新增跟随相机

source/src/ECS/Components/Camera.ts

@@ -88,6 +88,14 @@ class Camera extends Component {
         }
     }
 
+    public get position(){
+        return this.entity.transform.position;
+    }
+
+    public set position(value: Vector2){
+        this.entity.transform.position = value;
+    }
+
     public get transformMatrix(){
         if (this._areBoundsDirty)
             this.updateMatrixes();

source/src/ECS/Components/FollowCamera.ts

@@ -0,0 +1,115 @@
+class FollowCamera extends Component {
+    public camera: Camera;
+    public followLerp = 0.1;
+    public deadzone: Rectangle = new Rectangle();
+    public focusOffset: Vector2 = new Vector2();
+    public mapLockEnabled: boolean;
+    public mapSize: Vector2 = new Vector2();
+
+    private _targetEntity: Entity;
+    private _cameraStyle: CameraStyle;
+    private _worldSpaceDeadZone: Rectangle = new Rectangle();
+    private _desiredPositionDelta: Vector2 = new Vector2();
+    private _targetCollider: Collider;
+
+    constructor(targetEntity: Entity, cameraStyle: CameraStyle = CameraStyle.lockOn){
+        super();
+
+        this._targetEntity = targetEntity;
+        this._cameraStyle = cameraStyle;
+        this.camera = null;
+    }
+
+    public onAddedToEntity(){
+        if (!this.camera)
+            this.camera = this.entity.scene.camera;
+
+        this.follow(this._targetEntity, this._cameraStyle);
+    }
+
+    public follow(targetEntity: Entity, cameraStyle: CameraStyle = CameraStyle.cameraWindow){
+        this._targetEntity = targetEntity;
+        this._cameraStyle = cameraStyle;
+        let cameraBounds = this.camera.bounds;
+
+        switch (this._cameraStyle){
+            case CameraStyle.cameraWindow:
+                let w = cameraBounds.width / 6;
+                let h = cameraBounds.height / 3;
+                this.deadzone = new Rectangle((cameraBounds.width - w) / 2, (cameraBounds.height - h) / 2, w, h);
+                break;
+            case CameraStyle.lockOn:
+                this.deadzone = new Rectangle(cameraBounds.width / 2, cameraBounds.height / 2, 10, 10);
+                break;
+        }
+    }
+
+    public update(){
+        let halfScreen = Vector2.multiply(this.camera.bounds.size, new Vector2(0.5));
+        this._worldSpaceDeadZone.x = this.camera.position.x - halfScreen.x + this.deadzone.x + this.focusOffset.x;
+        this._worldSpaceDeadZone.y = this.camera.position.y - halfScreen.y + this.deadzone.y + this.focusOffset.y;
+        this._worldSpaceDeadZone.width = this.deadzone.width;
+        this._worldSpaceDeadZone.height = this.deadzone.height;
+
+        if (this._targetEntity)
+            this.updateFollow();
+
+        this.camera.position = Vector2.lerp(this.camera.position, Vector2.add(this.camera.position, this._desiredPositionDelta), this.followLerp);
+        this.camera.entity.transform.roundPosition();
+
+        if (this.mapLockEnabled){
+            this.camera.position = this.clampToMapSize(this.camera.position);
+            this.camera.entity.transform.roundPosition();
+        }
+    }
+
+    private clampToMapSize(position: Vector2){
+        let halfScreen = Vector2.multiply(new Vector2(this.camera.bounds.width, this.camera.bounds.height), new Vector2(0.5));
+        let cameraMax = new Vector2(this.mapSize.x - halfScreen.x, this.mapSize.y - halfScreen.y);
+
+        return Vector2.clamp(position, halfScreen, cameraMax);
+    }
+
+    private updateFollow(){
+        this._desiredPositionDelta.x = this._desiredPositionDelta.y = 0;
+
+        if (this._cameraStyle == CameraStyle.lockOn){
+            let targetX = this._targetEntity.transform.position.x;
+            let targetY = this._targetEntity.transform.position.y;
+
+            if (this._worldSpaceDeadZone.x > targetX)
+                this._desiredPositionDelta.x = targetX - this._worldSpaceDeadZone.x;
+            else if(this._worldSpaceDeadZone.x < targetX)
+                this._desiredPositionDelta.x = targetX - this._worldSpaceDeadZone.x;
+
+            if (this._worldSpaceDeadZone.y < targetY)
+                this._desiredPositionDelta.y = targetY - this._worldSpaceDeadZone.y;
+            else if(this._worldSpaceDeadZone.y > targetY)
+                this._desiredPositionDelta.y = targetY - this._worldSpaceDeadZone.y;
+        } else {
+            if (!this._targetCollider){
+                this._targetCollider = this._targetEntity.getComponent<Collider>(Collider);
+                if (!this._targetCollider)
+                    return;
+            }
+
+            let targetBounds = this._targetEntity.getComponent<Collider>(Collider).bounds;
+            if (!this._worldSpaceDeadZone.containsRect(targetBounds)){
+                if (this._worldSpaceDeadZone.left > targetBounds.left)
+                    this._desiredPositionDelta.x = targetBounds.left - this._worldSpaceDeadZone.left;
+                else if(this._worldSpaceDeadZone.right < targetBounds.right)
+                    this._desiredPositionDelta.x = targetBounds.right - this._worldSpaceDeadZone.right;
+
+                if (this._worldSpaceDeadZone.bottom < targetBounds.bottom)
+                    this._desiredPositionDelta.y = targetBounds.bottom - this._worldSpaceDeadZone.bottom;
+                else if(this._worldSpaceDeadZone.top > targetBounds.top)
+                    this._desiredPositionDelta.y = targetBounds.top - this._worldSpaceDeadZone.top;
+            }
+        }
+    }
+}
+
+enum CameraStyle {
+    lockOn,
+    cameraWindow,
+}