clap

commit 9033a64e86adb7b56e8cb1b8ca003ff0837d187f
parent 91f9a918c1e57e92f1e102ab25b4f324e785ee6f
Author: Alexandre BIQUE <bique.alexandre@gmail.com>
Date:   Mon, 24 May 2021 09:08:10 +0200

Add logic to the gain plugin to adjust its port definition according to the track info.

Diffstat:
M
examples/plugins/gain/gain.cc
 | 
51
++++++++++++++++++++++++++++++++++++---------------
M
examples/plugins/gain/gain.hh
 | 
10
++++++++--
M
examples/plugins/plugin.hh
 | 
3
+++
M
include/clap/ext/draft/track-info.h
 | 
8
++++----

4 files changed, 51 insertions(+), 21 deletions(-)
diff --git a/examples/plugins/gain/gain.cc b/examples/plugins/gain/gain.cc
@@ -22,30 +22,52 @@ const clap_plugin_descriptor *Gain::descriptor() {
 Gain::Gain(clap_host *host) : Plugin(descriptor(), host) {}
 
 bool Gain::init() {
-   if (canUseTrackInfo()) {
-      clap_track_info info;
-      if (hostTrackInfo_->get_track_info(host_, &info))
-      {
-         channelCount_ = info.channel_count;
-         channelMap_ = info.channel_map;
-      }
-   }
-
+   updateChannelCount(false);
    return true;
 }
 
-clap_process_status Gain::process(const clap_process *process)
-{
+void Gain::updateChannelCount(bool shouldNotifyHost) {
+   if (!canUseTrackInfo())
+      return;
+
+   clap_track_info info;
+   if (!hostTrackInfo_->get(host_, &info))
+      return;
+
+   if (channelCount_ == info.channel_count)
+      return;
+
+   if (isActive_)
+      // we can't change our ports now, delay it
+      schedulePortUpdate_ = true;
+   else
+      channelCount_ = info.channel_count;
+
+   if (canChangeAudioPorts())
+      hostAudioPorts_->changed(host_);
+}
+
+bool Gain::activate(int sample_rate) { return true; }
+
+void Gain::deactivate() {
+   if (schedulePortUpdate_) {
+      schedulePortUpdate_ = false;
+      updateChannelCount(true);
+   }
+}
+
+void Gain::trackInfoChanged() { updateChannelCount(true); }
+
+clap_process_status Gain::process(const clap_process *process) {
    auto **in = process->audio_inputs[0].data32;
    auto **out = process->audio_outputs[0].data32;
 
    float k = 1;
 
-   for (int i = 0; i < process->frames_count; ++i)
-   {
+   for (int i = 0; i < process->frames_count; ++i) {
       for (int j = 0; j < channelCount_; ++j)
          out[j][i] = k * in[j][i];
    }
 
    return CLAP_PROCESS_CONTINUE_IF_NOT_QUIET;
-}
-\ No newline at end of file
+}
diff --git a/examples/plugins/gain/gain.hh b/examples/plugins/gain/gain.hh
@@ -10,10 +10,16 @@ public:
 
    static const clap_plugin_descriptor *descriptor();
 
-   bool init() override;
+protected:
+   bool                init() override;
+   bool                activate(int sample_rate) override;
+   void                deactivate() override;
    clap_process_status process(const clap_process *process) override;
 
+   void trackInfoChanged() override;
+   void updateChannelCount(bool shouldNotifyHost);
+
 private:
    int channelCount_ = 2;
-   int channelMap_ = CLAP_CHMAP_STEREO;
+   bool schedulePortUpdate_ = false;
 };
 \ No newline at end of file
diff --git a/examples/plugins/plugin.hh b/examples/plugins/plugin.hh
@@ -26,6 +26,8 @@ protected:
    virtual clap_process_status process(const clap_process *process) { return CLAP_PROCESS_SLEEP; }
    virtual const void *        extension(const char *id) { return nullptr; }
 
+   virtual void trackInfoChanged() {}
+
    /////////////////////
    // CLAP Interfaces //
    /////////////////////
@@ -54,6 +56,7 @@ protected:
    bool canUseHostLog() const noexcept;
    bool canUseThreadCheck() const noexcept;
    bool canUseTrackInfo() const noexcept;
+   bool canChangeAudioPorts() const noexcept;
 
    /////////////////////
    // Thread Checking //
diff --git a/include/clap/ext/draft/track-info.h b/include/clap/ext/draft/track-info.h
@@ -14,7 +14,7 @@ typedef struct clap_track_info {
    clap_id    id;
    int32_t    index;
    char       name[CLAP_NAME_SIZE];
-   char       path[512]; // Like "/group1/group2/drum-machine/drum-pad"
+   char       path[512]; // Like "/group1/group2/drum-machine/drum-pad-13"
    int32_t    channel_count;
    clap_chmap channel_map;
    clap_color color;
@@ -23,13 +23,13 @@ typedef struct clap_track_info {
 
 typedef struct clap_plugin_track_info {
    // [main-thread]
-   void (*track_info_changed)(clap_plugin *plugin);
+   void (*changed)(clap_plugin *plugin);
 } clap_plugin_track_info;
 
 typedef struct clap_host_track_info {
-   // Informs the host that the note names has changed.
+   // Get info about the track the plugin belongs to.
    // [main-thread]
-   bool (*get_track_info)(clap_host *host, clap_track_info *info);
+   bool (*get)(clap_host *host, clap_track_info *info);
 } clap_host_track_info;
 
 #ifdef __cplusplus