Atalasoft.Imaging.Codec.CadCam Namespace

GeometryHandler is a class that is used for extracting geometry from a DWG file. It consists of a series of methods that are called for each shape type in the as well as for changes in color and line style.

Nearly all of the OnBegin... methods return an enumerated value. This is to indicate to Distill whether or not the user GeometryHandler wants the geometry to be reduced further or not. The GeometryHandler base class implements all OnBegin... methods for shapes such that they return DwgReduction.Reduce. The GeometryHandler base class therefore causes a model to be fully reduced to primitives. Client code should subclass GeomtryHandler and override the methods they wish to intercept.

For example, an application that wishes to extract text from a DWG file would only need to override OnBeginText.

OnBeginPage should return true if the client wishes to process the page.

OnBeginDocument does not have a return value.

OnPolygon and OnPolyline represent primitives for which there is no further reduction.

All the OnBeginShape and OnEndShape methods take a shape ID parameter. This is unique ID that is assigned to every shape. This is to make it easier to identify when all reduction is done for a particular shape.

Many of the routines take arrays of double precision floating point numbers. These represent 3D coordinates of the shapes in the order X, Y, Z. The length of each array will always be a multiple of 3. At present, the Z coordinate is ignored since the shapes are projected onto a 2D sheet.