof_audio_decode,
+   vg_prof_audio_mix,
+   vg_prof_audio_dsp;
+
+/* 
+ * These functions are called from the main thread and used to prevent bad 
+ * access. TODO: They should be no-ops in release builds.
+ */
+static int audio_lock_checker_load(void)
+{
+   int value;
+   SDL_AtomicLock( &vg_audio.sl_checker );
+   value = vg_audio.sync_locked;
+   SDL_AtomicUnlock( &vg_audio.sl_checker );
+   return value;
+}
+
+static void audio_lock_checker_store( int value )
+{
+   SDL_AtomicLock( &vg_audio.sl_checker );
+   vg_audio.sync_locked = value;
+   SDL_AtomicUnlock( &vg_audio.sl_checker );
+}
+
+static void audio_require_lock(void)
+{
+   if( audio_lock_checker_load() )
+      return;
+
+   vg_error( "Modifying sound effects systems requires locking\n" );
+   abort();
+}
+
+void audio_lock(void)
+{
+   SDL_AtomicLock( &vg_audio.sl_sync );
+   audio_lock_checker_store(1);
+}
+
+void audio_unlock(void)
+{
+   audio_lock_checker_store(0);
+   SDL_AtomicUnlock( &vg_audio.sl_sync );
+}
+
+static void audio_mixer_callback( void *user, u8 *stream, int frame_count );
+void vg_audio_device_init(void)
+{
+   SDL_AudioSpec spec_desired, spec_got;
+   spec_desired.callback = audio_mixer_callback;
+   spec_desired.channels = 2;
+   spec_desired.format   = AUDIO_F32;
+   spec_desired.freq     = 44100;
+   spec_desired.padding  = 0;
+   spec_desired.samples  = AUDIO_FRAME_SIZE;
+   spec_desired.silence  = 0;
+   spec_desired.size     = 0;
+   spec_desired.userdata = NULL;
+
+   vg_audio.sdl_output_device = 
+      SDL_OpenAudioDevice( vg_audio.device_choice.buffer, 0, 
+                           &spec_desired, &spec_got,0 );
+
+   vg_info( "Start audio device (%u, F32, %u) @%s\n", 
+               spec_desired.freq,
+               AUDIO_FRAME_SIZE,
+               vg_audio.device_choice.buffer );
+
+   if( vg_audio.sdl_output_device ){
+      SDL_PauseAudioDevice( vg_audio.sdl_output_device, 0 );
+      vg_success( "Unpaused device %d.\n", vg_audio.sdl_output_device );
+   }
+   else{
+      vg_error( 
+         "SDL_OpenAudioDevice failed. Your default audio device must support:\n"
+         "  Frequency: 44100 hz\n"
+         "  Buffer size: 512\n"
+         "  Channels: 2\n"
+         "  Format: s16 or f32\n" );
+   }
+}
+
+void vg_audio_register(void)
+{
+   vg_console_reg_var( "debug_audio", &vg_audio.debug_ui, 
+                        k_var_dtype_i32, VG_VAR_CHEAT );
+   vg_console_reg_var( "debug_dsp", &vg_audio.debug_dsp,
+                        k_var_dtype_i32, VG_VAR_CHEAT );
+   vg_console_reg_var( "volume", &vg_audio.external_global_volume,
+                        k_var_dtype_f32, VG_VAR_PERSISTENT );
+   vg_console_reg_var( "vg_audio_device", &vg_audio.device_choice,
+                        k_var_dtype_str, VG_VAR_PERSISTENT );
+   vg_console_reg_var( "vg_dsp", &vg_audio.dsp_enabled,
+                        k_var_dtype_i32, VG_VAR_PERSISTENT );
+}
+
+void vg_audio_init(void)
+{
+   /* allocate memory */
+   /* 32mb fixed */
+   vg_audio.audio_pool = 
+      vg_create_linear_allocator( vg_mem.rtmemory, 1024*1024*32, 
+                                  VG_MEMORY_SYSTEM );
+
+   /* fixed */
+   u32 decode_size = AUDIO_DECODE_SIZE * AUDIO_CHANNELS;
+   vg_audio.decode_buffer = vg_linear_alloc( vg_mem.rtmemory, decode_size );
+
+   vg_dsp_init();
+   vg_audio_device_init();
+}
+
+void vg_audio_free(void)
+{
+   vg_dsp_free();
+   SDL_CloseAudioDevice( vg_audio.sdl_output_device );
+}
+
+/* 
+ * thread 1
+ */
+
+#define AUDIO_EDIT_VOLUME_SLOPE   0x1
+#define AUDIO_EDIT_VOLUME         0x2
+#define AUDIO_EDIT_LFO_PERIOD     0x4
+#define AUDIO_EDIT_LFO_WAVE       0x8
+#define AUDIO_EDIT_LFO_ATTACHMENT 0x10
+#define AUDIO_EDIT_SPACIAL        0x20
+#define AUDIO_EDIT_OWNERSHIP      0x40
+#define AUDIO_EDIT_SAMPLING_RATE  0x80
+
+void audio_channel_init( audio_channel *ch, audio_clip *clip, u32 flags )
+{
+   audio_require_lock();
+   ch->group = 0;
+   ch->world_id = 0;
+   ch->source = clip;
+   ch->flags = flags;
+   ch->colour = 0x00333333;
+
+   if( (ch->source->flags & AUDIO_FLAG_FORMAT) == k_audio_format_bird )
+      strcpy( ch->name, "[array]" );
+   else if( (ch->source->flags & AUDIO_FLAG_FORMAT) == k_audio_format_gen )
+      strcpy( ch->name, "[program]" );
+   else
+      vg_strncpy( clip->path, ch->name, 32, k_strncpy_always_add_null );
+
+   ch->allocated = 1;
+
+   ch->editable_state.relinquished = 0;
