/****************************************************************************
* VCGLib                                                            o o     *
* Visual and Computer Graphics Library                            o     o   *
*                                                                _   O  _   *
* Copyright(C) 2004-2016                                           \/)\/    *
* Visual Computing Lab                                            /\/|      *
* ISTI - Italian National Research Council                           |      *
*                                                                    \      *
* All rights reserved.                                                      *
*                                                                           *
* This program is free software; you can redistribute it and/or modify      *
* it under the terms of the GNU General Public License as published by      *
* the Free Software Foundation; either version 2 of the License, or         *
* (at your option) any later version.                                       *
*                                                                           *
* This program is distributed in the hope that it will be useful,           *
* but WITHOUT ANY WARRANTY; without even the implied warranty of            *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             *
* GNU General Public License (http://www.gnu.org/licenses/gpl.txt)          *
* for more details.                                                         *
*                                                                           *
****************************************************************************/

#include <GL/glew.h>
#include "trackball.h"
#include<set>

#include <wrap/gl/math.h>
#include <wrap/gl/space.h>

using namespace vcg;

Transform::Transform() {
  track.SetIdentity();
  radius=1.0f;
  center=Point3f(0,0,0);
}

Trackball::Trackball(): current_button(0), current_mode(NULL), inactive_mode(NULL),
			dragging(false), last_time(0), spinnable(true), spinning(false),
			history_size(10), fixedTimestepMode(false) {
  setDefaultMapping ();
}

Trackball::~Trackball()
{
	ClearModes();
	delete  inactive_mode;
}

void Trackball::ClearModes()
{
	// Note: people ofter maps different keys to the same modes.
	// so we should avoid double deletion of these double referenced modes.
	std::set<TrackMode *> goodModes;
	std::map<int, TrackMode *>::iterator it;
  for(it = modes.begin(); it != modes.end(); it++)
		if ((*it).second) goodModes.insert( (*it).second);

	std::set<TrackMode *>::iterator its;
	for(its = goodModes.begin(); its != goodModes.end(); its++)
			delete *its;

	modes.clear();
}

void Trackball::setDefaultMapping () {
  idle_and_keys_mode = NULL;

  inactive_mode = new InactiveMode ();
	ClearModes();
  modes[0] = NULL;

  modes[BUTTON_MIDDLE | KEY_ALT] =
  modes[BUTTON_LEFT] = new SphereMode ();

  modes[BUTTON_LEFT | KEY_CTRL] = new PanMode ();

  modes[BUTTON_MIDDLE] = new PanMode ();

  modes[WHEEL] =
  modes[BUTTON_LEFT | KEY_SHIFT] = new ScaleMode ();

  modes[BUTTON_LEFT | KEY_ALT] = new ZMode ();

}

void Trackball::SetIdentity() {
  track.SetIdentity();
  Reset();
}
void Trackball::SetPosition(const Point3f &c, int /* millisec */) {
  center = c;
}

void Trackball::GetView() {
  camera.GetView();
}

// the drawing code has been moved to the trackmodes
void Trackball::DrawPostApply() {
	if(current_mode !=NULL){
		current_mode->Draw(this);
	}else{
		if (inactive_mode != NULL) inactive_mode->Draw(this);
  }
}

void Trackball::Apply () {
  glTranslate (center);
  glMultMatrix (track.Matrix());
  glTranslate (-center);
}

void Trackball::ApplyInverse() {
  glTranslate(center);
  glMultMatrix(track.InverseMatrix());
  glTranslate(-center);
}

// T(c) S R T(t) T(-c) => S R T(S^(-1) R^(-1)(c) + t - c)
Matrix44f Trackball::Matrix() const{
  #ifndef VCG_USE_EIGEN
  Matrix44f r; track.rot.ToMatrix(r);
  Matrix44f sr    = Matrix44f().SetScale(track.sca, track.sca, track.sca) * r;
  Matrix44f s_inv = Matrix44f().SetScale(1/track.sca, 1/track.sca, 1/track.sca);
  Matrix44f t     = Matrix44f().SetTranslate(s_inv*r.transpose()*center + track.tra - center);

  return Matrix44f(sr*t);
  #else
  Eigen::Quaternionf rot(track.rot);
  Eigen::Translation3f tr( (1/track.sca) * (rot.inverse() * center) + track.tra - center );
  return ( Eigen::Scaling3f(track.sca) * (rot * tr) ).matrix();
  #endif
}

Matrix44f Trackball::InverseMatrix() const{
  return Inverse(Matrix());
}

void Trackball::Scale(const float s)
{
  track.sca*=s;
}

void Trackball::Translate(Point3f tr)
{
  Quaternionf irot = track.rot;
  irot.Invert();
  track.tra = last_track.tra + irot.Rotate(tr)/track.sca;
}

