renamed Surface source files

Sources/Surface.swift

@@ -62,12 +62,6 @@ public class Surface {
         cairo_surface_finish(internalPointer)
     }
 
-    /// Writes the surface's contents to a PNG file.
-    public final func writePNG(at filepath: String) {
-
-        cairo_surface_write_to_png(internalPointer, filepath)
-    }
-
     // MARK: - Accessors
 
     public final var type: SurfaceType {

Sources/ImageSurface.swift → Sources/SurfaceImage.swift

@@ -24,18 +24,22 @@ public extension Surface {
         /// The contents of bits within a pixel, but not belonging to the given format are undefined.
         public init?(format: ImageFormat, width: Int, height: Int) {
 
-            let internalFormat = cairo_format_t(format)
-
-            guard let internalPointer = cairo_image_surface_create(internalFormat, Int32(width), Int32(height))
+            guard let internalPointer = cairo_image_surface_create(cairo_format_t(format), Int32(width), Int32(height))
                 else { return nil }
 
             super.init(internalPointer)
         }
 
         /// Creates an image surface for the provided pixel data.
-        public init?(data: Data) {
+        public init?(data: Data, format: ImageFormat, width: Int, height: Int, stride: Int) {
+
+            var data = data
+
+            guard let internalPointer = data.withUnsafeMutableBytes({ (bytes: UnsafeMutablePointer<UInt8>) in
+                cairo_image_surface_create_for_data(bytes, cairo_format_t(format), Int32(width), Int32(height), Int32(stride)) })
+                else { return nil }
 
-            fatalError()
+            super.init(internalPointer)
         }
 
         // MARK: - Class Methods
@@ -51,6 +55,12 @@ public extension Surface {
 
         // MARK: - Accessors
 
+        /// Get the format of the surface.
+        public var format: ImageFormat? {
+
+            return ImageFormat(cairo_image_surface_get_format(internalPointer))
+        }
+
         /// Get the width of the image surface in pixels.
         public var width: Int {
 

Sources/SurfacePNG.swift

@@ -0,0 +1,18 @@
+//
+//  SurfacePNG.swift
+//  Cairo
+//
+//  Created by Alsey Coleman Miller on 6/5/17.
+//
+//
+
+import CCairo
+
+public extension Surface {
+
+    /// Writes the surface's contents to a PNG file.
+    public func writePNG(at filepath: String) {
+
+        cairo_surface_write_to_png(internalPointer, filepath)
+    }
+}