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// $Id: G4OpenGLImmediateSceneHandler.cc,v 1.24 2006/09/04 12:03:25 allison Exp $
// GEANT4 tag $Name: geant4-08-02-patch-01 $
//
// 
// Andrew Walkden  10th February 1997
// OpenGL immediate scene - draws immediately to buffer
//                           (saving space on server).

#ifdef G4VIS_BUILD_OPENGL_DRIVER

// Included here - problems with HP compiler if not before other includes?
#include "G4NURBS.hh"

// Here follows a special for Mesa, the OpenGL emulator.  Does not affect
// other OpenGL's, as far as I'm aware.   John Allison 18/9/96.
#define CENTERLINE_CLPP  /* CenterLine C++ workaround: */
// Also seems to be required for HP's CC and AIX xlC, at least.

#include "G4OpenGLImmediateSceneHandler.hh"

#include "G4OpenGLTransform3D.hh"
#include "G4Polyline.hh"
#include "G4Circle.hh"
#include "G4Square.hh"

G4OpenGLImmediateSceneHandler::G4OpenGLImmediateSceneHandler (G4VGraphicsSystem& system,
						const G4String& name):
G4OpenGLSceneHandler (system, fSceneIdCount++, name)
{}

G4OpenGLImmediateSceneHandler::~G4OpenGLImmediateSceneHandler ()
{}

#include <iomanip>

void G4OpenGLImmediateSceneHandler::AddPrimitivePreamble(const G4Visible& visible)
{
  const G4Colour& c = GetColour (visible);
  glColor3d (c.GetRed (), c.GetGreen (), c.GetBlue ());
}

void G4OpenGLImmediateSceneHandler::AddPrimitive (const G4Polyline& polyline)
{
  AddPrimitivePreamble(polyline);
  G4OpenGLSceneHandler::AddPrimitive(polyline);
}

void G4OpenGLImmediateSceneHandler::AddPrimitive (const G4Circle& circle)
{
  AddPrimitivePreamble(circle);
  G4OpenGLSceneHandler::AddPrimitive(circle);
}

void G4OpenGLImmediateSceneHandler::AddPrimitive (const G4Square& square)
{
  AddPrimitivePreamble(square);
  G4OpenGLSceneHandler::AddPrimitive(square);
}

void G4OpenGLImmediateSceneHandler::BeginPrimitives
(const G4Transform3D& objectTransformation) {
  G4VSceneHandler::BeginPrimitives (objectTransformation);
  glPushMatrix();
  G4OpenGLTransform3D oglt (objectTransformation);

  /*************************** Check matrix.
  const GLdouble* m = oglt.GetGLMatrix ();
  G4cout << "G4OpenGLTransform3D matrix:";
  for (int i = 0; i < 16; i++) {
    if ((i % 4) == 0) G4cout << '\n';
    G4cout << std::setw (15) << m[i];
  }
  G4cout << G4endl;
  *****************************************/

  glMultMatrixd (oglt.GetGLMatrix ());
}

void G4OpenGLImmediateSceneHandler::EndPrimitives ()
{
  glPopMatrix();

  // See all primitives immediately...
  glFlush ();

  G4VSceneHandler::EndPrimitives ();
}

void G4OpenGLImmediateSceneHandler::BeginPrimitives2D()
{
  G4VSceneHandler::BeginPrimitives2D();

  // Push current 3D world matrices and load identity to define screen
  // coordinates...
  glMatrixMode (GL_PROJECTION);
  glPushMatrix();
  glLoadIdentity();
  glOrtho (-1., 1., -1., 1., -DBL_MAX, DBL_MAX);
  glMatrixMode (GL_MODELVIEW);
  glPushMatrix();
  glLoadIdentity();
}

void G4OpenGLImmediateSceneHandler::EndPrimitives2D()
{
  // Pop current 3D world matrices back again...
  glMatrixMode (GL_PROJECTION);
  glPopMatrix();
  glMatrixMode (GL_MODELVIEW);
  glPopMatrix();

  // See all primitives immediately...
  glFlush ();

  G4VSceneHandler::EndPrimitives2D ();
}

void G4OpenGLImmediateSceneHandler::BeginModeling () {
  G4VSceneHandler::BeginModeling();
}

void G4OpenGLImmediateSceneHandler::EndModeling () {
  G4VSceneHandler::EndModeling ();
}

void G4OpenGLImmediateSceneHandler::ClearTransientStore () {
  G4VSceneHandler::ClearTransientStore ();

  // Make sure screen corresponds to graphical database...
  if (fpViewer) {
    fpViewer -> SetView ();
    fpViewer -> ClearView ();
    fpViewer -> DrawView ();
  }
}

void G4OpenGLImmediateSceneHandler::RequestPrimitives (const G4VSolid& solid)
{
  if (fReadyForTransients) {
    // Always draw transient solids, e.g., hits represented as solids.
    // (As we have no control over the order of drawing of transient
    // objects, we cannot do anything about transparent ones, as
    // below, so always draw them.)
    G4VSceneHandler::RequestPrimitives (solid);
    return;
  }

  // For non-transient (run-duration) objects, ensure transparent
  // objects are drawn last.  The problem of
  // blending/transparency/alpha is quite a tricky one - see History
  // of opengl-V07-01-01/2/3.
  // Get vis attributes - pick up defaults if none.
  const G4VisAttributes* pVA =
    fpViewer -> GetApplicableVisAttributes(fpVisAttribs);
  const G4Colour& c = pVA -> GetColour ();
  G4double opacity = c.GetAlpha ();

  if (!fSecondPass) {
    G4bool transparency_enabled = true;
    G4OpenGLViewer* pViewer = dynamic_cast<G4OpenGLViewer*>(fpViewer);
    if (pViewer) transparency_enabled = pViewer->transparency_enabled;
    if (transparency_enabled && opacity < 1.) {
      // On first pass, transparent objects are not drawn, but flag is set...
      fSecondPassRequested = true;
      return;
    }
  }

  // On second pass, opaque objects are not drwan...
  if (fSecondPass && opacity >= 1.) return;

  // Else invoke base class method...
  G4VSceneHandler::RequestPrimitives (solid);
}

G4int G4OpenGLImmediateSceneHandler::fSceneIdCount = 0;

#endif