/***************************************************************/
// DrawCircle () e DrawPlane() have been moved to trackutils.h
// the drawing code has been moved to the trackmodes
/*
void Trackball::DrawCircle() {
  int nside=DH.CircleStep;
  const double pi2=3.14159265*2.0;
  glBegin(GL_LINE_LOOP);
  for(double i=0;i<nside;i++){
    glNormal3d(cos(i*pi2/nside), sin(i*pi2/nside),  0.0);
    glVertex3d(cos(i*pi2/nside), sin(i*pi2/nside),  0.0);
  }
  glEnd();
  DrawPlaneHandle();
}

void Trackball::DrawPlane() {
  const int nl=10;
  float w=5.0f/3.0f;
  float u;
  glBegin(GL_LINES);
  glNormal3f(0.0,0.0,1.0);
  for( u=-w; u<=w+0.01f; u+=2*w/nl){
    glVertex3f(-w,	+u,	0);
    glVertex3f(+w,	+u,	0);
    glVertex3f(+u,	-w, 0);
    glVertex3f(+u,	+w, 0);
  }
  glEnd();
}
*/

void Trackball::ToAscii(char* result){
  float * f = (float*) &track;
  sprintf(result, "trackball(%f,%f,%f,%f,%f,%f,%f,%f)",
                  f[0],f[1],f[2],f[3],f[4],f[5],f[6],f[7] );
}

bool Trackball::SetFromAscii(const char * st){
  float * f = (float*) &track;
  int res=  sscanf(st, "trackball(%f,%f,%f,%f,%f,%f,%f,%f)",
                  f+0,f+1,f+2,f+3,f+4,f+5,f+6,f+7 );

  return (res==8);
}

// DrawPlaneHandle() e DrawIcon() have been moved to trackutils.h
// the drawing code has been moved to the trackmodes
/*
void Trackball::DrawPlaneHandle() {
  float r=1.0;
  float dr=r/10.0f;
  glBegin(GL_LINE_STRIP);
  glVertex3f(+r+dr,   +r,   0.0);
  glVertex3f(+r   ,   +r+dr,0.0);
  glVertex3f(+r-dr,   +r,   0.0);
  glVertex3f(+r   ,   +r-dr,0.0);
  glVertex3f(+r+dr,   +r,   0.0);
  glEnd();
  glBegin(GL_LINE_STRIP);
  glVertex3f(-r+dr,   -r,   0.0);
  glVertex3f(-r   ,   -r+dr,0.0);
  glVertex3f(-r-dr,   -r,   0.0);
  glVertex3f(-r   ,   -r-dr,0.0);
  glVertex3f(-r+dr,   -r,   0.0);
  glEnd();
}

void Trackball::DrawIcon() {
  glPushMatrix();

  glScale(radius);
  /// Here start the real drawing stuff
  float amb[4] ={.3f,.3f,.3f,1.0f};
  float col[4] ={.5f,.5f,.8f,1.0f};
  //float col2[4]={.9f,.9f,1.0f,1.0f};
  glPushAttrib(GL_ENABLE_BIT | GL_LINE_BIT | GL_CURRENT_BIT | GL_LIGHTING_BIT);


  if(current_mode == NULL ) glLineWidth(DH.LineWidthStill);
                       else glLineWidth(DH.LineWidthMoving);

  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glEnable(GL_LINE_SMOOTH);
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  glColor(DH.color);

  glMaterialfv(GL_FRONT_AND_BACK,GL_EMISSION,amb);
  glMaterialfv(GL_FRONT_AND_BACK,GL_DIFFUSE,col);
  glPushMatrix();
    DrawCircle();
    glPushMatrix();

      glRotatef(90,1,0,0);
      DrawCircle();
      glRotatef(90,0,1,0);
      DrawCircle();

    glPopMatrix();
  glPopMatrix();

  //glColor4f(1.0,.8f,.8f,1.0f);

  glPopAttrib();

  glPopMatrix();
}
*/

void Trackball::Reset() {
  track.SetIdentity();
  undo_track = track;
  std::map<int, TrackMode *>::iterator i;
  for(i = modes.begin(); i != modes.end(); i++){
   TrackMode * mode=(*i).second;
   if(mode!=NULL)
     mode->Reset();
  }
  if (inactive_mode != NULL) inactive_mode->Reset();
 }

