###########################################################################
# YafDay.py                          
###########################################################################
# Timed Daylight for Yafray
# This script home www.selleri.org/Blender
###########################################################################
# Copyright (C) 2003  Stefano <S68> Selleri
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
#
###########################################################################
# Revision History
# 25-03-2003 v. 00.00.01 - Project starts
###########################################################################

import os;
import re;
import sys;
import getopt;
import string;
from math import *

#######################################################################    
def main(argv):
#######################################################################    
# MAIN function
#######################################################################    

    Latitudo      = 43.754 
    Heading       = 180.0
    Start         = 6.0
    End           = 18.0
    Frames        = 100
    OnlyFiles     = 0
    OnlySky       = 0
    YafrayCommand = "yafray"
    
    try:
         opts, args = getopt.getopt(sys.argv[1:],"L:H:s:e:y:f:nhS",["help"]);
        
    except getopt.GetoptError:
        print "Use the -h or --help  switches for full help\n";
        sys.exit(2)
        
    for opt,arg in opts:
        if opt in ("-h", "--help"):
            YafDayHelp()
            sys.exit()
            
        elif opt == '-L':
            Latitudo = float(arg)

        elif opt == '-H':
            Heading = float(arg)
            
        elif opt == '-s':
            Start = float(arg)
            
        elif opt == '-e':
            End = float(arg)

        elif opt == '-f':
            Frames = int(arg)
            
        elif opt == '-n':
            OnlyFiles = 1

        elif opt == '-S':
            OnlySky = 1

        elif opt == '-y':
            YafrayCommand = arg

    if (len(args)>0):
        XMLfile = args[0]
        FP = open(XMLfile,"r")
        Skeleton = FP.read(-1)
        FP.close()

    else:
        if (OnlySky!=1):
            print "Use the -h or --help  switches for full help\n"
            sys.exit(2)
        
    
    Theta0 = pi/2 - (Latitudo*pi/180.)
    Phi0 = - Heading*(pi/180.)
    
    if (Frames>1):
        for f in range (Frames):
            t = pi * ( (End - Start)*f/(Frames-1) + Start ) / 12

            u = cos(t)
            v = sin(t)
            
            x1 = v 
            y1 = u * cos(Theta0)
            z1 = - u * sin(Theta0)

            x = x1 * cos(Phi0) + y1 * sin(Phi0)
            y = - x1 * sin(Phi0) + y1 * cos(Phi0)
            z = z1

            Sunsky = " type=\"sunsky\" name =\"Here Comes The Sun!\" turbidity =\"4.000000\" add_sun=\"on\"> <from x=\""+str(x)+"\" y=\""+str(y)+"\" z=\""+str(z)+"\"/>";

            if (OnlySky!=1):
                ss = re.search("<background(.*?)</background>",
                               Skeleton,re.S+re.I)
                s1 = Skeleton.replace(ss.group(1),Sunsky,1)
                s1 = re.sub("<outfile(.*?)/>",
                            "<outfile value=\"f"+string.zfill(str(f+1),4)+".tga\"/>",
                            s1,re.S+re.I)
                
                FO = open("frame"+string.zfill(str(f+1),4)+".xml","w")
                FO.write(s1)
                FO.close()
                
                if (OnlyFiles!=1):
                    os.system(YafrayCommand+" frame"+string.zfill(str(f+1),4)+".xml");
            else:
                print "<bacground>"+Sunsky+"</background>";

#######################################################################    
def YafDayHelp():
#######################################################################    
# Help function
#######################################################################    
    print "YafDay (C) 2003 Stefano <S68> Selleri - Released under GNU GPL\n"
    print "    Hacks a given YafRay XML file creating a daylight animation, "
    print "    i.e. a moving Sun\n";
    print "    Usage: python YafDay.py [-nS] [-s start] [-e end] [-f frames] "
    print "                                [-L Latitudo] [-H heading] [-y yafray] Base.xml\n"
    print "Base.xml    A YafRay XML file to be hacked. This is done by:"
    print "            REPALACING an EXISTING <background></bacground> group"
    print "            with an appropriate new one"
    print "            REPLACING the EXISTING outfile name with f#.tga with "
    print "            # an appropriate 4 digit number for the current frame."
    print "            New file is named frame#.xml\n"

    print "-n          if used the frame#.xml files are created, but yafray"
    print "            is not executed.\n"
    print "-S          if used computed <background> groups are printed to"
    print "            screen and no other operation at all is carried out.\n"

    print "-s start    Float number of the start hour of the day in 24h notation"
    print "            i.e. 6.5 is 6:30 am 19.25 is 7:15 pm [defaults to 6:00am]\n"
    print "-e end      Float number of the end hour of the day [defaults to 6:00pm]";
    print "-f frames   Integer number of frames to produce [defaults to 100]";
    
    print "-L Latitudo Float of the latitudo, in degrees. [defaults to 43.754 (Florence)]\n"
    print "-H Heading  Direction of the North in the Global coordinate system"
    print "            It is the angle (degrees) between the North and the positive y"
    print "            direction (well, not completely sure of this) [defaults to 180]\n" 
    print "-y yafray   The command line to launch yafray. Default is 'yafray' which"
    print "            of course works only if yafray is in the PATH...\n"
    
if __name__ == "__main__":
    main(sys.argv[1:])