/*
 *  OpenSCAD (www.openscad.at)
 *  Copyright (C) 2009  Clifford Wolf <clifford@clifford.at>
 *
 *  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 for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#define INCLUDE_ABSTRACT_NODE_DETAILS

#include "openscad.h"

#include <QMenu>
#include <QTime>
#include <QMenuBar>
#include <QSplitter>
#include <QFileDialog>
#include <QApplication>
#include <QProgressDialog>

QPointer<MainWindow> current_win;

MainWindow::MainWindow(const char *filename)
{
        root_ctx.functions_p = &builtin_functions;
        root_ctx.modules_p = &builtin_modules;
	root_ctx.set_variable("$fn", Value(0.0));
	root_ctx.set_variable("$fs", Value(1.0));
	root_ctx.set_variable("$fa", Value(12.0));

	root_module = NULL;
	absolute_root_node = NULL;
	root_raw_term = NULL;
	root_norm_term = NULL;
	root_chain = NULL;
#ifdef ENABLE_CGAL
	root_N = NULL;
#endif

	highlights_chain = NULL;
	background_chain = NULL;
	root_node = NULL;
	enableOpenCSG = false;

	s1 = new QSplitter(Qt::Horizontal, this);
	editor = new QTextEdit(s1);
	s2 = new QSplitter(Qt::Vertical, s1);
	screen = new GLView(s2);
	console = new QTextEdit(s2);

	{
		QMenu *menu = menuBar()->addMenu("&File");
		menu->addAction("&New", this, SLOT(actionNew()));
		menu->addAction("&Open...", this, SLOT(actionOpen()));
		menu->addAction("&Save", this, SLOT(actionSave()), QKeySequence(Qt::Key_F2));
		menu->addAction("Save &As...", this, SLOT(actionSaveAs()));
		menu->addAction("&Reload", this, SLOT(actionReload()), QKeySequence(Qt::Key_F3));
		menu->addAction("&Quit", this, SLOT(close()));
	}

	{
		QMenu *menu = menuBar()->addMenu("&Edit");
		menu->addAction("&Undo", editor, SLOT(undo()), QKeySequence(Qt::CTRL + Qt::Key_Z));
		menu->addAction("&Redo", editor, SLOT(redo()), QKeySequence(Qt::CTRL + Qt::SHIFT + Qt::Key_Z));
		menu->addSeparator();
		menu->addAction("Cu&t", editor, SLOT(cut()), QKeySequence(Qt::CTRL + Qt::Key_X));
		menu->addAction("&Copy", editor, SLOT(copy()), QKeySequence(Qt::CTRL + Qt::Key_C));
		menu->addAction("&Paste", editor, SLOT(paste()), QKeySequence(Qt::CTRL + Qt::Key_V));
		menu->addSeparator();
		menu->addAction("&Indent", this, SLOT(editIndent()), QKeySequence(Qt::CTRL + Qt::Key_I));
		menu->addAction("&Unindent", this, SLOT(editUnindent()), QKeySequence(Qt::CTRL + Qt::SHIFT + Qt::Key_I));
		menu->addSeparator();
		menu->addAction("C&omment", this, SLOT(editComment()), QKeySequence(Qt::CTRL + Qt::Key_D));
		menu->addAction("&Uncomment", this, SLOT(editUncomment()), QKeySequence(Qt::CTRL + Qt::SHIFT + Qt::Key_D));
		menu->addSeparator();
		menu->addAction("Zoom In", editor, SLOT(zoomIn()), QKeySequence(Qt::CTRL + Qt::Key_Plus));
		menu->addAction("Zoom Out", editor, SLOT(zoomOut()), QKeySequence(Qt::CTRL + Qt::Key_Minus));
	}

	{
		QMenu *menu = menuBar()->addMenu("&Design");
		menu->addAction("&Reload and Compile", this, SLOT(actionReloadCompile()), QKeySequence(Qt::Key_F4));
		menu->addAction("&Compile", this, SLOT(actionCompile()), QKeySequence(Qt::Key_F5));
#ifdef ENABLE_CGAL
		menu->addAction("Compile and &Render (CGAL)", this, SLOT(actionRenderCGAL()), QKeySequence(Qt::Key_F6));
#endif
		menu->addAction("Display &AST...", this, SLOT(actionDisplayAST()));
		menu->addAction("Display CSG &Tree...", this, SLOT(actionDisplayCSGTree()));
		menu->addAction("Display CSG &Products...", this, SLOT(actionDisplayCSGProducts()));
		menu->addAction("Export as &STL...", this, SLOT(actionExportSTL()));
		menu->addAction("Export as &OFF...", this, SLOT(actionExportOFF()));
	}