+   ch->editable_state.volume = 1.0f;
+   ch->editable_state.volume_target = 1.0f;
+   ch->editable_state.pan = 0.0f;
+   ch->editable_state.pan_target = 0.0f;
+   ch->editable_state.volume_rate = 0;
+   ch->editable_state.pan_rate = 0;
+   v4_copy((v4f){0.0f,0.0f,0.0f,1.0f},ch->editable_state.spacial_falloff);
+   ch->editable_state.lfo = NULL;
+   ch->editable_state.lfo_amount = 0.0f;
+   ch->editable_state.sampling_rate = 1.0f;
+   ch->editble_state_write_mask = 0x00;
+}
+
+void audio_channel_group( audio_channel *ch, u16 group )
+{
+   audio_require_lock();
+   ch->group = group;
+   ch->colour = (((u32)group * 29986577) & 0x00ffffff) | 0xff000000;
+}
+
+void audio_channel_world( audio_channel *ch, u8 world_id )
+{
+   audio_require_lock();
+   ch->world_id = world_id;
+}
+
+audio_channel *audio_get_first_idle_channel(void)
+{
+   audio_require_lock();
+   for( int i=0; i<AUDIO_CHANNELS; i++ ){
+      audio_channel *ch = &vg_audio.channels[i];
+
+      if( !ch->allocated ){
+         return ch;
+      }
+   }
+
+   return NULL;
+}
+
+audio_channel *audio_get_group_idle_channel( u16 group, u32 max_count )
+{
+   audio_require_lock();
+   u32 count = 0;
+   audio_channel *dest = NULL;
+
+   for( int i=0; i<AUDIO_CHANNELS; i++ ){
+      audio_channel *ch = &vg_audio.channels[i];
+
+      if( ch->allocated ){
+         if( ch->group == group ){
+            count ++;
+         }
+      }
+      else{
+         if( !dest )
+            dest = ch;
+      }
+   }
+
+   if( dest && (count < max_count) ){
+      return dest;
+   }
+
+   return NULL;
+}
+
+audio_channel *audio_get_group_first_active_channel( u16 group )
+{
+   audio_require_lock();
+   for( int i=0; i<AUDIO_CHANNELS; i++ ){
+      audio_channel *ch = &vg_audio.channels[i];
+      if( ch->allocated && (ch->group == group) )
+         return ch;
+   }
+   return NULL;
+}
+
+int audio_channel_finished( audio_channel *ch )
+{
+   audio_require_lock();
+   if( ch->readable_activity == k_channel_activity_end )
+      return 1;
+   else
+      return 0;
+}
+
+audio_channel *audio_relinquish_channel( audio_channel *ch )
+{
+   audio_require_lock();
+   ch->editable_state.relinquished = 1;
+   ch->editble_state_write_mask |= AUDIO_EDIT_OWNERSHIP;
+   return NULL;
+}
+
+void audio_channel_slope_volume( audio_channel *ch, f32 length, f32 new_vol )
+{
+   audio_require_lock();
+   ch->editable_state.volume_target = new_vol;
+   ch->editable_state.volume_rate   = length * 44100.0f;
+   ch->editble_state_write_mask |= AUDIO_EDIT_VOLUME_SLOPE;
+}
+
+void audio_channel_set_sampling_rate( audio_channel *ch, float rate )
+{
+   audio_require_lock();
+   ch->editable_state.sampling_rate = rate;
+   ch->editble_state_write_mask |= AUDIO_EDIT_SAMPLING_RATE;
+}
+
+void audio_channel_edit_volume( audio_channel *ch, f32 new_vol, int instant )
+{
+   audio_require_lock();
+   if( instant ){
+      ch->editable_state.volume = new_vol;
+      ch->editble_state_write_mask |= AUDIO_EDIT_VOLUME;
+   }
+   else{
+      audio_channel_slope_volume( ch, 0.05f, new_vol );
+   }
+}
+
+audio_channel *audio_channel_fadeout( audio_channel *ch, float length )
+{
+   audio_require_lock();
+   audio_channel_slope_volume( ch, length, 0.0f );
+   return audio_relinquish_channel( ch );
+}
+
+void audio_channel_fadein( audio_channel *ch, float length )
+{
+   audio_require_lock();
+   audio_channel_edit_volume( ch, 0.0f, 1 );
+   audio_channel_slope_volume( ch, length, 1.0f );
+}
+
+audio_channel *audio_channel_crossfade( audio_channel *ch, 
+                                        audio_clip *new_clip,
+                                        float length, u32 flags )
+{
+   audio_require_lock();
+   u32 cursor = 0;
+
+   if( ch )
+      ch = audio_channel_fadeout( ch, length );
+
+   audio_channel *replacement = audio_get_first_idle_channel();
+
+   if( replacement ){
+      audio_channel_init( replacement, new_clip, flags );
+      audio_channel_fadein( replacement, length );
+   }
+
+   return replacement;
+}
+
+void audio_channel_sidechain_lfo( audio_channel *ch, int lfo_id, f32 amount )
+{
+   audio_require_lock();
+   ch->editable_state.lfo = &vg_audio.oscillators[ lfo_id ];
+   ch->editable_state.lfo_amount = amount;
+   ch->editble_state_write_mask |= AUDIO_EDIT_LFO_ATTACHMENT;
+}
+
+void audio_channel_set_spacial( audio_channel *ch, v3f co, float range )
+{
+   audio_require_lock();
