initial

Dockerfile

+FROM python:alpine3.9
+
+EXPOSE 5000
+
+COPY . /app
+WORKDIR /app
+
+RUN  apk add --no-cache libgfortran build-base libstdc++ \
+                        libpng libpng-dev \
+                        freetype freetype-dev && \
+    # Install Python dependencies
+    pip3 install -v --no-cache-dir flask==1.0.2 matplotlib==3.0.3 && \
+    # Cleanup
+    apk del --purge build-base libgfortran libpng-dev freetype-dev && \
+    rm -vrf /var/cache/apk/*
+
+CMD python ./index.py

escher_pattern.py

+#!/usr/bin/env python3
+
+'''
+/**
+ * @file escher_pattern_class.py
+ * @brief escher pattern generator
+ * @par <b>License</b>:
+ *  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 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, see <http://www.gnu.org/licenses/>.
+*/
+'''
+
+import matplotlib.pyplot as plt
+from matplotlib.backends.backend_pdf import PdfPages
+
+import numpy as np
+
+from matplotlib.patches import Arc
+from matplotlib.patches import Circle
+from matplotlib.patches import Rectangle
+from matplotlib.patches import Polygon
+from matplotlib.patches import Wedge
+from matplotlib.patches import PathPatch
+
+import matplotlib as mpl
+
+from matplotlib import collections
+from matplotlib.path import Path
+
+import copy
+import math
+
+import sys
+
+'''
+requirements:
+  
+  - matplotlib, version 3.0.3
+  - BUG?: matplotlib, version 2.0.2 draws a little padding around which is not desired
+
+install:
+
+  - sudo pip3 install matplotlib
+  - sudo apt install python3-tk
+  
+'''
+
+class Escher_Pattern:
+
+  # units are mms but coordinates are in pt to compare with php script
+  MM2PT = 72.0/25.4
+  opts_k = {'facecolor':'black','edgecolor':'r','linewidth':0}
+  opts_w = {'facecolor':'white','edgecolor':'r','linewidth':0}
+  opts_b = {'facecolor':'blue', 'edgecolor':'r','linewidth':0}
+  opts_r = {'facecolor':'red', 'edgecolor':'r','linewidth':0}
+
+  # init
+  def __init__(self,
+               width    = 270,  # width in units
+               height   = 210,  # height in units
+               lpm      = 50,   # lines per meter
+               escher   = 2.0,  # curvature coefficient
+               rotate   = 5,    # degrees
+               units    = 'mm',
+               ):
+
+    self.width    = int(width*self.MM2PT)
+    self.height   = int(height*self.MM2PT)
+    self.lpm      = lpm
+    self.escher   = escher
+    self.angle   = rotate
+    self.units = units
+
+    self.basename = 'escher-pattern'
+    self.basename += '-ESCHER'+str(self.escher)
+    self.basename += '-LPM'+str(self.lpm)
+    self.basename += '-ROT'+str(self.angle)
+    self.basename += '-PAGE_WIDTH'+str(width)
+    self.basename += '-PAGE_HEIGHT'+str(height)
+
+    self.pdf_name = self.basename+".pdf"
+
+    plt.autoscale(tight=True)
+    plt.axis('off')
+    plt.margins(0.0)
+    #plt.rcParams["figure.figsize"] = [60,120]
+
+    self.fig, self.ax = plt.subplots()
+    self.fig.set_size_inches(self.width/72, self.height/72)
+
+    self.ax.get_xaxis().set_visible(False)
+    self.ax.get_yaxis().set_visible(False)
+    self.ax.set_aspect('equal')
+
+    self.ax.spines['top'].set_visible(False)
+    self.ax.spines['right'].set_visible(False)
+    self.ax.spines['left'].set_visible(False)
+    self.ax.spines['bottom'].set_visible(False)
+
+    self.ax.set_ylim([0,self.height])
+    self.ax.set_xlim([0,self.width])
+
+    self.ax.set_facecolor('white')
+
+    self.rotation = mpl.transforms.Affine2D().rotate_deg(-self.angle) + self.ax.transData
+
+    #print("init done")
+
+
+  # generate and place a patch
+  def generate_cell(self,x,y,tpts,template,halfAngle,r,ba):
+
+    for k,v in enumerate(template):
+
+      # even-even black cell
+      vcp = copy.copy(v)
+      if   (type(v)==Wedge):
+        vcp.set_center((tpts[k][0]+x,tpts[k][1]+y))
+      elif (type(v)==Rectangle):
+        vcp.set_xy((tpts[k][0]+x,tpts[k][1]+y))
+
+      self.ax.add_patch(vcp)
+      vcp.set_transform(self.rotation)
+
+      # do clipping
+      if   (type(v)==Wedge):
+
+        sin0 = math.sin(math.radians(halfAngle))
+        cos0 = math.cos(math.radians(halfAngle))
+
+        if ba[k]==0:
+          w0 = r - r*cos0
+          h0 = 2*r*sin0
+          x0 = tpts[k][0] + r - w0
+          y0 = tpts[k][1] - h0/2
+        if ba[k]==180:
+          w0 = r - r*cos0
+          h0 = 2*r*sin0
+          x0 = tpts[k][0] - r
+          y0 = tpts[k][1] - h0/2
+        if ba[k]==270:
+          w0 = 2*r*sin0
+          h0 = r - r*cos0
+          x0 = tpts[k][0] - w0/2
+          y0 = tpts[k][1] - r
+        if ba[k]==90:
+          w0 = 2*r*sin0
+          h0 = r - r*cos0
+          x0 = tpts[k][0] - w0/2
+          y0 = tpts[k][1] + r - h0
+
+
