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

[Luke J Crook]

Update of /project/corman-sdl/cvsroot/corman-sdl/engine
In directory common-lisp.net:/tmp/cvs-serv25748/engine

Modified Files:
	engine.lisp 
Log Message:

Date: Tue Apr 20 05:28:13 2004
Author: lcrook

Index: corman-sdl/engine/engine.lisp
diff -u corman-sdl/engine/engine.lisp:1.4 corman-sdl/engine/engine.lisp:1.5
--- corman-sdl/engine/engine.lisp:1.4	Mon Apr 19 21:07:55 2004
+++ corman-sdl/engine/engine.lisp	Tue Apr 20 05:28:13 2004
@@ -104,7 +104,15 @@
 
 
 
-(defvar objects nil)
+(let ((bitplanes nil))
+    (defun bitplanes ()
+        bitplanes)
+    (defun first-bitplane ()
+        (if (null (dl-prev bitplanes))
+            bitplanes
+            (setf bitplanes (dl-prev bitplanes))))
+    (defun set-bitplane (bitplane)
+        (setf bitplanes bitplane)))
 
 (defclass sprite ()
     (
@@ -140,11 +148,10 @@
     
 (defun find-bitplane (zorder bitplanes)
     (let ((bp bitplanes) (quit nil))
-        (sdl:fformat "bp == ~A, zorder == ~A~%" bp zorder)
         (loop
             (when (equal quit t) (return (values bp 'n)))
             (if (> zorder (get-zorder bp))          ; if test > current
-                (when (null (dl-next bp))   
+                (if (null (dl-next bp))   
                         (setf quit t)               ; end of list when next is null
                         (setf bp (dl-next bp)))     ; next node
                 (if (equal zorder (get-zorder bp))  
@@ -153,21 +160,23 @@
 
 (defun return-bitplane (zorder bitplanes)
     (when (null bitplanes)
-        (setf objects (dl-list (new-bitplane zorder)))
-        (setf bitplanes objects))
+        (set-bitplane (dl-list (new-bitplane zorder)))
+        (setf bitplanes (bitplanes)))
     (multiple-value-bind (bitplane pos) (find-bitplane zorder bitplanes)
         (cond
             ((equal pos 'c)
                 (values (dl-data bitplane)))
             ((equal pos 'p)
-                (values (dl-data (dl-insert (new-bitplane zorder) bitplane))))
+                (setf bitplane (dl-insert (new-bitplane zorder) bitplane))
+                (first-bitplane)
+                (values (dl-data bitplane)))
             ((equal pos 'n)
                 (values (dl-data (dl-append (new-bitplane zorder) bitplane)))))))
 
 
 (defun add-object (spr)
     (addto-bitplane 
-        (return-bitplane (sprite-zorder spr) objects)
+        (return-bitplane (sprite-zorder spr) (bitplanes))
         spr))