	{
		QMenu *menu = menuBar()->addMenu("&View");
#ifdef ENABLE_OPENCSG
		actViewModeOpenCSG = menu->addAction("OpenCSG", this, SLOT(viewModeOpenCSG()));
		actViewModeOpenCSG->setCheckable(true);
#endif
#ifdef ENABLE_CGAL
		actViewModeCGALSurface = menu->addAction("CGAL Surfaces", this, SLOT(viewModeCGALSurface()));
		actViewModeCGALGrid = menu->addAction("CGAL Grid Only", this, SLOT(viewModeCGALGrid()));
		actViewModeCGALSurface->setCheckable(true);
		actViewModeCGALGrid->setCheckable(true);
#endif
		actViewModeThrownTogether = menu->addAction("Thrown Together", this, SLOT(viewModeThrownTogether()));
		actViewModeThrownTogether->setCheckable(true);
		menu->addSeparator();
		actViewModeShowEdges = menu->addAction("Show Edges", this, SLOT(viewModeShowEdges()));
		actViewModeShowEdges->setCheckable(true);

		menu->addSeparator();
		menu->addAction("Top");
		menu->addAction("Bottom");
		menu->addAction("Left");
		menu->addAction("Right");
		menu->addAction("Front");
		menu->addAction("Back");
		menu->addAction("Diagonal");
		menu->addSeparator();
		menu->addAction("Perspective");
		menu->addAction("Orthogonal");
	}

	console->setReadOnly(true);
	current_win = this;

	PRINT("OpenSCAD (www.openscad.at)");
	PRINT("Copyright (C) 2009  Clifford Wolf <clifford@clifford.at>");
	PRINT("");
	PRINT("This program is free software; you can redistribute it and/or modify");
	PRINT("it under the terms of the GNU General Public License as published by");
	PRINT("the Free Software Foundation; either version 2 of the License, or");
	PRINT("(at your option) any later version.");
	PRINT("");

	editor->setTabStopWidth(30);

	if (filename) {
		this->filename = QString(filename);
		maybe_change_dir();
		setWindowTitle(this->filename);
		load();
	} else {
		setWindowTitle("New Document");
	}

#ifdef ENABLE_OPENCSG
	viewModeOpenCSG();
#else
	viewModeThrownTogether();
#endif

	setCentralWidget(s1);
	current_win = NULL;
}

MainWindow::~MainWindow()
{
	if (root_module)
		delete root_module;
	if (root_node)
		delete root_node;
#ifdef ENABLE_CGAL
	if (root_N)
		delete root_N;
#endif
}

void MainWindow::load()
{
	if (!filename.isEmpty())
	{
		QString text;
		FILE *fp = fopen(filename.toAscii().data(), "rt");
		if (!fp) {
			PRINTA("Failed to open file: %1 (%2)", filename, QString(strerror(errno)));
		} else {
			char buffer[513];
			int rc;
			while ((rc = fread(buffer, 1, 512, fp)) > 0) {
				buffer[rc] = 0;
				text += buffer;
			}
			fclose(fp);
			PRINTA("Loaded design `%1'.", filename);
		}
		editor->setPlainText(text);
	}
}

void MainWindow::maybe_change_dir()
{
	if (filename.isEmpty())
		return;

	int dir_end_index = filename.lastIndexOf("/");
	if (dir_end_index < 0)
		return;

	QString dirname = filename.mid(0, dir_end_index);
	if (chdir(dirname.toAscii().data()) < 0)
		return;

	filename = filename.mid(dir_end_index+1);
}

void MainWindow::find_root_tag(AbstractNode *n)
{
	foreach(AbstractNode *v, n->children) {
		if (v->modinst->tag_root)
			root_node = v;
		if (root_node)
			return;
		find_root_tag(v);
	}
}

void MainWindow::compile()
{
	PRINT("Parsing design (AST generation)...");
	QApplication::processEvents();

	if (root_module) {
		delete root_module;
		root_module = NULL;
	}

	if (absolute_root_node) {
		delete absolute_root_node;
		absolute_root_node = NULL;
	}

