[modify] affine fns are generic; [add] safe-slot util

1 files changed, 26 insertions, 0 deletions

diff --git a/src/protocol.lisp b/src/protocol.lisp
index f8386a6..bd436e6 100644
--- a/src/protocol.lisp
+++ b/src/protocol.lisp
@@ -33,3 +33,29 @@
 (defgeneric ensure-loaded (asset)
   (:documentation "Ensures that the asset is loaded into memory and
   ready for use. Returns the asset."))
+
+(defgeneric scale-by (thing amount)
+  (:documentation "Scale horizontal and vertical dimensions of THING by AMOUNT"))
+
+(defgeneric width (thing)
+  (:documentation "Returns the effective width, in screen coordinates, of the object in question"))
+
+(defgeneric (setf width) (new-width thing)
+  (:documentation "Sets the effective width of thing to new-width."))
+
+(defgeneric height (thing)
+  (:documentation "Returns effective height, in screen coordinates, of the object in question."))
+
+(defgeneric (setf height) (new-height thing)
+  (:documentation "sets the effective height of thing to new-height"))
+
+(defgeneric rotation (thing))
+(defgeneric (setf rotation) (newval thing))
+(defgeneric x (thing))
+(defgeneric (setf x) (newval thing))
+(defgeneric y (thing))
+(defgeneric (setf y) (newval thing))
+(defgeneric scale-x (thing))
+(defgeneric (setf scale-x) (newvval thing))
+(defgeneric scale-y (thing))
+(defgeneric (setf scale-y) (newval thing))