/*
 This file is part of the VRender library.
 Copyright (C) 2005 Cyril Soler (Cyril.Soler@imag.fr)
 Version 1.0.0, released on June 27, 2005.

 http://artis.imag.fr/Members/Cyril.Soler/VRender

 VRender 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.

 VRender 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 for more details.

 You should have received a copy of the GNU General Public License
 along with VRender; if not, write to the Free Software Foundation, Inc.,
 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
*/

/****************************************************************************

 Copyright (C) 2002-2014 Gilles Debunne. All rights reserved.

 This file is part of the QGLViewer library version 2.6.1.

 http://www.libqglviewer.com - contact@libqglviewer.com

 This file may be used under the terms of the GNU General Public License 
 versions 2.0 or 3.0 as published by the Free Software Foundation and
 appearing in the LICENSE file included in the packaging of this file.
 In addition, as a special exception, Gilles Debunne gives you certain 
 additional rights, described in the file GPL_EXCEPTION in this package.

 libQGLViewer uses dual licensing. Commercial/proprietary software must
 purchase a libQGLViewer Commercial License.

 This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

*****************************************************************************/

#include <assert.h>
#include <math.h>
#include <stdio.h>

#include "VRender.h"
#include "ParserGL.h"

using namespace vrender ;
using namespace std;

class ParserUtils
{
	public:
		static void NormalizeBufferCoordinates(GLint size, GLfloat * buffer, GLfloat MaxSize, GLfloat& zmin, GLfloat& zmax) ;

		static PtrPrimitive checkPoint(Point *& P);
		static PtrPrimitive checkSegment(Segment *& P);
		static PtrPrimitive checkPolygon(Polygone *& P);

		static void ComputeBufferBB(GLint size, GLfloat * buffer,
				GLfloat & xmin, GLfloat & xmax,
				GLfloat & ymin, GLfloat & ymax,
				GLfloat & zmin, GLfloat & zmax) ;

	private:
		static void print3DcolorVertex(GLint size, GLint * count, GLfloat * buffer) ;
		static void debug_printBuffer(GLint size, GLfloat *buffer) ;

		static void NormalizePrimitiveCoordinates(GLfloat * & loc,GLfloat MaxSize,GLfloat zmin,GLfloat zmax) ;
		static void ComputePrimitiveBB(	GLfloat * & loc,
				GLfloat & xmin,GLfloat & xmax,
				GLfloat & ymin,GLfloat & ymax,
				GLfloat & zmin,GLfloat & zmax);

		static const char *nameOfToken(int token);

		static const double EGALITY_EPS ;
};

const double ParserUtils::EGALITY_EPS = 0.00001 ;

void ParserGL::parseFeedbackBuffer(	GLfloat *buffer,int size,
												std::vector<PtrPrimitive>& primitive_tab,
												VRenderParams& vparams)
{
	int token;
	int nvertices = 0 ;
	nb_lines = 0 ;
	nb_polys = 0 ;
	nb_points = 0 ;
	nb_degenerated_lines = 0 ;
	nb_degenerated_polys = 0 ;
	nb_degenerated_points = 0 ;

	// pre-treatment of coordinates so as to get something more consistent

	_xmin = FLT_MAX ;
	_ymin = FLT_MAX ;
	_zmin = FLT_MAX ;
	_xmax = -FLT_MAX ;
	_ymax = -FLT_MAX ;
	_zmax = -FLT_MAX ;

	ParserUtils::ComputeBufferBB(size, buffer, _xmin,_xmax,_ymin,_ymax,_zmin,_zmax) ;

#ifdef DEBUGEPSRENDER
	printf("Buffer bounding box: %f %f %f %f %f %f\n",xmin,xmax,ymin,ymax,zmin,zmax) ;
#endif
	float Zdepth = max(_ymax-_ymin,_xmax-_xmin) ;
	ParserUtils::NormalizeBufferCoordinates(size,buffer,Zdepth,_zmin,_zmax) ;