	if (root_raw_term) {
		root_raw_term->unlink();
		root_raw_term = NULL;
	}

	if (root_norm_term) {
		root_norm_term->unlink();
		root_norm_term = NULL;
	}

	if (root_chain) {
		delete root_chain;
		root_chain = NULL;
	}

	foreach(CSGTerm *v, highlight_terms) {
		v->unlink();
	}
	highlight_terms.clear();
	if (highlights_chain) {
		delete highlights_chain;
		highlights_chain = NULL;
	}
	foreach(CSGTerm *v, background_terms) {
		v->unlink();
	}
	background_terms.clear();
	if (background_chain) {
		delete background_chain;
		background_chain = NULL;
	}
	root_node = NULL;
	enableOpenCSG = false;

	root_module = parse(editor->toPlainText().toAscii().data(), false);

	if (!root_module)
		goto fail;

	PRINT("Compiling design (CSG Tree generation)...");
	QApplication::processEvents();

	AbstractNode::idx_counter = 1;
	{
		ModuleInstanciation root_inst;
		absolute_root_node = root_module->evaluate(&root_ctx, &root_inst);
	}

	if (!absolute_root_node)
		goto fail;

	find_root_tag(absolute_root_node);
	if (!root_node)
		root_node = absolute_root_node;

	PRINT("Compiling design (CSG Products generation)...");
	QApplication::processEvents();

	double m[16];

	for (int i = 0; i < 16; i++)
		m[i] = i % 5 == 0 ? 1.0 : 0.0;

	root_raw_term = root_node->render_csg_term(m, &highlight_terms, &background_terms);

	if (!root_raw_term)
		goto fail;

	PRINT("Compiling design (CSG Products normalization)...");
	QApplication::processEvents();

	root_norm_term = root_raw_term->link();

	while (1) {
		CSGTerm *n = root_norm_term->normalize();
		root_norm_term->unlink();
		if (root_norm_term == n)
			break;
		root_norm_term = n;
	}

	if (!root_norm_term)
		goto fail;

	root_chain = new CSGChain();
	root_chain->import(root_norm_term);

	if (root_chain->polysets.size() > 1000) {
		PRINTF("WARNING: Normalized tree has %d elements!", root_chain->polysets.size());
		PRINTF("WARNING: OpenCSG rendering has been disabled.");
	} else {
		enableOpenCSG = true;
	}

	if (highlight_terms.size() > 0)
	{
		PRINTF("Compiling highlights (%d CSG Trees)...", highlight_terms.size());
		QApplication::processEvents();

		highlights_chain = new CSGChain();
		for (int i = 0; i < highlight_terms.size(); i++) {
			while (1) {
				CSGTerm *n = highlight_terms[i]->normalize();
				highlight_terms[i]->unlink();
				if (highlight_terms[i] == n)
					break;
				highlight_terms[i] = n;
			}
			highlights_chain->import(highlight_terms[i]);
		}
	}

	if (background_terms.size() > 0)
	{
		PRINTF("Compiling background (%d CSG Trees)...", background_terms.size());
		QApplication::processEvents();

		background_chain = new CSGChain();
		for (int i = 0; i < background_terms.size(); i++) {
			while (1) {
				CSGTerm *n = background_terms[i]->normalize();
				background_terms[i]->unlink();
				if (background_terms[i] == n)
					break;
				background_terms[i] = n;
			}
			background_chain->import(background_terms[i]);
		}
	}

	if (1) {
		PRINT("Compilation finished.");
		QApplication::processEvents();
	} else {
fail:
		PRINT("ERROR: Compilation failed!");
		QApplication::processEvents();
	}
}

void MainWindow::actionNew()
{
	filename = QString();
	setWindowTitle("New Document");
	editor->setPlainText("");
}

void MainWindow::actionOpen()
{
	current_win = this;
	QString new_filename = QFileDialog::getOpenFileName(this, "Open File", "", "OpenSCAD Designs (*.scad)");
	if (!new_filename.isEmpty())
	{
		filename = new_filename;
		maybe_change_dir();
		setWindowTitle(filename);

