I am developing a 2D shmup (i.e. Aero Fighters) and I was wondering what are the various ways to store a
level. Assuming that enemies are defined in their own xml file, how would you define when an enemy spawns in the level?
Would it be based on time? Updates? Distance?
Currently I do this based on "
level time" (the amount of time the
level is running - pausing doesn't update the time). Here is an example (the serialization was done by XNA):
<?xml version="1.0" encoding="utf-8"?>
<XnaContent xmlns:level="pekalicious.xanor.XanorContentShared.content.
level">
<Asset Type="level:Level">
<Enemies>
<Enemy>
<EnemyType>data/enemies/smallenemy</EnemyType>
<SpawnTime>PT0S</SpawnTime>
<NumberOfSpawns>60</NumberOfSpawns>
<SpawnOffset>PT0.2S</SpawnOffset>
</Enemy>
<Enemy>
<EnemyType>data/enemies/secondenemy</EnemyType>
<SpawnTime>PT0S</SpawnTime>
<NumberOfSpawns>10</NumberOfSpawns>
<SpawnOffset>PT0.5S</SpawnOffset>
</Enemy>
<Enemy>
<EnemyType>data/enemies/secondenemy</EnemyType>
<SpawnTime>PT20S</SpawnTime>
<NumberOfSpawns>10</NumberOfSpawns>
<SpawnOffset>PT0.5S</SpawnOffset>
</Enemy>
<Enemy>
<EnemyType>data/enemies/boss1</EnemyType>
<SpawnTime>PT30S</SpawnTime>
<NumberOfSpawns>1</NumberOfSpawns>
<SpawnOffset>PT0S</SpawnOffset>
</Enemy>
</Enemies>
</Asset>
</XnaContent>
Each Enemy element is basically a wave of specific enemy types. The type is defined in EnemyType while SpawnTime is the "
level time" this wave should appear. NumberOfSpawns and SpawnOffset is the number of enemies that will show up and the time it takes between each spawn respectively.
This could be a good idea or there could be better ones out there. I'm not sure. I would like to see some opinions and ideas.
I have two problems with this: spawning an enemy correctly and creating a
level editor. The
level editor thing is an entirely different problem (which I will probably post in the future :P).
As for spawning correctly, the problem lies in the fact that I have a variable update time and so I need to make sure I don't miss an enemy spawn because the spawn offset is too small, or because the update took a little more time. I kinda fixed it for the most part, but it seems to me that the problem is with how I store the
level.
So, any ideas? Comments?
Thank you in advance.
