Allow rendering above and below GameView

Author: STREGA

Sources/GateEngine/ECS/Base/ECSContext.swift

@@ -321,17 +321,22 @@ extension ECSContext {
         return shouldRender
     }
 
-    func updateRendering(into view: GameView, deltaTime: Float) {
+    func beginRendering() {
         if let performance = performance {
             performance.startRenderingSystems()
         }
-
+    }
+    
+    func updateRendering(into view: GameView, deltaTime: Float, for phase: RenderingSystem.Phase) {
         for system in self.renderingSystems {
+            guard type(of: system).phase == phase else {continue}
             self.performance?.beginStatForSystem(system)
             system.willRender(into: view, withTimePassed: deltaTime, context: self)
             self.performance?.endCurrentStatistic()
         }
-        
+    }
+    
+    func endRendering() {
         if let performance = performance {
             performance.endRenderingSystems()
             performance.finalizeRenderingSystemsFrameTime()

Sources/GateEngine/ECS/Base/RenderingSystem.swift

@@ -83,6 +83,16 @@
 
     }
 
+    
+    /**
+     The major sort order for rendering systems.
+
+     The phase value decides what layer this systems content will be drawn relative to it's owning GameView
+     */
+    open class var phase: Phase {
+        return .afterGameView
+    }
+    
     /**
      Provide a sorting order to ensure this system is processed at the right time.
 
@@ -96,6 +106,13 @@
         return .dontCare
     }
 }
+
+extension RenderingSystem {
+    public enum Phase: UInt {
+        /// Draws before the GameView, resulting in content below
+        case beforeGameView
+        /// Draws after the GameView, resulting in content ontop
+        case afterGameView
     }
 }
 

Sources/GateEngine/UI/GameViewController.swift

@@ -58,12 +58,19 @@ public final class GameView: View {
         }
 
         if let gameViewController {
-            let highPrecisionDeltaTime = self.deltaTimeHelper.getDeltaTime()
+            gameViewController.context.beginRendering()
 
+            let highPrecisionDeltaTime = self.deltaTimeHelper.getDeltaTime()
             let deltaTime = Float(highPrecisionDeltaTime)
 
-            gameViewController.context.updateRendering(into: self, deltaTime: deltaTime)
+            // Draw below content
+            gameViewController.context.updateRendering(into: self, deltaTime: deltaTime, for: .beforeGameView)
+            // Draw GameView
             gameViewController.render(context: gameViewController.context, into: self, withTimePassed: deltaTime)
+            // Draw above content
+            gameViewController.context.updateRendering(into: self, deltaTime: deltaTime, for: .afterGameView)
+            
+            gameViewController.context.endRendering()
 
             if mode == .offScreen {
                 canvas.insert(