		QString text;
		FILE *fp = fopen(filename.toAscii().data(), "rt");
		if (!fp) {
			PRINTA("Failed to open file: %1 (%2)", QString(filename), QString(strerror(errno)));
		} else {
			char buffer[513];
			int rc;
			while ((rc = fread(buffer, 1, 512, fp)) > 0) {
				buffer[rc] = 0;
				text += buffer;
			}
			fclose(fp);
			PRINTA("Loaded design `%1'.", QString(filename));
		}
		editor->setPlainText(text);
	}
	current_win = NULL;
}

void MainWindow::actionSave()
{
	current_win = this;
	FILE *fp = fopen(filename.toAscii().data(), "wt");
	if (!fp) {
		PRINTA("Failed to open file for writing: %1 (%2)", QString(filename), QString(strerror(errno)));
	} else {
		fprintf(fp, "%s", editor->toPlainText().toAscii().data());
		fclose(fp);
		PRINTA("Saved design `%1'.", QString(filename));
	}
	current_win = NULL;
}

void MainWindow::actionSaveAs()
{
	QString new_filename = QFileDialog::getSaveFileName(this, "Save File", filename, "OpenSCAD Designs (*.scad)");
	if (!new_filename.isEmpty()) {
		filename = new_filename;
		maybe_change_dir();
		setWindowTitle(filename);
		actionSave();
	}
}

void MainWindow::actionReload()
{
	current_win = this;
	load();
	current_win = NULL;
}

void MainWindow::editIndent()
{
	QTextCursor cursor = editor->textCursor();
	int p1 = cursor.selectionStart();
	QString txt = cursor.selectedText();

	txt.replace(QString(QChar(8233)), QString(QChar(8233)) + QString("\t"));
	if (txt.endsWith(QString(QChar(8233)) + QString("\t")))
		txt.chop(1);
	txt = QString("\t") + txt;

	cursor.insertText(txt);
	int p2 = cursor.position();
	cursor.setPosition(p1, QTextCursor::MoveAnchor);
	cursor.setPosition(p2, QTextCursor::KeepAnchor);
	editor->setTextCursor(cursor);
}

void MainWindow::editUnindent()
{
	QTextCursor cursor = editor->textCursor();
	int p1 = cursor.selectionStart();
	QString txt = cursor.selectedText();

	txt.replace(QString(QChar(8233)) + QString("\t"), QString(QChar(8233)));
	if (txt.startsWith(QString("\t")))
		txt.remove(0, 1);

	cursor.insertText(txt);
	int p2 = cursor.position();
	cursor.setPosition(p1, QTextCursor::MoveAnchor);
	cursor.setPosition(p2, QTextCursor::KeepAnchor);
	editor->setTextCursor(cursor);
}

void MainWindow::editComment()
{
	QTextCursor cursor = editor->textCursor();
	int p1 = cursor.selectionStart();
	QString txt = cursor.selectedText();

	txt.replace(QString(QChar(8233)), QString(QChar(8233)) + QString("//"));
	if (txt.endsWith(QString(QChar(8233)) + QString("//")))
		txt.chop(2);
	txt = QString("//") + txt;

	cursor.insertText(txt);
	int p2 = cursor.position();
	cursor.setPosition(p1, QTextCursor::MoveAnchor);
	cursor.setPosition(p2, QTextCursor::KeepAnchor);
	editor->setTextCursor(cursor);
}

void MainWindow::editUncomment()
{
	QTextCursor cursor = editor->textCursor();
	int p1 = cursor.selectionStart();
	QString txt = cursor.selectedText();

	txt.replace(QString(QChar(8233)) + QString("//"), QString(QChar(8233)));
	if (txt.startsWith(QString("//")))
		txt.remove(0, 2);

	cursor.insertText(txt);
	int p2 = cursor.position();
	cursor.setPosition(p1, QTextCursor::MoveAnchor);
	cursor.setPosition(p2, QTextCursor::KeepAnchor);
	editor->setTextCursor(cursor);
}

void MainWindow::actionReloadCompile()
{
	current_win = this;
	console->clear();

	load();
	compile();

#ifdef ENABLE_OPENCSG
	if (!actViewModeOpenCSG->isChecked() && !actViewModeThrownTogether->isChecked()) {
		viewModeOpenCSG();
	}
	else
#endif
	{
		screen->updateGL();
	}
	current_win = NULL;
}

void MainWindow::actionCompile()
{
	current_win = this;
	console->clear();

	compile();

#ifdef ENABLE_OPENCSG
	if (!actViewModeOpenCSG->isChecked() && !actViewModeThrownTogether->isChecked()) {
		viewModeOpenCSG();
	}
	else
#endif
	{
		screen->updateGL();
	}
	current_win = NULL;
}

