Move all engine stuff to GoRetro. Still many interactions between game and engine code that there should not be.

component_damage_giver.go

@@ -0,0 +1,58 @@
+package GoRetro
+
+/*
+ * --------------------
+ * damageGiver
+ * --------------------
+ * During a collision a damageReciever handles damage from
+ * a damageGiver
+ */
+
+type damageGiver struct {
+	container      *Element
+	damage         float64 // Damage per incident (or tick if damagePerists)
+	damageActive   bool    // Is currently able to issue damage
+	damagePersists bool    // Can this continue to damage once it's been hit
+}
+
+func NewDamageGiver(container *Element, damage float64, damagePersists bool) *damageGiver {
+	return &damageGiver{
+		container:      container,
+		damage:         damage,
+		damageActive:   true,
+		damagePersists: damagePersists,
+	}
+}
+
+func (dg *damageGiver) onDraw() error {
+	return nil
+}
+
+func (dg *damageGiver) onUpdate() error {
+	if dg.container.checkComponentIsPresent(&damageReceiver{}) {
+		dr := dg.container.getComponent(&damageReceiver{}).(*damageReceiver)
+		if dr.health <= 0 {
+			// We can't give damage any more if our reciever is at 0 (i.e. container is dead)
+			dg.damageActive = false
+		}
+	}
+	return nil
+}
+
+func (dg *damageGiver) onCollision(other *Element) error {
+	if !dg.damageActive {
+		return nil
+	}
+
+	if other.checkComponentIsPresent(&damageReceiver{}) {
+		// Find our victim and subtract damage
+		dr := other.getComponent(&damageReceiver{}).(*damageReceiver)
+		dr.health -= dg.damage
+
+		// If we don't continue to hand out damage then disable ourselves
+		if !dg.damagePersists {
+			dg.damageActive = false
+		}
+	}
+	return nil
+}