Fix image dimension derivation, add test images from http://pdpxart.t…

…umblr.com

Took 9 minutes

README.md

@@ -197,6 +197,7 @@ loading the image data into a internal image representation (bitmap). These flag
 This flag also has multiple alternate forms: `#RGB`, `#RGBA`, `#RRGGBB`. Each letter (`R`, `G`, `B` or `A`) is
 a hexadecimal digit.
 * `9` - This image is a ninepatch (currently available only for bitmap images) (see *Dimensions* below)
+* `scaling <algo>` - Use scaling algorithm `<algo>` available algorithms are `nearest`, `bilinear` and `bicubic`
 
 **Dimensions**  
 In image scaling flags, `<W>` or `<H>` can not only contain a positive decimal number, but also a single symbol `?`.

src/main/java/com/darkyen/resourcepacker/image/Image.kt

@@ -191,9 +191,9 @@ sealed class Image(val file:Resource.ResourceFile, private val canBeNinepatch:Bo
             }
 
             if (newWidth == -1) {
-                newWidth = Math.round((_width.toDouble() / _height.toDouble()) * newHeight).toInt()
+                newWidth = Math.round((_fileWidth.toDouble() / _fileHeight.toDouble()) * newHeight).toInt()
             } else {
-                newHeight = Math.round((_height.toDouble() / _width.toDouble()) * newWidth).toInt()
+                newHeight = Math.round((_fileHeight.toDouble() / _fileWidth.toDouble()) * newWidth).toInt()
             }
             _width = newWidth
             _height = newHeight