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#! /usr/bin/env python

# 
# Copyright (c) 2011 Brian House
# 
# 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 3 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 <http://www.gnu.org/licenses/gpl.html> for details.
# 

"""

Description
===========

A simple drawing interface for Python that wraps PIL and aggdraw.

For slightly more information, see http://blog.brianhouse.net/post/6836163797


Requirements
============

Python 2.6+
PIL http://www.pythonware.com/products/pil/
aggdraw http://effbot.org/zone/aggdraw-index.htm (for 64-bit systems (eg OSX), use https://bitbucket.org/2degrees/aggdraw-64bits/src)


Using
=====

See the __main__ function below for a quick example.

Note on colors:
Colors are specified as a tuple of R, G, B, A values in the default mode and H, S, V, A if hsv was indicated in the class constructor. Alpha is optional.
If ints are used, 0-255 is assumed, whereas floats imply a 0-1 scale. Values can be mixed.
'stroke' refers to the lines/borders of a shape, with the supplied 'thickness'. To draw shapes without borders, set thickness to 0 and specify a fill.

Also, note that, unlike Processing or Canvas, this is not a state machine -- values must be specified with every command.


Todo
====

Polygons / polylines
Rotated shapes

Mouse events:

cv.NamedWindow("radar")
def on_mouse(event, x, y, flags, param):
    if event == cv.CV_EVENT_LBUTTONUP:
        print("click: %s,%s" % (x, y))
    if event == cv.CV_EVENT_MOUSEMOVE:
        print("move: %s,%s" % (x, y))
cv.SetMouseCallback("radar", on_mouse)

Keyboard events:

key = cv.WaitKey(1)


"""

import aggdraw, colorsys, math, time
from PIL import Image, ImageFilter, ImageOps, ImageDraw, ImageFont
from log import log

class Context(object):
    """The drawing context"""    
       
    def __init__(self, width=800, height=600, background=None, hsv=False, flip=False, relative=False, margin=0):
        """ Create a drawing context of a given size and background color. 'hsv' specifies if we should use hsv color values instead of the default rgb.
            'flip' inverts the vertical axis.
            'relative' indicates that all methods will take x, y, width, and height values as floats from 0-1 scaled relatively across the canvas.
            'margin' adds margin pixels to all sides that are outside of the coordinate system.
            These flags may be useful for looking at scaled data without having to convert to pixel positions.
        """    
        self._width = float(width)
        self._height = float(height)
        self._hsv = hsv
        self.background = background
        if not background:
            self.background = (0.0, 0.0, 1.0) if self._hsv else (1.0, 1.0, 1.0)
        self._ctx = None
        self.mode = "RGBA" if len(self.background) > 3 else "RGB"
        self._image = Image.new(self.mode, (width, height), self._handle_color(self.background))
        self._verify_context()
        self._valid = True
        self._horiz = (lambda x: x + margin) if not relative else (lambda x: (x * (self.width - (2.0 * margin))) + margin)
        self._flip = flip
        self._perform_flip = (lambda y: float(self.height) - y) if flip else (lambda y: y)
        self._vert = (lambda y: self._perform_flip(y + margin)) if not relative else (lambda y: self._perform_flip((y * (self.height - (2.0 * margin))) + margin))
        
    def _verify_context(self):
        if not self._ctx:
            self._ctx = aggdraw.Draw(self._image)            

    def _render(self):
        if not self._valid and self._ctx:
            self._ctx.flush()
            self._valid = True            

    def _handle_color(self, args):
        if type(args) == float or type(args) == int:
            args = [args] * 3
        color = [0.0, 0.0, 0.0, 1.0]
        for i, arg in enumerate(args):
            color[i] = arg
            if type(arg) == int:
                color[i] /= 255.0
        if self._hsv:
            color[0], color[1], color[2] = colorsys.hsv_to_rgb(*color[:3])
        return int(color[0] * 255.0), int(color[1] * 255.0), int(color[2] * 255.0), int(color[3] * 255.0)

    """Public Methods"""

    @property
    def width(self):
        """Return the width of the drawing context."""
        return self._width
        
    @property
    def height(self):
        """Return the height of the drawing context."""        
        return self._height    

