#
# Jay Summet
# CS 1301 - October 14th, 2011
#
# Released to the public domain.
#
# Example code to find a green wall by marking all green pixels white and
# all non-green pixels black. Then it calculates the average X position of
# the white pixels.
#





from myro import *

#This function will take in a color picture and look
#for green pixels. If it finds a "green" pixel, it will
#mark it white (255,255,255) and any other color pixel
#it will mark black (0,0,0)
#It does not reutrn anything, but the image that was
#passed in gets modified.
def markGreen(pic):
    for pix in getPixels(pic):
        r = getRed(pix)
        g = getGreen(pix)
        b = getBlue(pix)
        if g / 1.5 > r and r < 100 and b < 100:
            setRed(pix,255)
            setGreen(pix,255)
            setBlue(pix,255)
        else:
            setRed(pix,0)
            setGreen(pix,0)
            setBlue(pix,0)

#This function counts the number of pixels that are
#white (vs black) in the picture and returns the count
#as a percentage of total pixels
def pctMarked(pic):
    count = 0
    totalPix = 0
    for pix in getPixels(pic):
        r = getRed(pix)
        totalPix = totalPix + 1
        if r == 255:
            count = count + 1

    pct = 100 * (count / float(totalPix) )
    return pct
        
#This function will calculate the average X position of
#all 'marked' pixels. (marked pixels are white)
def findAvgX(pic):
    pixelCount = 0
    totalXCount = 0
    for pix in getPixels(pic):
        g = getGreen(pix)
        if g == 255:
            pixelCount = pixelCount + 1
            x = getX(pix)
            totalXCount = totalXCount + x

    avgX = totalXCount / float(pixelCount)
    return(avgX)
    

    
def drawVLine(pic, x):
    pHeight = getHeight(pic)
    for y in range(pHeight):
        pix = getPixel(pic,x,y)
        setRed(pix,0)
        setGreen(pix,255)
        setBlue(pix,0)
        
init("/dev/rfcomm1")      
p = takePicture()
#p = loadPicture("rca1.gif")
p2 = copyPicture(p)
show(p, "orig")
markGreen(p2)
numGreen = pctMarked(p2)
print "percent marked is:", numGreen
if numGreen > 1.0:   
    print "Found a green wall!"
    avgX = findAvgX(p2)
    print "Avg X is:", avgX
    drawVLine(p2,int(avgX))
else:
    print "no wall in sight!"
show(p2)