Integrate ClickStream into PCM

7 files changed, 65 insertions, 73 deletions

diff --git a/ClickStream.cpp b/ClickStream.cpp
deleted file mode 100644
index 0448af1..0000000
--- a/ClickStream.cpp
+++ /dev/null
@@ -1,3 +0,0 @@
-#include "ClickStream.h"
-
-
diff --git a/ClickStream.h b/ClickStream.h
deleted file mode 100644
index c94f8de..0000000
--- a/ClickStream.h
+++ /dev/null
@@ -1,57 +0,0 @@
-#pragma once
-
-#include "config.h"
-
-#include <libreichwein/file.h>
-
-#include <cstring>
-#include <string>
-#include <vector>
-
-class ClickStream
-{
-public:
-  ClickStream(): m_phase(1000000)
-  {
-    std::string data_s = Reichwein::File::getFile("media/click.s16le");
-    m_data.resize(data_s.size() / 2); // src is in bytes
-    memcpy(m_data.data(), data_s.data(), data_s.size());
-  }
-
-  // generate 1 buffer size
-  void generate()
-  {
-    int i;
-    size_t j = m_phase;
-
-    for (i = 0; i < nframes; i++) {
-        if (j >= m_data.size())
-        {
-          buffer[i] = 0;
-        }
-        else
-        {
-          buffer[i] = m_data[j];
-        }
-        j++;
-    }
-
-    m_phase = j;
-  }
-
-  void click()
-  {
-    m_phase = 0;
-  }
-
-  int16_t* get_buffer()
-  {
-    return buffer;
-  }
-
-private:
-  std::vector<uint16_t> m_data;
-  size_t m_phase;
-  int16_t buffer[nframes];
-};
-
diff --git a/MIDI.h b/MIDI.h
index d71298d..23024c3 100644
--- a/MIDI.h
+++ b/MIDI.h
@@ -158,6 +158,13 @@ public:
      }
   }
 
+  void flush()
+  {
+    while (event_ready()) {
+      (void) read();
+    }
+  }
+
   void wait_for_event()
   {
     int result = poll(pfd, npfd, 10000);
diff --git a/Makefile b/Makefile
index 8667576..2cebb56 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,6 @@ SRCS= \
   main.cpp \
   MIDI.cpp \
   PCM.cpp \
-  ClickStream.cpp \
   config.cpp \
   UI.cpp \
   Timer.cpp \
diff --git a/PCM.h b/PCM.h
index bfa1e24..3e9b41d 100644
--- a/PCM.h
+++ b/PCM.h
@@ -1,22 +1,29 @@
 #pragma once
 
-#include "ClickStream.h"
-
 #include "config.h"
+#include "log.h"
+
+#include <libreichwein/file.h>
 
 #include <alsa/asoundlib.h>
 #include <fmt/format.h>
 
 #include <iostream>
 #include <string>
+#include <vector>
 
 using namespace std::string_literals;
 
 class PCM
 {
 public:
-  PCM(ClickStream& stream): m_stream(stream)
+  PCM(): m_phase(1000000)
   {
+    // prepare the sample
+    std::string data_s = Reichwein::File::getFile("media/click.s16le");
+    m_data.resize(data_s.size() / 2); // src is in bytes
+    memcpy(m_data.data(), data_s.data(), data_s.size());
+
     // non-blocking
     if ((err = snd_pcm_open(&handle, device, SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK)) < 0) {
       throw std::runtime_error(fmt::format("Playback open error: {}", snd_strerror(err)));
@@ -27,11 +34,11 @@ public:
                                   1,
                                   f_sample,
                                   1,
-                                  100000)) < 0) {   // latency in us
+                                  pcm_latency_us)) < 0) {   // latency in us
       throw std::runtime_error(fmt::format("Playback open error: {}", snd_strerror(err)));
     }
 
-    m_stream.generate();
+    generate();
 
     npfd = snd_pcm_poll_descriptors_count(handle);
     if (npfd < 0) {
@@ -69,6 +76,33 @@ public:
     free(pfd);
   }
 
+  void click()
+  {
+    snd_pcm_sframes_t delay;
+    if (0 > snd_pcm_delay(handle, &delay)) {
+    }
+
+    m_phase = 0; // - click_latency_frames + delay
+  }
+
+  // generate 1 buffer size
+  void generate()
+  {
+    int i;
+
+    for (i = 0; i < nframes; i++) {
+      if (m_phase < 0 || m_phase >= m_data.size())
+      {
+        buffer[i] = 0;
+      }
+      else
+      {
+        buffer[i] = m_data[m_phase];
+      }
+      m_phase++;
+    }
+  }
+
   int fd()
   {
     return pfd->fd;
@@ -77,7 +111,7 @@ public:
   // write from buffer to ALSA PCM
   void write()
   {
-    snd_pcm_sframes_t written = snd_pcm_writei(handle, m_stream.get_buffer(), nframes);
+    snd_pcm_sframes_t written = snd_pcm_writei(handle, buffer, nframes);
     if (written < 0) {
         if (written == -EPIPE) {
           std::cout << "Warning: PCM underrun" << std::endl;
@@ -93,7 +127,15 @@ public:
       std::cout << "Warning: written " << std::to_string(written) << " frames instead of "<< std::to_string(nframes) << std::endl;
     }
 
-    m_stream.generate();
+    snd_pcm_sframes_t avail;
+    snd_pcm_sframes_t delay;
+    if (0 > snd_pcm_avail_delay(handle, &avail, &delay)) {
+      log_cout << "Error detecting avail and delay" << std::endl;
+    } else {
+      log_cout << fmt::format("Delay: {}, avail. buffer; {} frames", delay, avail) << std::endl;
+    }
+
+    generate();
   }
 
   bool wait_for_event()
@@ -130,6 +172,8 @@ private:
   int npfd;
   struct pollfd* pfd;
 
-  ClickStream& m_stream;
+  std::vector<uint16_t> m_data;
+  int32_t m_phase;
+  int16_t buffer[nframes];
 };
 
diff --git a/config.h b/config.h
index b347113..f93e6a9 100644
--- a/config.h
+++ b/config.h
@@ -10,6 +10,8 @@ const snd_pcm_sframes_t nframes = 1024;   // ~1/44th sec buffer size
 const unsigned int f_sample = 44100;
 const int log_lines = 10;
 const int default_bpm = 120;
+const int pcm_latency_us = 100000;
+const int click_latency_frames = 10000;
 
 class Config
 {
diff --git a/main.cpp b/main.cpp
index ca8ec91..a58f7cd 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,5 +1,4 @@
 #include "Click.h"
-#include "ClickStream.h"
 #include "MIDI.h"
 #include "PCM.h"
 #include "Timer.h"
@@ -48,8 +47,7 @@ int main(void)
     std::shared_ptr<Click> click = note_click;
 
     MIDI midi;
-    ClickStream stream;
-    PCM pcm{stream};
+    PCM pcm;
     UI ui;
 
     pcm.write();
@@ -62,10 +60,12 @@ int main(void)
 
     // Signal-Slot Connections:
     midi.signal_note.connect([&](int channel, int note){note_click->receive_note(channel, note);});
-    note_click->signal_click.connect([&](){stream.click();});
+    note_click->signal_click.connect([&](){pcm.click();});
     timer_500ms.elapsed.connect([&](){ui.draw();});
     signal_count_loops.connect([&](){ui.count_main_loops();});
 
+    midi.flush();
+
     while (true) {
       debug_cout << "Main loop entered." << std::endl;
       signal_count_loops();