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1 Commits

Author SHA1 Message Date
Even Rouault
eaeca6274a
Add TIFFDeferStrileArrayWriting() and TIFFForceStrileArrayWriting()
Those advanced writing functions must be used in a particular sequence
to make their intended effect. Their aim is to control when/where
the [Strip/Tile][Offsets/ByteCounts] arrays are written into the file.

The purpose of this is to generate 'cloud-optimized geotiff' files where
the first KB of the file only contain the IFD entries without the potentially
large strile arrays. Those are written afterwards.

The typical sequence of calls is:
TIFFOpen()
[ TIFFCreateDirectory(tif) ]
Set fields with calls to TIFFSetField(tif, ...)
TIFFDeferStrileArrayWriting(tif)
TIFFWriteCheck(tif, ...)
 TIFFWriteDirectory(tif)
 ... potentially create other directories and come back to the above directory
TIFFForceStrileArrayWriting(tif): emit the arrays at the end of file

See test/defer_strile_writing.c for a practical example.
2019-05-25 11:37:34 +02:00