Pascal and Delphi

C++ to Delphi conversion

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Join Date: Nov 2009

Posts: 3

Reputation: MorrisL is an unknown quantity at this point

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MorrisL

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C++ to Delphi conversion

Nov 13th, 2009

I am trying to convert a piece of code into Delphi but fall down when it comes to this example :

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Pascal and Delphi Syntax (Toggle Plain Text)

void __stdcall GetBuffers( short **xBuffers, unsigned long nValues)
{
.......
memcpy(TargetA, xBuffers[0], nValues * sizeof(short));
memcpy(TargetB, xBuffers[1], nValues * sizeof(short));
memcpy(TargetC, xBuffers[3], nValues * sizeof(short));
memcpy(Targetd, xBuffers[4], nValues * sizeof(short));
}

Could you please help

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Join Date: Oct 2009

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Reputation: cao is an unknown quantity at this point

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cao

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Nov 13th, 2009

MemCpy (Destination, Source, Num)
destination - Pointer to the destination array where the content is to be copied
source - Pointer to the source of data to be copied
num - Number of bytes to copy.

Delphi
procedure Move(const Source; var Dest; Count: Integer);

Move(Source, Destination, SizeOf(Destinaton)); { SizeOf = safety! }

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Join Date: Nov 2009

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Reputation: MorrisL is an unknown quantity at this point

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MorrisL

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Clarification

Nov 13th, 2009

I am sorry for not being clear. It is not the moving that I have a problem with but the de-referencing of **xBuffers to xBuffers[0] to xBuffers[3]

Last edited by MorrisL; Nov 13th, 2009 at 10:15 am.

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Join Date: Nov 2009

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Reputation: BitFarmer is an unknown quantity at this point

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BitFarmer

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Nov 17th, 2009

If I am right, **ptr is a pointer to an array of pointers to short integers... in delphi it is not used like this (thanks, Lord!).

If you know the lengths of the arrays when coding:

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 Pascal and Delphi Syntax (Toggle Plain Text) 
var a: array[0..10, 0..20] of short;
var a: array[0..10, 0..20] of short;

Then you pass a as paramter, and use a[0] as the first pointer, a[1]... etc.

If the lengths are not know (as i suppose), you just make this:

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a: array of array of short;
a: array of array of short;

And in the code, to set the lengths:

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 Pascal and Delphi Syntax (Toggle Plain Text) 
SetLength(a, 10); //10 pointers to arrays of shorts;
for i:= Low(a) to High(a) do
  SetLength(a[i], 20); //Each one with 20 elements (could be different for each array)
SetLength(a, 10); //10 pointers to arrays of shorts;
for i:= Low(a) to High(a) do
  SetLength(a[i], 20); //Each one with 20 elements (could be different for each array)