Updated libs from the Adaptagrams project: libavoid, libcola and libvspc; changed the code to match the new API

Signed-off-by: Sylvain Chiron <chironsylvain@orange.fr>

1 files changed, 119 insertions, 42 deletions

diff --git a/src/libvpsc/constraint.h b/src/libvpsc/constraint.h
index a3173359c..271a2cfce 100644
--- a/src/libvpsc/constraint.h
+++ b/src/libvpsc/constraint.h
@@ -1,62 +1,139 @@
 /*
- * Authors:
- *   Tim Dwyer <tgdwyer@gmail.com>
+ * vim: ts=4 sw=4 et tw=0 wm=0
  *
- * Copyright (C) 2005 Authors
+ * libvpsc - A solver for the problem of Variable Placement with 
+ *           Separation Constraints.
  *
- * Released under GNU LGPL.  Read the file 'COPYING' for more information.
- */
+ * Copyright (C) 2005-2008  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.
+ *
+ * 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
+*/
+
+
+#ifndef VPSC_CONSTRAINT_H
+#define VPSC_CONSTRAINT_H
 
-#ifndef SEEN_REMOVEOVERLAP_CONSTRAINT_H
-#define SEEN_REMOVEOVERLAP_CONSTRAINT_H
+// cmath needs ::strcpy_s under MinGW so include cstring.
+#include <cstring>
 
+#include <cfloat>
 #include <iostream>
-#include "variable.h"
+#include <vector>
+#include <sstream>
+
+#include "libvpsc/variable.h"
+
 namespace vpsc {
 
-/**
- * A constraint determines a minimum or exact spacing required between
- * two variables.
- *
- */
+class Variable;
+typedef std::vector<Variable *> Variables;
+
+//! @brief A constraint determines a minimum or exact spacing required between
+//!        two Variable objects.
+//!
 class Constraint
 {
 	friend std::ostream& operator <<(std::ostream &os,const Constraint &c);
 public:
-	Variable *left;
+    //! @brief Constructs a minimum or exact spacing constraint between two
+    //!        Variable objects.
+    //!
+    //! (left + gap < right)  or (left + gap == right)
+    //!
+    //! @param[in] left      The left Variable.
+    //! @param[in] right     The right Variable.
+    //! @param[in] gap       The minimum or exact distance to separate the 
+    //!                      variables by.
+    //! @param[in] equality  Whether the separation is an exact distance or
+    //!                      not.  The default is false.
+	Constraint(Variable *left, Variable *right, double gap, 
+            bool equality = false);
+	~Constraint();
+
+    /**
+     *  @brief Returns a textual description of the constraint.
+     *
+     *  @return     A string describing the constraint.
+     */
+    std::string toString(void) const
+    {
+        std::stringstream stream;
+        stream << "Constraint: var(" << left->id << ") ";
+        if (gap < 0)
+        {
+            stream << "- " << -gap << " ";
+        }
+        else
+        {
+            stream << "+ " << gap << " ";
+        }
+        stream << ((equality) ? "==" : "<=");
+        stream << " var(" << right->id << ") ";
+        return stream.str();
+    }
+
+    inline double slack(void) const 
+    { 
+        if (unsatisfiable)
+        {
+            return DBL_MAX;
+        }
+        if (needsScaling)
+        {
+            return right->scale * right->position() - gap - 
+                    left->scale * left->position();
+        }
+        COLA_ASSERT(left->scale == 1);
+        COLA_ASSERT(right->scale == 1);
+        return right->unscaledPosition() - gap - left->unscaledPosition(); 
+    }
+
+    //! @brief The left Variable.
+    Variable *left;
+    //! @brief The right Variable.
 	Variable *right;
+    //! @brief The minimum or exact distance to separate the variables by.
 	double gap;
 	double lm;
-	Constraint(Variable *left, Variable *right, double gap, bool equality=false);
-    virtual ~Constraint();
-	inline double slack() const { return right->position() - gap - left->position(); }
 	long timeStamp;
 	bool active;
-	bool visited;
-	bool equality;
+    //! @brief Whether the separation is an exact distance or not.
+	const bool equality;
+    //! @brief Denote whether this constraint was unsatisifable (once the VPSC 
+    //!        instance has been solved or satisfied).
+	bool unsatisfiable;
+    bool needsScaling;
+    void *creator;
 };
-#include <float.h>
-#include "block.h"
-static inline bool compareConstraints(Constraint *const &l, Constraint *const &r) {
-	double const sl = 
-		l->left->block->timeStamp > l->timeStamp
-		||l->left->block==l->right->block
-		?-DBL_MAX:l->slack();
-	double const sr = 
-		r->left->block->timeStamp > r->timeStamp
-		||r->left->block==r->right->block
-		?-DBL_MAX:r->slack();
-	if(sl==sr) {
-		// arbitrary choice based on id
-		if(l->left->id==r->left->id) {
-			if(l->right->id<r->right->id) return true;
-			return false;
-		}
-		if(l->left->id<r->left->id) return true;
-		return false;
-	}
-	return sl < sr;
-}
+
+class CompareConstraints {
+public:
+	bool operator() (Constraint *const &l, Constraint *const &r) const;
+};
+
+//! @brief A vector of pointers to Constraint objects.
+typedef std::vector<Constraint*> Constraints;
+
+/** @brief Given a set of variables and constraints, returns a modified set
+ *         of constraints with all redundant equality constraints removed.
+ *
+ * VPSC doesn't work well with redundant equality constraints, usually showing
+ * them as unsatisfiable.  This function looks for cycles of equality 
+ * constraints and removes the redundant ones.
+ */
+extern Constraints constraintsRemovingRedundantEqualities(
+        const Variables& vars, const Constraints& constraints);
+
 }
 
-#endif // SEEN_REMOVEOVERLAP_CONSTRAINT_H
+#endif // VPSC_CONSTRAINT_H