ICustomSymbol.Draw Method
Draws the specified feature.
Draw(Feature feature, Drawable drawable)
Draws the specified feature.Syntax
public CustomSymbolCacheHint Draw (
Feature feature,
Drawable drawable
)Parameters
The feature to draw.
The drawable to draw on.
Return Value
A value indicating under which circumstances the result of the drawing calls just made can be cached.
Remarks
This method is called by the SymbolVisualizer to draw a symbol for a feature, in both 2D and 3D. In 3D, the supplied drawable is a temporary 2D bitmap; after the drawing this bitmap will be converted to a raster and drawn in 3D as a raster symbol.
The feature will always be in the coordinate reference system of the view. The 2D transform of the drawable will always be set up before each call so that the symbol should be drawn at the drawable coordinates (0, 0), in its natural scale and rotation.
The value returned from this method indicates under which circumstances Carmenta Engine may cache the visualization just produced by the call. If the visualization is cached, it may be reused the next time the feature (or even another feature with similar attributes) should be drawn, and Carmenta Engine does not need to call out to the custom symbol again. See CustomSymbolCacheHint for further information.
Please note that this is a different caching mechanism from the one described above, the symbol cache based on attribute values. This mechanism only works if the symbol is contained in a cached layer (like a TileLayer or a buffered OrdinaryLayer), or the symbol itself is cached in the symbol cache.
Platforms
Windows, Linux, Android