    @property    
    def image(self):
        """Return the drawing context as a PIL image."""
        if not self._valid:
            self._render()
        return self._image    
        
    def line(self, x1, y1=None, x2=None, y2=None, stroke=(0.0, 0.0, 0.0, 1.0), thickness=1.0):
        """Draw a line from x1,y1 to x2,y2, or between all points (as x,y pairs) in a list."""
        self._verify_context()
        stroke = self._handle_color(stroke)
        pen = aggdraw.Pen(stroke[:3], thickness, stroke[3])
        if type(x1) == tuple or type(x1) == list:
            points = []
            for point in x1:
                points.extend((self._horiz(point[0]), self._vert(point[1])))
            self._ctx.line(points, pen)
        else:            
            self._ctx.line((self._horiz(x1), self._vert(y1), self._horiz(x2), self._vert(y2)), pen)
        self._valid = False
        
    def curve(self, x1, y1, xc, yc, x2, y2, stroke=(0.0, 0.0, 0.0, 1.0), thickness=1.0, steps=100):
        """Draw a curve from x1,y1 to x2,y2 with control point xc, yc. TODO: arbitrary number of control points, dynamic steps selection."""                
        self._verify_context()
        stroke = self._handle_color(stroke)
        pen = aggdraw.Pen(stroke[:3], thickness, stroke[3])
        pt0 = self._horiz(x1), self._vert(y1)
        pt1 = self._horiz(xc), self._vert(yc)
        pt2 = self._horiz(x2), self._vert(y2)                
        points = []
        for i in xrange(steps):
            t = float(i) / steps
            x = ((1-t)**2 * pt0[0]) + (2 * (1-t) * t * pt1[0]) + (t**2 * pt2[0])
            y = ((1-t)**2 * pt0[1]) + (2 * (1-t) * t * pt1[1]) + (t**2 * pt2[1])
            points.extend((x, y))
        points.extend(pt2)
        self._ctx.line(points, pen)                    
        self._valid = False        
        
    def rect(self, x, y, width, height, stroke=(0.0, 0.0, 0.0, 1.0), thickness=1.0, fill=None):
        """Draw a rectangle with the upper left point at x,y."""
        self._verify_context()
        stroke = self._handle_color(stroke)
        pen = aggdraw.Pen(stroke[:3], thickness, stroke[3])  
        brush = None
        if fill:    
            fill = self._handle_color(fill)
            brush = aggdraw.Brush(fill[:3], fill[3])              
        self._ctx.rectangle((self._horiz(x), self._vert(y), self._horiz(x + width), self._vert(y + height)), pen, brush)   
        self._valid = False        

    def arc(self, center_x, center_y, radius_x, radius_y=None, start=0, end=360, stroke=(0.0, 0.0, 0.0, 1.0), thickness=1.0, fill=None):
        """ Draw an arc / ellipse / circle / pieslice. 'start' and 'end' are angles in degrees; 0 is 3:00 and degrees move clockwise.
            Specify both radius_x and radius_y to make ellipses; fill to make a pie slice.
        """
        self._verify_context()
        stroke = self._handle_color(stroke)
        pen = aggdraw.Pen(stroke[:3], thickness, stroke[3])
        brush = None
        if not radius_y:
            radius_y = radius_x
        if fill:    
            fill = self._handle_color(fill)
            brush = aggdraw.Brush(fill[:3], fill[3]) 
        coords = (self._horiz(center_x - radius_x), self._vert(center_y - radius_y), self._horiz(center_x + radius_x), self._vert(center_y + radius_y))                         
        if self._flip:
            coords = coords[0], coords[3], coords[2], coords[1]
        else:                
            tmp = 360 - start
            start = 360 - end
            end = tmp
        if start == 0 and end == 360:
            self._ctx.ellipse(coords, pen, brush)        
        elif fill:
            self._ctx.pieslice(coords, start, end, pen, brush)
        else:    
            self._ctx.arc(coords, start, end, pen)            
        self._valid = False        

