virtual-controller/extension-reaper-macos/src/main.cpp

// extension-reaper-macos — bare-minimum REAPER extension.
//
// Loads, registers one test action ("extension-reaper-macos: Hello"), and
// prints a confirmation to the REAPER console.
//
// Top-level story:
// - We tell the compiler which REAPER functions we need a box for.
// - REAPER loads our .dylib and calls our one required function, once.
// - We check we're actually loading, not unloading, and the version matches.
// - We fill our function box(es) with their real address.
// - We describe a new action and hand it to REAPER — it creates it, gives
//   us back a number.
// - We subscribe our own function to REAPER's "every action, any trigger"
//   stream.
// - We print "loaded successfully" — proof of everything up to that point,
//   but NOT proof the action/subscription actually works.
// - Setup's done. We now just sit in memory, doing nothing.
// - Later, any action anywhere in REAPER (click, key, MIDI, OSC) calls our
//   subscribed function.
// - It checks if the action was ours. If yes, react. If no, ignore.

// We tell the compiler which REAPER functions we need a box for. This file
// owns the real storage (REAPERAPI_IMPLEMENT), so this list has to cover
// everything used anywhere in the project, including tracking.cpp.
#define REAPERAPI_MINIMAL
#define REAPERAPI_WANT_ShowConsoleMsg
#define REAPERAPI_WANT_CountAutomationItems
#define REAPERAPI_WANT_GetSetAutomationItemInfo
#define REAPERAPI_WANT_CountTracks
#define REAPERAPI_WANT_GetTrack
#define REAPERAPI_WANT_CountTrackEnvelopes
#define REAPERAPI_WANT_GetTrackEnvelope
#define REAPERAPI_IMPLEMENT

#include "reaper_plugin.h"
#include "reaper_plugin_functions.h"
#include "tracking.h"
#include "socket.h"

#include <cstdio>

static int action1_id = 0;
static const char *kAction1IdStr = "EXTENSION_REAPER_MACOS_HELLO";
static const char *kAction1Name = "Hello Action List Display Name";

// Testing hookcommand2 again (REAPER's docs specifically recommend it for
// custom_action-registered actions), this time with debug prints kept in.
static bool Action1(KbdSectionInfo *sec, int command, int val, int val2, int relmode, HWND hwnd)
{
  // Unconditional — proves whether this callback is being reached at all,
  // and for which command IDs, regardless of whether it's ours.
  char buf[128];
  snprintf(buf, sizeof(buf), "[extension-reaper-macos] Action1 called: command=%d action1_id=%d\n", command, action1_id);
  ShowConsoleMsg(buf);

  if (command == action1_id)
  {
    ShowConsoleMsg("[extension-reaper-macos] Hello action triggered\n");
    return true;
  }

  ShowConsoleMsg("[extension-reaper-macos] ignored — not ours\n");
  return false;
}

// REAPER loads our .dylib and calls this once.
extern "C" REAPER_PLUGIN_DLL_EXPORT int REAPER_PLUGIN_ENTRYPOINT(REAPER_PLUGIN_HINSTANCE hInstance, reaper_plugin_info_t *rec)
{
  // Check we're actually loading, not unloading, and the version matches.
  if (!rec)
    return 0;
  if (rec->caller_version != REAPER_PLUGIN_VERSION)
    return 0;

  // Fill our function box(es) with their real address.
  if (REAPERAPI_LoadAPI(rec->GetFunc) != 0)
    return 0;

  // Describe a new action and hand it to REAPER — it creates it, gives us
  // back a number, which we save.
  custom_action_register_t actionDescription = {
    0,
    kAction1IdStr,
    kAction1Name,
    NULL,
  };
  action1_id = rec->Register("custom_action", &actionDescription);

  // Verify registration actually succeeded — Register returns 0 on failure,
  // and we've never checked that until now.
  char buf[128];
  snprintf(buf, sizeof(buf), "[extension-reaper-macos] action1_id = %d\n", action1_id);
  ShowConsoleMsg(buf);

  // Subscribe Action1 via hookcommand2 — REAPER's documented pairing for
  // custom_action-registered actions specifically.
  rec->Register("hookcommand2", (void *)Action1);

  // Envelope/automation-item polling now lives in tracking.cpp.
  RegisterTracking(rec);

  // Basic UDP socket listener lives in socket.cpp.
  RegisterSocket(rec);

  // Print "loaded successfully" — proof of everything above, but NOT proof
  // the action/subscription actually works.
  ShowConsoleMsg("[extension-reaper-macos] loaded successfully\n");

  // Setup's done. Return 1 = "keep me loaded." We now just sit in memory,
  // doing nothing, until Action1 gets called later.
  return 1;
}