+   if( ch->flags & AUDIO_FLAG_SPACIAL_3D ){
+      v3_copy( co, ch->editable_state.spacial_falloff );
+
+      if( range == 0.0f )
+         ch->editable_state.spacial_falloff[3] = 1.0f;
+      else
+         ch->editable_state.spacial_falloff[3] = 1.0f/range;
+
+      ch->editble_state_write_mask |= AUDIO_EDIT_SPACIAL;
+   }
+   else{
+      vg_warn( "Tried to set spacialization paramaters for 2D channel (%s)\n",
+               ch->name );
+   }
+}
+
+int audio_oneshot_3d( audio_clip *clip, v3f position, f32 range, f32 volume )
+{
+   audio_require_lock();
+   audio_channel *ch = audio_get_first_idle_channel();
+
+   if( ch ){
+      audio_channel_init( ch, clip, AUDIO_FLAG_SPACIAL_3D );
+      audio_channel_set_spacial( ch, position, range );
+      audio_channel_edit_volume( ch, volume, 1 );
+      ch = audio_relinquish_channel( ch );
+
+      return 1;
+   }
+   else
+      return 0;
+}
+
+int audio_oneshot( audio_clip *clip, f32 volume, f32 pan )
+{
+   audio_require_lock();
+   audio_channel *ch = audio_get_first_idle_channel();
+
+   if( ch ){
+      audio_channel_init( ch, clip, 0x00 );
+      audio_channel_edit_volume( ch, volume, 1 );
+      ch = audio_relinquish_channel( ch );
+
+      return 1;
+   }
+   else
+      return 0;
+}
+
+void audio_set_lfo_wave( int id, enum lfo_wave_type type, f32 coefficient )
+{
+   audio_require_lock();
+   audio_lfo *lfo = &vg_audio.oscillators[ id ];
+   lfo->editable_state.polynomial_coefficient = coefficient;
+   lfo->editable_state.wave_type = type;
+
+   lfo->editble_state_write_mask |= AUDIO_EDIT_LFO_WAVE;
+}
+
+void audio_set_lfo_frequency( int id, float freq )
+{
+   audio_require_lock();
+   audio_lfo *lfo = &vg_audio.oscillators[ id ];
+   lfo->editable_state.period = 44100.0f / freq;
+   lfo->editble_state_write_mask |= AUDIO_EDIT_LFO_PERIOD;
+}
+
+
+/* 
+ * Committers
+ * -----------------------------------------------------------------------------
+ */
+int audio_channel_load_source( audio_channel *ch )
+{
+   u32 format = ch->source->flags & AUDIO_FLAG_FORMAT;
+
+   if( format == k_audio_format_vorbis ){
+      /* Setup vorbis decoder */
+      u32 index = ch - vg_audio.channels;
+
+      u8 *buf = (u8*)vg_audio.decode_buffer,
+         *loc = &buf[AUDIO_DECODE_SIZE*index];
+
+      stb_vorbis_alloc alloc = {
+         .alloc_buffer = (char *)loc,
+         .alloc_buffer_length_in_bytes = AUDIO_DECODE_SIZE
+      };
+
+      int err;
+      stb_vorbis *decoder = stb_vorbis_open_memory( 
+            ch->source->data,
+            ch->source->size, &err, &alloc );
+
+      if( !decoder ){
+         vg_error( "stb_vorbis_open_memory failed on '%s' (%d)\n", 
+                     ch->source->path, err );
+         return 0;
+      }
+      else{
+         ch->source_length = stb_vorbis_stream_length_in_samples( decoder );
+         ch->handle.vorbis = decoder;
+      }
+   }
+   else if( format == k_audio_format_bird ){
+      u32 index = ch - vg_audio.channels;
+
+      u8 *buf = (u8*)vg_audio.decode_buffer;
+      struct synth_bird *loc = (void *)&buf[AUDIO_DECODE_SIZE*index];
+
+      memcpy( loc, ch->source->data, ch->source->size );
+      synth_bird_reset( loc );
+
+      ch->handle.bird = loc;
+      ch->source_length = synth_bird_get_length_in_samples( loc );
+   }
+   else if( format == k_audio_format_stereo ){
+      ch->source_length = ch->source->size / 2;
+   }
+   else if( format == k_audio_format_gen ){
+      ch->source_length = 0xffffffff;
+   }
+   else{
+      ch->source_length = ch->source->size;
+   }
+
+   return 1;
+}
+
+static void audio_decode_uncompressed_mono( i16 *src, u32 count, float *dst )
+{
+   for( u32 i=0; i<count; i++ ){
+      dst[ i*2 + 0 ] = ((float)src[i]) * (1.0f/32767.0f);
+      dst[ i*2 + 1 ] = ((float)src[i]) * (1.0f/32767.0f);
+   }
+}
+
+static inline float audio_lfo_pull_sample( audio_lfo *lfo )
+{
+   lfo->time ++;
+
+   if( lfo->time >= lfo->_.period )
+      lfo->time = 0;
+
+   float t  = lfo->time;
+         t /= (float)lfo->_.period;
+
+   if( lfo->_.wave_type == k_lfo_polynomial_bipolar ){
+      /*
+       *           #
+       *          # #
+       *          # #
+       *          #  #
+       * ###     #    ###
+       *    ##   #
+       *      #  #
+       *       # #
+       *       ##
+       */           
+
+      t *= 2.0f;
+      t -= 1.0f;
+
+      return (( 2.0f * lfo->sqrt_polynomial_coefficient * t ) /
