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KB10540 - Explanation of IncrementalPaint feature.

Note: Information in this Knowledge Base item is applicable to the obsolete DK 10 and earlier versions. The IncrementalPaint feature was replaced in the DK 11 with a new and improved feature for progressive background rendering basemaps described in KB10934.

Repainting (rendering/drawing) vector layers in TatukGIS products is performed in two phases - the draft presentation phase and final presentation phase. The draft phase presents a fast draw of only the vector geometry and the vector styles that are of a nature that can be drawn fast. Draft presentation omits difficult-to-render features such as labels, charts, complicated polygon fills, and some symbols. Final presentation phase generates a detailed paint of the map features in full, with complete vector styles, labels, etc. The two phase map drawing process enables possibilities for optimizing map rendering performance, particularly map redrawing between movement events (scrolling or zooming).

If the IncrementalPaint setting is turned ON, only the quick, phase 1 draft presentation of vector objects is performed upon map movements, with phase 2 full map presentation only when the map movement is paused for sufficient time to enable full map generation without hindering performance. The result can be a dramatic speed improvement with large data sets, particularly involving many layers or a very large raster image layer(s). If IncrementalPaint is turned OFF, vectors objects are repainted in full detail even during map movements, with greater consumption of computational resources and diminished performance.

The default IncrementalPaint settings are ON at the map level and OFF for each of the individual layers. This results in fast performance during map movements, but areas near the margins of the map window are not redrawn, i.e., appear as empty space during the movement.

The ability to set the IncrementalPaint feature at both the overall map level and for the individual layers allows for hybrid presentations, such as to maximize performance (speed) by performing draft presentation of just the most important layer(s) during map movements. For example, just a street map layer might be drawn (in draft mode) during map movements triggered by real time GPS tracking of a moving object at close zoom levels, with the other layers redrawn only when the map movement has paused.

The two stage drawing process does not apply to raster image layers. For best performance with large raster images, leave IncrementalPaint turned ON at the map level and turned OFF for the raster image layer.

Created: September 14, 2005, Modified: March 13, 2018