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zCParser related functions

This Ikarus part provides some useful functions to work with parser, its instances, symbols and stack.

Danger

Remember to always assign an instance to a correct class. If you assign an oCNpc pointer to oCItem class you won't be able to read any data from it.

Implementation

Ikarus.d on GitHub

Initialization

The best way to initialize all Ikarus functions is to call MEM_InitAll() in the Init_Global() initialization function.

Warning

If you want to use Ikarus in Gothic 1, it is best to define your own Init_Global() function and call it from every world initialization function.

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MEM_InitAll();

MEM_ReinitParser

Parser operations are initialized with this function. 

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func void MEM_ReinitParser()

Tip

It's worth noting that MEM_ReinitParser is also invoked by the MEM_InitAll function.

Pointers and instances

MEM_PtrToInst

Returns an instance pointed to by the pointer. If the pointer is null an error is thrown. 

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func MEMINT_HelperClass MEM_PtrToInst(var int ptr)
Parameters
  • var int ptr
    Pointer to return an instance from

Shortcut

In addition there is a function _^ with the same signature and functionality as MEM_PtrToInst. It is used as a shortcut, since the converting pointer to instance is commonly used while working with Ikarus.

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func MEMINT_HelperClass _^ (var int ptr)
Example

Following code 

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var oCNpc her; her = MEM_PtrToInst(heroPtr);
is equivalent to 
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var oCNpc her; her = _^(heroPtr);

MEM_NullToInst

Returns an instance from a null pointer. 

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func MEMINT_HelperClass MEM_NullToInst()

MEM_AssignInst

Takes an instance from a pointer and assigns it to a given instance. If the pointer is null an error is thrown. 

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func void MEM_AssignInst(var int inst, var int ptr)
Parameters
  • var int ptr
    Pointer to assign an instance from
  • var int inst
    Instance to which the pointer will be assigned
Example

Following code 

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var oCNpc inst;
MEM_AssignInst (inst, ptr);
is equivalent to 
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var oCNpc inst;
inst = MEM_PtrToInst(ptr);

MEM_AssignInstNull

Assigns null pointer to a given instance. 

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func void MEM_AssignInstNull(var int inst)
Parameters
  • var int inst
    Instance to which the null pointer will be assigned

MEM_InstToPtr

Returns a pointer to given instance. 

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func int MEM_InstToPtr(var int inst)
Parameters
  • var int inst
    The instance to which the pointer is returned

MEM_InstGetOffset

Alias to MEM_InstToPtr. Returns a pointer to given instance. 

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func int MEM_InstGetOffset(var int inst)
Parameters
  • var int inst
    The instance to which the pointer is returned

MEM_CpyInst

Returns a copy of a given instance 

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func MEMINT_HelperClass MEM_CpyInst(var int inst)
Parameters
  • var int inst
    Instance to copy
example

Following code 

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selfCopy = MEM_CpyInst (self);
is equivalent to 
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selfCopy = MEM_PtrToInst (MEM_InstToPtr (self));

Call function

You don't always know at compile time when you want to call which function. For example, if you want to call the condition function of a mob that the player has in focus, you are at a loss at compile time because you have no idea which mob the player will choose. Ikarus provides a way to call functions based on their name or symbol index. In the example of the mob, the name of the condition function can simply be looked up in the mob.

Note

The functions below also work for externals without any restrictions.

Passing Parameters

If the function to be called has parameters, these must first be placed on the data stack. The parameters must be pushed in the correct order, from left to right.

MEM_PushIntParam

Passes an integer as a parameter to the called function. 

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func void MEM_PushIntParam (var int param)
Parameters
  • var int param
    Integer to pass as a function parameter

MEM_PushInstParam

Passes an instance as a parameter to the called function. 

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func void MEM_PushInstParam (var int inst)
Parameters
  • var int inst
    Instance to pass as a function parameter

MEM_PushStringParam

Passes a string as a parameter to the called function. 

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func void MEM_PushStringParam (var string str)
Parameters
  • var string str
    String to pass as a function parameter

The call

MEM_Call

Calls a function. 

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func void MEM_Call(var func fnc)
Parameters
  • var func fnc
    Function to be called

MEM_CallByID

Calls a function by its ID. 

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func void MEM_CallByID (var int symbID)
Parameters
  • var int symbID
    The ID of the function to be called

MEM_CallByPtr

Calls a function by its pointer. 

