geant4/source/analysis/g4tools/include/tools/hatcher

// Copyright (C) 2010, Guy Barrand. All rights reserved.
// See the file tools.license for terms.

#ifndef tools_hatcher
#define tools_hatcher

/**
 *  
 * hatcher is a class to draw Hatch in a 3D polyline plane
 * A hatch is caracterise by a direction (dirAngle), a spacing to get 
 * second hatch,
 * an offset, and a stripWidth :
 * - offset value : between 0-1, This value set the offset of
 *   the hatch.0 meen that the hatch  will touch the first point
 *   of the polyline, and 1 meen that first hatch will be draw
 *   at a 'spacing' distance to first point
 * - offsetVec : the 3D point from where a hatch had to pass. This is 
 *   very usefull to have hach continuing in different polygones
 *
 * The compute_polyline() method<br> 
 * By default:
 * - spacing = .1;
 * - dirAngle = PI/4;
 * - offsetValue = 0;
 * - stripWidth=0.0;
 * 
 * A way to get all points and vertices and to draw them can be :
 * <pre>
 *  iindex =0;
 *  icoord =0;
 *  for (unsigned int a=0;a<sbHatch.number_of_vertices();a++) {
 *    for (unsigned int b=0;b<sbHatch.number_of_vertices()[a];b++) {
 *      coordinate3->point.set1Value(icoord,sbHatch.get_points()[icoord]);
 *      indexedFaceSet->coordIndex.set1Value(iindex,icoord);
 *      iindex++;
 *      icoord ++;
 *    }
 *    indexedFaceSet->coordIndex.set1Value(iindex,SO_END_LINE_INDEX);
 *    iindex++;
 *  }
 * </pre>
 *
 * @author Laurent Garnier
 * Creation : on Fri Jan 05 2004
 * Last update : 9 April 2004
 *
 */

#include "lina/vec3f"
#include "lina/vec2f"
#include "mathf"
#include <cfloat> // for FLT_MAX

namespace tools {

class hatcher {
public:
  hatcher()
  :fShift(.1f)
  ,fDirAngle(fpi()/4)
  ,fOffsetValue(.0f)
  ,fOffset(vec3f(FLT_MAX,FLT_MAX,FLT_MAX))
  ,fPrecisionFactor (.0001f) // good value to get rid of some errors
  ,fStripWidth(0.0)
  ,fFirstNumHatch(0)
  ,fNumberHatchToDraw(0)
  ,fFirstPolyline(true)
  ,fResolveResult(UNDEFINED)
  {}
  virtual ~hatcher() {}
protected:
  hatcher(const hatcher& a_from)
  :fNormal(a_from.fNormal)
  ,fShift(a_from.fShift)
  ,fDirAngle(a_from.fDirAngle)
  ,fOffsetValue(a_from.fOffsetValue)
  ,fOffset(a_from.fOffset)
  ,fShiftVec(a_from.fShiftVec)
  ,fPrecisionFactor(a_from.fPrecisionFactor)
  ,fDirVec(a_from.fDirVec)
  ,fStripWidth(a_from.fStripWidth)
  ,fPoints(a_from.fPoints)
  ,fVertices(a_from.fVertices)
  ,fConflictNumHatchLineTab(a_from.fConflictNumHatchLineTab)
  ,fHatchShiftToMatchPointVec(a_from.fHatchShiftToMatchPointVec)
  ,fFirstNumHatch(a_from.fFirstNumHatch)
  ,fNumberHatchToDraw(a_from.fNumberHatchToDraw)
  ,fFirstPolyline(a_from.fFirstPolyline)
  ,fResolveResult(a_from.fResolveResult)
  {}
  hatcher& operator=(const hatcher& a_from){
    fNormal = a_from.fNormal;
    fShift = a_from.fShift;
    fDirAngle = a_from.fDirAngle;
    fOffsetValue = a_from.fOffsetValue;
    fOffset = a_from.fOffset;
    fShiftVec = a_from.fShiftVec;
    fPrecisionFactor = a_from.fPrecisionFactor;
    fDirVec = a_from.fDirVec;
    fStripWidth = a_from.fStripWidth;
    fPoints = a_from.fPoints;
    fVertices = a_from.fVertices;
    fConflictNumHatchLineTab = a_from.fConflictNumHatchLineTab;
    fHatchShiftToMatchPointVec = a_from.fHatchShiftToMatchPointVec;
    fFirstNumHatch = a_from.fFirstNumHatch;
    fNumberHatchToDraw = a_from.fNumberHatchToDraw;
    fFirstPolyline = a_from.fFirstPolyline;
    fResolveResult = a_from.fResolveResult;
    return *this;
  }
public:  
  /**
  * draw the hatch into the polyline bounding box given in argument
  * You have to get all compute points by the get_points() method
  * Number of points can be get by number_of_points()
  * The  number of vertices in the return polyline can be get by number_of_vertices()
  * and vertice table by get_vertices
  * @return FALSE if :
  *    - All points are not in the same plan
  *    - There is a precision error on one or more point
  */
  bool compute_polyline (vec3f* listPoints,unsigned int number);


