--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lightsim/lightsim.py	Wed Jul 03 09:37:57 2002 +0000
@@ -0,0 +1,142 @@
+# lightsim.py by Drew Perttula, 6/28/2002
+
+version="1.01"
+
+from __future__ import division
+import Image, ImageTk, ImageChops,ImageEnhance
+from Tkinter import Tk,Label,Scale,DoubleVar,Frame
+import time, glob
+
+class Imagemixer(Label):
+    """tk widget that can load images (based on a glob pattern: each file should
+    be named like 'scene.light') and displays a weighted mix of the images"""
+    def __init__(self,parent,*k,**kw):
+        Label.__init__(self,parent,*k,**kw)
+        self.im={}
+
+        self.itk = ImageTk.PhotoImage(Image.new('RGB',(100,100)))
+        self.config(image=self.itk)
+        self.loadedscale=0
+        self.amounts={}
+        
+    def loadallimgs(self,basename,scalefactor=1.0):
+        """load images from disk, scale them immediately, subtract off
+        the image called 'ambient' (if present) from all other
+        images. Given basename like path/to/foo, loads images with
+        names like path/to/foo.light1, path/to/foo.light2, etc.  The
+        filename after the . is considered to be the light name
+        throughout the program.  """
+
+        if self.loadedscale==scalefactor: # already loaded at this scale
+            return
+        
+        self.im={}
+        ambientimg=None
+        sizenotset=1
+        for fullname in glob.glob(basename+".*"):
+            x=fullname[fullname.find('.')+1:]
+            self.im[x]=Image.open(fullname)
+            if scalefactor!=1.0:
+                self.im[x]=self.im[x].resize([a*scalefactor for a in self.im[x].size])
+            if x=='ambient':
+                ambientimg=self.im[x]
+            if sizenotset:
+                self.config(width=self.im[x].size[0],height=self.im[x].size[1])
+                self.itk=ImageTk.PhotoImage(Image.new('RGB',self.im[x].size))
+                self.config(image=self.itk)
+                sizenotset=0
+
+        # subtract off an image called 'ambient' from all the rest
+        if ambientimg is not None:
+            for k in self.im.keys():
+                if k!='ambient':
+                    self.im[k] = ImageChops.subtract(self.im[k],ambientimg)
+
+        self.loadedscale=scalefactor
+        self._remix() # update the image
+
+    def _remix(self):
+        """mix all the images in self.im together according to the
+        weights in self.amounts.  Each of those attributes are dicts
+        with the light names for keys."""
+        global fpslabel
+        i=None
+        amounts = self.amounts
+        layers=0
+        start=time.time()
+        for k in self.im.keys():
+            scale =amounts.get(k,0)
+            if scale!=0:
+                layers+=1
+                acc=ImageEnhance.Brightness(self.im[k]).enhance(scale) # scale the image before adding
+    #            acc = ImageChops.add(base,self.im[k],1/scale) ## slower!
+                if i==None:
+                    i=acc # use first layer directly
+                else:
+                    i=ImageChops.add(i,acc) # add subsequent layers
+        dur = time.time()-start
+        fps=1.0/dur
+        fpslabel.config(text="%.02f fps, %.02f layers/sec"%(fps,layers/dur))
+        if i is not None:
+            self.itk.paste(i) # put image i in the PhotoImage
+
+    def setamounts(self,amounts):
+        self.amounts = amounts.copy()
+        self._remix()
+
+    def lightnames(self):
+        return self.im.keys()
+
+basename='room'
+
+root=Tk()
+
+# Imagemixer._remix accesses this label, so it needs a name
+fpslabel=Label()
+fpslabel.pack()
+
+Label(root,text="Use +/- to change image scale").pack()
+
+mix=Imagemixer(root,relief='raised',bd=3)
+
+scalefactor=.5
+mix.loadallimgs(basename,scalefactor)
+mix.pack()
+
+#
+# +/- keys should reload the images at new scales
+#
+def changescale(by=0):
+    global mix,scalefactor
+    scalefactor+=by
+    mix.loadallimgs(basename,scalefactor)
+root.bind("<Key-plus>",lambda ev: changescale(.15))
+root.bind("<Key-minus>",lambda ev: changescale(-.15))
+         
+amountvars={} # each light name maps to a Tkinter.DoubleVar object which the Scale adjusts
+
+def redraw(*args):
+    global l,amountvars,update
+    # read the value out of each Scale
+    amounts = dict([(k,v.get()) for k,v in amountvars.items()])
+    mix.setamounts(amounts)
+    
+for x in mix.lightnames():
+    # the Scale sets this; the redraw() callback reads it
+    amountvars[x]=DoubleVar()
+
+    # a new frame for each slider row
+    f=Frame(root,bd=1,relief='groove')
+    f.pack(fill='x',expand=1)
+    # title
+    Label(f,text=x,width=10,anchor='e').pack(side='left')
+    # slider
+    s=Scale(f,from_=0,to=1,res=.01,
+            orient='horiz',
+            variable=amountvars[x],command=redraw)
+    s.pack(side='left',fill='x',expand=1)
+    if x=='ambient': # the 'ambient' level (if present) starts at 1
+        s.set(1)
+
+root.mainloop()
+