Files
OCCT/src/BRepMesh/BRepMesh_Classifier.hxx
oan 7bd071edb1 0026106: BRepMesh - revision of data model
Removed tight connections between data structures, auxiliary tools and algorithms in order to create extensible solution, easy for maintenance and improvements;
Code is separated on several functional units responsible for specific operation for the sake of simplification of debugging and readability;
Introduced new data structures enabling possibility to manipulate discrete model of particular entity (edge, wire, face) in order to perform computations locally instead of processing an entire model.

The workflow of updated component can be divided on six parts:
* Creation of model data structure: source TopoDS_Shape passed to algorithm is analyzed and exploded on faces and edges. For each topological entity corresponding reflection is created in data model. Note that underlying algorithms use data model as input and access it via common interface which allows user to create custom data model with necessary dependencies between particular entities;
* Discretize edges 3D & 2D curves: 3D curve as well as associated set of 2D curves of each model edge is discretized in order to create coherent skeleton used as a base in faces meshing process. In case if some edge of source shape already contains polygonal data which suites specified parameters, it is extracted from shape and stored to the model as is. Each edge is processed separately, adjacency is not taken into account;
* Heal discrete model: source TopoDS_Shape can contain problems, such as open-wire or self-intersections, introduced during design, exchange or modification of model. In addition, some problems like self-intersections can be introduced by roughly discretized edges. This stage is responsible for analysis of discrete model in order to detect and repair faced problems or refuse model’s part for further processing in case if problem cannot be solved;
* Preprocess discrete model: defines actions specific for implemented approach to be performed before meshing of faces. By default, iterates over model faces and checks consistency of existing triangulations. Cleans topological faces and its adjacent edges from polygonal data in case of inconsistency or marks face of discrete model as not required for computation;
* Discretize faces: represents core part performing mesh generation for particular face based on 2D discrete data related to processing face. Caches polygonal data associated with face’s edges in data model for further processing and stores generated mesh to TopoDS_Face;
* Postprocess discrete model: defines actions specific for implemented approach to be performed after meshing of faces. By default, stores polygonal data obtained on previous stage to TopoDS_Edge objects of source model.

Component is now spread over IMeshData, IMeshTools, BRepMeshData and BRepMesh units.

<!break>

1. Extend "tricheck" DRAW-command in order to find degenerated triangles.

2. Class BRepMesh_FastDiscret::Parameters has been declared as deprecated.

3. NURBS range splitter: do not split intervals without necessity. Intervals are split only in case if it is impossible to compute normals directly on intervals.

4. Default value of IMeshTools_Parameters::MinSize has been changed. New value is equal to 0.1*Deflection.

5. Correction of test scripts:

1) perf mesh bug27119: requested deflection is increased from 1e-6 to 1e-5 to keep reasonable performance (but still reproducing original issue)
2) bugs mesh bug26692_1, 2: make snapshot of triangulation instead of wireframe (irrelevant)

Correction in upgrade guide.
2018-11-02 17:06:40 +03:00

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// Created on: 2016-07-07
// Copyright (c) 2016 OPEN CASCADE SAS
// Created by: Oleg AGASHIN
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.
#ifndef _BRepMesh_Classifier_HeaderFile
#define _BRepMesh_Classifier_HeaderFile
#include <Standard.hxx>
#include <Standard_Macro.hxx>
#include <TopAbs_State.hxx>
#include <IMeshData_Types.hxx>
#include <NCollection_Handle.hxx>
#include <memory>
class gp_Pnt2d;
class CSLib_Class2d;
//! Auxilary class intended for classification of points
//! regarding internals of discrete face.
class BRepMesh_Classifier : public Standard_Transient
{
public:
//! Constructor.
Standard_EXPORT BRepMesh_Classifier();
//! Destructor.
Standard_EXPORT virtual ~BRepMesh_Classifier();
//! Performs classification of the given point regarding to face internals.
//! @param thePoint Point in parametric space to be classified.
//! @return TopAbs_IN if point lies within face boundaries and TopAbs_OUT elsewhere.
Standard_EXPORT TopAbs_State Perform(const gp_Pnt2d& thePoint) const;
//! Registers wire specified by sequence of points for
//! further classification of points.
//! @param theWire Wire to be registered. Specified by sequence of points.
//! @param theTolUV Tolerance to be used for calculations in parametric space.
//! @param theUmin Lower U boundary of the face in parametric space.
//! @param theUmax Upper U boundary of the face in parametric space.
//! @param theVmin Lower V boundary of the face in parametric space.
//! @param theVmax Upper V boundary of the face in parametric space.
Standard_EXPORT void RegisterWire(
const NCollection_Sequence<const gp_Pnt2d*>& theWire,
const std::pair<Standard_Real, Standard_Real>& theTolUV,
const std::pair<Standard_Real, Standard_Real>& theRangeU,
const std::pair<Standard_Real, Standard_Real>& theRangeV);
DEFINE_STANDARD_RTTI_INLINE (BRepMesh_Classifier, Standard_Transient)
private:
NCollection_Vector<NCollection_Handle<CSLib_Class2d> > myTabClass;
IMeshData::VectorOfBoolean myTabOrient;
};
#endif