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func void MEM_CallByPtr(var int ptr)
Parameters
  • var int ptr
    The pointer of the function to be called

MEM_CallByOffset

Calls a function by its offset. 

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func void MEM_CallByOffset(var int offset)
Parameters
  • var int offset
    The offset of the function to be called

MEM_CallByString

Calls a function by its name. 

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func void MEM_CallByString (var string fnc)
Parameters
  • var string fnc
    The name of the function IN CAPITAL LETTERS.

Return value

If a function has a return value, it should be fetched from the data stack after it is called, otherwise stack overflows can occur under unfavorable circumstances (aside from that, you may simply want the return value because it contains important information).

MEM_PopIntResult

Retrieves an integer returned by the called function. 

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func int MEM_PopIntResult()
Return value

The function returns an integer returned by the previously called script function.

MEM_PopStringResult

Retrieves a daedalus string returned by the called function. 

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func string MEM_PopStringResult()
Return value

The function returns a string returned by the previously called script function.

MEM_PopInstResult

Retrieves an instance returned by the called function. 

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func MEMINT_HelperClass MEM_PopInstResult()
Return value

The function returns an instance returned by the previously called script function.

Function stuff

MEM_GetFuncID

Returns the ID of the given function. 

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func int MEM_GetFuncID(var func fnc)
Parameters
  • var func fnc
    The function whose ID is returned

MEM_GetFuncPtr

Returns the pointer of the given function. 

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func int MEM_GetFuncPtr(var func fnc)
Parameters
  • var func fnc
    The function whose pointer is returned

MEM_GetFuncOffset

Returns the offset of the given function. 

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func int MEM_GetFuncOffset(var func fnc)
Parameters
  • var func fnc
    The function whose offset is returned

MEM_GetFuncIDByOffset

MEM_GetFuncID, but with an offset as a parameter. 

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func int MEM_GetFuncIDByOffset(var int offset)
Parameters
  • var int offset
    Offset of a function whose ID is returned

Return value

The function returns an ID of a function with a given offset.

MEM_ReplaceFunc

Replaces the f1 function with f2 function so if you call the first function, the second function is called. 

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func void MEM_ReplaceFunc(var func f1, var func f2)
Parameters
  • var func f1
    Function to replace
  • var func f2
    Function called instead of f1

Parser stack

MEM_GetFrameBoundary

Returns the address/pointer to the boundary of a stack frame (ESP). 

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func int MEM_GetFrameBoundary()

MEM_GetCallerStackPos

Retrieves the stack position (pop position) of the caller's caller (look at the example for better understanding). 

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func int MEM_GetCallerStackPos()
Return value

The function returns an integer representing the stack position of the caller's caller.

Example

After calling B() from within A(), when MEM_GetCallerStackPos() is invoked in function B(), it retrieves the stack position of the caller's caller, which is function A() in this case. Therefore, the variable adr will contain the stack position of function A(). 

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func void A(){
    B();
};

func void B(){
    int adr; adr = MEM_GetCallerStackPos();
    // Now, 'adr' will contain the stack position of A.
};

MEM_SetCallerStackPos

Sets the stack position (pop position) of the caller's caller. 

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func void MEM_SetCallerStackPos(var int popPos)
Parameters
  • var int popPos
    An integer parameter representing the new stack position of the caller's caller

Get address

MEM_GetAddress_Init

Initializes the MEM_GetIntAddress, MEM_GetFloatAddress and MEM_GetStringAddress functions. 

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func void MEM_GetAddress_Init()

Tip

It's worth noting that MEM_GetAddress_Init is also invoked by the MEM_InitAll function.

MEM_GetIntAddress

Returns an address of a given integer. 

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func int MEM_GetIntAddress(var int i)
Parameters
  • var int i
    Integer whose address is returned

Shortcut

In addition there is a function _@ with the same signature and functionality as MEM_GetIntAddress.

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func int _@(var int i)

MEM_GetFloatAddress

Returns an address of a given daedalus float. 

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func int MEM_GetFloatAddress(var float f)
Parameters
  • var float f
    Float whose address is returned

Shortcut

In addition there is a function _@f with the same signature and functionality as MEM_GetFloatAddress.

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func int _@s(var string s)

MEM_GetStringAddress

Returns an address of a given string. 

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func int MEM_GetStringAddress(var string s)
Parameters
  • var string s
    String whose address is returned

Shortcut

In addition there is a function _@s with the same signature and functionality as MEM_GetStringAddress.

