Improvements to resizing/reorientation

XIONControlPanel/Controllers/VisualizationViewController.swift

@@ -15,20 +15,24 @@ import SceneKit
 
 let π = CGFloat(Double.pi)
 
-class VisualizationViewController: UIViewController
+class VisualizationViewController: UIViewController, SCNSceneRendererDelegate
 {
-    fileprivate var _scene:             SCNScene = SCNScene()
-    fileprivate var _sceneView:         SCNView?
-    fileprivate var _cameraNode:        SCNNode = SCNNode()
-    fileprivate var _lightNode:         SCNNode = SCNNode()
-    fileprivate var _cubletsNode:       SCNNode = SCNNode()
-    fileprivate var _cublets:           [SCNNode] = []
-    fileprivate var _percentActivated:  Float = 0.0
+    fileprivate let _scene:              SCNScene = SCNScene()
+    fileprivate let _cameraNode:         SCNNode = SCNNode()
+    fileprivate let _lightNode:          SCNNode = SCNNode()
+    fileprivate var _cubletsNode:        SCNNode = SCNNode()
+    fileprivate var _sceneView:          SCNView?
+    fileprivate var _cublets:            [SCNNode] = []
+    fileprivate var _percentActivated:   Float = 0.0
+    
+    fileprivate let _rendererDataQueue:  DispatchQueue = DispatchQueue(label: "RendererQueue")
+    fileprivate var _rendererViewBounds: CGRect = .zero
     
     static fileprivate let cubletsDimensions = 5
     static fileprivate let cubletsSize = 1.0
     static fileprivate let cubletsSpacing = 2.0
     static fileprivate let rotationAnimationKey = "RotationAnimation"
+    static fileprivate let cameraAdditionalDistance = Float(8.0)
     
     // MARK: Overrides
     
@@ -39,6 +43,7 @@ class VisualizationViewController: UIViewController
         view.backgroundColor = UIColor.black
         view.scene = _scene
         view.allowsCameraControl = false
+        view.delegate = self
         
         _sceneView = view
         self.view = view
@@ -68,6 +73,16 @@ class VisualizationViewController: UIViewController
         _sceneView?.stop(nil)
     }
     
+    override func viewDidLayoutSubviews()
+    {
+        super.viewDidLayoutSubviews()
+        
+        let bounds = self.view.bounds
+        _rendererDataQueue.async {
+            self._rendererViewBounds = bounds
+        }
+    }
+        
     // MARK: API
     
     var connectionStatus: ConnectionStatus = .disconnected
@@ -146,6 +161,13 @@ class VisualizationViewController: UIViewController
         _percentActivated = percentage
     }
     
+    // MARK: SCNSceneRendererDelegate
+    
+    func renderer(_ renderer: SCNSceneRenderer, updateAtTime time: TimeInterval)
+    {
+        _recomputeCameraDistance()
+    }
+    
     // MARK: Internal
     
     internal func _setupCamera()
@@ -153,7 +175,6 @@ class VisualizationViewController: UIViewController
         let camera = SCNCamera()
         
         _cameraNode.camera = camera
-        _cameraNode.position = SCNVector3Make(0.0, 0.0, 30.0)
         _scene.rootNode.addChildNode(_cameraNode)
         
         let centerNode = SCNNode()
@@ -169,12 +190,9 @@ class VisualizationViewController: UIViewController
         let light = SCNLight()
         light.type = SCNLight.LightType.omni
         light.color = UIColor.white
-        
-        _lightNode = SCNNode()
         _lightNode.light = light
-        _lightNode.position = _cameraNode.position
         
-        _scene.rootNode.addChildNode(_lightNode)
+        _cameraNode.addChildNode(_lightNode)
     }
     
     internal func _setupModel()
@@ -240,6 +258,36 @@ class VisualizationViewController: UIViewController
         _sceneView?.technique = technique
     }
     
+    internal func _recomputeCameraDistance()
+    {
+        // compute how far the camera must be from the origin in order to fit the
+        // entire scene into the current viewport size.
+        
+        guard let renderer = _sceneView else { return }
+        guard let camera = _cameraNode.camera else { return }
+        
+        let viewBounds = _rendererDataQueue.sync { _rendererViewBounds }
+        let worldMin = renderer.unprojectPoint(SCNVector3(
+            viewBounds.origin.x,
+            viewBounds.origin.y,
+            0.0
+        ))
+        let worldMax = renderer.unprojectPoint(SCNVector3(
+            viewBounds.origin.x + viewBounds.size.width,
+            viewBounds.origin.y + viewBounds.size.height,
+            0.0
+        ))
+        let farX = worldMax.x - worldMin.x
+        
+        let fov = Float(camera.fieldOfView)
+        let aabb = _cubletsNode.boundingBox
+        let minO = (aabb.max.x - aabb.min.x) / farX
+        let halfMinO = minO / 2.0
+        let cameraDistance = (halfMinO / tan(fov)) + Self.cameraAdditionalDistance
+        
+        _cameraNode.position = SCNVector3Make(0.0, 0.0, cameraDistance)
+    }
+    
     internal func _beginModelResetTimer()
     {
         /* since this visualization is running all the time, trigonometric functions begin