+        # correction, so the shadow line from Rectange is not seen
+        if ba[k]==0:
+          x0 -= w0
+          w0 *= 2
+        if ba[k]==180:
+          w0 *= 2
+        if ba[k]==270:
+          h0 *= 2
+        if ba[k]==90:
+          y0 -= h0
+          h0 *= 2
+
+        cp = Rectangle((x0,y0),w0,h0,**self.opts_w, lw=0)
+        vcp2 = copy.copy(cp)
+
+        xy = vcp2.get_xy()
+        vcp2.set_xy((xy[0]+x,xy[1]+y))
+        path = vcp2.get_path()
+        transform = vcp2.get_transform()
+        path = transform.transform_path(path)
+        vcp2 = PathPatch(path, fc='none', ec='none', lw=0)
+        self.ax.add_patch(vcp2)
+        # rotate here
+        vcp2.set_transform(self.rotation)
+
+        vcp.set_clip_path(vcp2)
+
+
+  # generate the whole pattern
+  def generate(self):
+
+    side = 500/self.lpm*self.MM2PT
+
+    # escher pattern
+    if (self.escher>0):
+
+      # no rounding
+      Size = side
+      qSize = Size/4
+      hSize = Size/2
+      a = self.escher*(math.sqrt(2)-1.0)
+      r = (a*a+1)/(2*a)*qSize
+      r2 = r*r
+      h = math.sqrt(r2-qSize*qSize)
+      dc = 2*qSize-h
+      halfAngle = math.degrees(math.atan(qSize/h))
+      center = dc+r
+
+      ba = [
+        None,
+        0,
+        180,
+        270,
+        90,
+        180,
+        0,
+        90,
+        270
+      ]
+
+      tpts = [
+          [center-hSize,   center-hSize],
+          [center-Size+dc, center-qSize],
+          [center-dc,      center+qSize],
+          [center-qSize,   center+Size-dc],
+          [center+qSize,   center+dc],
+          [center+Size-dc, center+qSize],
+          [center+dc,      center-qSize],
+          [center+qSize,   center-Size+dc],
+          [center-qSize,   center-dc]
+        ]
+
+      template = [
+        Rectangle( tpts[0],  Size, Size, **self.opts_k),
+        Wedge(     tpts[1],  r, ba[1]-halfAngle, ba[1]+halfAngle, **self.opts_w),
+        Wedge(     tpts[2],  r, ba[2]-halfAngle, ba[2]+halfAngle, **self.opts_k),
+        Wedge(     tpts[3],  r, ba[3]-halfAngle, ba[3]+halfAngle, **self.opts_w),
+        Wedge(     tpts[4],  r, ba[4]-halfAngle, ba[4]+halfAngle, **self.opts_k),
+        Wedge(     tpts[5],  r, ba[5]-halfAngle, ba[5]+halfAngle, **self.opts_w),
+        Wedge(     tpts[6],  r, ba[6]-halfAngle, ba[6]+halfAngle, **self.opts_k),
+        Wedge(     tpts[7],  r, ba[7]-halfAngle, ba[7]+halfAngle, **self.opts_w),
+        Wedge(     tpts[8],  r, ba[8]-halfAngle, ba[8]+halfAngle, **self.opts_k)
+      ]
+
+    # checker board
+    else:
+
+      halfAngle = 0
+      r = 0
+
+      ba = [
+        None
+      ]
+
+      tpts = [
+        [0,0]
+      ]
+
+      template = [
+        Rectangle(tpts[0],side,side, **self.opts_k)
+      ]
+
+    # calc how much more is needed for the rotation
+    abs_angle_rad = math.radians(abs(self.angle))
+    extra_w = self.height*math.tan(abs_angle_rad) # + side
+    extra_h = self.width *math.tan(abs_angle_rad) # + side
+    # would like to pass (0,0)
+    extra_w = int(extra_w/(2*side)+1)*2*side
+    extra_h = int(extra_h/(2*side)+1)*2*side
+
+    a = np.arange(-extra_w, self.width +extra_w, 2*side)
+    b = np.arange(-extra_h, self.height+extra_h, 2*side)
+
+    for x, y in [(x,y) for x in a for y in b]:
+      self.generate_cell(x     ,y     ,tpts,template,halfAngle,r,ba)
+      self.generate_cell(x+side,y+side,tpts,template,halfAngle,r,ba)
+
+
+  # test 
+  def test(self):
+
+    x = [0, 100,   0]
+    y = [0,   0, 100]
+    self.ax.fill(x, y)
+
+    circ = Circle((0,0),0.01,color="red")
+    #circ.set_transform(t_end)
+    self.ax.add_patch(circ)
+    circ = Circle((100,0),1,color="red")
+    #circ.set_transform(t_end)
+    self.ax.add_patch(circ)
+    circ = Circle((0,100),1,color="red")
+    #circ.set_transform(t_end)
+    self.ax.add_patch(circ)
+    circ = Circle((50,50),1,color="red")
+    #circ.set_transform(t_end)
+    self.ax.add_patch(circ)
+
+  # save function
+  def save(self):
+
+    pp = PdfPages(self.pdf_name)
+    self.fig.tight_layout(pad=0)
+
+    #plt.show()
+
+    self.fig.savefig(pp,format='pdf',bbox_inches='tight',pad_inches=0)
+    #self.fig.savefig(pp,format='pdf',pad_inches=0)
+    pp.close()
+
+
+
+if __name__ == "__main__":
+
+  #ep = Escher_Pattern("test.pdf", escher=2.0, lpm=50, rotate=10)
+  #http://192.168.0.137/escher/escher_pattern.php?PAGE_WIDTH=1524&PAGE_HEIGHT=3048&LPM=2.705449885575893&ROTATE=14.036243467
+  #ep = Escher_Pattern(width= 1524, height= 3048, escher=0, lpm=2.705449885575893, rotate=10)
+  ep = Escher_Pattern(width= 1524, height= 3048, escher=2, lpm=2.705449885575893, rotate=14.036243467)
+  #ep = Escher_Pattern(width= 160, height= 320, escher=2, lpm=50, rotate=13)
+  ep.generate()
+  ep.save()