//interface
void Trackball::MouseDown(int button) {
  undo_track = track;
  current_button |= button;
  SetCurrentAction();
  Hits.clear();
}
void Trackball::MouseDown(int x, int y, int button) {
  undo_track = track;
  current_button |= button;
  SetCurrentAction();
  last_point = Point3f((float)x, (float)y, 0);
  Hits.clear();
}

void Trackball::MouseMove(int x, int y) {
  if(current_mode == NULL) return;
  if(last_point[2] == -1) { //changed mode in the middle of moving
    last_point = Point3f((float)x, (float)y, 0);
    return;
  }
  undo_track = track;
  current_mode->Apply(this, Point3f(float(x), float(y), 0));
}

bool Trackball::IsAnimating(unsigned int msec){
	bool res;
	if(idle_and_keys_mode == NULL) res=false; else res=idle_and_keys_mode->IsAnimating(this);

	if (!fixedTimestepMode)	{
  	if (msec==0) msec = clock()*1000/CLOCKS_PER_SEC;
	  if (!res) {
  	  last_time = msec;
	  }
	}
	return res;
}

void Trackball::Sync(unsigned int msec) {
	if (!fixedTimestepMode)	Animate(msec);
}

void Trackball::Animate(unsigned int msec){
	unsigned int delta;
	if (fixedTimestepMode) delta=msec;
	else {
		if (msec==0) msec = clock()*1000/CLOCKS_PER_SEC;
    delta = msec -last_time;
	  last_time = msec;
	}
	if(idle_and_keys_mode == NULL) return;
	idle_and_keys_mode->Animate(delta,this);
}

void Trackball::MouseUp(int /* x */, int /* y */, int button) {
  undo_track = track;
	ButtonUp(vcg::Trackball::Button(button));
  //current_button &= (~button);
  //SetCurrentAction();
}

// it assumes that a notch of 1.0 is a single step of the wheel
void Trackball::MouseWheel(float notch)
{
  undo_track = track;
	int buttons = current_button;
	current_button = WHEEL | (buttons&(KEY_SHIFT|KEY_CTRL|KEY_ALT));
	SetCurrentAction();
  if (current_mode == NULL)
  {
    //ScaleMode scalemode;
    //scalemode.Apply (this, notch);
  }
	else
	{
    current_mode->Apply(this, notch);
  }
	current_button = buttons;
	SetCurrentAction();
}

void Trackball::MouseWheel(float notch, int button)
{
  undo_track = track;
  current_button |= button;
  SetCurrentAction();
  if (current_mode == NULL) {
    ScaleMode scalemode;
    scalemode.Apply (this, notch);
  } else {
    current_mode->Apply (this, notch);
  }
  current_button &= (~button);
  SetCurrentAction ();
}

void Trackball::ButtonDown(Trackball::Button button, unsigned int msec) {
	Sync(msec);
  bool old_sticky=false, new_sticky=false;
  assert (modes.count (0));

	Button b=Button(current_button & MODIFIER_MASK);
  if ( ( modes.count (b) ) && ( modes[b] != NULL ) ) old_sticky = modes[b]->isSticky();

  current_button |= button;
	b=Button(current_button & MODIFIER_MASK);
	if ( ( modes.count (b) ) && ( modes[b] != NULL ) ) new_sticky = modes[b]->isSticky();

  if ( !old_sticky && !new_sticky) SetCurrentAction();

}

void Trackball::ButtonUp(Trackball::Button button) {
  bool old_sticky=false, new_sticky=false;
  assert (modes.count (0));

	Button b=Button(current_button & MODIFIER_MASK);
  if ( ( modes.count (b) ) && ( modes[b] != NULL ) ) old_sticky = modes[b]->isSticky();

  current_button &= (~button);
	b=Button(current_button & MODIFIER_MASK);
	if ( ( modes.count (b) ) && ( modes[b] != NULL ) ) new_sticky = modes[b]->isSticky();

  if ( !old_sticky && !new_sticky) SetCurrentAction();
}

void Trackball::Undo(){
  track = undo_track;
  if(current_mode != NULL)
    current_mode->Undo();
}


//spinning interface
void Trackball::SetSpinnable(bool /* on*/ ){}
bool Trackball::IsSpinnable() {
  return spinnable;
}
void Trackball::SetSpinning(Quaternionf &/* spin*/){}
void Trackball::StopSpinning(){}
bool Trackball::IsSpinning() {
  return spinning;
}

//navigation interface:
void Trackball::Back(){}
void Trackball::Forward(){}
void Trackball::Home(){}
void Trackball::HistorySize(int /* length */){}

void Trackball::SetCurrentAction ()
{
  //I use strict matching.
  assert (modes.count (0));
  if (!modes.count (current_button & MODIFIER_MASK)) {
    current_mode = NULL;
  } else {
    current_mode = modes[current_button & MODIFIER_MASK];
    if(current_mode != NULL)
      current_mode->SetAction();
  }
  last_point = Point3f (0, 0, -1);
  last_track = track;
}

////return center of trackball in Window coordinates.
//Point3f Trackball::ScreenOrigin() {
//  return camera.Project(ModelOrigin());
//}


//return center of trackball in Model coordinates
//Point3f Trackball::ModelOrigin() {
//  return center;
//}

//Matrix44f Trackball::ScreenToModel() {
//  return camera.inverse;
//}
//
//Similarityf Trackball::ModelToLocal() {
//  Similarityf m = local * last_track;
//  return m;
//}

