From 413f2e9d1b454b6f507ea41d2ced17e41c01b7fb Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Thu, 20 Jan 2022 11:01:00 -0700
Subject: [PATCH] triggerbox: implement (?) JumpTrigger follow action

---
 libs/ardour/ardour/types.h | 10 +++++++++-
 libs/ardour/enums.cc       |  1 +
 libs/ardour/triggerbox.cc  | 14 ++++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/libs/ardour/ardour/types.h b/libs/ardour/ardour/types.h
index 6159fdd43d..1a7c913c1c 100644
--- a/libs/ardour/ardour/types.h
+++ b/libs/ardour/ardour/types.h
@@ -836,12 +836,13 @@ struct FollowAction {
 		LastTrigger,
 		AnyTrigger,
 		OtherTrigger,
+		JumpTrigger,
 	};
 
 	/* We could theoretically limit this to default_triggers_per_box but
 	 * doing it this way makes it likely that this will not change. Could
 	 * be worth a constexpr-style compile time assert to check
-	 * default_triggers_per_box < 64.
+	 * default_triggers_per_box < 64
 	 */
 
 	typedef std::bitset<64> Targets;
@@ -854,6 +855,13 @@ struct FollowAction {
 	FollowAction (Type t, std::string const & bitstring) : type (t), targets (bitstring) {}
 	FollowAction (std::string const &);
 
+	static Targets target_any () { Targets t; t.set(); return t; }
+	static Targets target_other (uint8_t skip) { Targets t; t.set (); t.reset (skip); return t; }
+	static Targets target_next_wrap (uint8_t from) { Targets t; if (from < t.size() - 1) { t.set (from + 1); } else { t.set (0); } return t; }
+	static Targets target_prev_wrap (uint8_t from) { Targets t; if (from) { t.set (from - 1); } else { t.set (t.size() - 1); } return t; }
+	static Targets target_next_nowrap (uint8_t from) { Targets t; if (from < t.size() - 1) { t.set (from + 1); } return t; }
+	static Targets target_prev_nowrap (uint8_t from) { Targets t; if (from) { t.set (from - 1); } return t; }
+
 	bool operator!= (FollowAction const & other) const {
 		return other.type != type || other.targets != targets;
 	}
diff --git a/libs/ardour/enums.cc b/libs/ardour/enums.cc
index a64154872d..315b6e77f9 100644
--- a/libs/ardour/enums.cc
+++ b/libs/ardour/enums.cc
@@ -871,6 +871,7 @@ setup_enum_writer ()
 	REGISTER_CLASS_ENUM (FollowAction, LastTrigger);
 	REGISTER_CLASS_ENUM (FollowAction, AnyTrigger);
 	REGISTER_CLASS_ENUM (FollowAction, OtherTrigger);
+	REGISTER_CLASS_ENUM (FollowAction, JumpTrigger);
 	REGISTER (_FollowAction);
 
 	REGISTER_CLASS_ENUM (Trigger, OneShot);
diff --git a/libs/ardour/triggerbox.cc b/libs/ardour/triggerbox.cc
index 69d5be13fa..fa0f4e27bc 100644
--- a/libs/ardour/triggerbox.cc
+++ b/libs/ardour/triggerbox.cc
@@ -2995,6 +2995,9 @@ TriggerBox::determine_next_trigger (uint32_t current)
 {
 	uint32_t n;
 	uint32_t runnable = 0;
+	std::vector<int32_t> possible_targets;
+
+	possible_targets.reserve (default_triggers_per_box);
 
 	/* count number of triggers that can actually be run (i.e. they have a region) */
 
@@ -3157,6 +3160,17 @@ TriggerBox::determine_next_trigger (uint32_t current)
 		}
 		return n;
 
+	case FollowAction::JumpTrigger:
+		for (std::size_t n = 0; n < default_triggers_per_box; ++n) {
+			if (fa.targets.test (n) && all_triggers[n]->region()) {
+				possible_targets.push_back (n);
+			}
+		}
+		if (possible_targets.empty()) {
+			return 1;
+		}
+		return possible_targets[_pcg.rand (possible_targets.size())];
+
 
 	/* NOTREACHED */
 	case FollowAction::Stop: