Problem Set: On Game Update Interval
This section contains a number of selected problems for the On Update Interval section.
It is recommended that you review the problems, and complete a few before moving on to the next section.
Problem #1: Counting Time
Create a variable, ||variables:count||
,
that will store the number of updates that occur.
Set it to 0 to start.
Create an ||game:on game update interval||
event with an interval
of 2000 ms.
In this event, increment ||variables:count||
.
Create another ||game:on game update interval||
event,
with an interval of 5000 ms.
In this event, ||game:splash||
the value of ||variables:count||
to the screen.
Problem #2: Smiles All Around!
Create an ||game:on game update interval||
event with an interval
of 1500 ms.
In this event, create a ||sprites:Sprite||
with an image of a smiley face.
Place the ||sprites:sprite||
in a ||math:random||
position on the screen,
and set it’s ||sprites:lifespan||
to 10000 ms.
Problem #3: Enemies Inbound
Use an ||game:on game update interval||
event with an interval
of 1000 ms to create ||sprites:projectile sprites||
that move
from the left side of the screen to the right side.
Set the initial ||sprites:y position||
for each ||sprites:projectile||
to a ||math:random||
value between 0 and ||scene:screen.height||
.
These ||sprites:projectiles||
can serve as enemies for a player to avoid.
Problem #4: Asteroids!
The ||math:Math.percentChance||
function can be used to generate a
||logic:boolean||
value with a chance of being ||logic:true||
or ||logic:false||
.
This allows for an easy way to introduce a bit of variety into your games,
by introducing ||math:random||
behavior.
When used in a reoccurring event,
||math:Math.percentChance||
can be used to simulate behaviors that occur
on a random interval.
For example, in an ||game:on game update||
event,
the function can be used to cause an action to occur on a given percent of the
||game:updates||
in the game.
Create an ||game:on game update interval||
event that occurs every 300 ms.
In the event, create an asteroid ||sprites:projectile||
with
||math:random||
||sprites:x||
and ||sprites:y||
velocities between
-100 and 100.
Use an ||logic:if||
statement and ||math:Math.percentChance||
to
make the ||sprites:projectile||
be created in only 20 percent of the
||game:updates||
, rather than in each ||game:update||
.