/*************************************************************************
*  Copyright (C) 2004 by Olivier Galizzi                                 *
*  olivier.galizzi@imag.fr                                               *
*                                                                        *
*  Copyright (C) 2008 by Sergei Dorofeenko                               *
*  sega@users.berlios.de                                                 *
*                                                                        *
*  © 2008 Václav Šmilauer <eudoxos@arcig.cz>                             *
*                                                                        *
*  © 2008 Bruno Chareyre <bruno.chareyre@grenoble-inp.fr                 *
*                                                                        *
*  This program is free software; it is licensed under the terms of the  *
*  GNU General Public License v2 or later. See file LICENSE for details. *
*************************************************************************/

#ifdef YADE_OPENGL

#include "Gl1_Primitives.hpp"
#include <lib/opengl/OpenGLWrapper.hpp>
#include <core/Scene.hpp>

namespace yade { // Cannot have #include directive inside.

YADE_PLUGIN((Gl1_Aabb)(Gl1_Box)(Gl1_Facet));
YADE_PLUGIN((GlBoundFunctor)(GlShapeFunctor)(GlIGeomFunctor)(GlIPhysFunctor)(GlStateFunctor)
            (GlBoundDispatcher)(GlShapeDispatcher)(GlIGeomDispatcher)(GlIPhysDispatcher)
            (GlStateDispatcher));


void Gl1_Aabb::go(const shared_ptr<Bound>& bv, Scene* scene){
	Aabb* aabb = static_cast<Aabb*>(bv.get());
	glColor3v(bv->color);
	if(!scene->isPeriodic){
		glTranslatev(Vector3r(.5*(aabb->min+aabb->max)));
		glScalev(Vector3r(aabb->max-aabb->min));
	} else {
		glTranslatev(Vector3r(scene->cell->shearPt(scene->cell->wrapPt(.5*(aabb->min+aabb->max)))));
		glMultMatrixd(scene->cell->getGlShearTrsfMatrix());
		glScalev(Vector3r(aabb->max-aabb->min));
	}
	glutWireCube(1);
}

void Gl1_Box::go(const shared_ptr<Shape>& cg, const shared_ptr<State>&,bool wire,const GLViewInfo&)
{
	glColor3v(cg->color);
	Vector3r &extents = (static_cast<Box*>(cg.get()))->extents;
	glScale(2*extents[0],2*extents[1],2*extents[2]);
	if (wire) glutWireCube(1);
	else glutSolidCube(1);
}


bool Gl1_Facet::normals=false;

void Gl1_Facet::go(const shared_ptr<Shape>& cm, const shared_ptr<State>& ,bool wire,const GLViewInfo&)
{   
	Facet* facet = static_cast<Facet*>(cm.get());
	const vector<Vector3r>& vertices = facet->vertices;
	const Vector3r* ne = facet->ne;
	const Real& icr = facet->icr;

	if(cm->wire || wire){
		// facet
		glBegin(GL_LINE_LOOP);
			glColor3v(normals ? Vector3r(1,0,0): cm->color);
		   glVertex3v(vertices[0]);
		   glVertex3v(vertices[1]);
		   glVertex3v(vertices[2]);
	    glEnd();
		if(!normals) return;
		// facet's normal 
		glBegin(GL_LINES);
			glColor3(0.0,0.0,1.0); 
			glVertex3(0.0,0.0,0.0);
			glVertex3v(facet->normal);
		glEnd();
		// normal of edges
		glColor3(0.0,0.0,1.0); 
		glBegin(GL_LINES);
			glVertex3(0.0,0.0,0.0); glVertex3v(Vector3r(icr*ne[0]));
			glVertex3(0.0,0.0,0.0);	glVertex3v(Vector3r(icr*ne[1]));
			glVertex3(0.0,0.0,0.0);	glVertex3v(Vector3r(icr*ne[2]));
		glEnd();
	} else {
		glDisable(GL_CULL_FACE); 
		Vector3r normal=(facet->vertices[1]-facet->vertices[0]).cross(facet->vertices[2]-facet->vertices[1]); normal.normalize();
		glColor3v(cm->color);
		glBegin(GL_TRIANGLES);
			glNormal3v(normal); // this makes every triangle different WRT the light direction; important!
			glVertex3v(facet->vertices[0]);
			glVertex3v(facet->vertices[1]);
			glVertex3v(facet->vertices[2]);
		glEnd();
	}
}

