Step 9 of 12

Write player.py and draw Bob

Time to make Bob. Open bobgame/player.py

import pygame

from .settings import (
    ARROW_COLOR, BOB_RADIUS, BOB_SPEED, HAIR_COLOR, HEIGHT, SKIN_COLOR, WIDTH,
)


class Bob:
    def __init__(self) -> None:
        self.pos = pygame.Vector2(WIDTH / 2, HEIGHT / 2)
        self.facing = pygame.Vector2(0, -1)

    def draw(self, surface: pygame.Surface) -> None:
        center = (round(self.pos.x), round(self.pos.y))
        pygame.draw.circle(surface, SKIN_COLOR, center, BOB_RADIUS)
        # Hair: ring around the head plus a cap on the back half.
        pygame.draw.circle(surface, HAIR_COLOR, center, BOB_RADIUS, 4)
        back = self.pos - self.facing * (BOB_RADIUS * 0.35)
        pygame.draw.circle(
            surface, HAIR_COLOR, (round(back.x), round(back.y)), BOB_RADIUS * 0.6
        )

Bob is another class, another blueprint.

• self.pos is Bob's position. A Vector2 is a pair of numbers, x (how far across) and y (how far down). In games, (0, 0) is the top-left corner and y gets bigger as you go down, which is the opposite of the maths you do at school. We start Bob in the middle of the window, WIDTH / 2 across and HEIGHT / 2 down.
• self.facing is the direction Bob looks. It is also a Vector2, but this time think of it as an arrow with a length of 1 that points somewhere. (0, -1) means 0 across and 1 up (remember, up is negative), so he starts looking at the top of the screen.
• draw paints Bob onto a surface (the canvas, in our case the window). pygame.draw.circle takes a canvas, a colour, a centre and a size.
• First we draw a skin coloured circle. Then we draw a hair coloured circle with a 4 on the end, which means "only draw the outline, 4 pixels thick". That gives a ring of hair. Lastly we draw a smaller hair circle slightly towards Bob's back. We find that spot by going from his centre in the opposite direction (the minus sign) of where he faces. From above, it looks like he has hair on the back of his head.
• round(...) turns a decimal like 400.4 into a whole number, because pixels can't be cut in half.

Now we need the game to make a Bob and draw him. Change game.py in three places

from .player import Bob

add that near the top, below import pygame. Then in __init__ add one line

        self.bob = Bob()

below self.clock = .... And in step draw him after the background is painted

        self.screen.fill(BG_COLOR)
        self.bob.draw(self.screen)
        pygame.display.flip()

The order matters. If we drew Bob first and then painted the background, we'd cover him up!

Run it again. You should see a round head with hair in the middle of the window. He's not moving yet, so let's fix that.