A program to place words randomly on a canvas. Words are place around a spiral starting from the center. Uses AABB – AABB bounding box collision detection for letter-letter collision.

Ref: Real-time Collision Detection by Christer Ericson

"""
May 9, 2019
A program to palce a list of words, randomly on a canvas.
Places words around spiral. Uses bounding box collision detection.
Author: jithesh Kuyyalil https://jitheshkuyyalil.com
Date: April 26, 2019
"""
from PIL import Image, ImageDraw, ImageFont
import numpy as np
from random import randint
from spiral import spiral
img = Image.new("L", (500, 500))
#word = "b"
word_list = ['a', 'b', 'c', 'd', 'e', 'f']
#word_list = 'thebookthiefishere'
font_size = 50
font_path = 'DroidSansMono.ttf'
draw = ImageDraw.Draw(img)
font = ImageFont.truetype(font_path, font_size)
# save bounding box co-ordinates [[(), ()], [(), ()]]
box_coord = []
for word in word_list: # for each letter
# x, y, where the word/letter is placed, somewhere top-left
sp = spiral(500, 500, 250, 250)
count = 0
while True:
x, y = next(sp)
# font metrics to construct bounding box around letter
(x1, y1, x2, y2) = font.getmask(word).getbbox()
(width, baseline), (offset_x, offset_y) = font.font.getsize(word)
# top left corner
rect_1 = (x1 + x + offset_x, y1 + y + offset_y)
# bottom right corner. Not clear about -1
# Rectangle fits well with -1.
rect_2 = (x2 + x + offset_x -1, y2 + y + offset_y)
intersect = False # both letter-boundary, letter-letter collision
# boundary collision testing - boundary (0,0), (500,500)
# hitting the boundary
if not (rect_2[0] < 500 and rect_2[1] < 500):
intersect = True
# only if letter doesn't hit boundary
if intersect == False:
# checking for collision
if box_coord != []:
#print(box_coord)
for box in box_coord:
# not intersecting
if (rect_1[0] > box[1][0]) or (rect_2[0] < box[0][0]):
continue
# intersecting
if (rect_1[1] > box[1][1]) or (rect_2[1] < box[0][1]):
continue
intersect = True
break # interesecting; find new x, y
if not intersect :
#draw.rectangle([rect_1, rect_2], outline='white')
draw.text((x, y), word, fill='white', font=font) # 175, 90
box_coord.append([rect_1, rect_2])
break
count = count + 1;
if count > 500 * 500:
break
img.show()

#### Python code to generate spiral co-ordinates.

"""
A program to generate spiral co-ordinates in a 2D square lattice.
Algorithm due to Can Berk Güder at stackoverflow.com
author: jithesh kuyyalil
Date: May 1, 2019
"""
def spiral(m, n, Xc = 0, Yc = 0):
# 0, 0 at the top left corner
# Xc, Yc somewhere on the canvas
x = 0
y = 0
dx = 0
dy = -1
for i in range(max(m,n)**2):
if (-m/2 < x <= m/2) and (-n/2 < y <= n/2): # from each matrix \
# what is necessary
#print(x, y)
if Xc != 0 or Yc != 0:
yield x + Xc, y + Yc
else:
yield x, y
if x == y or (x < 0 and x == -y) or (x > 0 and x == 1-y): # each turn \
# change dx and dy
temp = dx
dx = -dy
dy = temp
#print('dx, dy ', dx, dy)
x = x + dx
y = y + dy
if __name__ == '__main__':
import matplotlib.pyplot as plt
sp = spiral(300,300, 150, 150)
X = []
Y = []
for i in range(150):
#print(next(x))
x, y = next(sp)
X.append(x)
Y.append(y)
plt.plot(X, Y, 'o')
plt.show()