[corman-sdl-cvs] CVS update: corman-sdl/ffi/engine.lisp

[Luke J Crook]

Update of /project/corman-sdl/cvsroot/corman-sdl/ffi
In directory common-lisp.net:/tmp/cvs-serv6276/ffi

Modified Files:
	engine.lisp 
Log Message:

Date: Thu Jul  8 01:48:34 2004
Author: lcrook

Index: corman-sdl/ffi/engine.lisp
diff -u corman-sdl/ffi/engine.lisp:1.1 corman-sdl/ffi/engine.lisp:1.2
--- corman-sdl/ffi/engine.lisp:1.1	Tue Apr 13 10:09:40 2004
+++ corman-sdl/ffi/engine.lisp	Thu Jul  8 01:48:34 2004
@@ -73,15 +73,21 @@
                 (return obj)
                 (setf obj (dl-next obj))))))
 
-(defstruct (zlevel)
-        zorder
-        start
-        end)
-
+;;;;; End: Link list functions
+;;;;;
 
 
+(defun create-display-list ()
+    (let ((display-list nil))
+        (defun init-display-list ()
+            (setf display-list nil))
+        (defun display-list ()
+            display-list)))
 
-(defvar objects nil)
+(defstruct (level)
+        zorder
+        start
+        end)
 
 (defclass sprite ()
     (
@@ -90,32 +96,46 @@
         (y :accessor sprite-y :initform 0 :initarg :y)
         (zorder :accessor sprite-zorder :initform 0 :initarg :zorder)))
 
+(defun new-level (zorder)
+    (make-level :zorder zorder))
 
-(defun addto-level (zlevel obj)
+(defun addto-level (level object)
     (cond 
-        ((null (zlevel-end zlevel))
-            (setf (zlevel-end zlevel) (dl-list obj))
-            (setf (zlevel-start zlevel) (zlevel-end zlevel)))
+        ((null (level-end level))
+            (setf (level-end level) (dl-list object))
+            (setf (level-start level) (level-end level)))
         (t
-            (setf (zlevel-end zlevel) (dl-append obj (zlevel-end zlevel))))))
+            (setf (level-end level) (dl-append object (level-end level))))))
+
+;Removes a node from the level.
+(defun remove-node-from-level (level object)
+    (when (null (dl-next object))
+        (setf (level-end level) (dl-prev object)))
+    (when (null (dl-prev object))
+        (setf (level-start level) (dl-next object)))
+    (dl-remove object))
+
+;Finds the node containing object, then calls remove-node-from-level
+(defun remove-from-level (level object)
+    (let ((obj (dl-find (level-start level) 
+        #'(lambda (node)
+            (if (equal (dl-data node) object)
+                node
+                nil)))))
+        (when obj
+            (remove-node-from-level level obj))))
 
-(defun add-level (objects level)
+(defun add-level (level objects)
     (cond 
-        ((null (zlevel-end zlevel))
-            (setf (zlevel-end zlevel) (dl-list obj))
-            (setf (zlevel-start zlevel) (zlevel-end zlevel)))
+        ((null objects)
+            (setf objects (dl-list level)))
+        ((null (level-end level))
+            (setf (level-end level) (dl-list objects))
+            (setf (level-start level) (level-end level)))
         (t
-            (setf (zlevel-end zlevel) (dl-append obj (zlevel-end zlevel))))))
+            (setf (level-end level) (dl-append objects (level-end level))))))
 
-(defun remove-from-level (zlevel obj)
-    (when (null (dl-next obj))
-        (setf (zlevel-end zlevel) (dl-prev obj)))
-    (when (null (dl-prev obj))
-        (setf (zlevel-start zlevel) (dl-next obj)))
-    (dl-remove obj))
 
-(defun new-zlevel (zorder)
-    (make-zlevel :zorder zorder))
 
 (defun new-find-zlevel (zorder)
     #'(lambda (dl)