Collision detection system

main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/inpututil"
+	"gitlab.com/kbr4/9heroja/collision"
 	"gitlab.com/kbr4/9heroja/configuration"
 	"gitlab.com/kbr4/9heroja/hero"
 	"gitlab.com/kbr4/9heroja/input"
@@ -51,6 +52,7 @@ type Game struct {
 	hero    *hero.Hero
 	terrain *terrain.Terrain
 	zombies []*zombie.Zombie
+	world   *collision.World
 }
 
 func (g *Game) Update() error {
@@ -63,17 +65,18 @@ func (g *Game) Update() error {
 		g.terrain.Move()
 		g.hero.Walk()
 	}
+	g.world.NotifyAboutCollisions()
 	return nil
 }
 
 func (g *Game) Draw(screen *ebiten.Image) {
 	g.terrain.DrawTerrain(screen)
-	g.hero.DrawHero(screen)
 	for _, z := range g.zombies {
 		z.OffsetX = g.terrain.PositionX
 		z.OffsetY = g.terrain.PositionY
 		z.DrawZombie(screen)
 	}
+	g.hero.DrawHero(screen)
 }
 
 func (g *Game) Layout(outsideWidth, outsideHeight int) (screenWidth, screenHeight int) {
@@ -86,10 +89,12 @@ var GameInstance *Game
 func init() {
 
 	GameInstance = &Game{}
+	GameInstance.world = collision.NewWorld()
 	GameInstance.control = &input.Keyboard{}
 	GameInstance.hero = hero.NewHero()
 	GameInstance.zombies = []*zombie.Zombie{zombie.NewZombie(), zombie.NewZombie(), zombie.NewZombie(), zombie.NewZombie(), zombie.NewZombie()}
 
+	GameInstance.world.AddEntity(GameInstance.hero)
 	// put zombies in random places on the screen but not too close to the hero or each other
 	for _, z := range GameInstance.zombies {
 		z.X = float64(configuration.Random(50, screenWidth-50))
@@ -99,6 +104,7 @@ func init() {
 			z.Y = float64(configuration.Random(0, screenHeight))
 		}
 		z.Walk()
+		GameInstance.world.AddEntity(z)
 	}
 
 	GameInstance.terrain = terrain.NewTerrain()