#----------------------------------------------------------------------
# Introduction to simple graphics
#
# Copyright (C) February 13, 2017 -- Dr. William T. Verts
#----------------------------------------------------------------------

#----------------------------------------------------------------------
# While the makePicture function requires a filename of a graphics
# file (.GIF, .JPG, etc.), makeEmptyPicture creates a blank canvas.
# The following program creates and shows a white 800x600 canvas.
#----------------------------------------------------------------------

def Main1():
    Canvas = makeEmptyPicture(800,600)
    show(Canvas)
    return

#----------------------------------------------------------------------
# The following program creates and shows a yellow 800x600 canvas.
# The color is optional, and may be black, red, green, blue, magenta,
# cyan, yellow, white, or gray.  If omitted, white is assumed.
# The color may also be synthesized from RGB components (see Main3).
#----------------------------------------------------------------------

def Main2():
    Canvas = makeEmptyPicture(800,600,yellow)
    show(Canvas)
    return

#----------------------------------------------------------------------
# The following program creates and shows an orange 800x600 canvas,
# where the color is mixed from R=255, G=128, and B=0 (the limits on
# all three values are between 0...255).
#----------------------------------------------------------------------

def Main3():
    Canvas = makeEmptyPicture(800,600,makeColor(255,128,0))
    show(Canvas)
    return

#----------------------------------------------------------------------
# The synthesized color may be assigned to a variable, and then used
# anywhere colors are expected.
#----------------------------------------------------------------------

def Main4():
    MyColor = makeColor(255,128,0)
    Canvas = makeEmptyPicture(800,600,MyColor)
    show(Canvas)
    return

#----------------------------------------------------------------------
# Let's draw a blue line between <100,50> and <400,200>
#----------------------------------------------------------------------

def Main5():
    MyColor = makeColor(255,128,0)
    Canvas = makeEmptyPicture(800,600,MyColor)
    show(Canvas)
    addLine(Canvas, 100, 50, 400, 200, blue)
    return

#----------------------------------------------------------------------
# Let's draw a black line between <100,50> and <400,200>
#----------------------------------------------------------------------

def Main6():
    MyColor = makeColor(255,128,0)
    Canvas = makeEmptyPicture(800,600,MyColor)
    show(Canvas)
    addLine(Canvas, 100, 50, 400, 200)  # If color omitted, assume black
    return
    
#----------------------------------------------------------------------
# How do we draw rectangles?  Write a function!  Notice that the
# LineColor has a default value of black - if the 6th parameter is
# included it must be a color passed into LineColor, but if omitted 
# LineColor is assumed to be black.
#----------------------------------------------------------------------

def Rectangle (Canvas, X, Y, Width, Height, LineColor=black):
    addLine(Canvas, X,       Y,        X,       Y+Height, LineColor)      # Left Line
    addLine(Canvas, X+Width, Y,        X+Width, Y+Height, LineColor)      # Right Line
    addLine(Canvas, X,       Y,        X+Width, Y,        LineColor)      # Top Line
    addLine(Canvas, X,       Y+Height, X+Width, Y+Height, LineColor)      # Bottom Line
    return    

def Main7():
    MyColor = makeColor(255,128,0)
    Canvas = makeEmptyPicture(800,600,MyColor)
    show(Canvas)
    Rectangle(Canvas, 200,100,300,200)
    repaint(Canvas)
    return

#----------------------------------------------------------------------
# However, JES has an addRect function with the same parameters.
#----------------------------------------------------------------------
    
def Main8():
    MyColor = makeColor(255,128,0)
    Canvas = makeEmptyPicture(800,600,MyColor)
    show(Canvas)
    addRect(Canvas, 200,100,300,200)
    repaint(Canvas)
    return

#----------------------------------------------------------------------
# The lesson is that you can use the tools you have to build the tools
# you need, but sometimes there is already a tool that does what you
# want.  That is the case with Rectangle/addRect.  We don't need the
# Rectangle function.  There is also an addOval function, with the same
# parameters as addRect, BUT THERE IS NO CIRCLE function.
#----------------------------------------------------------------------

def Main9():
    MyColor = makeColor(255,128,0)
    Canvas = makeEmptyPicture(800,600,MyColor)
    show(Canvas)
    addOval(Canvas, 200,100,300,200)
    addRect(Canvas, 200,100,300,200)  # Rect drawn on top of the oval
    repaint(Canvas)
    return

#----------------------------------------------------------------------
# So, if we want to have a circle function that takes in center X,
# center Y, and radius, then we have to write one.  But, all we can
# use is the addOval function, which expects its reference point at
# the upper left corner, not the center.  We need to have our circle
# function figure out from center and radius where the upper left
# corner is located.
#----------------------------------------------------------------------
    
def Circle (Canvas, CenterX, CenterY, Radius, LineColor=black):
    addOval(Canvas, CenterX-Radius, CenterY-Radius, 2*Radius, 2*Radius, LineColor)
    return

def Main10():
    MyColor = makeColor(255,128,0)
    Canvas = makeEmptyPicture(800,600,MyColor)
    show(Canvas)
    addOval(Canvas, 200,100,300,200)
    addRect(Canvas, 200,100,300,200)
    Circle (Canvas, 200,100,100,red)
    repaint(Canvas)
    return