#encoding:latin-1
from numpy import *
from pylab import *

import sys, os, glob, textwrap

from  pgm_utils import *

###############################################################################
###
### creates movie with several rectangles fading in and out    
###                                                                        
### frames are stored in pgm format below directory 'movie_dir'.
###                                                             
### if imagemagick is avaliable the program builds an animated 
### gif.                                                      
###                                                          
###############################################################################


M,N = 70, 70
movie_dir="movie/"

try:
    os.mkdir(movie_dir)
except Exception, dir_exists:
    pass 


def draw_rectangle(img, val, x0, y0, w, h):
    for x in range(x0, x0+w):
        for y in range(y0, y0+h):
            img[x,y] = val
    return img


#### configure animated objects  ##############################################

#  illumination increases from color_min to 1 in time [tmin, tmid]   
#  and          decreases from 1 to color_min in time [tmid, tmax]  
#  tmid is (tmin+tmax)/2.0                                         

color_min = 0.1 # no black rectangles !

object_data = [ 
            #  x0  y0  w   h     tmin tmax          
            ( (10, 10, 20, 20), (0,   20) ),
            ( (20, 20, 20, 20), (5,   25) ),
            ( (30, 30, 20, 20), (10,  30) ),
            ( (40, 40, 20, 20), (15,  35) ),
    ]


#### draw and save every frame ################################################

tmax = max( t for (_, (_,t)) in object_data)
for t in range(tmax):

    print "frame %3d of %d" % (t+1, tmax)
    img = zeros((M,N), float)

    for dimensions, (tmin, tmax) in object_data:
        if t < tmin or t>tmax: continue

        tmid = (tmin+tmax)/2.0
        if t < tmid:
            val = (t-tmin)/(tmid-tmin)
        else:
            val = (tmax-t)/(tmax-tmid)

        val = color_min + (1.0-color_min)*val 
        draw_rectangle(img, val, *dimensions)

    save_pgm(os.path.join(movie_dir, "frame%03d.pgm" % t), img)

print
print "seperate images written to", movie_dir
print

#### try to call imagemagics convert commandlinetool for building #############
#### animated gif                                                

print "try to make animated gif:",
try:
    os.system("convert -delay 20 -loop 0 %s movie.gif" % 
                               os.path.join(movie_dir,"frame*.pgm"))

except Exception, convert_does_not_exist:
    print "failed to call imagemagick"
else:
    print "animated movie.gif written"