change extended type
BlitzMax Forums/BlitzMax Programming/change extended type
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If I setup a main character typetype character end type Then extend it with warrior and wizard type warrior extends character end type type wizard extends character end type what if a wizard wants to change classes into a warrior? also is there a way of printing the name of the type? like for example printing the name "Warrior" or "Wizard" from the type name. (Without putting in a field called 'character type' into the type) |
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| You cant. In a case like this, youd be better off making a single "player" type, and having sub "roles" instead. Its almost the same as a "character type" as you call it, but at least you can extend the "roles" all you want. edit: about the name part, you could use an abstract method returning a string, or even Reflection. |
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| thanks for the quick reply you mean with no extending of types? just normal usage like you would use in blitz basic? EDIT= hmm another idea What If I created a character type and then created extra types that contain the "AI" like this type character end type type warrior method attack end method end type type wizard method attack end method end type How could I get a 'character' to use the method attack depending on what kind of character he was? |
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I was thinking something like this:
Type TPlayer
Field Class:TClass
Method Attack()
Class.Attack()
EndMethod
EndType
Type TClass
Method Attack() Abstract
EndType
Type TWizard Extends TClass
Method Attack()
EndMethod
EndType
If you keep all player critical stuff out of the Class types, you could swap them at will. edit: Yep, seems like you had it all figured out already =) |
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| thanks for your help where would the TWarrior fit into the above example? like this? type TWarrior extends TClass method attack() end method end type so how would you actually create a warrior and a wizard? (using the NEW command) I tried doing this but it said 'attack' is not recognized
Graphics 640,480
charlist:TList=CreateList()
w:wizard=New wizard
i:warrior=New warrior
c:char=New char
c.class=w:wizard
c.name="Harry"
ListAddLast charlist,c
c:char=New char
c.class=i:warrior
c.name="Fred"
ListAddLast charlist,c
While Not KeyHit(key_escape)
For c:char=EachIn charlist
attack
Next
End
Flip
Cls
Wend
End
Type Char
Field name$
Field Class:TClass
Method attack()
Class.attack()
EndMethod
EndType
Type TClass
Method attack() Abstract
EndType
Type warrior Extends TClass
Method attack()
Print "swing sword"
EndMethod
EndType
Type wizard Extends TClass
Method attack()
Print "cast spell"
End Method
End Type
EDIT-duh I forgot to put c. before 'attack' |
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| If you will be swapping roles often perhaps consider each player simply has a list (not in the tlist meaning) of legal abilities and actions, and some fields containing their class name/appearance etc. Then not only can you change easily you can also customize abilities. If you want there to be "concrete" class types and not allow the player customization (too much customization can be a bad thing!) then simply be very strict about what abilities can be used with which and the player will never know there aren't distinct class types running under the hood. In my opinion you should extend types when they have very different natures and behaviours. Wizard and warrior might sound different but they are both player types with the ability to walk etc. As an example of what I mean, extending an enemy type into goblin, mage etc wouldn't be a good idea in my opinion. Extending into walkingmonster, flyingmonster etc would. |
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| true, I am very new to OO programming having only used B3D so far. So all advice is welcome |
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Or you could just have a "toWarrior()" method on your Wizard class (and vice versa) which returns a new warrior object and do something like this (myCharacter is of type character, currently representing a wizard instance):myCharacter = myCharacter.toWarrior()Now myCharacter is of type character, but it represents a warrior instead. Whether this is feasible (or even desirable) depends entirely on how your data is modeled - but in the absence of duck typing / dynamic typing, there isn't really much you can do about it. |
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| hmm not sure how that works |
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Type TDOB 'date of birth
Field day:Int, month:Int, year:Int
Method toAge:TAge()
Local age:TAge = New TAge
'code here to convert dob into an age in years
Return age
End Method
End Type
Type TAge 'age in years
Field years:Float 'the years will need to be stored as decimal to get an accurate dob
Method toDOB:TDOB()
Local dob:TDOB = New TDOB
'code here to convert years into dob
Return dob
End Method
End Type
Local age:TAge = New TAge
age.years = 20
Local dob:TDOB = age.toDOB()
Not tested but should show the point, even if it's a trivial example. (Notice a New is not required for the last line). |
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| i hate classes in rpg style game. GURPS says everything |
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| Hm I'm not against the idea of classes as such, but with the same old ones, they do get a bit cliché :) |
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| Czar, the last line: Local dob:TDOB = age.toDOB() dob is a local 'type pointer' but toDOB() function returns a number doesnt it? so it will return an integer which will be incompatible and cause it to not compile? |
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| I agree with Czar Flavius. That's how I'd do it. |
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| Look at the method declaration. The toDOB function is of type TDOB, so the function returns a TDOB object. I forgot some () which I will now put in. Method toDOB:TDOB() If it returned and integer it would be Method toDOB:Int() But in terms of your game I don't think this kind of type conversion would be the best idea. |
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