1 files changed, 21 insertions, 4 deletions
diff --git a/internal/engine/tick.go b/internal/engine/tick.go
index d6d470a..419867d 100644
--- a/internal/engine/tick.go
+++ b/internal/engine/tick.go
@@ -1,12 +1,11 @@
 package engine
 
 import (
+	"math/rand"
 	"sync"
 	"time"
 )
 
-const TickDuration = 600 * time.Millisecond
-
 type Callback func() bool
 
 type subscriber struct {
@@ -49,14 +48,17 @@ func (e *Engine) Unsubscribe(id uint64) {
 	delete(e.subscribers, id)
 }
 
-func (e *Engine) Start() {
+func (e *Engine) Start(tickLengthMs int) {
 	e.mu.Lock()
 	defer e.mu.Unlock()
 	if e.running {
 		return
 	}
 	e.running = true
-	e.ticker = time.NewTicker(TickDuration)
+	if tickLengthMs < 50 {
+		tickLengthMs = 50
+	}
+	e.ticker = time.NewTicker(time.Duration(tickLengthMs) * time.Millisecond)
 	e.stopCh = make(chan struct{})
 
 	go func() {
@@ -103,3 +105,18 @@ func (e *Engine) processTick() {
 		}
 	}
 }
+
+func FractionalTicks(base, speed float64) int {
+	if speed <= 0 {
+		speed = 1
+	}
+	value := base / speed
+	if value < 1 {
+		value = 1
+	}
+	floor := int(value)
+	if rand.Float64() < value-float64(floor) {
+		return floor + 1
+	}
+	return floor
+}