3 files changed, 131 insertions, 0 deletions
diff --git a/src/core/affine.lisp b/src/core/affine.lisp
new file mode 100644
index 0000000..cabe17c
--- /dev/null
+++ b/src/core/affine.lisp
@@ -0,0 +1,69 @@
+;;;; affine.lisp
+
+(in-package #:wheelwork)
+
+(defclass/std affine (unit)
+  ((cached-model cached-projected-matrix cached-application :a)
+   (base-width base-height :r :std 1.0 :doc "Determined by content.")
+   (scale-x scale-y :std 1.0)
+   (rotation x y :std 0.0)))
+
+(defmethod (setf closer-mop:slot-value-using-class) :after
+    (newval class (affine affine) slot)
+  (case (closer-mop:slot-definition-name slot)
+    ((x y scale-x scale-y rotation)
+     (setf (cached-model affine) nil
+           (cached-projected-matrix affine) nil))))
+
+(defun scale-by (affine amount)
+  (with-slots (scale-x scale-y) affine
+    (setf scale-x (* amount scale-x)
+          scale-y (* amount scale-y))))
+
+(defun set-width-preserve-aspect (affine new-width)
+  (scale-by affine (/ new-width (width affine))))
+
+(defun set-height-preserve-aspect (affine new-height)
+  (scale-by affine (/ new-height (height affine) )))
+
+(defun width (affine)
+  (with-slots (scale-x base-width) affine
+    (* scale-x base-width)))
+
+(defun height (affine)
+  (with-slots (scale-y base-height) affine
+    (* scale-y base-height)))
+
+(defun (setf width) (newval affine)
+  (with-slots (scale-x base-width) affine
+    (setf scale-x (coerce (/ newval base-width) 'single-float))))
+
+(defun (setf height) (newval affine)
+  (with-slots (scale-y base-height) affine
+    (setf scale-y (coerce (/ newval base-height) 'single-float))))
+
+(defmethod model-matrix :around ((u affine))
+  (or (cached-model u)
+      (setf (cached-model u)
+            (call-next-method))))
+
+(defmethod model-matrix ((u affine))
+  (let ((m (mat:meye 4)))
+    (with-slots (x y base-width scale-x base-height scale-y rotation) u 
+      (let ((uw (* base-width scale-x))
+            (uh (* base-height scale-y)))
+        (mat:nmtranslate m (vec:vec x y 0.0))
+
+        (mat:nmtranslate m (vec:v* 0.5 (vec:vec uw uh 0.0)))
+        (mat:nmrotate  m vec:+vz+ rotation)
+        (mat:nmtranslate m (vec:v* -0.5 (vec:vec uw uh 0.0)))
+        
+        (mat:nmscale m (vec:vec uw uh 1.0))))
+    m))
+
+
+(defun projected-matrix (affine)
+  (or (cached-projected-matrix affine)
+      (setf (cached-projected-matrix affine)
+            (mat:marr (mat:m* (application-projection (app-of-unit affine))
+                              (model-matrix affine))))))
diff --git a/src/core/container.lisp b/src/core/container.lisp
new file mode 100644
index 0000000..af01ff1
--- /dev/null
+++ b/src/core/container.lisp
@@ -0,0 +1,32 @@
+;;;; units/container.lisp
+
+(in-package #:wheelwork)
+
+
+(defclass/std container (unit)
+  ((units :with :a))
+  (:documentation "Just a list of units. Made into a class so that
+  transformation affine transformations methods can be specialzied on
+  whole groups of units"))
+
+(defmethod drop-unit ((unit unit))
+  "Removes a unit from its container. Returns T if the unit actually was removed."
+  (when-let (container (unit-container unit))
+    (setf
+     (container-units container) (delete unit (container-units container))
+     (unit-container unit) nil)
+    t))
+
+(defmethod add-unit ((container container) (unit unit))
+  "Adds a unit to the end of a container (thus affecting render
+order). Makes sure to remove the unit from its current container if
+necessary."
+  (when (unit-container unit)
+    (drop-unit unit))
+  (push unit  (container-units container))
+  (setf (unit-container unit) container)
+  unit)
+
+(defmethod cleanup ((container container))
+  (dolist (u (container-units container))
+    (cleanup u)))
diff --git a/src/core/unit.lisp b/src/core/unit.lisp
new file mode 100644
index 0000000..20e05e2
--- /dev/null
+++ b/src/core/unit.lisp
@@ -0,0 +1,30 @@
+;;;; units/unit.lisp
+
+(in-package #:wheelwork)
+
+(defclass/std unit ()
+  ((cached-application  :a)
+   (container :with :a)))
+
+(defmethod (setf closer-mop:slot-value-using-class) :after
+    (newval class (unit unit) slot)
+  (case (closer-mop:slot-definition-name slot)
+    (container
+     (setf (cached-application unit) nil))))
+
+
+(defun app-of-unit (unit)
+  "Returns the APPLICATION instance, if any, of which this UNIT is a
+part. NIL indicates that the unit has not been added to any container
+in this application."
+  (or (cached-application unit) 
+      (setf (cached-application unit) 
+            (labels ((rec (u)
+                       (when-let (c (unit-container u))
+                         (etypecase c
+                           (application c)
+                           (unit (rec c))
+                           (null nil)))))
+              (rec unit)))))
+
+