fix memory leaks + minor refactor

Sources/Voxelotl/Application.swift

@@ -31,15 +31,15 @@ public class Application {
     if cfg.flags.contains(.highDPI) {
       windowFlags |= SDL_WindowFlags(SDL_WINDOW_HIGH_PIXEL_DENSITY)
     }
-    window = SDL_CreateWindow(cfg.title, cfg.width, cfg.height, windowFlags)
+    window = SDL_CreateWindow(cfg.title, cfg.frame.w, cfg.frame.h, windowFlags)
     guard window != nil else {
       printErr("SDL_CreateWindow() error: \(String(cString: SDL_GetError()))")
       return .exitFailure
     }
 
     // Get window metrics
-    var backBufferWidth: Int32 = 0, backBufferHeight: Int32 = 0
-    guard SDL_GetWindowSizeInPixels(window, &backBufferWidth, &backBufferHeight) >= 0 else {
+    var backBuffer = Size<Int32>.zero
+    guard SDL_GetWindowSizeInPixels(window, &backBuffer.w, &backBuffer.h) >= 0 else {
       printErr("SDL_GetWindowSizeInPixels() error: \(String(cString: SDL_GetError()))")
       return .exitFailure
     }
@@ -49,7 +49,7 @@ public class Application {
     do {
       let layer = unsafeBitCast(SDL_Metal_GetLayer(view), to: CAMetalLayer.self)
       layer.displaySyncEnabled = cfg.vsyncMode == .off ? false : true
-      self.renderer = try Renderer(layer: layer, size: .init(Int(backBufferWidth), Int(backBufferHeight)))
+      self.renderer = try Renderer(layer: layer, size: Size<Int>(backBuffer))
     } catch RendererError.initFailure(let message) {
       printErr("Renderer init error: \(message)")
       return .exitFailure
@@ -122,9 +122,9 @@ public class Application {
     del.update(gameTime)
 
     do {
-      try renderer!.beginFrame()
-      del.draw(renderer!, gameTime)
-      renderer!.endFrame()
+      try renderer!.newFrame {
+        del.draw($0, gameTime)
+      }
     } catch RendererError.drawFailure(let message) {
       printErr("Renderer draw error: \(message)")
       return .exitFailure
@@ -182,15 +182,13 @@ public struct ApplicationConfiguration {
     case adaptive
   }
 
-  let width: Int32
-  let height: Int32
+  let frame: Size<Int32>
   let title: String
   let flags: Flags
   let vsyncMode: VSyncMode
 
-  public init(width: Int32, height: Int32, title: String, flags: Flags, vsyncMode: VSyncMode) {
-    self.width = width
-    self.height = height
+  public init(frame: Size<Int32>, title: String, flags: Flags, vsyncMode: VSyncMode) {
+    self.frame = frame
     self.title = title
     self.flags = flags
     self.vsyncMode = vsyncMode

Sources/Voxelotl/Rectangle.swift

@@ -42,6 +42,10 @@ public struct Size<T: AdditiveArithmetic>: Equatable {
 
 extension Size where T: BinaryInteger {
   static var one: Self { .init(T(1), T(1)) }
+
+  init<O>(_ other: Size<O>) where O: BinaryInteger {
+    self.init(T(other.w), T(other.h))
+  }
 }
 
 struct Rect<T: AdditiveArithmetic>: Equatable {

Sources/Voxelotl/Renderer.swift

@@ -55,9 +55,7 @@ public class Renderer {
   private var depthStencilState: MTLDepthStencilState
   private var depthTextures: [MTLTexture]
 
-  private var _commandBuf: MTLCommandBuffer!
-  private var _encoder: MTLRenderCommandEncoder!
-  private var _rt: (any CAMetalDrawable)!
+  private var _encoder: MTLRenderCommandEncoder! = nil
 
   private var vtxBuffer: MTLBuffer, idxBuffer: MTLBuffer
   private var defaultTexture: MTLTexture
@@ -201,6 +199,7 @@ public class Renderer {
   }
 
   static func loadTexture(_ device: MTLDevice, _ queue: MTLCommandQueue, image2D image: Image2D) throws -> MTLTexture {
+    try autoreleasepool {
       let texDesc = MTLTextureDescriptor()
       texDesc.width  = image.width
       texDesc.height = image.height
@@ -245,9 +244,11 @@ public class Renderer {
 
       return newTexture
     }
+  }
 
   private static func createDepthTexture(_ device: MTLDevice, _ size: Size<Int>, format: MTLPixelFormat
   ) -> MTLTexture? {
+    autoreleasepool {
       let texDescriptor = MTLTextureDescriptor.texture2DDescriptor(
         pixelFormat: format,
         width:       size.w,
@@ -267,6 +268,7 @@ public class Renderer {
 
       return depthStencilTexture
     }
+  }
 
   static func makeViewport(rect: Rect<Int>, znear: Double = 0.0, zfar: Double = 1.0) -> MTLViewport {
     MTLViewport(
@@ -288,41 +290,56 @@ public class Renderer {
     self._aspectRatio = Float(self.backBufferSize.w) / Float(self.backBufferSize.h)
   }
 
