* Merge from trunk

* Update to new snapping API
* Modify the join action slightly

(bzr r8846.2.11)

1 files changed, 255 insertions, 0 deletions

diff --git a/src/libavoid/vpsc.h b/src/libavoid/vpsc.h
new file mode 100644
index 000000000..4d6d8ce61
--- /dev/null
+++ b/src/libavoid/vpsc.h
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+/*
+ * vim: ts=4 sw=4 et tw=0 wm=0
+ *
+ * libavoid - Fast, Incremental, Object-avoiding Line Router
+ *
+ * Copyright (C) 2005-2009  Monash University
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * See the file LICENSE.LGPL distributed with the library.
+ *
+ * Licensees holding a valid commercial license may use this file in
+ * accordance with the commercial license agreement provided with the 
+ * library.
+ *
+ * This library 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.  
+ *
+ * Author(s):   Tim Dwyer  <Tim.Dwyer@csse.monash.edu.au>
+ *
+ * --------------
+ *
+ * This file contains a slightly modified version of Solver() from libvpsc:
+ * A solver for the problem of Variable Placement with Separation Constraints.
+ * It has the following changes from the Adaptagrams VPSC version:
+ *  -  The required VPSC code has been consolidated into a single file.
+ *  -  Unnecessary code (like Solver) has been removed.
+ *  -  The PairingHeap code has been replaced by a STL priority_queue.
+ *
+ * Modifications:  Michael Wybrow  <mjwybrow@users.sourceforge.net>
+ *
+*/
+
+#ifndef LIBAVOID_VPSC_H
+#define LIBAVOID_VPSC_H
+
+#include <vector>
+#include <list>
+#include <set>
+#include <queue>
+
+namespace Avoid {
+
+class Variable;
+class Constraint;
+typedef std::vector<Variable*> Variables;
+typedef std::vector<Constraint*> Constraints;
+class CompareConstraints {
+public:
+    bool operator() (Constraint *const &l, Constraint *const &r) const;
+};
+struct PositionStats {
+    PositionStats() : scale(0), AB(0), AD(0), A2(0) {}
+    void addVariable(Variable* const v);
+    double scale;
+    double AB;
+    double AD;
+    double A2;
+};
+
+typedef std::priority_queue<Constraint*,std::vector<Constraint*>,
+        CompareConstraints> Heap;
+
+class Block
+{
+    typedef Variables::iterator Vit;
+    typedef Constraints::iterator Cit;
+    typedef Constraints::const_iterator Cit_const;
+
+    friend std::ostream& operator <<(std::ostream &os,const Block &b);
+public:
+    Variables *vars;
+    double posn;
+    //double weight;
+    //double wposn;
+    PositionStats ps;
+    Block(Variable* const v=NULL);
+    ~Block(void);
+    Constraint* findMinLM();
+    Constraint* findMinLMBetween(Variable* const lv, Variable* const rv);
+    Constraint* findMinInConstraint();
+    Constraint* findMinOutConstraint();
+    void deleteMinInConstraint();
+    void deleteMinOutConstraint();
+    void updateWeightedPosition();
+    void merge(Block *b, Constraint *c, double dist);
+    Block* merge(Block *b, Constraint *c);
+    void mergeIn(Block *b);
+    void mergeOut(Block *b);
+    void split(Block *&l, Block *&r, Constraint *c);
+    Constraint* splitBetween(Variable* vl, Variable* vr, Block* &lb, Block* &rb);
+    void setUpInConstraints();
+    void setUpOutConstraints();
+    double cost();
+    bool deleted;
+    long timeStamp;
+    Heap *in;
+    Heap *out;
+    bool getActivePathBetween(Constraints& path, Variable const* u,
+               Variable const* v, Variable const *w) const;
+    bool isActiveDirectedPathBetween(
+            Variable const* u, Variable const* v) const;
+    bool getActiveDirectedPathBetween(Constraints& path, Variable const * u, Variable const * v) const;
+private:
+    typedef enum {NONE, LEFT, RIGHT} Direction;
+    typedef std::pair<double, Constraint*> Pair;
+    void reset_active_lm(Variable* const v, Variable* const u);
+    void list_active(Variable* const v, Variable* const u);
+    double compute_dfdv(Variable* const v, Variable* const u);
