def create_ship(x, y, **kwargs):
return Entity(
x,
y,
shape=Polygon.from_pointlist([
Vector(+0, +8),
Vector(-5, -8),
Vector(+5, -8),
]),
color=Color(50, 100, 200),
**kwargs,
)
def create_asteroid(x, y, **kwargs):
bright = randint(20, 50)
return Entity(
x,
y,
shape=Polygon.from_pointlist([
Vector(+0, -6),
Vector(-5, +6),
Vector(+5, +6),
]),
color=Color(1 * bright, 3 * bright, 2 * bright),
**kwargs,
)
def get_centerpoint(self):
"""Get the center of mass for the polygon"""
xes = [p.x for p in self.points]
yes = [p.y for p in self.points]
return Vector(float(sum(xes)) / len(xes), float(sum(yes)) / len(yes))
def intersect_lineseg_lineseg(p1, p2, q1, q2):
"""Intersect two line segments
@type p1: Vector
@param p1: The first point on the first line segment
@type p2: Vector
@param p2: The second point on the first line segment
@type q1: Vector
@param q1: The first point on the secondline segment
@type q2: Vector
@param q2: The second point on the second line segment
"""
if max(q1.x, q2.x) < min(p1.x, p2.x): return None
if min(q1.x, q2.x) > max(p1.x, p2.x): return None
if max(q1.y, q2.y) < min(p1.y, p2.y): return None
if min(q1.y, q2.y) > max(p1.y, p2.y): return None
ll = __intersect_line_line_u(p1, p2, q1, q2)
if ll == None: return None
if ll[0] < 0 or ll[0] > 1: return None
if ll[1] < 0 or ll[1] > 1: return None
return Vector(p1.x + ll[0] * (p2.x - p1.x), p1.y + ll[0] * (p2.y - p1.y))
def intersect_lineseg_ray(p1, p2, q1, q2):
"""Intersect a line segment and a ray
@type p1: Vector
@param p1: The starting point of the line segment
@type p2: Vector
@param p2: The ending point of the line segment
@type q1: Vector
@param q1: The first point on the ray
@type q2: Vector
@param q2: The second point on the ray
@return: The point of intersection or None
"""
ll = __intersect_line_line_u(p1, p2, q1, q2)
if ll == None: return None
if ll[0] < 0 or ll[0] > 1: return None
if ll[1] < 0: return None
return Vector(p1.x + ll[0] * (p2.x - p1.x), p1.y + ll[0] * (p2.y - p1.y))
def __mul__(self, val):
if isinstance(val, Vector):
x = val.x * self.data[0][0] + val.y * self.data[0][1] + self.data[
0][2]
y = val.x * self.data[1][0] + val.y * self.data[1][1] + self.data[
1][2]
return Vector(x, y)
elif isinstance(val, Transform):
data = [[0 for y in range(3)] for x in range(3)]
for i in range(3):
for j in range(3):
for k in range(3):
data[i][j] += self.data[i][k] * val.data[k][j]
return Transform(data)
elif isinstance(val, Polygon):
p_transform = [self * v for v in val.points]
return Polygon.from_pointlist(p_transform)
else:
raise ValueError("Unknown multiplier: %s" % val)
def from_tuples(tuples):
"""Create a polygon from 2-tuples
@type tuples: List
@param tuples: List of tuples of x,y coordinates
"""
p = Polygon()
p.points = [Vector(t[0], t[1]) for t in tuples]
return p
def find_point_in_poly(pts):
# find point inside of pts according to http://www.exaflop.org/docs/cgafaq/cga2.html#Subject%202.06:%20How%20do%20I%20find%20a%20single%20point%20inside%20a%20simple%20polygonu
# alternative approaches at http://stackoverflow.com/questions/9797448/get-a-point-inside-the-polygon, http://www.dummies.com/how-to/content/how-to-pinpoint-the-center-of-a-triangle.html
def threeways(iterable):
import itertools
args = [iter(iterable)] * 3
return itertools.izip_longest(fillvalue=None, *args)
for a, b, c in threeways(pts):
avgx = sum([each.x for each in (a, b, c)]) / 3.0
avgy = sum([each.y for each in (a, b, c)]) / 3.0
triangle_center = Vector(avgx, avgy)
if Polygon.contains_point_s([a, b, c], triangle_center):
print "triangle", (a, b, c), triangle_center
return triangle_center
def regular(center, radius, points): """Create a regular polygon @type center: Vector @param center: The center point of the polygon @type radius: float @param radius: The radius of the polygon @type points: int @param points: The number of polygon points. 3 will create a triangle, 4 a square, and so on. """ angular_increment = 2 * math.pi / points p = Polygon() for i in range(points): p.add_point( Vector(center.x + radius * math.cos(i * angular_increment), center.y + radius * math.sin(i * angular_increment)) ) return p