  /**
  * test if the polygone given is correct for hatching
  * @return FALSE if :
  *    - All points are not in the same plan
  *    - Number of points <3
  *    - Offset point is not in the same plan
  *    - There is less than three different points
  *    - The vector from point[0],point[1] is colinear to point[0],lastPoint
  */
  bool check_polyline(vec3f* listPoints,unsigned int number);

  void set_spacing(float a) {fShift = a;}       //set the spacing for this hatch.
  void set_angle(float a) {fDirAngle = a;}      //set the Direction angle for the hatch in radians.
  void set_offset(float a) {fOffsetValue = a;}  //set the offset value for this hatch.
  void set_offset_point(vec3f a) {fOffset = a;}  //set the offset Point for this hatch.
  void set_precision_factor(float a) {fPrecisionFactor = a;} //set the precision factor for computing (0.0001 is default).
  
  bool set_strip_width(float a) {
    // set the strip width value(0 is default and means no strip).
    if (a<0 || a>1) {
      fStripWidth = 0;
      return false;
    }
    fStripWidth = a;
    return true;
  }

  float get_spacing()const {return fShift;}
  float get_angle()const {return fDirAngle;}
  float get_offset()const {return fOffsetValue;}
  const vec3f& get_offset_point() {return fOffset;}
  float get_precision_factor()const {return fPrecisionFactor;}
  float get_strip_width()const {return fStripWidth;}
  const vec3f& get_normal() {return fNormal;}

  //size_t number_of_points() const {return fPoints.size();} //get the number of points compute for this hatch.
  /** vector of compute points<br>
   * Be careful with this function because it can return a set of non convex
   * polygone if you have a non convex polygone at beginning !So, when you want
   * to draw it, you have to use a tesselisation algorithm first
   */
  const std::vector<vec3f>& points() {return fPoints;}
  
  //size_t number_of_vertices() const {return fVertices.size();} //get the number of vertices compute for this hatch.
  /** vector of numbers of vertices */
  const std::vector<unsigned int>& vertices() {return fVertices;}

protected:
  
  /**
  * draw the hatch into the polyline bounding box given in argument
  * @return FALSE if :
  *    - All points are not in the same plan
  *    - There is a precision error on one or more point
  */
  bool compute_single_polyline (vec3f* listPoints,unsigned int number);

  
  /**
  * Compute a vector system equation aA+bB=C
  * return SbVec2f(0,0) if there is an error
  * set the resolveResult variable to the error code :
  * COLINEAR if A and B are 
  * PRECISION_ERROR if there is a lack of precision in computing
  * Z_ERROR if there s no solution for Z
  * UNDEFINED never throw
  * return a SbVec2f  for result. a is 'x' value and b is 'y' if it is correct
  */
  vec2f resolve_system(const vec3f& A,const vec3f& B,const vec3f& C);


protected:
  /** normal vector for the current polyline */
  vec3f fNormal;

  /** Spacing vector between two hatch */
  float fShift; // Absloute distance between two hatch in the polyline plan  */
  
  /** The angle (given in radians) is the one between the first
   * line (point 1-point0) and the hatch lines, in the polyline plan.
   * Given in the direct axis ((point1-point0),(lastPoint-point0),
   * normalPlanVec). The angle in compute only one time for the first polyline.
   * Changes on angle value for others polyline will not take effect.This is to
   * perform correct hatching between the polylines
   */
  float fDirAngle;
  
  /** between 0-1. This value set the offset of the hatch.0 meen 
  * that the hatch will touch the first point of the polyline, 
  * and 1 meen that first hatch will be draw
  * at a 'spacing' distance to first point
  */
  float fOffsetValue;

  /** first point of the hatch. 
   * offset = firstPolylinePoint+ShiftVec*offsetValue 
   */
  vec3f fOffset;

  /** Orientation vector for the hatch  */
  vec3f fShiftVec;

  /** factor for compute error between two points */
  float fPrecisionFactor;
  
  /** hatch direction Vector */
  vec3f  fDirVec;

  /** strip with size : set to 0 by default
   * between 0 and 1.0 means no strip, 0.5 means strip size is 
   * half of distance between two hatches
   */
  float fStripWidth;

  /** vector list of points */
  std::vector<vec3f> fPoints;

  /** vector vertices number */
  std::vector<unsigned int> fVertices;
 
  /** conflict line table */
  std::vector< std::vector<int> > fConflictNumHatchLineTab;

  /** hatchShiftToMatchPointVec tab*/
  std::vector<float> fHatchShiftToMatchPointVec;

  /** first hatch number to draw */
  int fFirstNumHatch;

  /**number of hatch to draw */
  unsigned int fNumberHatchToDraw;

  bool fFirstPolyline;
  enum ResolveErrors{
    OK = 0,
    COLINEAR,
    Z_ERROR,
    PRECISION_ERROR,
    UNDEFINED
  };
  ResolveErrors fResolveResult;
};

}

#include "hatcher.icc"

#endif