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func int _@s(var string s)

STR_GetAddressInit

Alias to MEM_GetAddress_Init, kept for downward compatibility. 

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func void STR_GetAddressInit()

STR_GetAddress

Function similar to MEM_GetStringAddress. There is a guarantee, that this function works initialized i.e. invokes MEM_GetAddress_Init, but the first time may only return an address of a copy of the string. 

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func int STR_GetAddress(var string str)

Static arrays

Accessing static arrays like this below is very tedious in Daedalus. 

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var int myStaticArray[42];
It is not possible to access myStaticArray[i] with a variable index i, but only with a constant. This changes with the following functions.

Danger

Neither function performs any kind of validity check. If the value passed is not an array or offsets are beyond the boundaries of the array passed, the behavior is undefined.

MEM_InitStatArrs

Initializes static arrays read and write functions. 

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func void MEM_InitStatArrs()

MEM_WriteStatArr

Changes the value at the offset of a static integer-array. 

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func void MEM_WriteStatArr (var int array, var int offset, var int value)
Parameters
  • var int array
    Array which will be edited
  • var int offset
    Array index at which value will be edited
  • var int value
    The new value

MEM_ReadStatArr

Reads the value at the specific offset of a static integer-array. 

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func int MEM_ReadStatArr (var int array, var int offset)
Parameters
  • var int array
    Array to get a value from
  • var int offset
    Array index of the value to return

Return value

The function returns an integer value from the offset of a given static array.

MEM_WriteStatStringArr

Changes the value at the offset of a static string-array. 

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func void MEM_WriteStatStringArr(var string array, var int offset, var string value)
Parameters
  • var string array
    Array which will be edited
  • var int offset
    Array index at which value will be edited
  • var string value
    The new value

MEM_ReadStatStringArr

Reads the value at the specific offset of a static string-array. 

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func string MEM_ReadStatStringArr(var string array, var int offset)
Parameters
  • var string array
    Array to get a value from
  • var int offset
    Array index of the value to return

Return value

The function returns a string form the offset of a given static array.

Parser symbol

MEM_SetCurrParserSymb

Makes currParserSymb point to the symbol of the specified instance. 

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func void MEM_SetCurrParserSymb (var int inst)
Parameters
  • var int inst
    Instance to whose symbol currParserSymb will be set

currParserSymb

An instance representing current parser symbol. 

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INSTANCE currParserSymb (zCPar_Symbol);

MEM_FindParserSymbol

Returns the index of the parser symbol with name inst if such a symbol exists. 

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func int MEM_FindParserSymbol(var string inst)
Parameters
  • var string inst
    Name of the symbol to be found

Return value

The function returns the index of the parser symbol with name inst if such a symbol exists. If non exists, a warning is issued and -1 is returned.

MEM_GetSymbolIndex

Alias to MEM_FindParserSymbol. Returns the index of the parser symbol with name inst if such a symbol exists. 

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func int MEM_GetSymbolIndex(var string inst)
Parameters
  • var string inst
    Name of the symbol to be found

Return value

The function returns the index of the parser symbol with name inst if such a symbol exists. If non exists, a warning is issued and -1 is returned.

MEM_GetParserSymbol

Looks for the parser symbol with the name inst and returns a pointer to the appropriate zCPar_Symbol structure. 

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func int MEM_GetParserSymbol (var string inst)
Parameters
  • var string inst
    Name of the symbol to be found

Return value

The function returns the appropriate zCPar_Symbol structure of the parser symbol with name inst if such a symbol exists. If non exists, a warning is issued and 0 is returned.

MEM_GetSymbol

Alias to MEM_GetParserSymbol. Looks for the parser symbol with the name inst and returns a pointer to the appropriate zCPar_Symbol structure. 

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func int MEM_GetSymbol(var string inst)
Parameters
  • var string inst
    Name of the symbol to be found

Return value

The function returns the appropriate zCPar_Symbol structure of the parser symbol with name inst if such a symbol exists. If non exists, a warning is issued and 0 is returned.

MEM_GetSymbolByIndex

MEM_GetParserSymbol, but with ID (index) as a parameter. 

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func int MEM_GetSymbolByIndex(var int id)
Parameters
  • var string inst
    ID (index) of the symbol to be found

Return value

The function returns the appropriate zCPar_Symbol structure of the parser symbol with name inst if such a symbol exists. If non exists, a warning is issued and 0 is returned.