Can you give objects String ID's?

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superman3275

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Posted: 9th Feb 2013 06:58

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On every tutorial I've looked up, you create objects and give them an "ID". Coming from C++, this feature seems extremely hard to manage. Objects can't have meaningful names and telling the difference between them is complicated. One work-around is creating a user-defined type which holds the object and accessing the object through the user defined type. However even then, your code quickly gets Messy. Is there any way to give an object a string ID rather than a number?

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TheComet

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Posted: 9th Feb 2013 17:08

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I must question your decision to move to a more primitive language, but that's beside the point.

The easiest option would be to use constants (known as #define in C++):

+ Code Snippet

rem list of objects
#constant PLAYER_OBJECT 1
#constant ENEMY_OBJECT 2

rem later on...

rem make player
load object "player.x", PLAYER_OBJECT

rem make enemy
load object "enemy.x", ENEMY_OBJECT

Unfortunately, DBP doesn't support enumerators or anything fancy like that, so you'll have to manually define each object ID as you go.

The other more complex method would be to make yourself a function that handles a small database of object strings and object IDs. It could be implemented like this:

+ Code Snippet

load object "player.x", AddObject( "PLAYER_OBJECT" )

And later on you would access it like this:

+ Code Snippet

move object getObjectID( "PLAYER_OBJECT" ), 10

The way you implement it is up to you.

TheComet

http://blankflankstudios.tumblr.com/
"ZIP files are such a retarded format!" - Phaelax

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Zotoaster

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Posted: 9th Feb 2013 17:19 Edited at: 9th Feb 2013 17:19

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I made a tutorial a while back that may be of interest to you.

http://forum.thegamecreators.com/?m=forum_view&t=115298&b=1

"everyone forgets a semi-colon sometimes." - Phaelax

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Sergey K

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Posted: 9th Feb 2013 17:27

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type TObjType
    ObjNum as Integer
    ObjName as String
    Inuse as Boolean
endtype
dim ObjList(0) as TObjType
autocam off
move camera -260
sync on
sync rate 60

//ccreating object by name..
make object cube RegisterObjByName("MyCube"),100
make object cube RegisterObjByName("MyCube2"),50

move object up GetObjNumByName("MyCube2"),100
do
    yrotate object GetObjNumByName("MyCube"),object angle y(GetObjNumByName("MyCube"))+1
    yrotate object GetObjNumByName("MyCube2"),object angle y(GetObjNumByName("MyCube2"))-1
    sync
LOOP

//this function will remove that name + object from array database
function DeleteObjectByName(Name as String)
    a as integer
    Name = Lower$(Name)
    for a = 0 to array count(ObjList(0))-1
        if Name = ObjList(a).ObjName
            ObjList(a).InUse = 0
            ObjList(a).ObjName = ""
            ObjList(a).ObjNum = 0
        endif  
    NEXT a
ENDFUNCTION

//it will convert object names to numbers
function GetObjNumByName(Name as String)
    a as integer
    Res as integer
    Res = -1
    Name = Lower$(Name)
    for a = 0 to array count(ObjList(0))-1
        if ObjList(a).InUse = 1
            if Name = ObjList(a).ObjName then Res = ObjList(a).ObjNum : exitfunction Res 
        endif   
    NEXT a
    a = -1
ENDFUNCTION Res

//Registering a new object as object NAME
function RegisterObjByName(Name as String)
a as integer
b as integer
a = FindFreeObject()
b = FindFreeObjType()
if b = -1
    dim ObjList(array count(ObjList(0))+1) as TObjType
    b = array count(ObjList(0))-1
ENDIF
ObjList(b).InUse = 1
ObjList(b).ObjName = Lower$(Name)
ObjList(b).ObjNum = a
endfunction a

//buffer function..
function FindFreeObjType()
    a as integer
    for a = 0 to array count(ObjList(0))-1
        if ObjList(a).Inuse = 0 then exitfunction a
    NEXT a
    a = -1
ENDFUNCTION a

//buffer function
function FindFreeObject()
    a as integer
    a = 0
    repeat
        inc a
    UNTIL object exist(a) = 0
ENDFUNCTION a

+ Code Snippet

type TObjType
    ObjNum as Integer
    ObjName as String
    Inuse as Boolean
endtype
dim ObjList(0) as TObjType
autocam off
move camera -260
sync on
sync rate 60


//ccreating object by name..
make object cube RegisterObjByName("MyCube"),100
make object cube RegisterObjByName("MyCube2"),50

move object up GetObjNumByName("MyCube2"),100
do
    yrotate object GetObjNumByName("MyCube"),object angle y(GetObjNumByName("MyCube"))+1
    yrotate object GetObjNumByName("MyCube2"),object angle y(GetObjNumByName("MyCube2"))-1
    sync
LOOP


//this function will remove that name + object from array database
function DeleteObjectByName(Name as String)
    a as integer
    Name = Lower$(Name)
    for a = 0 to array count(ObjList(0))-1
        if Name = ObjList(a).ObjName
            ObjList(a).InUse = 0
            ObjList(a).ObjName = ""
            ObjList(a).ObjNum = 0
        endif  
    NEXT a
ENDFUNCTION


//it will convert object names to numbers
function GetObjNumByName(Name as String)
    a as integer
    Res as integer
    Res = -1
    Name = Lower$(Name)
    for a = 0 to array count(ObjList(0))-1
        if ObjList(a).InUse = 1
            if Name = ObjList(a).ObjName then Res = ObjList(a).ObjNum : exitfunction Res 
        endif   
    NEXT a
    a = -1
ENDFUNCTION Res