#ifdef ENABLE_CGAL

static void report_func(const class AbstractNode*, void *vp, int mark)
{
	QProgressDialog *pd = (QProgressDialog*)vp;
	int v = (int)((mark*100.0) / progress_report_count);
	pd->setValue(v < 100 ? v : 99);
	QString label;
	label.sprintf("Rendering Polygon Mesh using CGAL (%d/%d)", mark, progress_report_count);
	pd->setLabelText(label);
	QApplication::processEvents();
}

void MainWindow::actionRenderCGAL()
{
	current_win = this;
	console->clear();

	compile();

	if (!root_module || !root_node)
		return;

	if (root_N) {
		delete root_N;
		root_N = NULL;
	}

	PRINT("Rendering Polygon Mesh using CGAL...");
	QApplication::processEvents();

	QTime t;
	t.start();

	QProgressDialog *pd = new QProgressDialog("Rendering Polygon Mesh using CGAL...", QString(), 0, 100);
	pd->setValue(0);
	pd->setAutoClose(false);
	pd->show();
	QApplication::processEvents();

	progress_report_prep(root_node, report_func, pd);
	root_N = new CGAL_Nef_polyhedron(root_node->render_cgal_nef_polyhedron());
	progress_report_fin();

	PRINTF("Number of vertices currently in CGAL cache: %d", AbstractNode::cgal_nef_cache.totalCost());
	PRINTF("Number of objects currently in CGAL cache: %d", AbstractNode::cgal_nef_cache.size());
	QApplication::processEvents();

	PRINTF("   Simple:     %6s", root_N->is_simple() ? "yes" : "no");
	QApplication::processEvents();
	PRINTF("   Valid:      %6s", root_N->is_valid() ? "yes" : "no");
	QApplication::processEvents();
	PRINTF("   Vertices:   %6d", (int)root_N->number_of_vertices());
	QApplication::processEvents();
	PRINTF("   Halfedges:  %6d", (int)root_N->number_of_halfedges());
	QApplication::processEvents();
	PRINTF("   Edges:      %6d", (int)root_N->number_of_edges());
	QApplication::processEvents();
	PRINTF("   Halffacets: %6d", (int)root_N->number_of_halffacets());
	QApplication::processEvents();
	PRINTF("   Facets:     %6d", (int)root_N->number_of_facets());
	QApplication::processEvents();
	PRINTF("   Volumes:    %6d", (int)root_N->number_of_volumes());
	QApplication::processEvents();

	int s = t.elapsed() / 1000;
	PRINTF("Total rendering time: %d hours, %d minutes, %d seconds", s / (60*60), (s / 60) % 60, s % 60);

	if (!actViewModeCGALSurface->isChecked() && !actViewModeCGALGrid->isChecked()) {
		viewModeCGALSurface();
	} else {
		screen->updateGL();
	}

	PRINT("Rendering finished.");

	delete pd;
	current_win = NULL;

}

#endif /* ENABLE_CGAL */

void MainWindow::actionDisplayAST()
{
	current_win = this;
	QTextEdit *e = new QTextEdit(NULL);
	e->setTabStopWidth(30);
	e->setWindowTitle("AST Dump");
	if (root_module) {
		e->setPlainText(root_module->dump("", ""));
	} else {
		e->setPlainText("No AST to dump. Please try compiling first...");
	}
	e->show();
	e->resize(600, 400);
	current_win = NULL;
}

void MainWindow::actionDisplayCSGTree()
{
	current_win = this;
	QTextEdit *e = new QTextEdit(NULL);
	e->setTabStopWidth(30);
	e->setWindowTitle("CSG Tree Dump");
	if (root_node) {
		e->setPlainText(root_node->dump(""));
	} else {
		e->setPlainText("No CSG to dump. Please try compiling first...");
	}
	e->show();
	e->resize(600, 400);
	current_win = NULL;
}

void MainWindow::actionDisplayCSGProducts()
{
	current_win = this;
	QTextEdit *e = new QTextEdit(NULL);
	e->setTabStopWidth(30);
	e->setWindowTitle("CSG Products Dump");
	e->setPlainText(QString("\nCSG before normalization:\n%1\n\n\nCSG after normalization:\n%2\n\n\nCSG rendering chain:\n%3\n\n\nHighlights CSG rendering chain:\n%4\n\n\nBackground CSG rendering chain:\n%5\n").arg(root_raw_term ? root_raw_term->dump() : "N/A", root_norm_term ? root_norm_term->dump() : "N/A", root_chain ? root_chain->dump() : "N/A", highlights_chain ? highlights_chain->dump() : "N/A", background_chain ? background_chain->dump() : "N/A"));
	e->show();
	e->resize(600, 400);
	current_win = NULL;
}

void MainWindow::actionExportSTL()
{
	current_win = this;

