def __init__(self, verts, direction, lin_speed=0.0, rot_speed=0.0,
pos=Vector(0, 0), rot=0.0, scale=1.0):
"""Creates a new Entity
Args:
verts: the vertices defining the shape of the entity
direction: the direction of the entity
lin_speed: the linear speed of the entity
rot_speed: the rotational speed of the entity
pos: the position of the entity
rot: the rotation of the entity (in degrees)
scale: the scale of the entity
Returns:
a new Entity
"""
self._shape = Shape(verts, pos, rot, scale)
self.pos = pos
self.rot = rot
self.scale = scale
self.lin_speed = lin_speed
self.rot_speed = rot_speed
self._direction = direction.normalize()
class Entity(object):
"""Base class for defining an entity in the
game (such as a ship, asteroid, etc.)
The Entity class is a base class for all the objects in
the game, including the player, the asteroids, and anything
else. It is defined graphically by a shape. The class also
stores the current position, rotation, and scale of the objects
which are used when it is drawn to the screen, as well as a
direction vector which defines where the entity is pointing.
Attributes:
_shape: the shape graphically defining the entity
pos: the position of the entity
rot: the rotation of the entity (in degrees)
scale: the scale of the entity
lin_speed: the linear speed of the entity
rot_speed: the rotational speed of the entity
_direction: the direction of the entity (used for movement)
"""
def __init__(self, verts, direction, lin_speed=0.0, rot_speed=0.0,
pos=Vector(0, 0), rot=0.0, scale=1.0):
"""Creates a new Entity
Args:
verts: the vertices defining the shape of the entity
direction: the direction of the entity
lin_speed: the linear speed of the entity
rot_speed: the rotational speed of the entity
pos: the position of the entity
rot: the rotation of the entity (in degrees)
scale: the scale of the entity
Returns:
a new Entity
"""
self._shape = Shape(verts, pos, rot, scale)
self.pos = pos
self.rot = rot
self.scale = scale
self.lin_speed = lin_speed
self.rot_speed = rot_speed
self._direction = direction.normalize()
def update(self, dt):
"""Updates the entity's shape
Args:
dt: the amount of time since the last update
window: the game window
"""
# Move and rotate the entity
self.pos += self._direction * self.lin_speed
self.rot += self.rot_speed
self.rot = wrap_angle(self.rot)
# Set new values
self._shape.update(self.pos, self.rot, self.scale)
# Reflect across the screen, if necessary
self._reflect_across_screen()
def draw(self):
"""Draws the entity onto the screen
"""
# Defer this to the shape
self._shape.draw()
def collides(self, other):
"""Checks whether this entity collides with another one
Args:
other: the other entity to test collision with
Returns:
True if the entities collide, False if they do not
"""
return self._shape.collides(other._shape)
def _reflect_across_screen(self):
"""Checks if the entity needs to be reflected across the
screen and generates a new position if it does
"""
# Start with the current position
new_pos = Vector(self.pos.x, self.pos.y)
# For each side of the screen, check if the entity has
# exceeded the bounds using the approximate length
# Check horizontal
# Left-side
if (self.pos.x + self._shape.effective_length < 0):
dist = abs(0 - (self.pos.x + self._shape.effective_length))
new_pos.x = WINDOW_WIDTH + dist
# Right-side
elif (self.pos.x - self._shape.effective_length > WINDOW_WIDTH):
dist = abs((self.pos.x - self._shape.effective_length) -
WINDOW_WIDTH)
new_pos.x = -dist
# Check vertical
# Bottom
if (self.pos.y + self._shape.effective_length < 0):
dist = abs(0 - (self.pos.y + self._shape.effective_length))
new_pos.y = WINDOW_HEIGHT + dist
# Top
elif (self.pos.y - self._shape.effective_length > WINDOW_HEIGHT):
dist = abs((self.pos.y - self._shape.effective_length) -
WINDOW_HEIGHT)
new_pos.y = -dist
# Set the new position of the entity.
# If no reflection was needed, it's just the original position
self.pos = new_pos
# Direction stored as a property to ensure normalization
@property
def direction(self):
return self._direction
@direction.setter
def direction(self, value):
self._direction = value.normalize()
def __init__(self, size, datum=Datum()):
Shape.__init__(self, size, datum)
self.shape = 'circle'
self.radius = self.radius()
