kdu_region_compositor::process

Call this function regularly (e.g. during an idle processing loop, or within a tight loop in a processing thread) until is_processing_complete returns false. You will generally need to start calling the function again after making any changes to the compositing layers, scale, orientation, overlays, or buffered region. You may use the returned new_region to control all painting in your image application, except where the screen must be repainted after being overwritten by an independent event.

This function may catch and rethrow an integer exception generated by a kdu_error handler if an error occurred in processing the underlying code-stream.

False only under one of the following two conditions. In either case, new_region is guaranteed to be empty upon return.

• All processing for the current compositing buffer surface was already complete before this function entered; this can be verified by calling is_processing_complete.
• During processing, the function encountered a code-stream tile-component which does not have sufficient DWT levels to permit rendering at the current scale; this can be verified by calling get_total_composition_dims. In response, the application may wish to increase the scale and recommence rendering.

suggested_increment [int]

new_region [kdu_dims &]