/*
 * Copyright 2007, Ingo Weinhold <bonefish@cs.tu-berlin.de>.
 * All rights reserved. Distributed under the terms of the MIT License.
 */
#ifndef LAYOUT_OPTIMIZER_H
#define LAYOUT_OPTIMIZER_H

#include <List.h>
#include <math.h>

static const double kEqualsEpsilon = 0.000001;


namespace BPrivate {
namespace Layout {

class LayoutOptimizer {
public:
                                                                LayoutOptimizer(int32 variableCount);
                                                                ~LayoutOptimizer();

                        status_t                        InitCheck() const;

                        LayoutOptimizer*        Clone() const;

                        bool                            AddConstraint(int32 left, int32 right,
                                                                        double value, bool equality);
                        bool                            AddConstraintsFrom(
                                                                        const LayoutOptimizer* solver);
                        void                            RemoveAllConstraints();

                        bool                            Solve(const double* desired, double size,
                                                                        double* values);

private:
                        bool                            _Solve(const double* desired, double* values);
                        bool                            _SolveSubProblem(const double* d, int am,
                                                                        double* p);
                        void                            _SetResult(const double* x, double* values);


                        struct Constraint;

                        int32                           fVariableCount;
                        BList                           fConstraints;
                        double*                         fVariables;
                        double**                        fTemp1;
                        double**                        fTemp2;
                        double**                        fZtrans;
                        double**                        fQ;
                        double**                        fActiveMatrix;
                        double**                        fActiveMatrixTemp;
};

}       // namespace Layout
}       // namespace BPrivate

using BPrivate::Layout::LayoutOptimizer;


inline bool
fuzzy_equals(double a, double b)
{
        return fabs(a - b) < kEqualsEpsilon;
}


#endif  // LAYOUT_OPTIMIZER_H