#39 - adds docs to camera stuff

app/camera/main.go

@@ -12,27 +12,32 @@ import (
 )
 
 type CameraDemo struct {
-	game.GameSceneWithCamera
-	game *game.Game
+	game.GameSceneWithCamera // type embedding
 
-	cameraComponent *components.Camera
+	game            *game.Game
+	cameraComponent *components.Camera // to control the camera
 }
 
 func (s *CameraDemo) Init() error {
 
 	w, h := s.game.WindowSize()
 	s.Camera = *camera.NewCamera(w, h)
-	s.cameraComponent = &components.Camera{Zoom: 1, CameraMode: camera.CameraModeCenter}
+	s.cameraComponent = &components.Camera{
+		Zoom:       1.0,
+		CameraMode: camera.CameraModeDefault,
+	}
 
 	s.Systems = append(s.Systems,
 		&systems.SpriteRenderer{EntityManager: &s.EntityManager},
 		&systems.Controller{EntityManager: &s.EntityManager},
 		&systems.MovementSystem{EntityManager: &s.EntityManager},
 		&systems.TextRenderer{EntityManager: &s.EntityManager},
 		&systems.PerformanceMonitor{EntityManager: &s.EntityManager},
+
 		systems.NewCameraSystem(&s.EntityManager, &s.Camera),
 	)
 
+	// the objects int the world
 	fps := s.EntityManager.NewEntity()
 	game.FPSCounter(fps, 1024)
 
@@ -77,7 +82,8 @@ func main() {
 	game.AddScene("Demo", &demo)
 	game.SetScene("Demo")
 
-	ebiten.SetFullscreen(true)
+	ebiten.SetFullscreen(false)
+	ebiten.SetWindowSize(800, 600)
 
 	if err := ebiten.RunGame(game); err != nil {
 		log.Fatalf("failed to start game: %s", err)

game/ecs/systems/cameraSystem.go

@@ -9,6 +9,7 @@ import (
 	"github.com/hajimehoshi/ebiten/v2"
 )
 
+// CameraSystem controls the camera by reading cameraComponent and setting values on the actual camera
 type CameraSystem struct {
 	EntityManager *ecs.EntityManager
 	camera        *camera.Camera
@@ -26,7 +27,8 @@ func (s *CameraSystem) Draw(screen *ebiten.Image) {}
 
 func (s *CameraSystem) Update() error {
 
-	entities := s.EntityManager.FindByComponents(components.TransformType, components.CameraType)
+	// find the entity with the camera attached and positioned in the world
+	entities := s.EntityManager.FindByComponents(components.CameraType, components.TransformType)
 
 	if len(entities) != 1 {
 		return errors.New("expected exactly 1 entity with camera attached")

game/sceneWithCamera.go

@@ -21,6 +21,7 @@ func (s *GameSceneWithCamera) Init() error {
 func (s *GameSceneWithCamera) Draw(screen *ebiten.Image) {
 
 	s.Camera.Surface.Clear()
+
 	for _, v := range s.Systems {
 		v.Draw(s.Camera.Surface)
 	}