#!/usr/bin/python2.4
# see http://www.sgi.com/software/opengl/advanced97/notes/node57.html for accum notes

from __future__ import division
import sys, time
import numarray as num
import Tkinter as tk
import Image

try:
    from OpenGL import Tk as Togl
    from OpenGL.GL import *
except ImportError:
    sys.path.append("/usr/lib/python2.4/site-packages/OpenGL/Tk/linux2-tk8.4")
    from OpenGL.GL import *
    import Togl
  

def xxxdrawWithAlpha(imgString, w, h, alpha):
    # this one should be faster because GL does the alpha adjust, but
    # i don't think it works yet
    
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
    
    glClear(GL_COLOR_BUFFER_BIT)
    #glBlendColor(1, 1, 1, mag) # needs ARB_imaging
    glDrawPixels(w, h, GL_RGBA, GL_UNSIGNED_BYTE, imgString)

class Surface(Togl.Opengl):
    width = 512
    height = 270
    imgRescaleTo = 100
    def __init__(self, master, filenames):
        Togl.Opengl.__init__(self, master=master, width = self.width,
                             height = self.height, double = True, depth = 0)

        self.levels = {} # filename : brightness
  
        self.image = {} # filename : imgstr
        for filename in filenames:
            im = Image.open(filename)
            if self.imgRescaleTo:
                im.thumbnail((self.imgRescaleTo, self.imgRescaleTo))
            im = im.transpose(Image.FLIP_TOP_BOTTOM)
            self.imageWidth = im.size[0]
            self.imageHeight = im.size[1]
            self.image[filename] = im.convert("RGBA").tostring()
  
        self.set_centerpoint(0, 0, 0)
  
        glDisable(GL_CULL_FACE)
        glShadeModel(GL_FLAT)
        print 'GL_ARB_imaging', 'GL_ARB_imaging' in glGetString(GL_EXTENSIONS)
        import OpenGL
        print OpenGL.__version__

        self.bind("<Configure>", self.configure)

    def configure(self, ev):
#        import pdb; pdb.set_trace()
        self.width, self.height = ev.width, ev.height
  
    def drawWithAlpha(self, imgString, w, h, alpha):
        """without opengl extensions"""
        if alpha == 0:
            return
        t = time.time()
        ar = num.reshape(num.fromstring(imgString, dtype='uint8'),
                         (w * h, 4))
        #print "  tonum", time.time() - t
        if alpha != 1:
            ar[:,3] *= alpha

        #print "  scl", time.time() - t
        glPixelZoom(self.width / w, self.height / h)
        glDrawPixels(w, h,
                     GL_RGBA, GL_UNSIGNED_BYTE, ar.tostring())
        #print "  draw", time.time() - t

    def redraw(self, event=None):
        """you set self.levels to dict and call tkRedraw"""
        assert 'GL_ARB_imaging' in glGetString(GL_EXTENSIONS).split()
    
        glClearColor(0.0, 0.0, 0.0, 0)
        glClear( GL_COLOR_BUFFER_BIT |GL_ACCUM_BUFFER_BIT)
        glEnable(GL_BLEND)
        glBlendFunc(GL_SRC_ALPHA, GL_DST_ALPHA)
#        l=glGenLists(1)
#        glNewList(l,GL_COMPILE)
#        glEndList()

        # drawing to glAccum might be good
        for filename, mag in self.levels.items():
            #print "pic %s at %f" % (filename, mag)
            self.drawWithAlpha(self.image[filename],
                               self.imageWidth, self.imageHeight, mag)

    def newLevels(self, event=None, levels=None):
        self.levels = levels
        self.tkRedraw()
  
def main():
    root = tk.Frame()
    root.pack(expand=True, fill='both')
    QuitButton = tk.Button(root, {'text':'Quit'})
    QuitButton.bind('<ButtonRelease-1>', sys.exit)
    QuitButton.pack()

    filenames=['skyline/bg.png',
               'skyline/cyc-lo-red.png',
               'skyline/cyc-lo-grn.png',
               ]
    
    scales = {} # filename : scale
    for f in filenames:
        scales[f] = tk.Scale(
            root, label=f, from_=0, to=1, res=.05, orient='horiz',
            command=lambda *args: ogl.newLevels(
              levels=dict([(f, s.get()) for f,s in scales.items()])))
        scales[f].pack()
    ogl = Surface(root, filenames)
    ogl.pack(side='top', expand=True, fill='both')

    ogl.mainloop()

if __name__ == '__main__':
    main()
                
demo = Surface