//Registering a new object as object NAME
function RegisterObjByName(Name as String)
a as integer
b as integer
a = FindFreeObject()
b = FindFreeObjType()
if b = -1
    dim ObjList(array count(ObjList(0))+1) as TObjType
    b = array count(ObjList(0))-1
ENDIF
ObjList(b).InUse = 1
ObjList(b).ObjName = Lower$(Name)
ObjList(b).ObjNum = a
endfunction a

//buffer function..
function FindFreeObjType()
    a as integer
    for a = 0 to array count(ObjList(0))-1
        if ObjList(a).Inuse = 0 then exitfunction a
    NEXT a
    a = -1
ENDFUNCTION a

//buffer function
function FindFreeObject()
    a as integer
    a = 0
    repeat
        inc a
    UNTIL object exist(a) = 0
ENDFUNCTION a

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Sasuke

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Posted: 9th Feb 2013 18:26

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Is TheComet's avatar on speed? Looks like at any minute Rainbow Dash is gonna fly through my screen and turn Super Saiyan!

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Sergey K

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Posted: 10th Feb 2013 07:31

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Quote: "Is TheComet's avatar on speed? Looks like at any minute Rainbow Dash is gonna fly through my screen and turn Super Saiyan!"

Turn of the 3D Glasses

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Sph!nx

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Posted: 10th Feb 2013 13:11

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I do this:

+ Code Snippet

global object#

Loading code:

+ Code Snippet

object# = find free object()
load object "object.x", object#

Regards Sph!nx
www.mental-image.net

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Ortu

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Posted: 10th Feb 2013 19:42 Edited at: 10th Feb 2013 19:54

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that just picks an unused number, it doesnt match the object to a name as string in any way, you cant later reference a particular object by 'object#' because that variable will only give you the last object created.

i usually just store the obj number as part of a udt, for meaningful objects, you will need a udt to store a variety of other information anyways. position, state, attributes etc

+ Code Snippet

type charData
   x as float
   y as float
   z as float
   obj as integer
   name as string
endtype

dim chars(0) as charData

you can then iterate the array to process all character objects, or to find a specific one by name

general scene objects like buildings, rocks, trees, etc dont really need names, especially if you do nothing with them beyond loading. for things you need to go back and animate like trees mabye, you can just add them to an array of integers: trees(0) and iterate through by index with no need for names.

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Jambo B

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Posted: 10th Feb 2013 19:56

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If speed is the most important thing in your project, you need to reference object numbers directly, as TheComet says above:

#constant PLAYER_OBJECT 1
#constant ENEMY_OBJECT 2

During compilation, any references to PLAYER_OBJECT, for example, will be replaced with 1.

A call to a function like this:

yrotate object GetObjNum("EnemyShip"),object angle y(GetObjNum("EnemyShip"))+1

will slow your program down because GetObjNum is being executed twice in this single command. If you do this in every iteration of your main loop, for many objects, the speed difference will be noticeable.

HTH,

James

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Ortu

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Posted: 10th Feb 2013 20:10 Edited at: 10th Feb 2013 20:18

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in such a usage you can call the get function once at the start and set to a variable, then you can replace all subsequent calls to the get function with the vriable to speed things up.

+ Code Snippet

   ship = GetObjNum("EnemyShip")
   yrotate object ship,object angle y(ship)+1

better still, by tracking the angle data in a udt, you can also eliminate the call to object angle y and similar for further speed gains

+ Code Snippet

   ship = GetObjIndx("EnemyShip")
   ships(ship).angY = wrapvalue(ships(ship).angY + 1)
   yrotate object ships(ship).obj,ships(ship).angY

while using the constants is faster its really not practical for a large number of objects, and makes the project rather inflexible.

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Sergey K

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Posted: 10th Feb 2013 21:14

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@ Ortu: there is no need to rewrite my reply.

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Ortu

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Posted: 10th Feb 2013 22:15 Edited at: 10th Feb 2013 22:35

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well i hadnt read your reply since it was just a lengthy block of code with no actual reply text to tell what it was about. additionally, i was replying to posts well after yours which were still discussing the subject, as your post didnt settle and end the thread, further discussion is still valid.

edit, sorry i don't mean to bristle, no one is trying to steal your thunder, i'm just here to help the same as you are, my replies to posted questions really had nothing to do with you in any way.

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Chris Tate

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Posted: 10th Feb 2013 22:29 Edited at: 10th Feb 2013 22:31

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@superman3275

You can name your objects with strings like so:

+ Code Snippet

Set Limb Name ObjectID, 0, "Name" // Requires matrix1 utilities in the DLL section of the forums

If you want to create a dictionary (string lookup); you can use one of the following Key/Value pair solutions:

+ Code Snippet

objId = Lua Int("ObjectName") // or Lua Int("Class.Object") - Requires a LUA plugin, ask if you want a recommendation

or

+ Code Snippet

objId = IntVal( Lookup$( LookupID, "Group/Object", "0" ) ) // Last parameter is default. Requires Matrix1

or

+ Code Snippet

objId = EVALUATE EXPRESSION("ObjectName") // requires styx

Like with all dictionary references they will be slower than direct ones. DBPRO does not have a dictionary system, so you have to make one if it is important. Frankly, I can't see the problem with simply using UDTs to store object references. If you are using a good IDE like Indigo, then organizing objects into types and autocompleting references should be straight forward.

@Sph!nx

Quote: "object# = find free object()
load object "object.x", object#"

You should use integers or DWords for IDs; an object ID does not need a decimal point, and the conversion will slow things down

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Ortu

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Posted: 10th Feb 2013 22:40

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Quote: "You can name your objects with strings like so: "

neat! ive worked with limb names like handR to glue a weapon but never thought of naming limb 0 for the object as a whole

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DarkBASIC Professional Discussion / Can you give objects String ID's?