def intersect_line_line(p1, p2, q1, q2):
"""Intersect two lines
@type p1: Vector
@param p1: The first point of the first line
@type p2: Vector
@param p2: The second point of the first line
@type q1: Vector
@param q1: The first point of the second line
@type q2: Vector
@param q2: The second point of the second line
@return: The point of intersection or None
"""
ll = __intersect_line_line_u(p1, p2, q1, q2)
if ll == None: return None
return Vector(p1.x + ll[0] * (p2.x - p1.x), p1.y + ll[0] * (p2.y - p1.y))
def contains_point_s(pts, p) : """Checks if the polygon defined by the point list pts contains the point p""" # see if we find a line segment that p is on for a,b in list(zip(pts[0:], pts[1:])) + [(pts[-1], pts[0])]: d = distance_point_lineseg_squared(p, a, b) if d < EPSILON * EPSILON: return 2 # p is not on the boundary, cast ray and intersect to see if we are inside intersections = set(intersect_poly_ray(pts, p, p + Vector(1,0))) # filter intersection points that are boundary points for int_point in filter(lambda x: x in pts, intersections): i = pts.index(int_point) prv = pts[i-1] nxt = pts[(i+1) % len(pts)] if point_orientation(p, int_point, nxt) == point_orientation(p,int_point, prv): intersections.remove(int_point) # we are inside if we have an odd amount of polygon intersections return 1 if len(intersections) % 2 == 1 else 0
def parse_vec(s):
x, y = s.split(",")
return Vector(float(x), float(y))
def convert_element(e, transform):
"""Convert an SVG path element to one or multiple Py2D polygons."""
# get data from the <path> element
id = e.get("id")
d = e.get("d")
#print "CONVERTING %s: %s" % (id, d)
def parse_commands(draw_commands):
"""Generator Function to parse a SVG draw command sequence into command and parameter tuples"""
tokens = draw_commands.split(" ")
while tokens:
# find the next token that is a command
par_index = next(i for i, v in enumerate(tokens[1:] + ["E"])
if re.match('^[a-zA-Z]$', v)) + 1
# first token should always be the command, rest the parameters
cmd = tokens[0]
pars = tokens[1:par_index]
# remove the parsed tokens
del tokens[:par_index]
yield cmd, pars
def parse_vec(s):
x, y = s.split(",")
return Vector(float(x), float(y))
polys = []
verts = []
relative_pos = Vector(0.0, 0.0)
last_control = None
for cmd, pars in parse_commands(d):
#print "cmd: %s, pars: %s" % (cmd, pars)
if cmd == "m" or cmd == "l":
for p in pars:
relative_pos += parse_vec(p)
verts.append(relative_pos)
elif cmd == "M" or cmd == "L":
for p in pars:
relative_pos = parse_vec(p)
verts.append(relative_pos)
elif cmd == "c" or cmd == "C":
# create cubic polybezier
for i in range(0, len(pars), 3):
c1, c2, b = parse_vec(pars[i]), parse_vec(
pars[i + 1]), parse_vec(pars[i + 2])
if cmd == "c":
# convert to relative
c1 += relative_pos
c2 += relative_pos
b += relative_pos
bez = flatten_cubic_bezier(relative_pos, b, c1, c2,
bezier_max_divisions,
bezier_max_flatness)
last_control = c2
relative_pos = b
verts.extend(bez)
elif cmd == "s" or cmd == "S":
# shorthand / smooth cubic polybezier
for i in range(0, len(pars), 2):
c2, b = parse_vec(pars[i]), parse_vec(pars[i + 1])
c1 = relative_pos + (relative_pos - last_control)
if cmd == "s":
# convert to relative
c2 += relative_pos
b += relative_pos
bez = flatten_cubic_bezier(relative_pos, b, c1, c2,
bezier_max_divisions,
bezier_max_flatness)
last_control = c2
relative_pos = b
verts.extend(bez)
elif cmd == "z":
# close line by only moving relative_pos to first vertex
polys.append(transform * Polygon.from_pointlist(verts))
relative_pos = verts[0]
verts = []
else:
warnings.warn(
"Unrecognized SVG path command: %s - path skipped" % cmd)
polys = []
break
if verts:
polys.append(transform * Polygon.from_pointlist(verts))
#print "----"
return id, polys
def get_triangle():
return Polygon.from_pointlist([
Vector(1.1, 2.2),
Vector(3.3, 4.4),
Vector(5.5, 6.6),
])