// Spheres==========================================

bool Gl1_Sphere::wire;
bool Gl1_Sphere::stripes;
int  Gl1_Sphere::glutSlices;
int  Gl1_Sphere::glutStacks;
Real  Gl1_Sphere::quality;
bool  Gl1_Sphere::localSpecView;
bool Gl1_Sphere::circleView;
Real Gl1_Sphere::circleRelThickness;
vector<Vector3r> Gl1_Sphere::vertices, Gl1_Sphere::faces;
int Gl1_Sphere::glStripedSphereList=-1;
int Gl1_Sphere::glGlutSphereList=-1;
Real  Gl1_Sphere::prevQuality=0;
string Gl1_Sphere::prevDisplayMode="";
char Gl1_Sphere::circleAllowedRotationAxis;
char  Gl1_Sphere::prevCircleAllowedRotationAxis='z';

void Gl1_Sphere::go(const shared_ptr<Shape>& cm, const shared_ptr<State>& ,bool wire2, const GLViewInfo&)
{
	glClearDepth(1.0f);
	glEnable(GL_NORMALIZE);

	Real r=(static_cast<Sphere*>(cm.get()))->radius;
	glColor3v(cm->color);
	if (circleView) {
			bool somethingChanged = (std::abs(quality-prevQuality)>0.001 || prevDisplayMode!="torus" || prevCircleAllowedRotationAxis!=circleAllowedRotationAxis);
			if (somethingChanged) {
				prevCircleAllowedRotationAxis=circleAllowedRotationAxis;
				prevDisplayMode="torus";
				glDeleteLists(glGlutSphereList,1);
				glGlutSphereList = glGenLists(1);
				  glNewList(glGlutSphereList,GL_COMPILE);
				    glEnable(GL_LIGHTING);
				    glShadeModel(GL_SMOOTH);
 				    switch (tolower(circleAllowedRotationAxis)) { //rotate the torus according to the axis from which we want to look at it.
					  case 'z':break; //Initial torus axis is z, nothing to do
					  case 'x':glRotatef(90,0,1,0);break;
					  case 'y':glRotatef(90,1,0,0);break;
					  default:cerr<<"Error in Gl1_Sphere::go, circleAllowedRotationAxis should be \"x\", \"y\" or \"z\"."<<endl;
				    }
				    glutSolidTorus(0.5*circleRelThickness*r,r*(1.0-circleRelThickness/2.),int(std::round(quality*glutStacks)),int(std::round(quality*glutSlices))); //generate torus
				  glEndList();
			}
			glCallList(glGlutSphereList);
	} else {
		if (wire || wire2) {
			glutWireSphere(r,int(std::round(quality*glutSlices)),int(std::round(quality*glutStacks)));
		} else {
			//Check if quality has been modified or if previous lists are invalidated (e.g. by creating a new qt view), then regenerate lists
			bool somethingChanged = (std::abs(quality-prevQuality)>0.001 || glIsList(glStripedSphereList)!=GL_TRUE || prevDisplayMode!="sphere");
			if (somethingChanged) {
				initStripedGlList();
				initGlutGlList();
				prevQuality=quality;
				prevDisplayMode="sphere";
			}
			glScale(r,r,r);
			if(stripes) {
				glCallList(glStripedSphereList);
			} else {
				glCallList(glGlutSphereList);
			}
		}
	}
	return;
}
YADE_PLUGIN((Gl1_Sphere));

