From: John Tsiombikas <nuclear@mutantstargoat.com>
Date: Sat, 17 Sep 2016 03:45:31 +0000 (+0300)
Subject: lazy meshing
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=antikythera;a=commitdiff_plain;h=2c8e92970f198061a0cefdb59c2d0ec8c58409c9

lazy meshing
---

diff --git a/src/machine.cc b/src/machine.cc
index 1a78452..274362a 100644
--- a/src/machine.cc
+++ b/src/machine.cc
@@ -9,6 +9,7 @@ static float delta_angle(float a, float b);
 Machine::Machine()
 {
 	meshing = 0;
+	meshing_valid = false;
 	visited = 0;
 }
 
@@ -29,6 +30,7 @@ Machine::~Machine()
 void Machine::add_gear(Gear *g)
 {
 	gears.push_back(g);
+	meshing_valid = false;
 }
 
 void Machine::add_motor(int gearidx, float speed_hz)
@@ -39,6 +41,11 @@ void Machine::add_motor(int gearidx, float speed_hz)
 	motors.push_back(m);
 }
 
+void Machine::invalidate_meshing()
+{
+	meshing_valid = false;
+}
+
 void Machine::calc_meshing()
 {
 	int ngears = (int)gears.size();
@@ -142,6 +149,11 @@ void Machine::update(float dt)
 {
 	int ngears = (int)gears.size();
 
+	if(!meshing_valid) {
+		calc_meshing();
+		meshing_valid = true;
+	}
+
 	memset(visited, 0, ngears * sizeof *visited);
 	for(size_t i=0; i<motors.size(); i++) {
 		int gidx = motors[i].drive;
diff --git a/src/machine.h b/src/machine.h
index f222cd7..5513e02 100644
--- a/src/machine.h
+++ b/src/machine.h
@@ -13,6 +13,7 @@ class Machine {
 private:
 	std::vector<Gear*> gears;
 	bool **meshing;
+	bool meshing_valid;
 	bool *visited;	/* used for update_gear */
 
 	std::vector<Motor> motors;
@@ -26,6 +27,7 @@ public:
 	void add_gear(Gear *g);	/* takes ownership */
 	void add_motor(int gearidx, float speed_hz);
 
+	void invalidate_meshing();
 	void calc_meshing();
 
 	void update(float dt);
diff --git a/src/main.cc b/src/main.cc
index 7efc114..6fc85ba 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -88,7 +88,6 @@ bool init()
 	machine->add_gear(gear3);
 
 	machine->add_motor(0, 1.0);
-	machine->calc_meshing();
 
 	start_time = glutGet(GLUT_ELAPSED_TIME);
 	return true;