Source code for arcade.physics_engines

"""
Physics engines for top-down or platformers.
"""
# pylint: disable=too-many-arguments, too-many-locals, too-few-public-methods

from arcade.geometry import check_for_collision_with_list
from arcade.geometry import check_for_collision
from arcade.sprite import Sprite
from arcade.sprite_list import SpriteList


[docs]class PhysicsEngineSimple: """ This class will move everything, and take care of collisions. """ def __init__(self, player_sprite: Sprite, walls: SpriteList): """ Constructor. """ assert(isinstance(player_sprite, Sprite)) assert(isinstance(walls, SpriteList)) self.player_sprite = player_sprite self.walls = walls
[docs] def update(self): """ Move everything and resolve collisions. """ # --- Move in the x direction self.player_sprite.center_x += self.player_sprite.change_x # Check for wall hit hit_list = \ check_for_collision_with_list(self.player_sprite, self.walls) # If we hit a wall, move so the edges are at the same point if len(hit_list) > 0: if self.player_sprite.change_x > 0: for item in hit_list: self.player_sprite.right = min(item.left, self.player_sprite.right) elif self.player_sprite.change_x < 0: for item in hit_list: self.player_sprite.left = max(item.right, self.player_sprite.left) else: print("Error, collision while player wasn't moving.") # --- Move in the y direction self.player_sprite.center_y += self.player_sprite.change_y # Check for wall hit hit_list = \ check_for_collision_with_list(self.player_sprite, self.walls) # If we hit a wall, move so the edges are at the same point if len(hit_list) > 0: if self.player_sprite.change_y > 0: for item in hit_list: self.player_sprite.top = min(item.bottom, self.player_sprite.top) elif self.player_sprite.change_y < 0: for item in hit_list: self.player_sprite.bottom = max(item.top, self.player_sprite.bottom) else: print("Error, collision while player wasn't moving.")
[docs]class PhysicsEnginePlatformer: """ This class will move everything, and take care of collisions. """ def __init__(self, player_sprite: Sprite, platforms: SpriteList, gravity_constant: float = 0.5): """ Constructor. """ self.player_sprite = player_sprite self.platforms = platforms self.gravity_constant = gravity_constant
[docs] def can_jump(self) -> bool: """ Method that looks to see if there is a floor under the player_sprite. If there is a floor, the player can jump and we return a True. """ # --- Move in the y direction self.player_sprite.center_y -= 2 # Check for wall hit hit_list = \ check_for_collision_with_list(self.player_sprite, self.platforms) self.player_sprite.center_y += 2 if len(hit_list) > 0: return True else: return False
[docs] def update(self): """ Move everything and resolve collisions. """ # print(f"Spot A ({self.player_sprite.center_x}, {self.player_sprite.center_y})") # --- Add gravity self.player_sprite.change_y -= self.gravity_constant # --- Move in the y direction self.player_sprite.center_y += self.player_sprite.change_y # Check for wall hit hit_list = check_for_collision_with_list(self.player_sprite, self.platforms) # If we hit a wall, move so the edges are at the same point if len(hit_list) > 0: if self.player_sprite.change_y > 0: for item in hit_list: self.player_sprite.top = min(item.bottom, self.player_sprite.top) # print(f"Spot X ({self.player_sprite.center_x}, {self.player_sprite.center_y})") elif self.player_sprite.change_y < 0: for item in hit_list: while check_for_collision(self.player_sprite, item): # self.player_sprite.bottom = item.top <- Doesn't work for ramps self.player_sprite.bottom += 0.25 if item.change_x != 0: self.player_sprite.center_x += item.change_x # print(f"Spot Y ({self.player_sprite.center_x}, {self.player_sprite.center_y})") else: pass # TODO: The code below can't execute, as "item" doesn't # exist. In theory, this condition should never be arrived at. # Collision while player wasn't moving, most likely # moving platform. # if self.player_sprite.center_y >= item.center_y: # self.player_sprite.bottom = item.top # else: # self.player_sprite.top = item.bottom self.player_sprite.change_y = min(0.0, hit_list[0].change_y) # print(f"Spot B ({self.player_sprite.center_x}, {self.player_sprite.center_y})") self.player_sprite.center_y = round(self.player_sprite.center_y, 2) # print(f"Spot Q ({self.player_sprite.center_x}, {self.player_sprite.center_y})") # --- Move in the x direction self.player_sprite.center_x += self.player_sprite.change_x check_again = True while check_again: check_again = False # Check for wall hit hit_list = check_for_collision_with_list(self.player_sprite, self.platforms) # If we hit a wall, move so the edges are at the same point if len(hit_list) > 0: change_x = self.player_sprite.change_x if change_x > 0: for item in hit_list: # print(f"Spot 1 ({self.player_sprite.center_x}, {self.player_sprite.center_y})") # See if we can "run up" a ramp self.player_sprite.center_y += change_x if len(check_for_collision_with_list(self.player_sprite, self.platforms)) > 0: self.player_sprite.center_y -= change_x self.player_sprite.right = min(item.left, self.player_sprite.right) # print(f"Spot R ({self.player_sprite.center_x}, {self.player_sprite.center_y})") check_again = True break # else: # print("Run up ok 1") # print(f"Spot 2 ({self.player_sprite.center_x}, {self.player_sprite.center_y})") elif change_x < 0: for item in hit_list: # See if we can "run up" a ramp self.player_sprite.center_y -= change_x if len(check_for_collision_with_list(self.player_sprite, self.platforms)) > 0: # Can't run up the ramp, reverse self.player_sprite.center_y += change_x self.player_sprite.left = max(item.right, self.player_sprite.left) # print(f"Reverse 1 {item.right}, {self.player_sprite.left}") # Ok, if we were shoved back to the right, we need to check this whole thing again. check_again = True break # print(f"Spot 4 ({self.player_sprite.center_x}, {self.player_sprite.center_y})") else: print("Error, collision while player wasn't moving.\n" "Make sure you aren't calling multiple updates, like " "a physics engine update and an all sprites list update.") # print(f"Spot E ({self.player_sprite.center_x}, {self.player_sprite.center_y})") for platform in self.platforms: if platform.change_x != 0 or platform.change_y != 0: platform.center_x += platform.change_x if platform.boundary_left is not None \ and platform.left <= platform.boundary_left: platform.left = platform.boundary_left if platform.change_x < 0: platform.change_x *= -1 if platform.boundary_right is not None \ and platform.right >= platform.boundary_right: platform.right = platform.boundary_right if platform.change_x > 0: platform.change_x *= -1 if check_for_collision(self.player_sprite, platform): if platform.change_x < 0: self.player_sprite.right = platform.left if platform.change_x > 0: self.player_sprite.left = platform.right platform.center_y += platform.change_y if platform.boundary_top is not None \ and platform.top >= platform.boundary_top: platform.top = platform.boundary_top if platform.change_y > 0: platform.change_y *= -1 if platform.boundary_bottom is not None \ and platform.bottom <= platform.boundary_bottom: platform.bottom = platform.boundary_bottom if platform.change_y < 0: platform.change_y *= -1
# self.player_sprite.center_x = round(self.player_sprite.center_x, 2) # print(f"Spot C ({self.player_sprite.center_x}, {self.player_sprite.center_y})") # print()