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On 11/11/2012 9:25 AM, Even Rouault wrote:
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<pre wrap="">The value of a new function is code clarity. It's not just computing
pData, it's that the nBufXSize and nBufYSize become the size of the
cropped region, not the size of the actual buffer,
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I don't understand what you mean, sorry. Perhaps you should show the code. I
understand that better than English ;-)</pre>
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No problem - your English is a whole lot better than my French :-)<br>
<blockquote><font face="Courier New, Courier, monospace">GDALRasterBand::WriteCropToBand(int
nCropSizeX, // width of the cropped region<br>
int nCropSizeY, // height of the
cropped region<br>
int nXOffset, // offset to the
left edge of the cropped region<br>
int nYOffset, // offset to the
top of the cropped region<br>
void * pBuf, // pointer to
the buffer (uncropped)<br>
GDALDataType eBufType, // data
type in the buffer<br>
int nPixelSpace, // byte offset
from one pixel to the next<br>
int nLineSpace) // byte offset
from one line to the next<br>
{<br>
void * pData = pBuf + nYOffset * nLineSpace + nXOffset *
nPixelSpace;<br>
this->RasterIO(GF_Write, 0, 0, this->nRasterXSize,
this->nRasterYSize, <br>
pData, nCropSizeX, nCropSizeY, eBuftype,
nPixelSpace, nLineSpace);<br>
}</font><br>
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The code is obviously not very complicated. The value is that when
you're reading code you can tell immediately that what's happening
is the buffer is being cropped and written. If written directly in
terms of RasterIO the intent is buried in the computation of the
parameters, making it less clear.<br>
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<pre wrap="">Not sure to understand that. The presence of nBufXSize, nBufYsize in your
proposal allows subsampling/oversampling. Perhaps you meant something
else with decimation/replication ?
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You're right. nPixelSpace and nLineSpace now become required, no
default values will work.
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Not understanding that either.</pre>
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Sorry, not very clear. I agree that nBufXSize, nBufYSize are no
longer necessary - they are read from the class variables. We could
leave these vars in and continue to support decimation replication,
I suppose. <br>
My comment about nPixelSpace, nLineSpace is that these will have to
be supplied, because we count on them to step through the buffer.
They can no longer have default values.<br>
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