# Copyright (C) 2002-2006  Alexei Gilchrist and Paul Cochrane
# 
# 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.

# $Id: quantumcircuits.py,v 1.12 2006/03/01 09:59:03 paultcochrane Exp $

'''
Quantum circuits objects library
'''

__revision__ = '$Revision: 1.12 $'

from pyscript import Color, Group, Area, Rectangle, P, Circle, \
        Dot, Path, C, TeX

class Boxed(Group, Area):
    '''
    Draws a box around an object,
    the box can be placed according to standard Area tags
    '''
        
    def __init__(self, obj, **options):
        bbox = obj.bbox()

        pad = .1
        w = bbox.width + 2*pad
        h = bbox.height + 2*pad

        self.width = w
        self.height = h
        self.bg = options.get('bg', Color(1))
        if options.has_key('bg'):
            del options['bg']

        apply(Group.__init__, (self,), options)
        apply(Area.__init__, (self,), options)

        obj.c = P(w/2., h/2.)

        self.append(
            Rectangle(width=w, height=h, bg=self.bg),
            obj,
            )

class Circled(Group, Area):
    """
    Draws a circle around an object
    """
        
    def __init__(self, obj, **options):
        bbox = obj.bbox()

        pad = .1
        r = max( bbox.width+2*pad, bbox.height+2*pad )/2.0

        self.width = 2.0*r
        self.height = 2.0*r
        
        self.bg = options.get('bg', Color(1))
        if options.has_key('bg'):
            del options['bg']

        apply(Group.__init__, (self,), options)
        apply(Area.__init__, (self,), options)

        obj.c = P(r, r)

        self.append(
            Circle(r=r, bg=self.bg, c=P(r, r)),
            obj,
            )

def cbox(obj, x, yt, yc):
    '''
    @param obj: the object to put a box around
    @type obj: object

    @param x: x position of line and centre of box
    @type x: float

    @param yt: y position of target
    @type yt: float

    @param yc: y position of control
    @type yc: float

    @return: a controlled box
    '''
    g = Group(
        Path(P(x, yt), P(x, yc)),
        Boxed(obj, c=P(x, yt), bg=Color(1)),
        Dot(P(x, yc)),
        )
    return g

def detector(**options):
    '''
    @return: a D shaped detector
    '''
    r = 0.3
    c = 0.65*r
    path = [
        P(0, -r), 
        P(0, r), 
        C(P(c, r), P(r, c)), 
        P(r, 0), 
        C(P(r, -c), P(c, -r)), 
        P(0, -r)
        ]
    options['bg'] = options.get('bg', Color(.8))
    options['closed'] = 1
    p = apply(Path, path, options)
    a = Area(width=r, height=2*r, e=P(0, 0))
    
    return Group(a, p)
    
def classicalpath(*paths):
    '''
    @param paths: 1 or more Path() objects

    @return: classical path
    '''
    g = Group()

    for path in paths:
        g.append(path.copy(linewidth=2, fg=Color(0)))

    # reuse these paths
    for path in paths:
        g.append(path(linewidth=1, fg=Color(1)))

    return g

# Rail
def Rail(w=P(0, 0), length=1.0, labelIn=None, labelOut=None, buff=0.05):
    """
    A Rail of a quantum circuit diagram

    @param length: length of the rail
    @type length: float

    @param labelIn: input label
    @type labelIn: string

    @param labelOut: output label
    @type labelOut: string

    @param buff: buffer of space between the end of the rail and the label
    @type buff: float
    """
    if labelIn is not None and labelOut is not None:
        return Group(
            Path(w+P(0, 0), w+P(length, 0)),
            TeX(labelIn, e=w-P(buff, 0)),
            TeX(labelOut, w=w+P(buff+length, 0))
            )
    elif labelIn is not None and labelOut is None:
        return Group(
            Path(w+P(0, 0), w+P(length, 0)),
            TeX(labelIn, e=w-P(buff, 0))
            )
    elif labelIn is None and labelOut is not None:
        return Group(
            Path(w+P(0, 0), w+P(length, 0)),
            TeX(labelOut, w=w+P(buff+length, 0))
            )
    else:
        return Group(
            Path(w+P(0, 0), w+P(length, 0))
            )
            
# CNOT (controlled not)
def Cnot(c=P(0, 0), targetDist=1.0, direction="up"):
    """
    Controlled NOT gate

    @param targetDist: distance to the target rail
    @type targetDist: float

    @param direction: in which direction is the target rail?  up/down
    @type direction: string
    """
    if direction is "up":
        return Group(
            Circle(r=0.06, bg=Color("black"), c=c),
            Circle(r=0.2, c=c+P(0, targetDist)),
            Path(c, c+P(0, targetDist+0.2))
            )
    elif direction is "down":
        return Group(
            Circle(r=0.06, bg=Color("black"), c=c),
            Circle(r=0.2, c=c+P(0, -targetDist)),
            Path(c, c+P(0, -targetDist-0.2))
            )

# Hadamard gate
def HGate(c=P(0, 0), side=0.5):
    """
    Hadamard get

    @param side: length of the box side
    @type side: float
    """
    return Group(
        Rectangle(width=side, height=side, c=c, bg=Color("white")),
        TeX(r'H', c=c)
        )

