# Starmap - plot a file of star coordinates
#
# This program plots a field of stars from the stars.txt taken from
# http://nifty.stanford.edu/2009/reid-starmap/
#
#Uses Calico and included Graphics library

from Graphics import *



#Opens the specified file and reads in the X and Y coordinates of each star
#Returns a list of tuples with the X and Y coordinates.
def readStarData(filename):

    starList = []

    myFile = open(filename, "r")

    starData = myFile.readlines()

    print("length of starData is:", len(starData) )

    for starLine in starData:
        tempList = starLine.split()
        xStr = tempList[0]
        yStr = tempList[1]

        x = float( xStr)
        y = float( yStr)

        starTuple = (x,y)
        starList.append( starTuple )

    
    return( starList)

#Converts between starfile cordinates (-1.0 to 1.0) to
# window coordinates (0 to windowSize)

def convertPoint(starFileX, starFileY, windowSize):
   halfWinSize = windowSize // 2
   windowX = int( (halfWinSize * starFileX) + halfWinSize )
   windowY = int( (halfWinSize * starFileY) + halfWinSize )
   return (windowX, windowY)




# Creates a Window and draws all stars into it. Stars in the starData
# parameter are assumed to be in the format generated by the readStarData
# function (above)
def plotStarData(starData, winSize):
    myWin = Window("StarMap", winSize,winSize)



    myWin.setBackground( Color("black") )

    for star in starData:
        X = star[0]
        Y = star[1]

        #This will convert coordinate spaces
        X,Y  = convertPoint(X,Y,winSize)

        #Draw the dot.
        d = Dot(X,Y)
        d.outline = Color("white")   
        d.fill = Color("white")
        d.draw(myWin)
        
    print("All finished plotting stars!")



#To draw a star map, you have to do two things:
#First, read the data:
myStarList = readStarData("stars.txt")

#Then, plot the data!
plotStarData( myStarList,700)