Game Development Reference
In-Depth Information
The backpack feature gives you easy access to oten-used sprites and scripts. Over ime, you
will probably collect a standard set of objects to place in your backpack and carry with you at
all imes. Think of standard movements and keyboard control scripts; for example, if you build
a series of games or animaions, you might also reuse the same character sprites oten.
Engage thrusters
Now that we have a cannon and some ammo, we can start doing something about those
enemies running free. In this game, we will place cannons on the stage with a mouse click.
The cannons will aim towards the cursor point. So contrary to most Tower Defense games,
you will have to aim at the enemies manually by poining the mouse at them. The cannons
will ire cannonballs automaically.
Like with the targets in the Arillery Game and the enemies in this one, we will script
a base object that spawns clones to muliply the cannons and cannonballs as shown in
the following steps:
1. Click on the cannon sprite in the
Sprites
view and open the
Script
tab.
2. Throw away the script from the previous game by right-clicking and choosing
delete
,
or drag-and-drop the enire script back into the
script block
menu.
3. Start a new script with a
when <green lag> clicked
block.
4. Atach a
forever
loop.
5. Place a
go to <mouse-pointer>
block inside. This will cause the cannon sprite to
always be where the mouse cursor is poining. If your cannon seems to be ofset
from the mouse pointer, check whether its center point is aligned properly.
6. Start another script with a
when this sprite clicked
block.
7. Atach a
create clone of <myself>
block.
8. That's all you need to start placing cannons on the stage.
9. Start a third script with a
when I start as a clone
block to script the created clones.
10. Atach a
go to front
block to make sure the cannons are placed on top of the
other graphics.
11. Add a
forever
loop.
