split splosions and projectiles into separate files

projectile.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	v "bitbucket.org/hackerbots/vector"
+)
+
+type Projectile struct {
+	Id       string    `json:"id"`
+	Position v.Point2d `json:"position"`
+	MoveTo   v.Point2d `json:"-"`
+	Radius   int       `json:"radius"`
+	Speed    float32   `json:"-"`
+	Damage   int       `json:"-"`
+}
+
+func (p *Projectile) Tick(g *game) {
+	vec := p.MoveTo.Sub(p.Position)
+	v_norm := vec.Normalize()
+	v_scaled := v_norm.Scale(p.Speed * delta)
+	newPos := p.Position.Add(v_scaled)
+
+	hit_player := false
+	for player := range g.players {
+		if player.Robot.Id == p.Id {
+			continue
+		}
+		dist := v.Distance(player.Robot.Position, p.Position)
+		if dist < 5.0 {
+			hit_player = true
+		}
+	}
+
+	// Are we going to intersect the destination zone in this tick?
+	r_dest := v.Rect2d{
+		A: v.Point2d{X: p.MoveTo.X - 3, Y: p.MoveTo.Y - 3},
+		B: v.Point2d{X: p.MoveTo.X + 3, Y: p.MoveTo.Y + 3}}
+
+	travel := newPos.Sub(p.Position)
+	arrived, _, _ := v.RectIntersection(r_dest, p.Position, travel)
+	if arrived || hit_player {
+		delete(g.projectiles, p)
+
+		// Spawn a splosion
+		splo := &Splosion{
+			Id:        p.Id,
+			Position:  p.Position,
+			Radius:    p.Radius,
+			MaxDamage: 10,
+			MinDamage: 5,
+			Lifespan:  8,
+		}
+		g.splosions[splo] = true
+
+		for player := range g.players {
+			dist := v.Distance(player.Robot.Position, p.Position)
+			if dist < float32(p.Radius) {
+
+				// TODO map damage Max to Min based on distance from explosion
+				if player.Robot.Health > 0 {
+					player.Robot.Health -= p.Damage
+					if player.Robot.Health <= 0 {
+					}
+				}
+			}
+		}
+	} else {
+		p.Position.X = newPos.X
+		p.Position.Y = newPos.Y
+	}
+}