fix build by converting cxx backend to swift

Sources/SwiftFrontend/Application.swift

@@ -7,17 +7,15 @@
 
 import Foundation
 import SDL3
-import SwiftBackend
 
 class Application {
   private var window: OpaquePointer? = nil
   private var renderer: OpaquePointer? = nil
 
+  private var balls = BallWorld()
   private var lastCounter: UInt64 = 0
 
   private func initialize() -> ApplicationExecutionState {
-    FuckYou.fuck()
-    
     guard SDL_Init(SDL_INIT_VIDEO) >= 0 else {
       print("SDL_Init() error: \(String(cString: SDL_GetError()))")
       return .exitFailure
@@ -40,6 +38,15 @@ class Application {
     SDL_SetRenderVSync(renderer, 1)
     SDL_SetRenderLogicalPresentation(renderer, 512, 512, SDL_LOGICAL_PRESENTATION_LETTERBOX, SDL_SCALEMODE_BEST)
 
+    let ballOrigin = SIMD2(Float(width), Float(height)) * 0.5
+    for _ in 0..<10 {
+      balls.add(
+        position: ballOrigin,
+        angle: Float(arc4random()) / Float(UInt32.max),
+        size: Float(arc4random_uniform(32 - 3) + 3)
+      )
+    }
+
     lastCounter = SDL_GetPerformanceCounter()
 
     return .running
@@ -71,10 +78,22 @@ class Application {
   }
 
   private func paint(_ deltaTime: Float) -> ApplicationExecutionState {
+    balls.update(deltaTime)
+
     SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255)
     SDL_RenderClear(renderer)
 
     SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255)
+    for ball in balls.balls {
+      let position = ball.position, size = ball.size
+      var rect = SDL_FRect(
+        x: position.x - size,
+        y: position.y - size,
+        w: size * 2.0,
+        h: size * 2.0
+      )
+      SDL_RenderFillRect(renderer, &rect)
+    }
 
     SDL_RenderPresent(renderer)
     return .running

Sources/SwiftFrontend/Ball.swift

@@ -0,0 +1,55 @@
+import Foundation
+import simd
+
+struct BallWorld {
+  var balls: [Ball] = []
+
+  mutating func add(position: SIMD2<Float>, angle: Float, size: Float) {
+    balls.append(Ball(position: position, angle: angle, size: size))
+  }
+
+  mutating func update(_ deltaTime: Float) {
+    for i in balls.indices {
+      balls[i].update(deltaTime)
+    }
+  }
+}
+
+struct Ball {
+  public static let speed: Float = 80.0
+  public static let worldSize: Float = 512.0
+
+  var _position: SIMD2<Float>, _velocity: SIMD2<Float>
+  var _size: Float
+
+  init(position: SIMD2<Float>, angle: Float, size ballSize: Float) {
+    _position = position
+    _velocity = SIMD2<Float>(
+       cos(angle * Float.pi * 2.0),
+      -sin(angle * Float.pi * 2.0)
+    )
+    _size = ballSize
+  }
+
+  public mutating func update(_ deltaTime: Float) {
+    _position += _velocity * Self.speed * deltaTime
+    if (_position.x < _size) {
+      _velocity.x = -_velocity.x
+      _position.x = _size
+    } else if (_position.x > Self.worldSize - _size) {
+      _velocity.x = -_velocity.x
+      _position.x = Self.worldSize - _size
+    }
+    if (_position.y < _size) {
+      _velocity.y = -_velocity.y
+      _position.y = _size
+    } else if (_position.y > Self.worldSize - _size) {
+      _velocity.y = -_velocity.y
+      _position.y = Self.worldSize - _size
+    }
+  }
+
+  var position: SIMD2<Float> { return _position }
+  var velocity: SIMD2<Float> { return _velocity }
+  var size: Float { return _size }
+}

Sources/SwiftFrontend/CMakeLists.txt

@@ -1,5 +1,5 @@
-add_executable(SwiftFrontend MACOSX_BUNDLE main.swift Application.swift)
-target_link_libraries(SwiftFrontend PRIVATE SwiftBackend SDLSwift)
+add_executable(SwiftFrontend MACOSX_BUNDLE main.swift Application.swift Ball.swift)
+target_link_libraries(SwiftFrontend PRIVATE SDLSwift)
 set_target_properties(SwiftFrontend PROPERTIES
   XCODE_ATTRIBUTE_ENABLE_HARDENED_RUNTIME NO
   XCODE_EMBED_FRAMEWORKS "${SDL3}"