【Python】四角形の重複した部分

matplotlibでRectangleを2つ描画する時に重複している部分の四角形を描画する．
intersectionというらしい．

まずは適当な四角形を作る．

recs=[]
recs.append(matplotlib.patches.Rectangle((10,10),300,60, color='r', fill=False))
recs.append(matplotlib.patches.Rectangle((5,5),20,20, color='b', fill=False))
recs.append(matplotlib.patches.Rectangle((150,5),20,20, color='b', fill=False))
recs.append(matplotlib.patches.Rectangle((300,5),20,20, color='b', fill=False))
recs.append(matplotlib.patches.Rectangle((5,55),20,20, color='b', fill=False))
recs.append(matplotlib.patches.Rectangle((150,55),20,20, color='b', fill=False))
recs.append(matplotlib.patches.Rectangle((300,55),20,20, color='b', fill=False))

recs.append(matplotlib.patches.Rectangle((200,90),100,90, color='b', fill=False))
recs.append(matplotlib.patches.Rectangle((100,100),300,20, color='b', fill=False))

recs.append(matplotlib.patches.Rectangle((100,200),100,60, color='b', fill=False))
recs.append(matplotlib.patches.Rectangle((80,160),160,130, color='b', fill=False))

描画する．

fig = plt.figure()
ax = fig.add_subplot(1,1,1,xlim =500,ylim=300)
for rec in recs:
    ax.add_patch(rec)
plt.show()

それぞれの四角形に関して，重なってるかどうか総当りで判定する．
重なってるならh=1,重なってないならh=0．

for f in recs:
    for s in recs:
        if f == s:
            pass
	else:
            h = f.get_path().intersects_path(s.get_path())

重なっている四角形を再度作りなおす．

nr = []
if h == 1:
    fx = f.get_x()
    fy = f.get_y()
    fw = f.get_width()
    fh = f.get_height()
    sx = s.get_x()
    sy = s.get_y()
    sw = s.get_width()
    sh = s.get_height()
    if fx <= sx and fy <= sy and fx+fw <= sx+sw and sx <= fx+fw and fy+fh <= sy+sh and fy+fh >= sy:
        nr.append(matplotlib.patches.Rectangle((sx,sy),fx+fw-sx,fy+fh-sy,color='gray',fill=True,alpha =0.9))
    if fx >= sx and fy <= sy and fx+fw >= sx+sw and fx <= sx+sw and fy+fh <= sy+sh and fy+fh >= sy:
        nr.append(matplotlib.patches.Rectangle((fx,sy),sx+sw-fx,fy+fh-sy,color='green',fill=True,alpha =0.9))
    if fx <= sx and fy <= sy and fx+fw >= sx+sw and fy+fh <= sy+sh and fy+fh >= sy:
        nr.append(matplotlib.patches.Rectangle((sx,sy),sw,fy+fh-sy,color='black',fill=True,alpha =0.9))
    if fx <= sx and fy >= sy and fx+fw >= sx+sw and sy+sh >= fy and sy+sh<=fy+fh:
        nr.append(matplotlib.patches.Rectangle((sx,fy),sw,sy+sh-fy,color='r',fill=True,alpha =0.9))
    if fx > sx and fy >= sy and fx+fw <= sx+sw and fy+fh <= sy+sh:
        nr.append(matplotlib.patches.Rectangle((fx,fy),fw,fh,color='c',fill=True,alpha =0.9))
    if sx < fx and fy <= sy and sy <= fy+fh and fy+fh >= sy+sh and sx+sw >= fx+fw:
        nr.append(matplotlib.patches.Rectangle((fx,sy),fw,sh,color='y',fill=True,alpha =0.9))

それを描画する．