+              /* --------------------------------------- */
+               ( 1.0f + lfo->_.polynomial_coefficient * t*t )
+              
+             ) * (1.0f-fabsf(t));
+   }
+   else{
+      return 0.0f;
+   }
+}
+
+static void audio_channel_get_samples( audio_channel *ch, 
+                                       u32 count, float *buf )
+{
+   vg_profile_begin( &_vg_prof_audio_decode );
+
+   u32 remaining = count;
+   u32 buffer_pos = 0;
+
+   u32 format = ch->source->flags & AUDIO_FLAG_FORMAT;
+
+   while( remaining ){
+      u32 samples_this_run = VG_MIN(remaining, ch->source_length - ch->cursor);
+      remaining -= samples_this_run;
+
+      float *dst = &buf[ buffer_pos * 2 ]; 
+      
+      if( format == k_audio_format_stereo ){
+         for( int i=0;i<samples_this_run; i++ ){
+            dst[i*2+0] = 0.0f;
+            dst[i*2+1] = 0.0f;
+         }
+      }
+      else if( format == k_audio_format_vorbis ){
+         int read_samples = stb_vorbis_get_samples_float_interleaved_stereo( 
+               ch->handle.vorbis,
+               dst,
+               samples_this_run );
+
+         if( read_samples != samples_this_run ){
+            vg_warn( "Invalid samples read (%s)\n", ch->source->path );
+
+            for( int i=0; i<samples_this_run; i++ ){
+               dst[i*2+0] = 0.0f;
+               dst[i*2+1] = 0.0f;
+            }
+         }
+      }
+      else if( format == k_audio_format_bird ){
+         synth_bird_generate_samples( ch->handle.bird, dst, samples_this_run );
+      }
+      else if( format == k_audio_format_gen ){
+         void (*fn)( void *data, f32 *buf, u32 count ) = ch->source->func;
+         fn( ch->source->data, dst, samples_this_run );
+      }
+      else{
+         i16 *src_buffer = ch->source->data,
+             *src        = &src_buffer[ch->cursor];
+
+         audio_decode_uncompressed_mono( src, samples_this_run, dst );
+      }
+
+      ch->cursor += samples_this_run;
+      buffer_pos += samples_this_run;
+      
+      if( (ch->flags & AUDIO_FLAG_LOOP) && remaining ){
+         if( format == k_audio_format_vorbis )
+            stb_vorbis_seek_start( ch->handle.vorbis );
+         else if( format == k_audio_format_bird )
+            synth_bird_reset( ch->handle.bird );
+
+         ch->cursor = 0;
+         continue;
+      }
+      else
+         break;
+   }
+
+   while( remaining ){
+      buf[ buffer_pos*2 + 0 ] = 0.0f;
+      buf[ buffer_pos*2 + 1 ] = 0.0f;
+      buffer_pos ++;
+
+      remaining --;
+   }
+
+   vg_profile_end( &_vg_prof_audio_decode );
+}
+
+static void audio_channel_mix( audio_channel *ch, float *buffer )
+{
+   float framevol_l = vg_audio.internal_global_volume,
+         framevol_r = vg_audio.internal_global_volume;
+
+   float frame_samplerate = ch->_.sampling_rate;
+
+   if( ch->flags & AUDIO_FLAG_SPACIAL_3D ){
+      v3f delta;
+      v3_sub( ch->_.spacial_falloff, vg_audio.internal_listener_pos, delta );
+
+      float dist = v3_length( delta ),
+            vol  = vg_maxf( 0.0f, 1.0f - ch->_.spacial_falloff[3]*dist );
+
+      if( dist <= 0.01f ){
+         
+      }
+      else{
+         v3_muls( delta, 1.0f/dist, delta );
+         float pan = v3_dot( vg_audio.internal_listener_ears, delta );
+         vol = powf( vol, 5.0f );
+
+         framevol_l *= (vol * 0.5f) * (1.0f - pan);
+         framevol_r *= (vol * 0.5f) * (1.0f + pan);
+
+         if( !(ch->source->flags & AUDIO_FLAG_NO_DOPPLER) ){
+            const float vs = 323.0f;
+
+            float dv = v3_dot(delta,vg_audio.internal_listener_velocity);
+            float doppler = (vs+dv)/vs;
+                  doppler = vg_clampf( doppler, 0.6f, 1.4f );
+                  
+            if( fabsf(doppler-1.0f) > 0.01f )
+               frame_samplerate *= doppler;
+         }
+      }
+
+      if( !vg_validf( framevol_l ) || 
+          !vg_validf( framevol_r ) ||
+          !vg_validf( frame_samplerate ) ){
+         vg_fatal_error( "Invalid sampling conditions.\n"
+                         "This crash is to protect your ears.\n"
+                         "  channel: %p (%s)\n"
+                         "  sample_rate: %f\n"
+                         "  volume: L%f R%f\n"
+                         "  listener: %.2f %.2f %.2f [%.2f %.2f %.2f]\n",
+                         ch, ch->name, frame_samplerate, 
+                         framevol_l, framevol_r,