	// now, read buffer
	GLfloat *end = buffer + size;

	GLfloat *loc = buffer ;
	int next_step = 0 ;
	int N = size/200 + 1 ;

	while (loc < end)
	{
		token = int(0.5f + *loc) ;
		loc++;

		if((end-loc)/N >= next_step)
			vparams.progress((end-loc)/(float)size, QGLViewer::tr("Parsing feedback buffer.")), ++next_step ;

		switch (token)
		{
			case GL_LINE_TOKEN:
			case GL_LINE_RESET_TOKEN:
				{
					Segment *S = new Segment(Feedback3DColor(loc),Feedback3DColor(loc+Feedback3DColor::sizeInBuffer())) ;

					primitive_tab.push_back(ParserUtils::checkSegment(S)) ;

					if(S == NULL)
						nb_degenerated_lines++ ;

					nb_lines++ ;
					loc += 2*Feedback3DColor::sizeInBuffer();
				}
				break;

			case GL_POLYGON_TOKEN:
				{
					nvertices = int(0.5f + *loc) ;
					loc++;

					std::vector<Feedback3DColor> verts ;

					for(int i=0;i<nvertices;++i)
						verts.push_back(Feedback3DColor(loc)),loc+=Feedback3DColor::sizeInBuffer() ;

					Polygone *P = new Polygone(verts) ;

					primitive_tab.push_back(ParserUtils::checkPolygon(P)) ;

					if(P == NULL)
						nb_degenerated_polys++ ;

					nb_polys++ ;
				}
				break ;

			case GL_POINT_TOKEN:
				{
					Point *Pt = new Point(Feedback3DColor(loc)) ;

					primitive_tab.push_back(Pt);//ParserUtils::checkPoint(Pt)) ;

					if(Pt == NULL)
						nb_degenerated_points++ ;

					nb_points++ ;
					loc += Feedback3DColor::sizeInBuffer();
				}
				break;
			default:
				break;
		}
	}

}

// Traitement des cas degeneres. Renvoie false si le polygone est degenere.
// Traitement des cas degeneres. Renvoie false si le segment est degenere.

PtrPrimitive ParserUtils::checkPoint(Point *& P)
{
	return P ;
}

PtrPrimitive ParserUtils::checkSegment(Segment *& P)
{
	if((P->vertex(0) - P->vertex(1)).infNorm() < EGALITY_EPS)
	{
		Point *pp = new Point(P->sommet3DColor(0)) ;
		delete P ;
		P = NULL ;

		return checkPoint(pp) ;
	}

	return P ;
}

PtrPrimitive ParserUtils::checkPolygon(Polygone *& P)
{
	if(P->nbVertices() != 3)
	{
		cout << "unexpected case: Polygon with " << P->nbVertices() << " vertices !" << endl ;
		delete P ;
		return NULL ;
	}

	if(P->FlatFactor() < FLAT_POLYGON_EPS)
	{
		// On ne traite que le cas du triangle plat, vu qu'on est sur d'avoir un triangle

		size_t n = P->nbVertices() ;

		for(size_t i=0;i<n;++i)
			if( (P->vertex(i) - P->vertex((i+1)%n)).norm() > EGALITY_EPS)
			{
				Segment *pp = new Segment(P->sommet3DColor((i+1)%n),P->sommet3DColor((i+2)%n)) ;
				delete P ;
				P = NULL ;

				return checkSegment(pp) ;
			}

		Point *pp = new Point(P->sommet3DColor(0)) ;
		delete P ;
		P = NULL ;

		return checkPoint(pp) ;
	}

	// No problem detected.

