From: daid <daid303@gmail.com>
Date: Thu, 28 Nov 2013 13:39:01 +0000 (+0100)
Subject: Add convex hulls for all objects and do collision detection with that. Add initial... 
X-Git-Tag: 14.01~54
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=4a56ab13a5e0302c3c50b32e0cb8770bbec7fa9a;p=cura.git

Add convex hulls for all objects and do collision detection with that. Add initial handling for the printerConnectionManager.
---

diff --git a/Cura/util/polygon.py b/Cura/util/polygon.py
new file mode 100644
index 00000000..746fb0ed
--- /dev/null
+++ b/Cura/util/polygon.py
@@ -0,0 +1,84 @@
+__copyright__ = "Copyright (C) 2013 David Braam - Released under terms of the AGPLv3 License"
+
+import numpy
+
+def convexHull(pointList):
+	def _isRightTurn((p, q, r)):
+		sum1 = q[0]*r[1] + p[0]*q[1] + r[0]*p[1]
+		sum2 = q[0]*p[1] + r[0]*q[1] + p[0]*r[1]
+
+		if sum1 - sum2 < 0:
+			return 1
+		else:
+			return 0
+
+	unique = {}
+	for p in pointList:
+		unique[p[0],p[1]] = 1
+
+	points = unique.keys()
+	points.sort()
+
+	# Build upper half of the hull.
+	upper = [points[0], points[1]]
+	for p in points[2:]:
+		upper.append(p)
+		while len(upper) > 2 and not _isRightTurn(upper[-3:]):
+			del upper[-2]
+
+	# Build lower half of the hull.
+	points = points[::-1]
+	lower = [points[0], points[1]]
+	for p in points[2:]:
+		lower.append(p)
+		while len(lower) > 2 and not _isRightTurn(lower[-3:]):
+			del lower[-2]
+
+	# Remove duplicates.
+	del lower[0]
+	del lower[-1]
+
+	return numpy.array(upper + lower, numpy.float32) - numpy.array([0.0,0.0], numpy.float32)
+
+def minkowskiHull(a, b):
+	points = numpy.zeros((len(a) * len(b), 2))
+	for n in xrange(0, len(a)):
+		for m in xrange(0, len(b)):
+			points[n * len(b) + m] = a[n] + b[m]
+	return convexHull(points.copy())
+
+def projectPoly(poly, normal):
+	pMin = numpy.dot(normal, poly[0])
+	pMax = pMin
+	for n in xrange(1 , len(poly)):
+		p = numpy.dot(normal, poly[n])
+		pMin = min(pMin, p)
+		pMax = max(pMax, p)
+	return pMin, pMax
+
+def polygonCollision(polyA, polyB):
+	for n in xrange(0, len(polyA)):
+		p0 = polyA[n-1]
+		p1 = polyA[n]
+		normal = (p1 - p0)[::-1]
+		normal[1] = -normal[1]
+		normal /= numpy.linalg.norm(normal)
+		aMin, aMax = projectPoly(polyA, normal)
+		bMin, bMax = projectPoly(polyB, normal)
+		if aMin > bMax:
+			return False
+		if bMin > aMax:
+			return False
+	for n in xrange(0, len(polyB)):
+		p0 = polyB[n-1]
+		p1 = polyB[n]
+		normal = (p1 - p0)[::-1]
+		normal[1] = -normal[1]
+		normal /= numpy.linalg.norm(normal)
+		aMin, aMax = projectPoly(polyA, normal)
+		bMin, bMax = projectPoly(polyB, normal)
+		if aMin > bMax:
+			return False
+		if aMax < bMin:
+			return False
+	return True