+                         vg_audio.internal_listener_pos[0],
+                         vg_audio.internal_listener_pos[1],
+                         vg_audio.internal_listener_pos[2],
+                         vg_audio.internal_listener_ears[0],
+                         vg_audio.internal_listener_ears[1],
+                         vg_audio.internal_listener_ears[2]
+                         );
+      }
+   }
+
+   u32 buffer_length = AUDIO_MIX_FRAME_SIZE;
+   if( frame_samplerate != 1.0f ){
+      float l = ceilf( (float)(AUDIO_MIX_FRAME_SIZE) * frame_samplerate );
+      buffer_length = l+1;
+   }
+
+   float pcf[ AUDIO_MIX_FRAME_SIZE * 2 * 2 ];
+
+   audio_channel_get_samples( ch, buffer_length, pcf );
+
+   vg_profile_begin( &_vg_prof_audio_mix );
+
+   float volume_movement = ch->volume_movement;
+   float const fvolume_rate = vg_maxf( 1.0f, ch->_.volume_rate );
+   const float inv_volume_rate = 1.0f/fvolume_rate;
+
+   float volume = ch->_.volume;
+   const float volume_start  = ch->volume_movement_start;
+   const float volume_target = ch->_.volume_target;
+
+   for( u32 j=0; j<AUDIO_MIX_FRAME_SIZE; j++ ){
+      volume_movement += 1.0f;
+      float movement_t = volume_movement * inv_volume_rate;
+            movement_t = vg_minf( movement_t, 1.0f );
+      volume           = vg_lerpf( volume_start, volume_target, movement_t );
+
+      float vol_norm = volume * volume;
+
+      if( ch->_.lfo )
+         vol_norm *= 1.0f + audio_lfo_pull_sample(ch->_.lfo) * ch->_.lfo_amount;
+
+      float vol_l = vol_norm * framevol_l,
+            vol_r = vol_norm * framevol_r,
+            sample_l,
+            sample_r;
+      
+      if( frame_samplerate != 1.0f ){
+         /* absolutely garbage resampling, but it will do
+          */
+
+         float sample_index = frame_samplerate * (float)j;
+         float t = vg_fractf( sample_index );
+
+         u32 i0 = floorf( sample_index ),
+             i1 = i0+1;
+
+         sample_l = pcf[ i0*2+0 ]*(1.0f-t) + pcf[ i1*2+0 ]*t;
+         sample_r = pcf[ i0*2+1 ]*(1.0f-t) + pcf[ i1*2+1 ]*t;
+      }
+      else{
+         sample_l = pcf[ j*2+0 ];
+         sample_r = pcf[ j*2+1 ];
+      }
+
+      buffer[ j*2+0 ] += sample_l * vol_l;
+      buffer[ j*2+1 ] += sample_r * vol_r;
+   }
+
+   ch->volume_movement += AUDIO_MIX_FRAME_SIZE;
+   ch->volume_movement  = VG_MIN( ch->volume_movement, ch->_.volume_rate );
+   ch->_.volume = volume;
+
+   vg_profile_end( &_vg_prof_audio_mix );
+}
+
+static void audio_mixer_callback( void *user, u8 *stream, int byte_count ){
+   /*
+    * Copy data and move edit flags to commit flags
+    * ------------------------------------------------------------- */
+   audio_lock();
+   int use_dsp = vg_audio.dsp_enabled;
+   
+   v3_copy( vg_audio.external_listener_pos, vg_audio.internal_listener_pos );
+   v3_copy( vg_audio.external_listener_ears, vg_audio.internal_listener_ears );
+   v3_copy( vg_audio.external_lister_velocity, 
+            vg_audio.internal_listener_velocity );
+   vg_audio.internal_global_volume = vg_audio.external_global_volume;
+
+   for( int i=0; i<AUDIO_CHANNELS; i++ ){
+      audio_channel *ch = &vg_audio.channels[i];
+
+      if( !ch->allocated )
+         continue;
+
+      if( ch->activity == k_channel_activity_alive ){
+         if( (ch->cursor >= ch->source_length) && 
+               !(ch->flags & AUDIO_FLAG_LOOP) )
+         {
+            ch->activity = k_channel_activity_end;
+         }
+      }
+
+      /* process relinquishments */
+      if( (ch->activity != k_channel_activity_reset) && ch->_.relinquished ){
+         if(   (ch->activity == k_channel_activity_end)
+            || (ch->_.volume == 0.0f)
+            || (ch->activity == k_channel_activity_error) )
+         {
+            ch->_.relinquished = 0;
+            ch->allocated = 0;
+            ch->activity = k_channel_activity_reset;
+            continue;
+         }
+      }
+
+      /* process new channels */
+      if( ch->activity == k_channel_activity_reset ){
+         ch->_ = ch->editable_state;
+         ch->cursor = 0;
+         ch->source_length = 0;
+         ch->activity = k_channel_activity_wake;
+      }
+
+      if( ch->editble_state_write_mask & AUDIO_EDIT_OWNERSHIP )
+         ch->_.relinquished = ch->editable_state.relinquished;
+      else
+         ch->editable_state.relinquished = ch->_.relinquished;
+
+