	return P ;
}


/* Write contents of one vertex to stdout. */

void ParserUtils::print3DcolorVertex(GLint size, GLint * count, GLfloat * buffer)
{
	printf("  ");
	for (size_t i = 0; i < Feedback3DColor::sizeInBuffer(); i++)
	{
		printf("%4.2f ", buffer[size - (*count)]);
		*count = *count - 1;
	}
	printf("\n");
}

void ParserUtils::debug_printBuffer(GLint size, GLfloat * buffer)
{
	GLint count;
	int token, nvertices;

	count = size;
	while (count) {
		token = int(buffer[size - count]);
		count--;
		switch (token)
		{
			case GL_PASS_THROUGH_TOKEN:
				printf("GL_PASS_THROUGH_TOKEN\n");
				printf("  %4.2f\n", buffer[size - count]);
				count--;
				break;
			case GL_POINT_TOKEN:
				printf("GL_POINT_TOKEN\n");
				print3DcolorVertex(size, &count, buffer);
				break;
			case GL_LINE_TOKEN:
				printf("GL_LINE_TOKEN\n");
				print3DcolorVertex(size, &count, buffer);
				print3DcolorVertex(size, &count, buffer);
				break;
			case GL_LINE_RESET_TOKEN:
				printf("GL_LINE_RESET_TOKEN\n");
				print3DcolorVertex(size, &count, buffer);
				print3DcolorVertex(size, &count, buffer);
				break;
			case GL_POLYGON_TOKEN:
				printf("GL_POLYGON_TOKEN\n");
				nvertices = int(buffer[size - count]) ;
				count--;
				for (; nvertices > 0; nvertices--)
					print3DcolorVertex(size, &count, buffer);
		}
	}
}

void ParserUtils::NormalizePrimitiveCoordinates(GLfloat * & loc,GLfloat MaxSize,GLfloat zmin,GLfloat zmax)
{
	int token;
	int nvertices, i;

	token = int(*loc) ;
	loc++;
	int size = Feedback3DColor::sizeInBuffer() ;

	switch (token)
	{
		case GL_LINE_RESET_TOKEN:
		case GL_LINE_TOKEN:
			{
				for (i = 0; i < 2; i++)
					(loc+size*i)[2] = ((loc+size*i)[2] - zmin)/(zmax-zmin)*MaxSize ;

				loc += 2*size;          /* Each vertex element in the feedback buffer is size GLfloats. */
				break;
			}
		case GL_POLYGON_TOKEN:
			{
				nvertices = int(*loc) ;
				loc++;

				for (i = 0; i < nvertices; i++)
					(loc+size*i)[2] = ((loc+size*i)[2] - zmin)/(zmax-zmin)*MaxSize ;

				loc += nvertices * size;  /* Each vertex element in the feedback buffer is size GLfloats. */
				break;
			}
		case GL_POINT_TOKEN:
			{
				loc[2] = (loc[2] - zmin)/(zmax-zmin)*MaxSize ;

				loc += size;           /* Each vertex element in the feedback buffer is size GLfloats. */
				break;
			}
		default:
			/* XXX Left as an excersie to the reader. */
#ifdef DEBUGEPSRENDER
			printf("%s (%d) not handled yet. Sorry.\n", ParserUtils::nameOfToken(token), token);
#endif
			;
	}
}

void ParserUtils::ComputePrimitiveBB(GLfloat * & loc,GLfloat & xmin,GLfloat & xmax,GLfloat & ymin,GLfloat & ymax, GLfloat & zmin,GLfloat & zmax)
{
	int token;
	int nvertices, i;

	token = int(*loc) ;
	loc++;
	int size = Feedback3DColor::sizeInBuffer() ;

	switch (token)
	{
		case GL_LINE_RESET_TOKEN:
		case GL_LINE_TOKEN:
			{
				for (i = 0; i < 2; i++)
				{
					Feedback3DColor f(loc+size*i) ;

					if(f.x() < xmin) xmin = GLfloat(f.x()) ;
					if(f.y() < ymin) ymin = GLfloat(f.y()) ;
					if(f.z() < zmin) zmin = GLfloat(f.z()) ;
					if(f.x() > xmax) xmax = GLfloat(f.x()) ;
					if(f.y() > ymax) ymax = GLfloat(f.y()) ;
					if(f.z() > zmax) zmax = GLfloat(f.z()) ;
				}