# Phase gate
def PGate(c=P(0, 0), side=0.5):
    """
    Phase gate

    @param side: length of the box side
    @type side: float
    """
    return Group(
        Rectangle(width=side, height=side, c=c, bg=Color("white")),
        TeX(r'P', c=c)
        )

# Controlled phase gate
def CPGate(c=P(0, 0), controlDist=1.0, direction="up", side=0.5):
    """
    Controlled phase gate

    @param controlDist: distance to the control
    @type controlDist: float

    @param direction: in which direction is the control?  up/down
    @type direction: string

    @param side: length of the box side
    @type side: float
    """    
    if direction is "up":
        return Group(
            Circle(c=c+P(0, controlDist), r=0.065, bg=Color("black")),
            Path(c+P(0, side/2.), c+P(0, controlDist)),
            Rectangle(width=side, height=side, c=c, bg=Color("white")),
            TeX(r'P', c=c)
            )
    elif direction is "down":
        return Group(
            Circle(c=c-P(0,controlDist), r=0.65, bg=Color("black")),
            Path(c-P(0, side/2.), c-P(0, controlDist)),
            Rectangle(width=side, height=side, c=c, bg=Color("white")),
            TeX(r'P', c=c)
            )

def Detector(e=P(0, 0), height=1.0, label=None):
    """
    Detector

    @param height: height of detector
    @type height: float

    @param label: detector label
    @type label: string
    """
    if label is not None:
        return Group(Path(e-P(0, height/2.0), e+P(0, height/2.0)),
		Circle(c=e, r=height/2.0, start=0, end=180), label)
    else:
        return Group(Path(e-P(0, height/2.0), e+P(0, height/2.0)),
		Circle(c=e, r=height/2.0, start=0, end=180))

# X gate
def XGate(c=P(0, 0), side=0.5):
    """
    X gate

    @param side: length of the box side
    @type side: float
    """
    return Group(
        Rectangle(width=side, height=side, c=c, bg=Color("white")),
        TeX(r'X', c=c)
        )

# Y gate
def YGate(c=P(0, 0), side=0.5):
    """
    Y gate

    @param side: length of the box side
    @type side: float
    """
    return Group(
        Rectangle(width=side, height=side, c=c, bg=Color("white")),
        TeX(r'Y', c=c)
        )

# Z gate
def ZGate(c=P(0, 0), side=0.5):
    """
    Z gate

    @param side: length of the box side
    @type side: float
    """
    return Group(
        Rectangle(width=side, height=side, c=c, bg=Color("white")),
        TeX(r'Z', c=c)
        )

# Controlled X gate
def CXGate(c=P(0, 0), controlDist=1.0, direction="up", side=0.5):
    """
    Controlled X gate

    @param controlDist: distance to the control
    @type controlDist: float

    @param direction: in which direction is the control?  up/down
    @type direction: string

    @param side: length of the box side
    @type side: float
    """
    if direction is "up":
        return Group(
            Circle(c=c+P(0, controlDist), r=0.065, bg=Color("black")),
            Path(c+P(0, side/2.), c+P(0, controlDist)),
            Rectangle(width=side, height=side, c=c, bg=Color("white")),
            TeX(r'X', c=c)
            )
    elif direction is "down":
        return Group(
            Circle(c=c-P(0, controlDist), r=0.65, bg=Color("black")),
            Path(c-P(0, side/2.), c-P(0, controlDist)),
            Rectangle(width=side, height=side, c=c, bg=Color("white")),
            TeX(r'X', c=c)
            )

# Controlled Y gate
def CYGate(c=P(0, 0), controlDist=1.0, direction="up", side=0.5):
    """
    Controlled Y gate

    @param controlDist: distance to the control
    @type controlDist: float

    @param direction: in which direction is the control?  up/down
    @type direction: string

    @param side: length of the box side
    @type side: float
    """
    if direction is "up":
        return Group(
            Circle(c=c+P(0, controlDist), r=0.065, bg=Color("black")),
            Path(c+P(0, side/2.), c+P(0, controlDist)),
            Rectangle(width=side, height=side, c=c, bg=Color("white")),
            TeX(r'Y', c=c)
            )
    elif direction is "down":
        return Group(
            Circle(c=c-P(0, controlDist), r=0.65, bg=Color("black")),
            Path(c-P(0, side/2.), c-P(0, controlDist)),
            Rectangle(width=side, height=side, c=c, bg=Color("white")),
            TeX(r'Y', c=c)
            )

# Controlled Z gate
def CZGate(c=P(0, 0), controlDist=1.0, direction="up", side=0.5):
    """
    Controlled Z gate

    @param controlDist: distance to the control
    @type controlDist: float

    @param direction: in which direction is the control?  up/down
    @type direction: string

    @param side: length of the box side
    @type side: float
    """    
    if direction is "up":
        return Group(
            Circle(c=c+P(0, controlDist), r=0.065, bg=Color("black")),
            Path(c+P(0, side/2.), c+P(0, controlDist)),
            Rectangle(width=side, height=side, c=c, bg=Color("white")),
            TeX(r'Z', c=c)
            )
    elif direction is "down":
        return Group(
            Circle(c=c-P(0, controlDist), r=0.65, bg=Color("black")),
            Path(c-P(0, side/2.), c-P(0,controlDist)),
            Rectangle(width=side, height=side, c=c, bg=Color("white")),
            TeX(r'Z', c=c)
            )

# vim: expandtab shiftwidth=4: