Patch:Keen (Keen 3)
This page contains patches relating to Keen as a sprite in Keen 3. That is, such things as the sprites used, the speeds and sounds. It does not cover patches relating to gameplay such as those that make levels scroll or change keys. Those can be found at Patch:Gameplay (Keen 3). It is divided into sections relating to the various sprite properties the patches involved. Being fluent with various sprite patch pages will help when working with these patches.
As little is known about Keen, there is less information here than for most sprites. Other related pages are Patch:Game start.
Behaviors with their own pages
Some behaviors are complex enough to have their own pages. The following pages relate to a single behavior of Keen in Keen Vorticons in general:
- Patch:Ice tiles (Keen slipping on ice)]]
- Patch:Keen dying (Vorticons)
- Patch:Keen jumping (Vorticons)
- Patch:Keen on map (Vorticons)
- Patch:Keen pogoing (Vorticons)
- Patch:Keen shooting (Vorticons)
- Patch:Keen's shot (Vorticons)
- Patch:Keen stunned
- Patch:Keen walking (Vorticons)
Keen's behavior is complex since he is the most complex sprite in the game, a lot of it relying on keys pressed and the player. As such only a few of his behaviors can be patched.
There are four references to dead Keen, the first stops the camera from following Dead Keen as he flies up offscreen, changing this to any other value makes the camera follow dead Keen. The second is Dead Keen's behavior. The third is unknown. The fourth stops dead Keen hitting other deadly stuff and dying again,, which could make the game loop forever.
|Patch: Keen 3 in-level|
Some animations of Keens don't need to be specified, since they're animation 0. Sadly these can't easily be patched. Keen does not seem to have a starting animation specified for example. In other cases the number of animation frames used seems to be defined in some manner different to other sprites.
Keen's shooting frames are complex, depending on what keys the player presses different frames can be used. This is all unnecessarily complex, however the 'use space to fire' patch (See Patch:Gameplay (Keen 3).) has the result that only the first set of animations matters.
Some patches are not here but are instead located on more specific pages, such as that for Keen's shot.
|Patch: Keen's animations|
Keen spawns 8 pixels lower than where he is placed, because he is not quite two tiles tall. If Keen's sprite height is changed this should also be changed by the same amount.
|Patch: Keen 3|
These are the sounds the sprite uses. Since almost all of the sounds in the game can be said to be made by or related to Keen, only the sounds the player sprite makes are listed here. Others should be found on their own patch pages such as Patch:Doors (Vorticons) for the door opening sound. Some sounds are missing.
|Patch: Keen 3 sounds|
%patch $7677 $0015W
Keen's collision is especially complex since he must react with nearly all sprite types. As such this is not handled in the way most sprites handle it, but instead what Keen does is read off a list, depending on what the colliding sprite's type is. These are locations in the code to go to. The list starts with the value for type 2 and goes to type 18. This allows you to change what certain sprite types do to Keen, even make up your own code for a sprite.
Each pointer points to a different 'collision' for Keen, so there are multiple collisions, each of which can be patched. Most collisions are exceedingly simple. Simply swapping pointer values can have big effects, for example making the Vortimoms stun Keen.
|Patch: Keen 3|
These are patches that do not fit into any of the above sections.
How closely the screen follows Keen
The screen follows the player by moving when the player is a certain distance from the screen boundary. That is, these patches control how close to the edge of the screen the player can get when not at a level edge. The values are in 256ths of a pixel, which is astonishingly precise. (It is best to round values to the nearest pixels, though all default values are rounded to the nearest tile.) Thus the player must be $3000 or $30 pixels (48 pixels, = 3 tiles) from the top of the screen before the screen moves up.
|Patch: Keen 3|