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Understand how to use Phaser's Arcade physics to add collisions to physics bodies in our game, particularly between the paddle and the ball.
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In the last video,
0:00
we prevented our paddle from going off
screen by adding some physics to it.
0:01
We also gave the ball some movement.
0:06
In this video, we're going to add
some collisions between the ball and
0:09
the paddle.
0:12
This is actually really easy to do
with Phaser In our creates function
0:13
below line 46 where we
set the ball bounce.
0:18
Let's add the following code or
press ENTER then
0:22
type this .physics.add.collider();.
0:27
The collider method in phaser allows us
to add collisions between two objects.
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Now, we can pass the two objects we want
to collide as arguments in the collider
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method.
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Since we want the ball to collide with the
paddle, we can pass them in as arguments.
0:43
So in the parentheses on line 47,
let's add the code (ball,paddle).
0:49
And that's it.
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Let's see what this does in the browser.
0:57
When we press space to launch the ball,
the ball hits the top screen boundary,
1:00
then bounces back and it hits the paddle.
1:04
But it doesn't bounce
after it hits the paddle.
1:08
In fact, it pushes the paddle down.
1:10
This is because the physics objects in
phaser are set to moveable by default,
1:13
which means an object can
be moved by another object.
1:18
This is usually okay.
1:23
But for our case, we don't want
the paddle to be moved by the ball.
1:25
Let's fix this in the code in
our create function below line
1:29
41 where we set the paddle
world collider bounds.
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Let's write this code,
will go to the end of line 41.
1:38
Press Enter and
right paddle.setImmovable().
1:42
The set immovable method
will make sure the paddle
1:49
doesn't move when it gets hit by the ball.
1:52
Let's test this in the browser.
1:56
Now when we launch the ball, it goes up,
1:58
hits the upper screen boundary,
comes down and hits the paddle, perfect.
2:00
However, if we move the paddle
out of the path of the ball,
2:06
the ball will hit the lower screen
boundary and bounce back up.
2:10
Ideally, we want the ball to move
past the lower screen boundary and
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disappear from the screen.
2:18
This again is really
easy to do with Phaser.
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Let's go ahead and do that in the code.
2:24
In our create function,
below line 48 where we add the collider
2:27
between the ball and the paddle,
let's add this code.
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We're going to press enter and write
2:36
this.physics.world.checkcollision.down=
false.
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This will make sure the ball doesn't
collide with the lower boundary.
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Make sure you've got the spelling
correct on the word check collision.
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Before we test this in the browser,
let's make a few more changes.
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We're going to add some
physics to the bricks so
3:03
that the ball can collide with them.
3:06
Let's scroll down to where
the brick groups are created.
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On line 51, before the word add, let's
add the word physics followed by a dot.
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Then on line 53, let's hit ENTER and
add the property immovable.
3:18
This is a Boolean value, which will set
to true, and this will make the bricks
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immovable, just like the set and
movable method on the paddle.
3:29
Now let's add some code so
that the pool can collide with the bricks.
3:33
At the beginning of line 51,
let's add the code
3:37
const brickGroup = this
will assign our groups
3:42
to a variable then just
below line 60 we'll add
3:47
the code this.physics.add.collider().
3:52
And inside the parentheses we'll give
it two arguments ball and brickGroup.
3:57
Now the ball should be
colliding with the bricks.
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Let's test this in the browser.
4:06
When we launch the ball you'll
see that it hits a brick.
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Then bounces back and can hit the paddle.
4:13
If we move the paddle out of the way,
4:16
the ball will go through the bottom
of the screen and disappear.
4:18
Perfect,our game is
starting to take shape, but
4:22
when we need to make the bricks disappear
once they've been hit by the ball.
4:25
The ball also needs to move at a 45-degree
angle when it's been hit by the brick.
4:31
We'll make all these
changes in the next video.
4:38
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