4. Copy Datatype

Copy Datatype

  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 19/05/2009 at 08:28, xxxxxxxx wrote:

    User Information:
    Cinema 4D Version:   11 
    Platform:   Windows  ;   Mac OSX  ; 
    Language(s) :     C++  ;

    ---------
    Hi,

    i have a basic problem with my datatype.
    I have overwritten the "=" - operator and want to write something like this.

    TestType a;
    TestType b = a;
    b //do something..

    My problem is, that Cinema treats them like pointers.
    So if i change b, a will be changed to.
    The Cinema "default" =-operator does the same. I thought it could be the CopyData-function, but it's not called from Cinema in this case.

    I hope you can help me.

    Thanks,

    Oli

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  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 19/05/2009 at 10:19, xxxxxxxx wrote:

    How is the operator defined? Definition should look something like this:

    > YourType& operator=(const YourType& src);

    And the implementation should look like this then:

    > YourType& YourType::operator =(const YourType& src) \> { \>      //Do Something with YourType data \>      return \*this; \> }

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  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 20/05/2009 at 01:51, xxxxxxxx wrote:

    So it is.
    Here the operator.

    > AixGeometry& AixGeometry::operator=(const AixGeometry& src){ \> \>      if(this == &src;){ \>            \>           return \*this; \>      } \>       \>         //Allocate memory Points \>      GeFree(this->pointArray); \>      this->pointArray = NULL; \>      this->pointArray = (AixPoint\* ) GeAlloc(sizeof(AixPoint) \* src.pointArraySize); \>       \>      this->pointArraySize = src.pointArraySize; \>       \>         //Allocate memory lines \>      GeFree(this->lineArray); \>      this->lineArray = NULL; \>      this->lineArray = (AixNline\* ) GeAlloc(sizeof(AixNline) \* src.lineArraySize); \>       \>      this->lineArraySize = src.lineArraySize; \>       \>      //Allocate memory Ngons \>      GeFree(this->ngonArray); \>      this->ngonArray = NULL; \>      this->ngonArray = (AixNgon\* ) GeAlloc(sizeof(AixNgon) \* src.ngonArraySize); \>       \>      this->ngonArraySize = src.ngonArraySize; \>       \>      //Points \>      for(LONG i = 0; i < src.pointArraySize - 1; i++){ \>            \>           this->pointArray[i] = src.pointArray[i]; \>      } \>       \>      //Lines \>      for(LONG l = 0; l < src.lineArraySize - 1; l++){ \>            \>           this->lineArray[l] = src.lineArray[l]; \>      } \>       \>      //Ngons \>      for(LONG j = 0; j < src.ngonArraySize - 1; j++){ \>            \>           this->ngonArray[j] = src.ngonArray[j]; \>      } \>            \>      //dirtyCount \>      this->dirtyCount = src.dirtyCount; \>       \>      this->additionalAttributes = src.additionalAttributes; \> \>      return \*this; \> }

    But if i comment it out, Cinema builds its own =operator internally, which does the same garbage :-).

    I have tried to write my DataType into GeData, copy the GeData into an other with its copy-function and read out the copied GeData. This doesn't work too.

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  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 20/05/2009 at 02:53, xxxxxxxx wrote:

    Did you try to pass the reference as a = *b; ?

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  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 20/05/2009 at 03:46, xxxxxxxx wrote:

    Ok this is funny.
    I have found a line in my code where i wrote something like this.

    AixGeometry cubeCache = *defaultCube; //defaultCube is a pointer on an    
                                                                              //AixGeometry

    In this case it seems to work correct. But why it doesn't work if i have two "concrete" AixGeometries.

    AixGeometry a;
    AixGeometry b;

    b = a;

    Is it not the same as b = *a if a is a pointer (AixGeometry* a)?

    Thanks,

    Oli

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  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 20/05/2009 at 07:48, xxxxxxxx wrote:

    Ok, i found another line where a = *b doesn't work :-(.
    I have written a copy-constructor with the same success. It can't be mere chance, that the function one time does it's work and one time not.

    I' m glad about every idea i get.

    cheers,

    Oli

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  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 20/05/2009 at 11:56, xxxxxxxx wrote:

    Do you have a copy constructer defined in your AixGeometry class?

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  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 25/05/2009 at 01:56, xxxxxxxx wrote:

    Hi,

    yes, i have tried this too. But no chance; same garbage.

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  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 25/05/2009 at 02:46, xxxxxxxx wrote:

    Actually the assignment operator must be called as a.operator=(b) is called in the case of a = b.

    But if you have both defined (you should have both defined), an explicit copy constructor and an assignment operator, the only chance (cause I don´t know the structure of the full class you have there) you should in the end try a copy assignment operator, to avoid shallow copying.

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  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 26/05/2009 at 02:26, xxxxxxxx wrote:

    So, i have tried this too; without success. I have also compared the memory-adresses - all correct. So i have to search anywhere else in my code.

    Thanks for your help,

    Oli

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  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 26/05/2009 at 02:30, xxxxxxxx wrote:

    hmm, then I really have no other idea either. :-/ I am curious in knowing the solution to your problem if you find out.

    Good luck

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  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 26/05/2009 at 06:16, xxxxxxxx wrote:

    I got it :-).
    AixGeometry works like a container for the other datatypes (points, lines etc). In one of them i have commented out the operator= not so long ago to debug something.

    So I summarise.
    To make deep copies of your datatype(s), you need the CopyData-function of each datatype, the operator= and the copyconstructor.
    If one of the last two functions doesn't exist, Cinema only makes a shallow copy.

    So thanks for your help,

    cheers Oli

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  • H

    THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

    On 26/05/2009 at 06:19, xxxxxxxx wrote:

    ah there you go. Glad you finally worked it out. The good ol power of three. :)

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