void Gl1_Sphere::subdivideTriangle(Vector3r& v1,Vector3r& v2,Vector3r& v3, int depth){
	Vector3r v;
	//Change color only at the appropriate level, i.e. 8 times in total, since we draw 8 mono-color sectors one after another
	if (depth==int(quality) || quality<=0){
		v = (v1+v2+v3)/3.0;
		GLfloat matEmit[4];
		if (v[1]*v[0]*v[2]>0){
			matEmit[0] = 0.3f;
			matEmit[1] = 0.3f;
			matEmit[2] = 0.3f;
			matEmit[3] = 1.f;
		}else{
			matEmit[0] = 0.15f;
			matEmit[1] = 0.15f;
			matEmit[2] = 0.15f;
			matEmit[3] = 0.2f;
		}
 		glMaterialfv(GL_FRONT, GL_EMISSION, matEmit);
	}
	if (depth==1){//Then display 4 triangles
		Vector3r v12 = v1+v2;
		Vector3r v23 = v2+v3;
		Vector3r v31 = v3+v1;
		v12.normalize();
		v23.normalize();
		v31.normalize();
		//Use TRIANGLE_STRIP for faster display of adjacent facets
		glBegin(GL_TRIANGLE_STRIP);
			glNormal3v(v1); glVertex3v(v1);
			glNormal3v(v31); glVertex3v(v31);
			glNormal3v(v12); glVertex3v(v12);
			glNormal3v(v23); glVertex3v(v23);
			glNormal3v(v2); glVertex3v(v2);
		glEnd();
		//terminate with this triangle left behind
		glBegin(GL_TRIANGLES);
			glNormal3v(v3); glVertex3v(v3);
			glNormal3v(v23); glVertex3v(v23);
			glNormal3v(v31); glVertex3v(v31);
		glEnd();
		return;
	}
	Vector3r v12 = v1+v2;
	Vector3r v23 = v2+v3;
	Vector3r v31 = v3+v1;
	v12.normalize();
	v23.normalize();
	v31.normalize();
	subdivideTriangle(v1,v12,v31,depth-1);
	subdivideTriangle(v2,v23,v12,depth-1);
	subdivideTriangle(v3,v31,v23,depth-1);
	subdivideTriangle(v12,v23,v31,depth-1);
}

void Gl1_Sphere::initStripedGlList() {
	if (!vertices.size()){//Fill vectors with vertices and facets
		//Define 6 points for +/- coordinates
		vertices.push_back(Vector3r(-1,0,0));//0
		vertices.push_back(Vector3r(1,0,0));//1
		vertices.push_back(Vector3r(0,-1,0));//2
		vertices.push_back(Vector3r(0,1,0));//3
		vertices.push_back(Vector3r(0,0,-1));//4
		vertices.push_back(Vector3r(0,0,1));//5
		//Define 8 sectors of the sphere
		faces.push_back(Vector3r(3,4,1));
		faces.push_back(Vector3r(3,0,4));
		faces.push_back(Vector3r(3,5,0));
		faces.push_back(Vector3r(3,1,5));
		faces.push_back(Vector3r(2,1,4));
		faces.push_back(Vector3r(2,4,0));
		faces.push_back(Vector3r(2,0,5));
		faces.push_back(Vector3r(2,5,1));
	}
	//Generate the list. Only once for each qtView, or more if quality is modified.
	glDeleteLists(glStripedSphereList,1);
	glStripedSphereList = glGenLists(1);
	glNewList(glStripedSphereList,GL_COMPILE);
	glEnable(GL_LIGHTING);
	glShadeModel(GL_SMOOTH);
	// render the sphere now
	for (int i=0;i<8;i++)
		subdivideTriangle(vertices[(unsigned int)faces[i][0]],vertices[(unsigned int)faces[i][1]],vertices[(unsigned int)faces[i][2]],1+ (int) quality);
	glEndList();

}

void Gl1_Sphere::initGlutGlList(){
	//Generate the "no-stripes" display list, each time quality is modified
	glDeleteLists(glGlutSphereList,1);
	glGlutSphereList = glGenLists(1);
	glNewList(glGlutSphereList,GL_COMPILE);
		glEnable(GL_LIGHTING);
		glShadeModel(GL_SMOOTH);
		glutSolidSphere(1.0,int(std::round(std::max(quality*glutSlices,(Real)2.))),int(std::round(std::max(quality*glutStacks,(Real)3.))));
	glEndList();
}

} // namespace yade

#endif /* YADE_OPENGL */
