physics.py

import math

# Calculate the collision between two objects
def calculate_collision(obj1, obj2):
    if obj1.rect.colliderect(obj2.rect):
        dx = (obj1.rect.centerx - obj2.rect.centerx)
        dy = (obj1.rect.centery - obj2.rect.centery)
        dist = math.sqrt(dx * dx + dy * dy)
        nx = dx / dist
        ny = dy / dist
        
        rel_vel_x = obj1.vel_x - (getattr(obj2, 'vel_x', 0))
        rel_vel_y = obj1.vel_y - (getattr(obj2, 'vel_y', 0))
        rel_vel_normal = rel_vel_x * nx + rel_vel_y * ny
        
        if rel_vel_normal < 0:
            e = 0.5
            impact_speed = -rel_vel_normal * e
            if hasattr(obj1, 'vel_x'):
                obj1.vel_x = impact_speed * nx
                obj1.vel_y = impact_speed * ny
            return True
    return False

# Calculate the damage done to a block by a bird
def calculate_damage(bird, block, impact_velocity):
    base_damage = math.sqrt(impact_velocity[0]**2 + impact_velocity[1]**2) * 0.1
    multiplier = bird.damage_multipliers.get(block.block_type, 1.0)
    return base_damage * multiplier