How to crop image in powerplant

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4 total messages Started by wall Thu, 09 Oct 2003 09:25

#665

Author: wall
Date: Thu, 09 Oct 2003 09:25

45 lines
2690 bytes

I want to get the image part which I selected in the whole image.

this is the code i worte:

// create the selected rect's size GWorld - theSelectImageGWorld
// the orignal image GWorld - theImageGWorld
LGWorld*	theSelectImageGWorld = NEW LGWorld( theSelectRect,32 );
ThrowIfNil_( theSelectImageGWorld ); 

PixMapHandle	theOPixMapH = ::GetGWorldPixMap(
theImageGWorld->GetMacGWorld() );
PixMapHandle	theSelectPixMapH = ::GetGWorldPixMap(
theSelectImageGWorld->GetMacGWorld() );
Ptr theOBaseAddr = ::GetPixBaseAddr( theOPixMapH );
Ptr theSelectBaseAddr = ::GetPixBaseAddr( theSelectPixMapH );
short  theORowBytes = ::GetPixRowBytes( theOPixMapH );
short  theSelectRowBytes = ::GetPixRowBytes( theSelectPixMapH );

::LockPixels( theOPixMapH );
::LockPixels( theSelectPixMapH );
{
	Ptr		theSrcPtr, theDstPtr;
	for(short theY = mSelRectToImageOrignal.top; theY <=
mSelRectToImageOrignal.bottom; theY++)
	{
		theSrcPtr = theOBaseAddr + theORowBytes * theY;
		theSrcPtr += mSelRectToImageOrignal.left << 2;
		theDstPtr = theSelectBaseAddr + theSelectRowBytes * ( theY -
mSelRectToImageOrignal.top );
		for (short theX = mSelRectToImageOrignal.left; theX <=
mSelRectToImageOrignal.right; theX++)
		{
			* ((long*) theDstPtr) = * ((long*) theSrcPtr);
			theDstPtr += 4;
			theSrcPtr += 4;
		}	
	}		
}
::UnlockPixels( theOPixMapH );
::UnlockPixels( theSelectPixMapH );

who know where is error in this code. because sometime when the code
perform here,project will crash.

sorry, my english is very poor.

Re: How to crop image in powerplant

#666

Author: Jon Summers
Date: Thu, 09 Oct 2003 13:04

23 lines
2318 bytes

in article 7328a61a.0310090125.3fd8c2aa@posting.google.com, wall at
heroin_c@hotmail.com wrote on 09/10/03 7:25 PM:

> who know where is error in this code. because sometime when the code
> perform here,project will crash.

You code crashes writing passed the end of the destination GWorld

off-by-one error /n./
Exceedingly common error induced in many ways, such as by writing <= N
instead of < N. 

fencepost error /n./
A problem with the discrete  equivalent of a boundary condition, often
exhibited in programs by iterative loops.  From the following problem: "If
you build a fence 100 feet long with posts 10 feet apart, how many posts do
you need?" (Either 9 or 11 is a better answer than the obvious 10.)
Fencepost errors come from counting things rather than the spaces between
them.
 
-- 
   jons(AT)vrtools(DOT)invalid

Re: How to crop image in powerplant

#667

Author: wall
Date: Fri, 10 Oct 2003 06:56

2 lines
1304 bytes

if I want to remove red eyes of selected part in the image.
how to do ?

Re: How to crop image in powerplant

#672

Author: Steven Fisher
Date: Mon, 13 Oct 2003 10:59

12 lines
2147 bytes

Jon Summers wrote:

> fencepost error /n./
> A problem with the discrete  equivalent of a boundary condition, often
> exhibited in programs by iterative loops.  From the following problem: "If
> you build a fence 100 feet long with posts 10 feet apart, how many posts do
> you need?" (Either 9 or 11 is a better answer than the obvious 10.)
> Fencepost errors come from counting things rather than the spaces between
> them.

That's a great term for it, Jon. Mind if I ask where you found that 
definition?

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