1 files changed, 71 insertions, 0 deletions
diff --git a/src/core-units/unit.lisp b/src/core-units/unit.lisp
new file mode 100644
index 0000000..939293b
--- /dev/null
+++ b/src/core-units/unit.lisp
@@ -0,0 +1,71 @@
+;;;; units/unit.lisp
+
+(in-package #:wheelwork)
+
+(defclass/std unit ()
+  ((cached-model cached-projected-matrix :a)
+   (container :with :a)
+   (base-width base-height :r :std 1.0 :doc "Determined by content.")
+   (scale-x scale-y :with :std 1.0)
+   (rotation x y :with :std 0.0)
+   (opacity :std 1.0 :doc "0.0 indicates it will not be rendred.")))
+
+
+(defun scale-by (unit amount)
+  (with-slots (scale-x scale-y) unit
+    (setf scale-x (* amount scale-x)
+          scale-y (* amount scale-y))))
+
+(defun set-width-preserve-aspect (unit new-width)
+  (scale-by unit (/ new-width (unit-width unit))))
+
+(defun set-height-preserve-aspect (unit new-height)
+  (scale-by unit (/ new-height (unit-height unit) )))
+
+(defmethod unit-width ((unit unit))
+  (with-slots (scale-x base-width) unit
+    (* scale-x base-width)))
+
+(defmethod unit-height ((unit unit))
+  (with-slots (scale-y base-height) unit
+    (* scale-y base-height)))
+
+(defmethod (setf unit-width) (newval (unit unit))
+  (with-slots (scale-x base-width) unit
+    (setf scale-x (coerce (/ newval base-width) 'single-float))))
+
+(defmethod (setf unit-height) (newval (unit unit))
+  (with-slots (scale-y base-height) unit
+    (setf scale-y (coerce (/ newval base-height) 'single-float))))
+
+(defmethod (setf closer-mop:slot-value-using-class) :after
+    (newval class (unit unit) slot)
+  (case (closer-mop:slot-definition-name slot)
+    ((x y scale-x scale-y rotation)
+     (setf (cached-model unit) nil
+           (cached-projected-matrix unit) nil))))
+
+(defmethod model-matrix :around ((u unit))
+  (or (cached-model u)
+      (setf (cached-model u)
+            (call-next-method))))
+
+(defmethod model-matrix ((u unit))
+  (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))
+
+(defmethod projected-matrix ((thing unit))
+  (or (cached-projected-matrix thing)
+      (setf (cached-projected-matrix thing)
+            (mat:marr (mat:m* (application-projection *application*)
+                              (model-matrix thing))))))