Physics.py

import pygame
from graphics import load_image
from config import GROUND_HEIGHT

"""Physics.py"""

"""
This file is part of The Last Caturai.

    The Last Caturai is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    The Last Caturai is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Foobar.  If not, see <http://www.gnu.org/licenses/>.
"""

"""Class that implement the physics of particles, such
    as characters, throwing weapons, etc."""

class Physics(pygame.sprite.Sprite):

    def __init__(self, img_path, position):
        super().__init__()
        # measures the change on X and Y
        self.__position_y__, self.__position_x__ = 0, 0
        # Fetch the rectangle object that has the dimensions of the image
        # Update the position of this object by setting the values of rect.x and rect.y
        self.image = load_image(img_path, True)
        self.rect = self.image.get_rect()
        self.position = position
        # speed component of the particle
        self.x_speed_vector_ = 0
        self.y_speed_vector_ = 0
        self.on_ground = True
        self.change_index = 0
        self.direction='D'
        self.index = 0
        self.velocity = 3
        self.world_shift = 0

    # Set the value of the speed vector
    def change_x_speed_vector(self, speed):
        self.x_speed_vector_ = abs(speed)

    # Set the angle of the movement in radians
    def change_y_speed_vector(self, angle):
        self.y_speed_vector_ = angle

    def move_right(self):
        self.direction='D'
        self.x_speed_vector_ = self.velocity
        self.change_index = 1

    def move_left(self):
        self.direction='I'
        self.x_speed_vector_ = -self.velocity
        self.change_index = 1

    def stop_moving(self):
        self.x_speed_vector_ = 0
        self.y_speed_vector_ = 0
        self.change_index = 0

    def gravity(self):
        if self.y_speed_vector_ < 0:
            self.y_speed_vector_ += 1

        else:
            self.y_speed_vector_ += 1
            if self.rect.y >= GROUND_HEIGHT:
                self.y_speed_vector_ = 0
                self.on_ground = True
                self.rect.y = GROUND_HEIGHT

    def update(self):
        self.gravity()

        self.rect.x += self.x_speed_vector_
        self.rect.y += self.y_speed_vector_

        self.index = ((self.rect.x + self.world_shift + self.change_index) // 30) % 2

        self.position = (self.rect.x, self.rect.y)