crop_paths

This commit is contained in:
Michael Fogleman 2017-12-01 22:26:14 -05:00
parent 3ff8ecb067
commit 5bdab1bb23
2 changed files with 48 additions and 1 deletions

View File

@ -2,7 +2,7 @@ from __future__ import division
from math import sin, cos, radians from math import sin, cos, radians
from .paths import simplify_paths, sort_paths, join_paths from .paths import simplify_paths, sort_paths, join_paths, crop_paths
try: try:
import cairo import cairo
@ -58,6 +58,9 @@ class Drawing(object):
def join_paths(self, tolerance): def join_paths(self, tolerance):
return Drawing(join_paths(self.paths, tolerance)) return Drawing(join_paths(self.paths, tolerance))
def crop_paths(self, x1, y1, x2, y2):
return Drawing(crop_paths(self.paths, x1, y1, x2, y2))
# def remove_duplicates(self): # def remove_duplicates(self):
# return Drawing(util.remove_duplicates(self.paths)) # return Drawing(util.remove_duplicates(self.paths))

View File

@ -62,3 +62,47 @@ def join_paths(paths, tolerance):
else: else:
result.append(list(path)) result.append(list(path))
return result return result
def crop_interpolate(x1, y1, x2, y2, ax, ay, bx, by):
t1 = (x1 - ax) / (bx - ax)
t2 = (y1 - ay) / (by - ay)
t3 = (x2 - ax) / (bx - ax)
t4 = (y2 - ay) / (by - ay)
ts = [t1, t2, t3, t4]
ts = [t for t in ts if t >= 0 and t <= 1]
t = min(ts)
x = ax + (bx - ax) * t
y = ay + (by - ay) * t
return (x, y)
def crop_path(path, x1, y1, x2, y2):
result = []
buf = []
previous_point = None
previous_inside = False
for x, y in path:
inside = x >= x1 and y >= y1 and x <= x2 and y <= y2
if inside:
if not previous_inside and previous_point:
px, py = previous_point
ix, iy = crop_interpolate(x1, y1, x2, y2, x, y, px, py)
buf.append((ix, iy))
buf.append((x, y))
else:
if previous_inside and previous_point:
px, py = previous_point
ix, iy = crop_interpolate(x1, y1, x2, y2, x, y, px, py)
buf.append((ix, iy))
result.append(buf)
buf = []
previous_point = (x, y)
previous_inside = inside
if buf:
result.append(buf)
return result
def crop_paths(paths, x1, y1, x2, y2):
result = []
for path in paths:
result.extend(crop_path(path, x1, y1, x2, y2))
return result