Previously graph layout was done using the Kamada-Kawai layout algorithm

implemented in Boost.  I am replacing this with a custom implementation of
a constrained stress-majorization algorithm.

The stress-majorization algorithm is more robust and has better convergence
characteristics than Kamada-Kawai, and also simple constraints can be placed
on node position (for example, to enforce downward-pointing edges, non-overlap constraints, or cluster constraints).

Another big advantage is that we no longer need Boost.

I've tested the basic functionality, but I have yet to properly handle
disconnected graphs or to properly scale the resulting layout.

This commit also includes significant refactoring... the quadratic program solver - libvpsc (Variable Placement with Separation Constraints) has been moved to src/libvpsc and the actual graph layout algorithm is in libcola.

(bzr r1394)

1 files changed, 0 insertions, 115 deletions

diff --git a/src/removeoverlap/remove_rectangle_overlap.cpp b/src/removeoverlap/remove_rectangle_overlap.cpp
deleted file mode 100755
index 9fbef647b..000000000
--- a/src/removeoverlap/remove_rectangle_overlap.cpp
+++ /dev/null
@@ -1,115 +0,0 @@
-/**
- * \brief remove overlaps between a set of rectangles.
- *
- * Authors:
- *   Tim Dwyer <tgdwyer@gmail.com>
- *
- * Copyright (C) 2005 Authors
- *
- * Released under GNU LGPL.  Read the file 'COPYING' for more information.
- */
-
-#include <iostream>
-#include <cassert>
-#include "generate-constraints.h"
-#include "solve_VPSC.h"
-#include "variable.h"
-#include "constraint.h"
-#ifdef RECTANGLE_OVERLAP_LOGGING
-#include <fstream>
-#include "blocks.h"
-using std::ios;
-using std::ofstream;
-using std::endl;
-#endif
-
-#define EXTRA_GAP 0.0001
-
-double Rectangle::xBorder=0;
-double Rectangle::yBorder=0;
-/**
- * Takes an array of n rectangles and moves them as little as possible
- * such that rectangles are separated by at least xBorder horizontally
- * and yBorder vertically
- *
- * Works in three passes: 
- * 1) removes some overlap horizontally
- * 2) removes remaining overlap vertically
- * 3) a last horizontal pass removes all overlap starting from original
- *    x-positions - this corrects the case where rectangles were moved 
- *    too much in the first pass.
- */
-void removeRectangleOverlap(unsigned n, Rectangle *rs[], double xBorder, double yBorder) {
-	try {
-	// The extra gap avoids numerical imprecision problems
-	Rectangle::setXBorder(xBorder+EXTRA_GAP);
-	Rectangle::setYBorder(yBorder+EXTRA_GAP);
-	Variable **vs=new Variable*[n];
-	for(unsigned int i=0;i<n;i++) {
-		vs[i]=new Variable(i,0,1);
-	}
-	Constraint **cs;
-	double *oldX = new double[n];
-	int m=generateXConstraints(n,rs,vs,cs,true);
-	for(unsigned int i=0;i<n;i++) {
-		oldX[i]=vs[i]->desiredPosition;
-	}
-	VPSC vpsc_x(n,vs,m,cs);
-#ifdef RECTANGLE_OVERLAP_LOGGING
-	ofstream f(LOGFILE,ios::app);
-	f<<"Calling VPSC: Horizontal pass 1"<<endl;
-	f.close();
-#endif
-	vpsc_x.solve();
-	for(unsigned int i=0;i<n;i++) {
-		rs[i]->moveCentreX(vs[i]->position());
-	}
-	for(int i = 0; i < m; ++i) {
-		delete cs[i];
-	}
-	delete [] cs;
-	// Removing the extra gap here ensures things that were moved to be adjacent to
-	// one another above are not considered overlapping
-	Rectangle::setXBorder(Rectangle::xBorder-EXTRA_GAP);
-	m=generateYConstraints(n,rs,vs,cs);
-	VPSC vpsc_y(n,vs,m,cs);
-#ifdef RECTANGLE_OVERLAP_LOGGING
-	f.open(LOGFILE,ios::app);
-	f<<"Calling VPSC: Vertical pass"<<endl;
-	f.close();
-#endif
-	vpsc_y.solve();
-	for(unsigned int i=0;i<n;i++) {
-		rs[i]->moveCentreY(vs[i]->position());
-		rs[i]->moveCentreX(oldX[i]);
-	}
-	delete [] oldX;
-	for(int i = 0; i < m; ++i) {
-		delete cs[i];
-	}
-	delete [] cs;
-	Rectangle::setYBorder(Rectangle::yBorder-EXTRA_GAP);
-	m=generateXConstraints(n,rs,vs,cs,false);
-	VPSC vpsc_x2(n,vs,m,cs);
-#ifdef RECTANGLE_OVERLAP_LOGGING
-	f.open(LOGFILE,ios::app);
-	f<<"Calling VPSC: Horizontal pass 2"<<endl;
-	f.close();
-#endif
-	vpsc_x2.solve();
-	for(int i = 0; i < m; ++i) {
-		delete cs[i];
-	}
-	delete [] cs;
-	for(unsigned int i=0;i<n;i++) {
-		rs[i]->moveCentreX(vs[i]->position());
-		delete vs[i];
-	}
-	delete [] vs;
-	} catch (char const *str) {
-		std::cerr<<str<<std::endl;
-		for(unsigned int i=0;i<n;i++) {
-			std::cerr << *rs[i]<<std::endl;
-		}
-	}
-}