+    double compute_dfdv(Variable* const v, Variable* const u, Constraint *&min_lm);
+    bool split_path(Variable*, Variable* const, Variable* const, 
+            Constraint* &min_lm, bool desperation);
+    bool canFollowLeft(Constraint const* c, Variable const* last) const;
+    bool canFollowRight(Constraint const* c, Variable const* last) const;
+    void populateSplitBlock(Block *b, Variable* v, Variable const* u);
+    void addVariable(Variable* v);
+    void setUpConstraintHeap(Heap* &h,bool in);
+};
+
+
+class Constraint;
+typedef std::vector<Constraint*> Constraints;
+class Variable
+{
+    friend std::ostream& operator <<(std::ostream &os, const Variable &v);
+    friend class Block;
+    friend class Constraint;
+    friend class IncSolver;
+public:
+    int id; // useful in log files
+    double desiredPosition;
+    double finalPosition;
+    double weight; // how much the variable wants to 
+                   // be at it's desired position
+    double scale; // translates variable to another space
+    double offset;
+    Block *block;
+    bool visited;
+    bool fixedDesiredPosition;
+    Constraints in;
+    Constraints out;
+    char *toString();
+    inline Variable(const int id, const double desiredPos=-1.0, 
+            const double weight=1.0, const double scale=1.0)
+        : id(id)
+        , desiredPosition(desiredPos)
+        , weight(weight)
+        , scale(scale)
+        , offset(0)
+        , block(NULL)
+        , visited(false)
+        , fixedDesiredPosition(false)
+    {
+    }
+    double dfdv() const {
+        return 2. * weight * ( position() - desiredPosition );
+    }
+private:
+    double position() const {
+        return (block->ps.scale*block->posn+offset)/scale;
+    }
+};
+
+
+class Constraint
+{
+    friend std::ostream& operator <<(std::ostream &os,const Constraint &c);
+public:
+    Variable *left;
+    Variable *right;
+    double gap;
+    double lm;
+    Constraint(Variable *left, Variable *right, double gap, bool equality=false);
+    ~Constraint();
+    double slack() const;
+    long timeStamp;
+    bool active;
+    const bool equality;
+    bool unsatisfiable;
+};
+/*
+ * A block structure defined over the variables such that each block contains
+ * 1 or more variables, with the invariant that all constraints inside a block
+ * are satisfied by keeping the variables fixed relative to one another
+ */
+class Blocks : public std::set<Block*>
+{
+public:
+    Blocks(Variables const &vs);
+    ~Blocks(void);
+    void mergeLeft(Block *r);
+    void mergeRight(Block *l);
+    void split(Block *b, Block *&l, Block *&r, Constraint *c);
+    std::list<Variable*> *totalOrder();
+    void cleanup();
+    double cost();
+private:
+    void dfsVisit(Variable *v, std::list<Variable*> *order);
+    void removeBlock(Block *doomed);
+    Variables const &vs;
+    int nvs;
+};
+
+extern long blockTimeCtr;
+
+struct UnsatisfiableException {
+    Constraints path;
+};
+struct UnsatisfiedConstraint {
+    UnsatisfiedConstraint(Constraint& c):c(c) {}
+    Constraint& c;
+};
+/*
+ * Variable Placement with Separation Constraints problem instance
+ */
+class IncSolver {
+public:
+    unsigned splitCnt;
+    bool satisfy();
+    bool solve();
+    void moveBlocks();
+    void splitBlocks();
+    IncSolver(Variables const &vs, Constraints const &cs);
+
+    ~IncSolver();
+    Variables const & getVariables() { return vs; }
+protected:
+    Blocks *bs;
+    unsigned m;
+    Constraints const &cs;
+    unsigned n;
+    Variables const &vs;
+    void printBlocks();
+    void copyResult();
+private:
+    bool constraintGraphIsCyclic(const unsigned n, Variable* const vs[]);
+    bool blockGraphIsCyclic();
+    Constraints inactive;
+    Constraints violated;
+    Constraint* mostViolated(Constraints &l);
+};
+
+struct delete_object
+{
+    template <typename T>
+    void operator()(T *ptr){ delete ptr;}
+};
+
+
+}
+
+#endif // AVOID_VPSC_H