top-down shooter sample

[Descrates]

import os import sys import math import pygame as pg

CAPTION = "Tank Turret: Mouse" SCREEN_SIZE = (500, 500) BACKGROUND_COLOR = (50, 50, 50) COLOR_KEY = (255, 0, 255)

class Turret(object): """Mouse guided lasers.""" def init(self, location): """Location is an (x,y) coordinate pair.""" self.original_barrel = TURRET.subsurface((0,0,150,150)) self.barrel = self.original_barrel.copy() self.base = TURRET.subsurface((300,0,150,150)) self.rect = self.barrel.get_rect(center=location) self.base_rect = self.rect.copy() self.angle = self.get_angle(pg.mouse.get_pos()) self.speed = 5

def update(self):
    key = pg.key.get_pressed()
    if key[pg.K_RIGHT] or key[pg.K_d]:
        self.rect.x += self.speed
    if key[pg.K_LEFT] or key[pg.K_a]:
        self.rect.x -= self.speed
    if key[pg.K_UP] or key[pg.K_w]:
        self.rect.y -= self.speed
    if key[pg.K_DOWN] or key[pg.K_s]:
        self.rect.y += self.speed

def get_angle(self, mouse):
    """
    Find the new angle between the center of the Turret and the mouse.
    """
    offset = (mouse[1]-self.rect.centery, mouse[0]-self.rect.centerx)
    self.angle = 135-math.degrees(math.atan2(*offset))
    self.barrel = pg.transform.rotate(self.original_barrel, self.angle)
    self.rect = self.barrel.get_rect(center=self.rect.center)

def get_event(self, event, objects):
    """Fire lasers on left click.  Recalculate angle if mouse is moved."""
    if event.type == pg.MOUSEBUTTONDOWN and event.button == 1:
        objects.add(Laser(self.rect.center, self.angle))
    elif event.type == pg.MOUSEMOTION:
        self.get_angle(event.pos)

def draw(self, surface):
    """Draw base and barrel to the target surface."""
    surface.blit(self.base, self.base_rect)
    surface.blit(self.barrel, self.rect)

class Laser(pg.sprite.Sprite): """ A class for our laser projectiles. Using the pygame.sprite.Sprite class this time, though it is just as easily done without it. """ def init(self, location, angle): """ Takes a coordinate pair, and an angle in degrees. These are passed in by the Turret class when the projectile is created. """ pg.sprite.Sprite.init(self) self.original_laser = TURRET.subsurface((150,0,150,150)) self.angle = -math.radians(angle-135) self.image = pg.transform.rotate(self.original_laser, angle) self.rect = self.image.get_rect(center=location) self.move = [self.rect.x, self.rect.y] self.speed_magnitude = 5 self.speed = (self.speed_magnitudemath.cos(self.angle), self.speed_magnitudemath.sin(self.angle)) self.done = False

def update(self, screen_rect):
    """
    Because pygame.Rect's can only hold ints, it is necessary to hold
    the real value of our movement vector in another variable.
    """
    self.move[0] += self.speed[0]
    self.move[1] += self.speed[1]
    self.rect.topleft = self.move
    self.remove(screen_rect)

def remove(self, screen_rect):
    """If the projectile has left the screen, remove it from any Groups."""
    if not self.rect.colliderect(screen_rect):
        self.kill()

class Control(object): """Why so controlling?""" def init(self): """ Prepare necessities; create a Turret; and create a Group for our laser projectiles. """ self.screen = pg.display.get_surface() self.screen_rect = self.screen.get_rect() self.done = False self.clock = pg.time.Clock() self.fps = 60.0 self.keys = pg.key.get_pressed() self.cannon = Turret((250,250)) self.objects = pg.sprite.Group()

def event_loop(self):
    """Events are passed on to the Turret."""
    for event in pg.event.get():
        self.keys = pg.key.get_pressed()
        if event.type == pg.QUIT or self.keys[pg.K_ESCAPE]:
            self.done = True
        self.cannon.get_event(event, self.objects)

def update(self):
    """Update all lasers."""
    self.objects.update(self.screen_rect)
    self.cannon.update()

def draw(self):
    """Draw all elements to the display surface."""
    self.screen.fill(BACKGROUND_COLOR)
    self.cannon.draw(self.screen)
    self.objects.draw(self.screen)

def display_fps(self):
    """Show the program's FPS in the window handle."""
    caption = "{} - FPS: {:.2f}".format(CAPTION, self.clock.get_fps())
    pg.display.set_caption(caption)

def main_loop(self):
    """"Same old story."""
    while not self.done:
        self.event_loop()
        self.update()
        self.draw()
        pg.display.flip()
        self.clock.tick(self.fps)
        self.display_fps()

if name == "main":

os.environ['SDL_VIDEO_CENTERED'] = '1'

pg.init()
pg.display.set_caption(CAPTION)
pg.display.set_mode(SCREEN_SIZE)
TURRET = pg.image.load("turret.png").convert()
TURRET.set_colorkey(COLOR_KEY)
run_it = Control()
run_it.main_loop()
pg.quit()
sys.exit()