def isThereAlreadyAGuideWithTheseProperties(thisLayer,guideposition,guideangle):
	if guideangle < 0:
		guideangle += 180
	if guideangle > 180:
		guideangle -= 180
	for thisGuide in thisLayer.guides:
		thisAngle = thisGuide.angle
		if thisAngle < 0:
			thisAngle += 180
		if thisAngle > 180:
			thisAngle -= 180
		if abs(thisAngle - guideangle) < 0.01 and abs(thisGuide.position.x - guideposition.x) < 0.01 and abs(thisGuide.position.y - guideposition.y) < 0.01:
			return True
	return False