+      if( ch->editble_state_write_mask & AUDIO_EDIT_VOLUME ){
+         ch->_.volume = ch->editable_state.volume;
+         ch->_.volume_target = ch->editable_state.volume;
+      }
+      else{
+         ch->editable_state.volume = ch->_.volume;
+      }
+      
+
+      if( ch->editble_state_write_mask & AUDIO_EDIT_VOLUME_SLOPE ){
+         ch->volume_movement_start = ch->_.volume;
+         ch->volume_movement = 0;
+         
+         ch->_.volume_target = ch->editable_state.volume_target;
+         ch->_.volume_rate   = ch->editable_state.volume_rate;
+      }
+      else{
+         ch->editable_state.volume_target = ch->_.volume_target;
+         ch->editable_state.volume_rate   = ch->_.volume_rate;
+      }
+
+
+      if( ch->editble_state_write_mask & AUDIO_EDIT_SAMPLING_RATE )
+         ch->_.sampling_rate = ch->editable_state.sampling_rate;
+      else
+         ch->editable_state.sampling_rate = ch->_.sampling_rate;
+
+
+      if( ch->editble_state_write_mask & AUDIO_EDIT_LFO_ATTACHMENT ){
+         ch->_.lfo        = ch->editable_state.lfo;
+         ch->_.lfo_amount = ch->editable_state.lfo_amount;
+      }
+      else{
+         ch->editable_state.lfo        = ch->_.lfo;
+         ch->editable_state.lfo_amount = ch->_.lfo_amount;
+      }
+
+
+      if( ch->editble_state_write_mask & AUDIO_EDIT_SPACIAL )
+         v4_copy( ch->editable_state.spacial_falloff,ch->_.spacial_falloff );
+      else
+         v4_copy( ch->_.spacial_falloff,ch->editable_state.spacial_falloff );
+
+
+      /* currently readonly, i guess */
+      ch->editable_state.pan_target = ch->_.pan_target;
+      ch->editable_state.pan        = ch->_.pan;
+      ch->editble_state_write_mask  = 0x00;
+   }
+
+   for( int i=0; i<AUDIO_LFOS; i++ ){
+      audio_lfo *lfo = &vg_audio.oscillators[ i ];
+
+      if( lfo->editble_state_write_mask & AUDIO_EDIT_LFO_WAVE ){
+         lfo->_.wave_type = lfo->editable_state.wave_type;
+
+         if( lfo->_.wave_type == k_lfo_polynomial_bipolar ){
+            lfo->_.polynomial_coefficient = 
+               lfo->editable_state.polynomial_coefficient;
+            lfo->sqrt_polynomial_coefficient = 
+               sqrtf(lfo->_.polynomial_coefficient);
+         }
+      }
+
+      if( lfo->editble_state_write_mask & AUDIO_EDIT_LFO_PERIOD ){
+         if( lfo->_.period ){
+            float t = lfo->time;
+                  t/= (float)lfo->_.period;
+
+            lfo->_.period = lfo->editable_state.period;
+            lfo->time = lfo->_.period * t;
+         }
+         else{
+            lfo->time = 0;
+            lfo->_.period = lfo->editable_state.period;
+         }
+      }
+
+      lfo->editble_state_write_mask = 0x00;
+   }
+
+   dsp_update_tunings();
+   audio_unlock();
+
+   /*
+    * Process spawns
+    * ------------------------------------------------------------- */
+   for( int i=0; i<AUDIO_CHANNELS; i++ ){
+      audio_channel *ch = &vg_audio.channels[i];
+
+      if( ch->activity == k_channel_activity_wake ){
+         if( audio_channel_load_source( ch ) )
+            ch->activity = k_channel_activity_alive;
+         else
+            ch->activity = k_channel_activity_error;
+      }
+   }
+
+   /*
+    * Mix everything 
+    * -------------------------------------------------------- */
+   int frame_count = byte_count/(2*sizeof(float));
+   
+   /* Clear buffer */
+   float *pOut32F = (float *)stream;
+   for( int i=0; i<frame_count*2; i ++ )
+      pOut32F[i] = 0.0f;
+
+   for( int i=0; i<AUDIO_LFOS; i++ ){
+      audio_lfo *lfo = &vg_audio.oscillators[i];
+      lfo->time_startframe = lfo->time;
+   }
+
+   for( int i=0; i<AUDIO_CHANNELS; i ++ ){
+      audio_channel *ch = &vg_audio.channels[i];
+
+      if( ch->activity == k_channel_activity_alive ){
+         if( ch->_.lfo )
+            ch->_.lfo->time = ch->_.lfo->time_startframe;
+
+         u32 remaining = frame_count,
+             subpos    = 0;
+
+         while( remaining ){
+            audio_channel_mix( ch, pOut32F+subpos );
+            remaining -= AUDIO_MIX_FRAME_SIZE;
+            subpos += AUDIO_MIX_FRAME_SIZE*2;
+         }
+      }
+   }
+
+   if( use_dsp ){
+      vg_profile_begin( &_vg_prof_dsp );
+      for( int i=0; i<frame_count; i++ )
+         vg_dsp_process( pOut32F + i*2, pOut32F + i*2 );
+      vg_profile_end( &_vg_prof_dsp );
+   }
+
+   audio_lock();
+
+   for( int i=0; i<AUDIO_CHANNELS; i ++ ){
