working on UIView rendering

Sources/Cacao/UIApplication.swift

@@ -122,7 +122,6 @@ public func UIApplicationMain(delegate: UIApplicationDelegate, options: CacaoOpt
 
         // inform responder chain
 
-
         // render to screen
         if needsDisplay {
 

Sources/Cacao/UIScreen.swift

@@ -65,23 +65,17 @@ public final class UIScreen {
     internal func update() {
 
         if needsLayout {
-
             windows.forEach { $0.layoutIfNeeded() }
         }
 
         renderer.drawColor = (0x00, 0x00, 0x00, 0xFF)
-
-        // get data for surface
-        let imageSurface = Surface(rgb: (Int(size.window.width), Int(size.window.height)), depth: 32).sdlAssert()
-
-        let texture = Texture(renderer: renderer, surface: imageSurface).sdlAssert()
+        renderer.clear()
 
         // render view hierarchy
 
 
         // render to screen
-        renderer.copy(texture)
-        renderer.clear()
+        renderer.copy(<#T##texture: Texture##Texture#>, source: <#T##SDL_Rect?#>, destination: <#T##SDL_Rect?#>)
         renderer.present()
 
         needsDisplay = false

Sources/Cacao/UIView.swift

@@ -6,8 +6,10 @@
 //  Copyright © 2016 PureSwift. All rights reserved.
 //
 
-import Silica
+import CSDL2
 import SDL
+import Silica
+import Cairo
 
 /// An object that represents a rectangular area on the screen and manages the content in that area.
 ///
@@ -415,34 +417,50 @@ open class UIView {
         return nil
     }
 
-
-
-
-
-
-
+    // MARK: - Drawing
 
     /// The backing rendering node / texture.
     ///
     /// Cacao's equivalent of `UIView.layer` / `CALayer`.
     /// Instead of the CoreGraphics API you could draw directly to the texture's pixel data.
-    public private(set) var texture: Texture!
-
-
+    private var texture: Texture!
+    private var surface: Cairo.Surface.Image!
 
     internal final var shouldRender: Bool { return isHidden == false && alpha > 0 }
 
-
-
-    // MARK: - Drawing
-
     open func draw(_ rect: CGRect) { /* implemented by subclasses */ }
 
+    private func createTexture(for renderer: Renderer) {
+
+        let width = Int(bounds.size.width)
+        let height = Int(bounds.size.height)
+
+        texture = Texture(renderer: renderer,
+                          format: PixelFormat.RawValue(SDL_PIXELFORMAT_ARGB8888),
+                          access: .streaming,
+                          width: width,
+                          height: height)!
+
+        surface = texture.withUnsafeMutableBytes { try! Cairo.Surface.Image.init(mutableBytes: $0.assumingMemoryBound(to: UInt8.self), format: .argb32, width: width, height: height, stride: $1) }
+
+
+    }
+
     internal final func render(in renderer: Renderer) {
 
         guard shouldRender
             else { return }
 
+        // create SDL texture
+        if texture == nil {
+            createTexture(for: renderer)
+        }
+
+        let context = try! Silica.Context(surface: surface, size: bounds.size)
+
+        // CoreGraphics drawing
+        draw(in: context)
+
 
     }