#ifdef ENABLE_CGAL
	if (!root_N) {
		PRINT("Nothing to export! Try building first (press F6).");
		current_win = NULL;
		return;
	}

	if (!root_N->is_simple()) {
		PRINT("Object isn't a single polyeder or otherwise invalid! Modify your design..");
		current_win = NULL;
		return;
	}

	QString stl_filename = QFileDialog::getSaveFileName(this, "Export STL File", "", "STL Files (*.stl)");
	if (stl_filename.isEmpty()) {
		PRINT("No filename specified. STL export aborted.");
		current_win = NULL;
		return;
	}

	CGAL_Polyhedron P;
	root_N->convert_to_Polyhedron(P);

	typedef CGAL_Polyhedron::Vertex                                 Vertex;
	typedef CGAL_Polyhedron::Vertex_const_iterator                  VCI;
	typedef CGAL_Polyhedron::Facet_const_iterator                   FCI;
	typedef CGAL_Polyhedron::Halfedge_around_facet_const_circulator HFCC;

	FILE *f = fopen(stl_filename.toAscii().data(), "w");
	if (!f) {
		PRINT("Can't open STL file for STL export.");
		current_win = NULL;
		return;
	}
	fprintf(f, "solid\n");

	QProgressDialog *pd = new QProgressDialog("Exporting object to STL file...",
			QString(), 0, root_N->number_of_facets() + 1);
	pd->setValue(0);
	pd->setAutoClose(false);
	pd->show();
	QApplication::processEvents();

	int facet_count = 0;
	for (FCI fi = P.facets_begin(); fi != P.facets_end(); ++fi) {
		HFCC hc = fi->facet_begin();
		HFCC hc_end = hc;
		Vertex v1, v2, v3;
		v1 = *VCI((hc++)->vertex());
		v3 = *VCI((hc++)->vertex());
		do {
			v2 = v3;
			v3 = *VCI((hc++)->vertex());
			double x1 = CGAL::to_double(v1.point().x());
			double y1 = CGAL::to_double(v1.point().y());
			double z1 = CGAL::to_double(v1.point().z());
			double x2 = CGAL::to_double(v2.point().x());
			double y2 = CGAL::to_double(v2.point().y());
			double z2 = CGAL::to_double(v2.point().z());
			double x3 = CGAL::to_double(v3.point().x());
			double y3 = CGAL::to_double(v3.point().y());
			double z3 = CGAL::to_double(v3.point().z());
			QString vs1, vs2, vs3;
			vs1.sprintf("%f %f %f", x1, y1, z1);
			vs2.sprintf("%f %f %f", x2, y2, z2);
			vs3.sprintf("%f %f %f", x3, y3, z3);
			if (vs1 != vs2 && vs1 != vs3 && vs2 != vs3) {
				
				double nx = (y1-y2)*(z1-z3) - (z1-z2)*(y1-y3);
				double ny = (z1-z2)*(x1-x3) - (x1-x2)*(z1-z3);
				double nz = (x1-x2)*(y1-y3) - (y1-y2)*(x1-x3);
				double n_scale = 1 / sqrt(nx*nx + ny*ny + nz*nz);
				fprintf(f, "  facet normal %f %f %f\n",
						nx * n_scale, ny * n_scale, nz * n_scale);
				fprintf(f, "    outer loop\n");
				fprintf(f, "      vertex %s\n", vs1.toAscii().data());
				fprintf(f, "      vertex %s\n", vs2.toAscii().data());
				fprintf(f, "      vertex %s\n", vs3.toAscii().data());
				fprintf(f, "    endloop\n");
				fprintf(f, "  endfacet\n");
			}
		} while (hc != hc_end);
		pd->setValue(facet_count++);
		QApplication::processEvents();
	}

	fprintf(f, "endsolid\n");
	fclose(f);