+      audio_channel *ch = &vg_audio.channels[i];
+      ch->readable_activity = ch->activity;
+   }
+
+   /* Profiling information 
+    * ----------------------------------------------- */
+   vg_profile_increment( &_vg_prof_audio_decode );
+   vg_profile_increment( &_vg_prof_audio_mix );
+   vg_profile_increment( &_vg_prof_dsp );
+
+   vg_prof_audio_mix = _vg_prof_audio_mix;
+   vg_prof_audio_decode = _vg_prof_audio_decode;
+   vg_prof_audio_dsp = _vg_prof_dsp;
+
+   vg_audio.samples_last = frame_count;
+
+   if( vg_audio.debug_dsp )
+      vg_dsp_update_texture();
+
+   audio_unlock();
+}
+
+void audio_clip_load( audio_clip *clip, void *lin_alloc )
+{
+   if( lin_alloc == NULL )
+      lin_alloc = vg_audio.audio_pool;
+
+   if( vg_audio.always_keep_compressed )
+   {
+      if( (clip->flags & AUDIO_FLAG_FORMAT) != k_audio_format_bird ){
+         clip->flags &= ~AUDIO_FLAG_FORMAT;
+         clip->flags |= k_audio_format_vorbis;
+      }
+   }
+
+   /* load in directly */
+   u32 format = clip->flags & AUDIO_FLAG_FORMAT;
+
+   /* TODO: This contains audio_lock() and unlock, but i don't know why
+    *       can probably remove them. Low priority to check this */
+
+   /* TODO: packed files for vorbis etc, should take from data if its not not 
+    *       NULL when we get the clip
+    */
+
+   if( format == k_audio_format_vorbis ){
+      if( !clip->path ){
+         vg_fatal_error( "No path specified, embeded vorbis unsupported" );
+      }
+
+      audio_lock();
+      clip->data = vg_file_read( lin_alloc, clip->path, &clip->size );
+      audio_unlock();
+
+      if( !clip->data )
+         vg_fatal_error( "Audio failed to load" );
+
+      float mb = (float)(clip->size) / (1024.0f*1024.0f);
+      vg_info( "Loaded audio clip '%s' (%.1fmb)\n", clip->path, mb );
+   }
+   else if( format == k_audio_format_stereo ){
+      vg_fatal_error( "Unsupported format (Stereo uncompressed)" );
+   }
+   else if( format == k_audio_format_bird ){
+      if( !clip->data ){
+         vg_fatal_error( "No data, external birdsynth unsupported" );
+      }
+
+      u32 total_size  = clip->size + sizeof(struct synth_bird);
+          total_size -= sizeof(struct synth_bird_settings);
+          total_size  = vg_align8( total_size );
+
+      if( total_size > AUDIO_DECODE_SIZE )
+         vg_fatal_error( "Bird coding too long\n" );
+
+      struct synth_bird *bird = vg_linear_alloc( lin_alloc, total_size );
+      memcpy( &bird->settings, clip->data, clip->size );
+
+      clip->data = bird;
+      clip->size = total_size;
+
+      vg_info( "Loaded bird synthesis pattern (%u bytes)\n", total_size );
+   }
+   else{
+      if( !clip->path ){
+         vg_fatal_error( "No path specified, embeded mono unsupported" );
+      }
+
+      vg_linear_clear( vg_mem.scratch );
+      u32 fsize;
+
+      stb_vorbis_alloc alloc = {
+         .alloc_buffer = vg_linear_alloc( vg_mem.scratch, AUDIO_DECODE_SIZE ),
+         .alloc_buffer_length_in_bytes = AUDIO_DECODE_SIZE
+      };
+
+      void *filedata = vg_file_read( vg_mem.scratch, clip->path, &fsize );
+
+      int err;
+      stb_vorbis *decoder = stb_vorbis_open_memory( 
+                            filedata, fsize, &err, &alloc );
+
+      if( !decoder ){
+         vg_error( "stb_vorbis_open_memory failed on '%s' (%d)\n", 
+                     clip->path, err );
+         vg_fatal_error( "Vorbis decode error" );
+      }
+
+      /* only mono is supported in uncompressed */
+      u32 length_samples = stb_vorbis_stream_length_in_samples( decoder ),
+          data_size      = length_samples * sizeof(i16);
+
+      audio_lock();
+      clip->data = vg_linear_alloc( lin_alloc, vg_align8(data_size) );
+      clip->size = length_samples;
+      audio_unlock();
+
+      int read_samples = stb_vorbis_get_samples_i16_downmixed( 
+                              decoder, clip->data, length_samples );
+
+      if( read_samples != length_samples )
+         vg_fatal_error( "Decode error" );
+
+#if 0
+      float mb = (float)(data_size) / (1024.0f*1024.0f);
+      vg_info( "Loaded audio clip '%s' (%.1fmb) %u samples\n", clip->path, mb,
+               length_samples );
+#endif
+   }
+}
+
+void audio_clip_loadn( audio_clip *arr, int count, void *lin_alloc )
+{
+   for( int i=0; i<count; i++ )
+      audio_clip_load( &arr[i], lin_alloc );
+}
+
+static void audio_require_clip_loaded( audio_clip *clip )
+{