    def spiral(self, center_x, center_y, radius_x, radius_y=None, start_degrees=0, end_degrees=5*360, stroke=(0.0, 0.0, 0.0, 1.0), thickness=1.0, resolution=0.01, clockwise=True):
        """Draws spirals"""
        self._verify_context()
        stroke = self._handle_color(stroke)
        pen = aggdraw.Pen(stroke[:3], thickness, stroke[3])
        center = self._horiz(center_x), self._vert(center_y)
        if not radius_y:
            radius_y = radius_x 
        turns = float(end_degrees) / 360
        radius_x /= math.pi * 2.0 * turns
        radius_y /= math.pi * 2.0 * turns
        points = []
        t = math.pi * 2.0 * (float(start_degrees) / 360)
        while t < math.pi * 2.0 * turns:
            x = (1 if clockwise else -1) * (t * math.cos(t) * radius_x) + center[0]
            y = (t * math.sin(t) * radius_y) + center[1]
            points.extend((x, y))
            t += resolution
        self._ctx.line(points, pen)                    
        self._valid = False        

    def text(self, text, font, x, y, stroke=(0.0, 0.0, 0.0, 1.0), size=18, center=False):
        """Draw text at x,y. 'font' should be the path to a TrueType font."""
        self._render()
        self._ctx = None # it's necessary to kill aggdraw before using Draw
        draw = ImageDraw.Draw(self._image)
        font = ImageFont.truetype(font, size)        
        size = draw.textsize(text, font=font)
        if center:
            x -= size[0] * 0.5
        y -= size[1] * 0.5
        stroke = self._handle_color(stroke)        
        draw.text((self._horiz(x), self._vert(y)), text, font=font, fill=stroke[:3])

    def blur(self):        
        """Apply a blur filter to the drawing context."""
        self._render()
        self._image = self._image.filter(ImageFilter.BLUR)
        self._ctx = None

    def smooth(self):
        """Apply a smoothing filter to the drawing context."""
        self._render()
        self._image = self._image.filter(ImageFilter.SMOOTH)
        self._ctx = None        

    def sharpen(self):
        """Apply a sharpen filter to the drawing context."""        
        self._render()
        self._image = self._image.filter(ImageFilter.SHARPEN)
        self._ctx = None        

    def contrast(self): # todo: autocontrast, except if there is an argument, then adjust contrast
        """Apply autocontrast to the drawing context."""            
        if self.mode != 'RGB':
            raise Exception("RGB mode required for 'contrast'")
        self._render()
        self._image = ImageOps.autocontrast(self._image)
        self._ctx = None        

    def show(self):
        """Display the drawing context."""     
        import cv   
        if not self._valid:
            self._render()
        self.image.show()

    def frame(self):
        """Show an animation loop via OpenCV"""
        if self.mode != 'RGB':
            raise Exception("RGB mode required for 'frame'")        
        if not self._valid:
            self._render()       
        import cv
        cv.ShowImage("drawing", pil_to_ipl(self.image))                
        key = cv.WaitKey(1)
            
    def clear(self):
        if self.mode != 'RGBA' or self.background[3] == 1.0:
            self.rect(0, 0, self.width, self.height, thickness=0.0, fill=self.background)
        else:
            self._image = Image.new(self.mode, self._image.size, self._handle_color(self.background))
            self._ctx = None
            self._valid = True


        
def pil_to_ipl(pil_image):
    """Convert a PIL image to ipl (OpenCV)"""    
    import cv
    cv_image = cv.CreateImageHeader(pil_image.size, cv.IPL_DEPTH_8U, 3)
    cv.SetData(cv_image, pil_image.rotate(180).tostring()[::-1])
    return cv_image

                
if __name__ == "__main__":
    
    # rainbow ellipse specified relatively and in hsv
    ctx = Context(640, 480, (0, 0, 0), relative=True, hsv=True)    
    for i in xrange(0, 100):
        v = (100 - i) / 100.0
        ctx.arc(0.5, 0.5, v, 0.75 * v, fill=(v, 1.0, 1.0), thickness=0)    
    ctx.blur()    
    ctx.show()
    
    # random rects, animated
    from random import random
    ctx = Context(640, 480) 
    while True:  
        x, y = random() * ctx.width, random() * ctx.height
        width, height = random() * 200, random() * 200
        fill = random(), random(), random(), random()
        ctx.rect(x, y, width, height, fill=fill)
        ctx.frame()