// Copyright (c) 1995-1999 Matra Datavision
// Copyright (c) 1999-2014 OPEN CASCADE SAS
//
// 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.

#include <Prs3d_Arrow.hxx>

#include <gp_Ax3.hxx>
#include <gp_Dir.hxx>
#include <gp_Pnt.hxx>
#include <gp_Trsf.hxx>
#include <Graphic3d_ArrayOfPolylines.hxx>
#include <Graphic3d_ArrayOfSegments.hxx>
#include <Graphic3d_Group.hxx>
#include <Prs3d_Presentation.hxx>
#include <Prs3d_ToolCylinder.hxx>
#include <Prs3d_ToolDisk.hxx>
#include <Prs3d_ToolSphere.hxx>

//=======================================================================
//function : Draw
//purpose  : 
//=======================================================================
void Prs3d_Arrow::Draw(const Handle(Graphic3d_Group)& theGroup,
                       const gp_Pnt& theLocation,
                       const gp_Dir& theDirection,
                       const Standard_Real theAngle,
                       const Standard_Real theLength)
{
  Handle(Graphic3d_ArrayOfSegments) aPrimitives = Prs3d_Arrow::DrawSegments(theLocation,
                                                  theDirection, theAngle, theLength, 15);
  theGroup->AddPrimitiveArray (aPrimitives);
}

//=======================================================================
//function : DrawSegments
//purpose  :
//=======================================================================
Handle(Graphic3d_ArrayOfSegments) Prs3d_Arrow::DrawSegments (const gp_Pnt& theLocation,
                                                             const gp_Dir& theDir,
                                                             const Standard_Real theAngle,
                                                             const Standard_Real theLength,
                                                             const Standard_Integer theNbSegments)
{
  Handle(Graphic3d_ArrayOfSegments) aSegments = new Graphic3d_ArrayOfSegments (theNbSegments + 1, 2 * (2 * theNbSegments));

  // center of the base circle of the arrow
  const gp_XYZ aC = theLocation.XYZ() + theDir.XYZ() * (-theLength);

  // construction of i,j mark for the circle
  gp_Dir aN;
  if (Abs(theDir.X()) <= Abs(theDir.Y())
   && Abs(theDir.X()) <= Abs(theDir.Z()))
  {
    aN = gp::DX();
  }
  else if (Abs(theDir.Y()) <= Abs(theDir.Z())
        && Abs(theDir.Y()) <= Abs(theDir.X()))
  {
    aN = gp::DY();
  }
  else
  {
    aN = gp::DZ();
  }

  const gp_Dir anXYZi = theDir.Crossed (aN.XYZ());
  const gp_XYZ anXYZj = theDir.XYZ().Crossed (anXYZi.XYZ());
  aSegments->AddVertex (theLocation);

  const Standard_Real Tg = Tan (theAngle);
  for (Standard_Integer aVertIter = 1; aVertIter <= theNbSegments; ++aVertIter)
  {
    const Standard_Real aCos = Cos (2.0 * M_PI / theNbSegments * (aVertIter - 1));
    const Standard_Real aSin = Sin (2.0 * M_PI / theNbSegments * (aVertIter - 1));

    const gp_Pnt pp(aC.X() + (aCos * anXYZi.X() + aSin * anXYZj.X()) * theLength * Tg,
                    aC.Y() + (aCos * anXYZi.Y() + aSin * anXYZj.Y()) * theLength * Tg,
                    aC.Z() + (aCos * anXYZi.Z() + aSin * anXYZj.Z()) * theLength * Tg);

    aSegments->AddVertex (pp);
  }

  Standard_Integer aNbVertices = theNbSegments + 1;
  Standard_Integer aFirstContourVertex = 2;
  Standard_Integer anEdgeCount = 0;
  for (Standard_Integer aVertIter = aFirstContourVertex; aVertIter <= aNbVertices; ++aVertIter)
  {
    aSegments->AddEdge (1);
    aSegments->AddEdge (aVertIter);
    ++anEdgeCount;
  }
  aSegments->AddEdge (aNbVertices);
  aSegments->AddEdge (aFirstContourVertex);
  ++anEdgeCount;

  for (Standard_Integer aVertIter = aFirstContourVertex; aVertIter <= aNbVertices - 1; ++aVertIter)
  {
    aSegments->AddEdge (aVertIter);
    aSegments->AddEdge (aVertIter + 1);
    ++anEdgeCount;
  }
  return aSegments;
}

// ============================================================================
// function : DrawShaded
// purpose  :
// ============================================================================
Handle(Graphic3d_ArrayOfTriangles) Prs3d_Arrow::DrawShaded (const gp_Ax1&          theAxis,
                                                            const Standard_Real    theTubeRadius,
                                                            const Standard_Real    theAxisLength,
                                                            const Standard_Real    theConeRadius,
                                                            const Standard_Real    theConeLength,
                                                            const Standard_Integer theNbFacettes)
{
  const Standard_Real aTubeLength = Max (0.0, theAxisLength - theConeLength);
  const Standard_Integer aNbTrisTube = (theTubeRadius > 0.0 && aTubeLength > 0.0)
                                     ? Prs3d_ToolCylinder::TrianglesNb (theNbFacettes, 1)
                                     : 0;
  const Standard_Integer aNbTrisCone = (theConeRadius > 0.0 && theConeLength > 0.0)
                                     ? (Prs3d_ToolDisk    ::TrianglesNb (theNbFacettes, 1)
                                      + Prs3d_ToolCylinder::TrianglesNb (theNbFacettes, 1))
                                     : 0;

  const Standard_Integer aNbTris = aNbTrisTube + aNbTrisCone;
  if (aNbTris == 0)
  {
    return Handle(Graphic3d_ArrayOfTriangles)();
  }

  Handle(Graphic3d_ArrayOfTriangles) anArray = new Graphic3d_ArrayOfTriangles (aNbTris * 3, 0, Standard_True);
  if (aNbTrisTube != 0)
  {
    gp_Ax3  aSystem (theAxis.Location(), theAxis.Direction());
    gp_Trsf aTrsf;
    aTrsf.SetTransformation (aSystem, gp_Ax3());

    Prs3d_ToolCylinder aTool (theTubeRadius, theTubeRadius, aTubeLength, theNbFacettes, 1);
    aTool.FillArray (anArray, aTrsf);
  }

  if (aNbTrisCone != 0)
  {
    gp_Pnt aConeOrigin = theAxis.Location().Translated (gp_Vec (theAxis.Direction().X() * aTubeLength,
                                                                theAxis.Direction().Y() * aTubeLength,
                                                                theAxis.Direction().Z() * aTubeLength));
    gp_Ax3  aSystem (aConeOrigin, theAxis.Direction());
    gp_Trsf aTrsf;
    aTrsf.SetTransformation (aSystem, gp_Ax3());
    {
      Prs3d_ToolDisk aTool (0.0, theConeRadius, theNbFacettes, 1);
      aTool.FillArray (anArray, aTrsf);
    }
    {
      Prs3d_ToolCylinder aTool (theConeRadius, 0.0, theConeLength, theNbFacettes, 1);
      aTool.FillArray (anArray, aTrsf);
    }
  }

  return anArray;
}