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void update_overlays( bool start_from_scratch)
Java: void Update_overlays( boolean start_from_scratch)
[Declared in "../apps/support/kdu_region_compositor.h"]
Call this function if you have made any changes in the metadata associated with a JPX data source and want them to be reflected on overlays folded into the composited image. This function does not actually paint any overlay data itself, but it does schedule the updates to be performed in subsequent calls to the process function.
You MUST call this function with start_from_scratch set to true, immediately after using jpx_metanode::delete to delete one or more metadata nodes. Otherwise, there is a risk that ongoing metadata manipulation in this object will cause an access violation.
If you have only added metadata, however, it is sufficient to call this function with start_from_scratch set to false.
If true, all overlay surfaces will be erased and all previously discovered metadata will be treated as invalid. Subsequent calls to process will then generate the metadata overlays from scratch. In fact, the next call to process may return a new region which represents the entire buffer surface, forcing the application to repaint the entire buffer.