index.py

+from flask import Flask
+from flask import request
+import flask
+
+import os
+import time
+
+from escher_pattern import Escher_Pattern
+
+app = Flask(__name__)
+
+@app.route("/")
+def generate_pattern():
+
+  # defaults
+  params = {
+    'LPM': 50,
+    'PAGE_WIDTH': 270,
+    'PAGE_HEIGHT': 210,
+    'ROTATE': 5,
+    'ESCHER': 2
+  }
+
+  for k,v in params.items():
+    rq_param = request.args.get(k)
+    if rq_param!=None:
+      params[k] = float(rq_param)
+
+  basename  = 'escher-pattern'
+  basename += '-ESCHER'+str(params['ESCHER'])
+  basename += '-LPM'+str(params['LPM'])
+  basename += '-ROT'+str(params['ROTATE'])
+  basename += '-PAGE_WIDTH'+str(params['PAGE_WIDTH'])
+  basename += '-PAGE_HEIGHT'+str(params['PAGE_HEIGHT'])
+  pdf_name  = basename+".pdf"
+
+  ep = Escher_Pattern(
+         width  = params['PAGE_WIDTH'],
+         height = params['PAGE_HEIGHT'],
+         escher = params['ESCHER'],
+         lpm    = params['LPM'],
+         rotate = params['ROTATE'])
+
+  ep.generate()
+  ep.save()
+
+  with open(pdf_name,'rb') as f:
+    contents = f.read()
+  os.remove(pdf_name)
+
+  filesize = str(len(contents))
+  filesize = filesize.encode('utf-8')
+
+  resp = flask.Response(contents)
+
+  resp.headers['Content-Type']        = 'application/pdf'
+  resp.headers['Cache-Control']       = 'public, must-revalidate, max-age=0'
+  resp.headers['Pragma']              = 'public'
+  resp.headers['Expires']             = 'Sat, 26 Jul 1997 05:00:00 GMT'
+  resp.headers['Last-Modified']       = time.strftime("%a, %d %b %Y %H:%M:%S GMT", time.gmtime())
+  resp.headers['Content-Length']      = str(len(contents))
+  resp.headers['Content-Disposition'] = 'inline; filename='+pdf_name+';'
+
+  return resp
+
+if __name__ == "__main__":
+  app.run(host="0.0.0.0", port=int("5000"), debug=True)