Byzantine Snowfall

actors/snowball.go

@@ -10,6 +10,7 @@ type Snowball struct {
 	color int
 	Probability float32
 	sureness float32
+	Byztantine bool
 }
 
 func (sm *Snowball) Setup(env *core.Environment, t *core.Turtle) {
@@ -23,37 +24,42 @@ func (sm *Snowball) Setup(env *core.Environment, t *core.Turtle) {
 }
 
 func (sm *Snowball) Run(env *core.Environment, t *core.Turtle) {
-	t.Wiggle()
-	am1 := t.Amount(env,1,"1")
-	am2 := t.Amount(env,1,"2")
+	if sm.Byztantine {
+		t.Wiggle()
+		t.Drop(env, 1, "2")
+	} else {
+		t.Wiggle()
+		am1 := t.Amount(env, 1, "1")
+		am2 := t.Amount(env, 1, "2")
 
-	if am1 > sm.sureness || am2 > sm.sureness {
-		if am1 > am2 {
-			if sm.color == 2 {
-				sm.sureness--
-			} else {
-				sm.sureness++
-			}
-			if sm.sureness == 0 {
-				sm.color = 1
-			}
-		} else if am2 > am1 {
-			if sm.color == 1 {
-				sm.sureness--
-			} else {
-				sm.sureness++
-			}
-			if sm.sureness == 0 {
-				sm.color = 2
+		if am1 > sm.sureness || am2 > sm.sureness {
+			if am1 > am2 {
+				if sm.color == 2 {
+					sm.sureness--
+				} else {
+					sm.sureness++
+				}
+				if sm.sureness == 0 {
+					sm.color = 1
+				}
+			} else if am2 > am1 {
+				if sm.color == 1 {
+					sm.sureness--
+				} else {
+					sm.sureness++
+				}
+				if sm.sureness == 0 {
+					sm.color = 2
+				}
 			}
 		}
-	}
 
-	if sm.sureness > 1 {
-		t.Drop(env, 1, strconv.Itoa(sm.color))
-	}
+		if sm.sureness > 1 {
+			t.Drop(env, 1, strconv.Itoa(sm.color))
+		}
 
-	t.Step(env)
+		t.Step(env)
+	}
 }
 
 

core/turtle.go

@@ -8,6 +8,7 @@ type Turtle struct {
 	xpos, ypos int
 	heading    int
 	actor      Actor
+	width,height int
 }
 
 type NilActor struct {
@@ -22,6 +23,8 @@ func (NilActor) Run(*Environment, *Turtle) {
 func NewTurtle(env *Environment, actor Actor) *Turtle {
 	for {
 		turtle := new(Turtle)
+		turtle.width = env.width
+		turtle.height = env.height
 		turtle.xpos = rand.Intn(env.width)
 		turtle.ypos = rand.Intn(env.height)
 		turtle.actor = actor
@@ -46,6 +49,19 @@ func (t *Turtle) setRandomHeading() {
 }
 
 func (t *Turtle) SetXY(x, y int) {
+
+	if x < 0 {
+		x = (t.width - 1)
+	} else if x >= t.width {
+		x = x % (t.width)
+	}
+
+	if y < 0 {
+		y = (t.height - 1)
+	} else if y >=t.height {
+		y = y % (t.height)
+	}
+
 	t.xpos = x
 	t.ypos = y
 }

graphics/graphics.go

@@ -97,7 +97,7 @@ func (g *Graphics) Render(env *core.Environment, turtles []*core.Turtle) {
 
 	// TODO: Move this into an environment specification
 	for name := range g.colorMap {
-		env.Evaporate(0.95, name)
+		env.Evaporate(0.99, name)
 	}
 
 	g.renderer.Present()

main.go

@@ -22,7 +22,7 @@ var width = flag.Int("width", 300, "width of environment")
 var height = flag.Int("height", 300, "height of environment")
 var pxsize = flag.Int("pxsize", 1, "pixels per tile edge")
 var numTurtles = flag.Int("numTurtles", 5000, "number of turtles")
-
+var byzantineTurtles = flag.Int("byzantineTurtles", 50,"in consensus simlulations, the number of turtles who will always vote 2")
 var prob = flag.Float64("distribution", .51, "drives the probability of color assignment of turtles in consensus models, closer to .5 results in more even assignment, closer to 0 or 1 biases in favor of a color.")
 
 func main() {
@@ -109,6 +109,18 @@ func main() {
 		env.InitPheromone("2")
 		g.ColorPheromone("1", [4]uint8{0x00, 0xFF, 0x80, 0x00})
 		g.ColorPheromone("2", [4]uint8{0xFF, 0x80, 0x00, 0x00})
+	case "snowball-byzantine":
+		honestTurtles := (*numTurtles)-(*byzantineTurtles)
+		for i := 0; i < honestTurtles; i++ {
+			turtles[i] = core.NewTurtle(env, &actors.Snowball{Probability:float32(*prob)})
+		}
+		for i := honestTurtles; i < honestTurtles+(*byzantineTurtles); i++ {
+			turtles[i] = core.NewTurtle(env, &actors.Snowball{Probability:float32(*prob), Byztantine:true})
+		}
+		env.InitPheromone("1")
+		env.InitPheromone("2")
+		g.ColorPheromone("1", [4]uint8{0x00, 0xFF, 0x80, 0x00})
+		g.ColorPheromone("2", [4]uint8{0xFF, 0x00, 0xa5, 0x00})
 	case "flocking":
 		for i := 0; i < *numTurtles; i++ {
 			turtles[i] = core.NewTurtle(env, &actors.Flocking{SniffDistance: 1})