-  func beginFrame() throws {
-    // Lock the semaphore here if too many frames are "in flight"
-    _ = inFlightSemaphore.wait(timeout: .distantFuture)
-
+  func newFrame(_ frameFunc: (Renderer) -> Void) throws {
+    try autoreleasepool {
       guard let rt = layer.nextDrawable() else {
         throw RendererError.drawFailure("Failed to get next drawable render target")
       }
-    self._rt = rt
 
-    passDescription.colorAttachments[0].texture = self._rt.texture
+      passDescription.colorAttachments[0].texture = rt.texture
       passDescription.depthAttachment.texture = self.depthTextures[self.currentFrame]
 
+      // Lock the semaphore here if too many frames are "in flight"
+      _ = inFlightSemaphore.wait(timeout: .distantFuture)
+
       guard let commandBuf: MTLCommandBuffer = queue.makeCommandBuffer() else {
         throw RendererError.drawFailure("Failed to make command buffer from queue")
       }
-    self._commandBuf = commandBuf
-    self._commandBuf.addCompletedHandler { _ in
+      commandBuf.addCompletedHandler { _ in
         self.inFlightSemaphore.signal()
       }
 
-    guard let encoder = self._commandBuf.makeRenderCommandEncoder(descriptor: passDescription) else {
+      guard let encoder = commandBuf.makeRenderCommandEncoder(descriptor: passDescription) else {
         throw RendererError.drawFailure("Failed to make render encoder from command buffer")
       }
+
+      encoder.setCullMode(.back)
+      encoder.setFrontFacing(.counterClockwise)  // OpenGL default
+      encoder.setViewport(Self.makeViewport(rect: self.frame))
+      encoder.setRenderPipelineState(pso)
+      encoder.setDepthStencilState(depthStencilState)
+      encoder.setFragmentTexture(cubeTexture ?? defaultTexture, index: 0)
+      encoder.setVertexBuffer(vtxBuffer,
+        offset: 0,
+        index: ShaderInputIdx.vertices.rawValue)
+
       self._encoder = encoder
+      frameFunc(self)
+      self._encoder = nil
 
-    self._encoder.setCullMode(.back)
-    self._encoder.setFrontFacing(.counterClockwise)  // OpenGL default
-    self._encoder.setViewport(Self.makeViewport(rect: self.frame))
-    self._encoder.setRenderPipelineState(pso)
-    self._encoder.setDepthStencilState(depthStencilState)
+      encoder.endEncoding()
+      commandBuf.present(rt)
+      commandBuf.commit()
 
-    self._encoder.setFragmentTexture(cubeTexture ?? defaultTexture, index: 0)
+      self.currentFrame &+= 1
+      if self.currentFrame == numFramesInFlight {
+        self.currentFrame = 0
+      }
+    }
   }
 
   func batch(instances: [Instance], camera: Camera) {
+    assert(self._encoder != nil, "batch can't be called outside of a frame being rendered")
     assert(instances.count < 52)
 
     var uniforms = ShaderUniforms(projView: camera.viewProjection)
@@ -339,10 +356,6 @@ public class Renderer {
           UInt8(instance.color.w * 0xFF)))
     }
 
-    self._encoder.setVertexBuffer(vtxBuffer,
-      offset: 0,
-      index: ShaderInputIdx.vertices.rawValue)
-
     // Ideal as long as our uniforms total 4 KB or less
     self._encoder.setVertexBytes(instances,
       length: instances.count * MemoryLayout<ShaderInstance>.stride,
@@ -359,21 +372,6 @@ public class Renderer {
       indexBufferOffset: 0,
       instanceCount: instances.count)
   }
-
-  func endFrame() {
-    self._encoder.endEncoding()
-    self._commandBuf.present(self._rt)
-    self._commandBuf.commit()
-
-    self._rt = nil
-    self._encoder = nil
-    self._commandBuf = nil
-
-    self.currentFrame &+= 1
-    if self.currentFrame == numFramesInFlight {
-      self.currentFrame = 0
-    }
-  }
 }
 
 enum RendererError: Error {

Sources/Voxelotl/main.swift

@@ -1,13 +1,9 @@
 import Darwin
 
-var rect = Rect(origin: .init(0, 0), size: .init(32, 32))
-rect.origin += Point(10, 10)
-
 let app = Application(
   delegate: Game(),
   configuration: ApplicationConfiguration(
-  width: 1280,
-  height: 720,
+  frame: Size(1280, 720),
   title: "Voxelotl Demo",
   flags: [ .resizable, .highDPI ],
   vsyncMode: .on(interval: 1)))