Improved documentation for SkyGames and support for rotated textures

sky/examples/game/lib/texture.dart

 part of sprites;
 
+/// A texture represents a rectangular area of an image and is typically used to draw a sprite to the screen.
+///
+/// Normally you get a reference to a texture from a [SpriteSheet], but you can also create one from an [Image].
 class Texture {
+  /// The image that this texture is a part of.
+  ///
+  ///     var textureImage = myTexture.image;
   final Image image;
+
+  /// The logical size of the texture, before being trimmed by the texture packer.
+  ///
+  ///     var textureSize = myTexture.size;
   final Size size;
+
+  /// The name of the image acts as a tag when acquiring a reference to it.
+  ///
+  ///     myTexture.name = "new_texture_name";
   String name;
+
+  /// The texture was rotated 90 degrees when being packed into a sprite sheet.
+  ///
+  ///     if (myTexture.rotated) drawRotated();
   final bool rotated;
+
+  /// The texture was trimmed when being packed into a sprite sheet.
+  ///
+  ///     bool trimmed = myTexture.trimmed
   final bool trimmed;
 
-  Rect frame;
-  Rect spriteSourceSize;
+  /// The frame of the trimmed texture inside the image.
+  ///
+  ///     Rect frame = myTexture.frame;
+  final Rect frame;
 
+  /// The offset and size of the trimmed texture inside the image.
+  ///
+  /// Position represents the offset from the logical [size], the size of the rect represents the size of the trimmed
+  /// texture.
+  ///
+  ///     Rect spriteSourceSize = myTexture.spriteSourceSize;
+  final Rect spriteSourceSize;
+
+  /// The default pivot point for this texture. When creating a [Sprite] from the texture, this is the pivot point that
+  /// will be used.
+  ///
+  ///     myTexture.pivot = new Point(0.5, 0.5);
   Point pivot;
 
+  /// Creates a new texture from an [Image] object.
+  ///
+  ///     var myTexture = new Texture(myImage);
   Texture(Image image) :
     size = new Size(image.width.toDouble(), image.height.toDouble()),
     image = image,
     trimmed = false,
     rotated = false,
     frame = new Rect.fromLTRB(0.0, 0.0, image.width.toDouble(), image.height.toDouble()),
     spriteSourceSize = new Rect.fromLTRB(0.0, 0.0, image.width.toDouble(), image.height.toDouble()),
     pivot = new Point(0.5, 0.5);
 
 
   Texture._fromSpriteFrame(this.image, this.name, this.size, this.rotated, this.trimmed, this.frame,
                            this.spriteSourceSize, this.pivot) {
   }
 
-  Texture textureFromRect(Rect rect, Point offset, bool rotated) {
-    // TODO: Implement this
-    return null;
-  }
+//  Texture textureFromRect(Rect rect, [String name = null]) {
+//    assert(rect != null);
+//    Rect frame = new Rect.fromLTRB();
+//    return new Texture._fromSpriteFrame(image, name, rect.size, false, false, );
+//  }
 }