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Update boing.py

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ryanlambie 2020-04-21 10:47:48 +01:00
parent 672be494cc
commit 8f512966f2
1 changed files with 8 additions and 8 deletions
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boing-master/boing.py
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@ -89,7 +89,7 @@ class Ball(Actor):
# The centre of each bat is 40 pixels from the edge of the screen, or to put it another way, 360 pixels
# from the centre of the screen. The bat is 18 pixels wide and the ball is 14 pixels wide. Given that these
# sprites are anchored from their centres, when determining if they overlap or touch, we need to look at
# their half-widths – 9 and 7. Therefore, if the centre of the ball is 344 pixels from the centre of the
# their half-widths - 9 and 7. Therefore, if the centre of the ball is 344 pixels from the centre of the
# screen, it can bounce off a bat (assuming the bat is in the right position on the Y axis - checked
# shortly afterwards).
# We also check the previous X position to ensure that this is the first frame in which the ball crossed the threshold.
@ -117,7 +117,7 @@ class Ball(Actor):
# and 2 metres per second down. Imagine this is taking place in space, so gravity isn't a factor.
# After the ball hits the bat, it's still going to be moving at 2 m/s down, but it's now going to be
# moving 1 m/s to the left instead of right. So its speed on the y-axis hasn't changed, but its
# direction on the x-axis has been reversed. This is extremely easy to code – "self.dx = -self.dx".
# direction on the x-axis has been reversed. This is extremely easy to code - "self.dx = -self.dx".
# However, games don't have to perfectly reflect reality.
# In Pong, hitting the ball with the upper or lower parts of the bat would make it bounce diagonally
# upwards or downwards respectively. This gives the player a degree of control over where the ball
@ -203,7 +203,7 @@ class Bat(Actor):
# Each bat has a timer which starts at zero and counts down by one every frame. When a player concedes a point,
# their timer is set to 20, which causes the bat to display a different animation frame. It is also used to
# decide when to create a new ball in the centre of the screen – see comments in Game.update for more on this.
# decide when to create a new ball in the centre of the screen - see comments in Game.update for more on this.
# Finally, it is used in Game.draw to determine when to display a visual effect over the top of the background
self.timer = 0
@ -244,11 +244,11 @@ class Bat(Actor):
# If the ball is close, we want to move towards its position on the Y axis. We also apply a small offset which
# is randomly generated each time the ball bounces. This is to make the computer player slightly less robotic
# – a human player wouldn't be able to hit the ball right in the centre of the bat each time.
# - a human player wouldn't be able to hit the ball right in the centre of the bat each time.
target_y_2 = game.ball.y + game.ai_offset
# The final step is to work out the actual Y position we want to move towards. We use what's called a weighted
# average – taking the average of the two target Y positions we've previously calculated, but shifting the
# average - taking the average of the two target Y positions we've previously calculated, but shifting the
# balance towards one or the other depending on how far away the ball is. If the ball is more than 400 pixels
# (half the screen width) away on the X axis, our target will be half the screen height (target_y_1). If the
# ball is at the same position as us on the X axis, our target will be target_y_2. If it's 200 pixels away,
@ -274,7 +274,7 @@ class Game:
self.ball = Ball(-1)
# Create an empty list which will later store the details of currently playing impact
# animations – these are displayed for a short time every time the ball bounces
# animations - these are displayed for a short time every time the ball bounces
self.impacts = []
# Add an offset to the AI player's target Y position, so it won't aim to hit the ball exactly
@ -327,8 +327,8 @@ class Game:
if self.bats[p].timer > 0 and game.ball.out():
screen.blit("effect" + str(p), (0,0))
# Draw bats, ball and impact effects – in that order. Square brackets are needed around the ball because
# it's just an object, whereas the other two are lists – and you can't directly join an object onto a
# Draw bats, ball and impact effects - in that order. Square brackets are needed around the ball because
# it's just an object, whereas the other two are lists - and you can't directly join an object onto a
# list without first putting it in a list
for obj in self.bats + [self.ball] + self.impacts:
obj.draw()