	PRINT("STL export finished.");

	delete pd;
#endif /* ENABLE_CGAL */
	current_win = NULL;
}

void MainWindow::actionExportOFF()
{
	current_win = this;
	PRINTA("Function %1 is not implemented yet!", QString(__PRETTY_FUNCTION__));
	current_win = NULL;
}

void MainWindow::viewModeActionsUncheck()
{
#ifdef ENABLE_OPENCSG
	actViewModeOpenCSG->setChecked(false);
#endif
#ifdef ENABLE_CGAL
	actViewModeCGALSurface->setChecked(false);
	actViewModeCGALGrid->setChecked(false);
#endif
	actViewModeThrownTogether->setChecked(false);
}

#ifdef ENABLE_OPENCSG

class OpenCSGPrim : public OpenCSG::Primitive
{
public:
	OpenCSGPrim(OpenCSG::Operation operation, unsigned int convexity) :
			OpenCSG::Primitive(operation, convexity) { }
	PolySet *p;
	virtual void render() {
		p->render_surface(PolySet::COLOR_NONE);
	}
};

static void renderCSGChainviaOpenCSG(CSGChain *chain, GLint *shaderinfo, bool highlight, bool background)
{
	std::vector<OpenCSG::Primitive*> primitives;
	int j = 0;
	for (int i = 0;; i++)
	{
		bool last = i == chain->polysets.size();

		if (last || chain->types[i] == CSGTerm::UNION)
		{
			OpenCSG::render(primitives);
			glDepthFunc(GL_EQUAL);
			if (shaderinfo)
				glUseProgram(shaderinfo[0]);
			for (; j < i; j++) {
				if (highlight) {
					chain->polysets[j]->render_surface(PolySet::COLOR_HIGHLIGHT, shaderinfo);
				} else if (background) {
					chain->polysets[j]->render_surface(PolySet::COLOR_BACKGROUND, shaderinfo);
				} else if (chain->types[j] == CSGTerm::DIFFERENCE) {
					chain->polysets[j]->render_surface(PolySet::COLOR_CUTOUT, shaderinfo);
				} else {
					chain->polysets[j]->render_surface(PolySet::COLOR_MATERIAL, shaderinfo);
				}
			}
			if (shaderinfo)
				glUseProgram(0);
			for (unsigned int k = 0; k < primitives.size(); k++) {
				delete primitives[k];
			}
			glDepthFunc(GL_LEQUAL);
			primitives.clear();
		}

		if (last)
			break;

		OpenCSGPrim *prim = new OpenCSGPrim(chain->types[i] == CSGTerm::DIFFERENCE ?
				OpenCSG::Subtraction : OpenCSG::Intersection, chain->polysets[i]->convexity);
		prim->p = chain->polysets[i];
		primitives.push_back(prim);
	}
}

static void renderGLThrownTogether(void *vp);

static void renderGLviaOpenCSG(void *vp)
{
	MainWindow *m = (MainWindow*)vp;
	if (!m->enableOpenCSG) {
		renderGLThrownTogether(vp);
		return;
	}
	static int glew_initialized = 0;
	if (!glew_initialized) {
		glew_initialized = 1;
		glewInit();
	}
	if (m->root_chain) {
		GLint *shaderinfo = m->screen->shaderinfo;
		if (!shaderinfo[0])
			shaderinfo = NULL;
		renderCSGChainviaOpenCSG(m->root_chain, m->actViewModeShowEdges->isChecked() ? shaderinfo : NULL, false, false);
		if (m->background_chain) {
			renderCSGChainviaOpenCSG(m->background_chain, m->actViewModeShowEdges->isChecked() ? shaderinfo : NULL, false, true);
		}
		if (m->highlights_chain) {
			renderCSGChainviaOpenCSG(m->highlights_chain, m->actViewModeShowEdges->isChecked() ? shaderinfo : NULL, true, false);
		}
	}
}

void MainWindow::viewModeOpenCSG()
{
	viewModeActionsUncheck();
	actViewModeOpenCSG->setChecked(true);
	screen->renderfunc = renderGLviaOpenCSG;
	screen->renderfunc_vp = this;
	screen->updateGL();
}