+   if( clip->data && clip->size )
+      return;
+
+   audio_unlock();
+   vg_fatal_error( "Must load audio clip before playing! \n" );
+}
+
+/* 
+ * Debugging
+ */
+
+void audio_debug_ui( 
+
+#ifdef VG_3D
+      m4x4f
+#else
+      m3x3f 
+#endif
+      mtx_pv ){
+
+   if( !vg_audio.debug_ui )
+      return;
+
+   audio_lock();
+
+   glBindTexture( GL_TEXTURE_2D, vg_dsp.view_texture );
+   glTexSubImage2D( GL_TEXTURE_2D, 0, 0, 0, 256, 256, 
+                     GL_RGBA, GL_UNSIGNED_BYTE,
+                     vg_dsp.view_texture_buffer );
+
+   /* 
+    * Profiler
+    * -----------------------------------------------------------------------
+    */
+
+   float budget = ((double)vg_audio.samples_last / 44100.0) * 1000.0;
+   vg_profile_drawn( (struct vg_profile *[]){ &vg_prof_audio_decode,
+                                              &vg_prof_audio_mix,
+                                              &vg_prof_audio_dsp}, 3, 
+                     budget, (ui_rect){ 4, VG_PROFILE_SAMPLE_COUNT*2 + 8,
+                                        512, 0 }, 0, 0 );
+
+
+   char perf[128];
+       
+   /* Draw UI */
+   ui_rect window = {
+      0,
+      0,
+      800,
+      AUDIO_CHANNELS * 18
+   };
+
+   if( vg_audio.debug_dsp ){
+      ui_rect view_thing = { 4, vg.window_y-512-4, 512, 512 };
+      ui_image( view_thing, vg_dsp.view_texture );
+   }
+
+   ui_rect overlap_buffer[ AUDIO_CHANNELS ];
+   u32 overlap_length = 0;
+
+       /* Draw audio stack */
+       for( int i=0; i<AUDIO_CHANNELS; i ++ ){
+      audio_channel *ch = &vg_audio.channels[i];
+
+      ui_rect row;
+      ui_split( window, k_ui_axis_h, 18, 1, row, window );
+
+      if( !ch->allocated ){
+         ui_fill( row, 0x50333333 );
+         continue;
+      }
+
+      const char *formats[] =
+      {
+         "   mono   ",
+         "  stereo  ", 
+         "  vorbis  ",
+         "   none0  ",
+         "   none1  ",
+         "   none2  ",
+         "   none3  ",
+         "   none4  ",
+         "synth:bird",
+         "   none5  ",
+         "   none6  ",
+         "   none7  ",
+         "   none8  ",
+         "   none9  ",
+         "  none10  ",
+         "  none11  ",
+      };
+
+      const char *activties[] =
+      {
+         "reset",
+         "wake ",
+         "alive",
+         "end  ",
+         "error"
+      };
+
+      u32 format_index = (ch->source->flags & AUDIO_FLAG_FORMAT)>>9;
+
+      snprintf( perf, 127, "%02d[%#04x.%#06x]%c%c%cD %s [%s] %4.2fv'%s'", 
+               i,
+               ch->world_id, ch->group,
+               (ch->editable_state.relinquished)? 'r': '_',
+               0?                                 'r': '_',
+               0?                                 '3': '2',
+               formats[format_index],
+               activties[ch->readable_activity],
+               ch->editable_state.volume,
+               ch->name );
+
+      ui_fill( row, 0xa0000000 | ch->colour );
+      ui_text( row, perf, 1, k_ui_align_middle_left, 0 );
+      
+#ifdef VG_3D
+      if( AUDIO_FLAG_SPACIAL_3D ){
+         v4f wpos;
+         v3_copy( ch->editable_state.spacial_falloff, wpos );
+
+         wpos[3] = 1.0f;
+         m4x4_mulv( mtx_pv, wpos, wpos );
+
+         if( wpos[3] > 0.0f ){
+            v2_muls( wpos, (1.0f/wpos[3]) * 0.5f, wpos );
+            v2_add( wpos, (v2f){ 0.5f, 0.5f }, wpos );
+            
+            ui_rect wr;
+            wr[0] = vg_clampf(wpos[0] * vg.window_x, -32000.0f,32000.0f);
+            wr[1] = vg_clampf((1.0f-wpos[1]) * vg.window_y,-32000.0f,32000.0f);
+            wr[2] = 1000;
+            wr[3] = 17;
+            
+            for( int j=0; j<12; j++ ){
+               int collide = 0;
+               for( int k=0; k<overlap_length; k++ ){
+                  ui_px *wk = overlap_buffer[k];
+                  if( ((wr[0] <= wk[0]+wk[2]) && (wr[0]+wr[2] >= wk[0])) &&
+                      ((wr[1] <= wk[1]+wk[3]) && (wr[1]+wr[3] >= wk[1])) )
+                  {
+                     collide = 1;
+                     break;
+                  }
+               }
+
+               if( !collide )
+                  break;
+               else
+                  wr[1] += 18;
+            }
+
+            ui_text( wr, perf, 1, k_ui_align_middle_left, 0 );
+            rect_copy( wr, overlap_buffer[ overlap_length ++ ] );
+         }
+      }
+#endif
+       }
+
+   audio_unlock();
+}