				loc += 2*size;          /* Each vertex element in the feedback
													buffer is size GLfloats. */
				break;
			}
		case GL_POLYGON_TOKEN:
			{
				nvertices = int(*loc) ;
				loc++;

				for (i = 0; i < nvertices; i++)
				{
					Feedback3DColor f(loc+size*i) ;

					if(f.x() < xmin) xmin = GLfloat(f.x()) ;
					if(f.y() < ymin) ymin = GLfloat(f.y()) ;
					if(f.z() < zmin) zmin = GLfloat(f.z()) ;
					if(f.x() > xmax) xmax = GLfloat(f.x()) ;
					if(f.y() > ymax) ymax = GLfloat(f.y()) ;
					if(f.z() > zmax) zmax = GLfloat(f.z()) ;
				}

				loc += nvertices * size;  /* Each vertex element in the
													  feedback buffer is size GLfloats. */
				break;
			}
		case GL_POINT_TOKEN:
			{
				Feedback3DColor f(loc) ;

				if(f.x() < xmin) xmin = GLfloat(f.x()) ;
				if(f.y() < ymin) ymin = GLfloat(f.y()) ;
				if(f.z() < zmin) zmin = GLfloat(f.z()) ;
				if(f.x() > xmax) xmax = GLfloat(f.x()) ;
				if(f.y() > ymax) ymax = GLfloat(f.y()) ;
				if(f.z() > zmax) zmax = GLfloat(f.z()) ;

				loc += size;           /* Each vertex element in the feedback
												  buffer is size GLfloats. */
				break;
			}
		default:
			/* XXX Left as an excersie to the reader. */
#ifdef DEBUGEPSRENDER
			printf("Incomplete implementation.  Unexpected token (%d).\n", token);
#endif
			;
	}
}

void ParserUtils::NormalizeBufferCoordinates(GLint size, GLfloat * buffer, GLfloat MaxSize, GLfloat& zmin,GLfloat& zmax)
{
	GLfloat *loc, *end;

	if(zmax == zmin)
	{
#ifdef DEBUGEPSRENDER
		printf("Warning: zmin = zmax in NormalizePrimitiveCoordinates\n") ;
#endif
		return ;
	}

	loc = buffer;
	end = buffer + size;

	while (loc < end)
		NormalizePrimitiveCoordinates(loc,MaxSize,zmin,zmax);

	zmin = 0.0 ;
	zmax = MaxSize ;
}

void ParserUtils::ComputeBufferBB(GLint size, GLfloat * buffer,
		     GLfloat & xmin, GLfloat & xmax,
		     GLfloat & ymin, GLfloat & ymax,
		     GLfloat & zmin, GLfloat & zmax)
{
	GLfloat *loc, *end;

	loc = buffer;
	end = buffer + size;

	while (loc < end)
		ComputePrimitiveBB(loc,xmin,xmax,ymin,ymax,zmin,zmax);
}

typedef struct _DepthIndex {
  GLfloat *ptr;
  GLfloat depth;
} DepthIndex;

const char *ParserUtils::nameOfToken(int token)
{
	switch(token)
	{
		case GL_PASS_THROUGH_TOKEN: 	return "GL_PASS_THROUGH_TOKEN" ;
		case GL_POINT_TOKEN: 			return "GL_POINT_TOKEN" ;
		case GL_LINE_TOKEN: 				return "GL_LINE_TOKEN" ;
		case GL_POLYGON_TOKEN: 			return "GL_POLYGON_TOKEN" ;
		case GL_BITMAP_TOKEN: 			return "GL_BITMAP_TOKEN" ;
		case GL_DRAW_PIXEL_TOKEN:		return "GL_DRAW_PIXEL_TOKEN" ;
		case GL_COPY_PIXEL_TOKEN:		return "GL_COPY_PIXEL_TOKEN" ;
		case GL_LINE_RESET_TOKEN:		return "GL_LINE_RESET_TOKEN" ;
		default:
										  		return "(Unidentified token)" ;
	}
}

