Collision detection system

zombie/zombie.go

@@ -3,6 +3,7 @@ package zombie
 import (
 	"bytes"
 	"github.com/hajimehoshi/ebiten/v2"
+	"gitlab.com/kbr4/9heroja/collision"
 	"gitlab.com/kbr4/9heroja/configuration"
 	"gitlab.com/kbr4/9heroja/resources"
 	"image"
@@ -25,6 +26,7 @@ type Zombie struct {
 	Y         float64
 	OffsetX   float64
 	OffsetY   float64
+	IsDead    bool
 }
 
 type spritePosition struct {
@@ -57,7 +59,10 @@ func (z *Zombie) DrawZombie(screen *ebiten.Image) {
 	op.GeoM.Reset()
 	op.GeoM.Translate(z.X+z.OffsetX, z.Y+z.OffsetY)
 	op.GeoM.Scale(1, 1)
-
+	// Apply red tint if the zombie is dead
+	if z.IsDead {
+		op.ColorScale.Scale(1, 0, 0, 1) // Scale the red channel up, green and blue down.
+	}
 	screen.DrawImage(zombieImage.SubImage(image.Rect(p.x+1, p.y, p.x+resources.ZombieTileSize, p.y+resources.HeroTileSize)).(*ebiten.Image), op)
 }
 
@@ -73,23 +78,26 @@ func init() {
 }
 
 func NewZombie() *Zombie {
-	hero := &Zombie{
+	zombie := &Zombie{
 		step:      0,
 		IsWalking: false,
+		IsDead:    false,
 	}
 
 	go func() {
 		for {
 			select {
 			case <-walkTicker.C:
-				hero.step++
-				if hero.step > 3 {
-					hero.step = 0
+				if zombie.IsWalking {
+					zombie.step++
+					if zombie.step > 3 {
+						zombie.step = 0
+					}
 				}
 			}
 		}
 	}()
-	return hero
+	return zombie
 }
 
 func (z *Zombie) Walk() {
@@ -109,6 +117,36 @@ func (z *Zombie) ChangeDirection(d configuration.Direction) {
 
 func (z *Zombie) Stop() {
 	z.step = 2
-	walkTicker.Stop()
 	z.IsWalking = false
 }
+
+func (z *Zombie) CollisionShape() collision.Polygon {
+	if !z.IsDead {
+		return collision.Polygon{
+			Points: []collision.Point{
+				{X: z.X + z.OffsetX, Y: z.Y + z.OffsetY},
+				{X: z.X + z.OffsetX + 32, Y: z.Y + z.OffsetY},
+				{X: z.X + z.OffsetX + 32, Y: z.Y + z.OffsetY + 32},
+				{X: z.X + z.OffsetX, Y: z.Y + z.OffsetY + 32},
+			},
+		}
+	} else {
+		return collision.Polygon{
+			Points: []collision.Point{},
+		}
+	}
+}
+
+func (z *Zombie) CollisionObjectType() collision.ObjectType {
+	return collision.Zombie
+}
+
+func (z *Zombie) HandleCollisionEvent(other collision.Collidable) {
+	coll := other.CollisionObjectType()
+	switch coll {
+	case collision.Hero:
+		z.Stop()
+		z.IsDead = true
+
+	}
+}