#endif /* ENABLE_OPENCSG */

#ifdef ENABLE_CGAL

// a little hackish: we need access to default-private members of
// CGAL::OGL::Nef3_Converter so we can implement our own draw function
// that does not scale the model. so we define 'class' to 'struct'
// for this header..
//
// theoretically there could be two problems:
// 1.) defining language keyword with the pre processor is illegal afair
// 2.) the compiler could use a different memory layout or name mangling for structs
//
// both does not seam to be the case with todays compilers...
//
#define class struct
#include <CGAL/Nef_3/OGL_helper.h>
#undef class

static void renderGLviaCGAL(void *vp)
{
	MainWindow *m = (MainWindow*)vp;
	if (m->root_N) {
		CGAL::OGL::Polyhedron P;
		CGAL::OGL::Nef3_Converter<CGAL_Nef_polyhedron>::convert_to_OGLPolyhedron(*m->root_N, &P);
		P.init();
		if (m->actViewModeCGALSurface->isChecked())
			P.set_style(CGAL::OGL::SNC_BOUNDARY);
		if (m->actViewModeCGALGrid->isChecked())
			P.set_style(CGAL::OGL::SNC_SKELETON);
#if 0
		P.draw();
#else
		if (P.style == CGAL::OGL::SNC_BOUNDARY) {
			glCallList(P.object_list_+2);
			if (m->actViewModeShowEdges->isChecked()) {
				glDisable(GL_LIGHTING);
				glCallList(P.object_list_+1);
				glCallList(P.object_list_);
			}
		} else {
			glDisable(GL_LIGHTING);
			glCallList(P.object_list_+1);
			glCallList(P.object_list_);
		}
#endif
	}
}

void MainWindow::viewModeCGALSurface()
{
	viewModeActionsUncheck();
	actViewModeCGALSurface->setChecked(true);
	screen->renderfunc = renderGLviaCGAL;
	screen->renderfunc_vp = this;
	screen->updateGL();
}

void MainWindow::viewModeCGALGrid()
{
	viewModeActionsUncheck();
	actViewModeCGALGrid->setChecked(true);
	screen->renderfunc = renderGLviaCGAL;
	screen->renderfunc_vp = this;
	screen->updateGL();
}

#endif /* ENABLE_CGAL */

static void renderGLThrownTogetherChain(MainWindow *m, CSGChain *chain, bool highlight, bool background)
{
	glDepthFunc(GL_LEQUAL);
	QHash<PolySet*,int> polySetVisitMark;
	bool showEdges = m->actViewModeShowEdges->isChecked();
	for (int i = 0; i < chain->polysets.size(); i++) {
		if (polySetVisitMark[chain->polysets[i]]++ > 0)
			continue;
		if (highlight) {
			chain->polysets[i]->render_surface(PolySet::COLOR_HIGHLIGHT);
			if (showEdges) {
				glDisable(GL_LIGHTING);
				chain->polysets[i]->render_edges(PolySet::COLOR_HIGHLIGHT);
				glEnable(GL_LIGHTING);
			}
		} else if (background) {
			chain->polysets[i]->render_surface(PolySet::COLOR_BACKGROUND);
			if (showEdges) {
				glDisable(GL_LIGHTING);
				chain->polysets[i]->render_edges(PolySet::COLOR_BACKGROUND);
				glEnable(GL_LIGHTING);
			}
		} else if (chain->types[i] == CSGTerm::DIFFERENCE) {
			chain->polysets[i]->render_surface(PolySet::COLOR_CUTOUT);
			if (showEdges) {
				glDisable(GL_LIGHTING);
				chain->polysets[i]->render_edges(PolySet::COLOR_CUTOUT);
				glEnable(GL_LIGHTING);
			}
		} else {
			chain->polysets[i]->render_surface(PolySet::COLOR_MATERIAL);
			if (showEdges) {
				glDisable(GL_LIGHTING);
				chain->polysets[i]->render_edges(PolySet::COLOR_MATERIAL);
				glEnable(GL_LIGHTING);
			}
		}
	}
}


static void renderGLThrownTogether(void *vp)
{
	MainWindow *m = (MainWindow*)vp;
	if (m->root_chain)
		renderGLThrownTogetherChain(m, m->root_chain, false, false);
	if (m->background_chain)
		renderGLThrownTogetherChain(m, m->background_chain, false, true);
	if (m->highlights_chain)
		renderGLThrownTogetherChain(m, m->highlights_chain, true, false);
}

void MainWindow::viewModeThrownTogether()
{
	viewModeActionsUncheck();
	actViewModeThrownTogether->setChecked(true);
	screen->renderfunc = renderGLThrownTogether;
	screen->renderfunc_vp = this;
	screen->updateGL();
}

void MainWindow::viewModeShowEdges()
{
	screen->updateGL();
}