From cca66b9ec4e494c1d919bff0f71a820d8afab1fa Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 20:24:48 +0200
Subject: Adding upstream version 1.2.2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 src/3rdparty/adaptagrams/libvpsc/block.cpp | 647 +++++++++++++++++++++++++++++
 1 file changed, 647 insertions(+)
 create mode 100644 src/3rdparty/adaptagrams/libvpsc/block.cpp

(limited to 'src/3rdparty/adaptagrams/libvpsc/block.cpp')

diff --git a/src/3rdparty/adaptagrams/libvpsc/block.cpp b/src/3rdparty/adaptagrams/libvpsc/block.cpp
new file mode 100644
index 0000000..dfcf6c9
--- /dev/null
+++ b/src/3rdparty/adaptagrams/libvpsc/block.cpp
@@ -0,0 +1,647 @@
+/*
+ * vim: ts=4 sw=4 et tw=0 wm=0
+ *
+ * libvpsc - A solver for the problem of Variable Placement with 
+ *           Separation Constraints.
+ *
+ * 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
+*/
+
+/*
+ * @brief A block is a group of variables that must be moved together to improve
+ * the goal function without violating already active constraints.
+ * The variables in a block are spanned by a tree of active constraints.
+ *
+ */
+
+#include "libvpsc/block.h"
+#include "libvpsc/variable.h"
+#include <cassert>
+#include "libvpsc/pairing_heap.h"
+#include "libvpsc/constraint.h"
+#include "libvpsc/exceptions.h"
+#include "libvpsc/blocks.h"
+
+#ifdef LIBVPSC_LOGGING
+#include <fstream>
+using std::ios;
+using std::ofstream;
+using std::endl;
+#endif
+
+#define __NOTNAN(p) (p)==(p)
+
+namespace vpsc {
+void PositionStats::addVariable(Variable* v) {
+    double ai=scale/v->scale;
+    double bi=v->offset/v->scale;
+    double wi=v->weight;
+    AB+=wi*ai*bi;
+    AD+=wi*ai*v->desiredPosition;
+    A2+=wi*ai*ai;
+    /*
+#ifdef LIBVPSC_LOGGING
+    ofstream f(LOGFILE,ios::app);
+    f << "adding v[" << v->id << "], blockscale=" << scale << ", despos=" 
+      << v->desiredPosition << ", ai=" << ai << ", bi=" << bi
+      << ", AB=" << AB << ", AD=" << AD << ", A2=" << A2;
+#endif
+*/
+}
+void Block::addVariable(Variable* v) {
+    v->block=this;
+    vars->push_back(v);
+    if(ps.A2==0) ps.scale=v->scale;
+    //weight+= v->weight;
+    //wposn += v->weight * (v->desiredPosition - v->offset);
+    //posn=wposn/weight;
+    ps.addVariable(v);
+    posn=(ps.AD - ps.AB) / ps.A2;
+    COLA_ASSERT(__NOTNAN(posn));
+    /*
+#ifdef LIBVPSC_LOGGING
+    ofstream f(LOGFILE,ios::app);
+    f << ", posn=" << posn << endl;
+#endif
+*/
+}
+Block::Block(Blocks *blocks, Variable* const v)
+    : vars(new std::vector<Variable*>)
+    , posn(0)
+    //, weight(0)
+    //, wposn(0)
+    , deleted(false)
+    , timeStamp(0)
+    , in(nullptr)
+    , out(nullptr)
+    , blocks(blocks)
+{
+    if(v!=nullptr) {
+        v->offset=0;
+        addVariable(v);
+    }
+}
+
+void Block::updateWeightedPosition() {
+    //wposn=0;
+    ps.AB=ps.AD=ps.A2=0;
+    for (Vit v=vars->begin();v!=vars->end();++v) {
+        //wposn += ((*v)->desiredPosition - (*v)->offset) * (*v)->weight;
+        ps.addVariable(*v);
+    }
+    posn=(ps.AD - ps.AB) / ps.A2;
+    COLA_ASSERT(__NOTNAN(posn));
+#ifdef LIBVPSC_LOGGING
+    ofstream f(LOGFILE,ios::app);
+    f << ", posn=" << posn << endl;
+#endif
+}
+Block::~Block(void)
+{
+    delete vars;
+    delete in;
+    delete out;
+}
+void Block::setUpInConstraints() {
+    setUpConstraintHeap(in,true);
+}
+void Block::setUpOutConstraints() {
+    setUpConstraintHeap(out,false);
+}
+void Block::setUpConstraintHeap(PairingHeap<Constraint*,CompareConstraints>* &h,bool in) {
+    delete h;
+    h = new PairingHeap<Constraint*,CompareConstraints>();
+    for (Vit i=vars->begin();i!=vars->end();++i) {
+        Variable *v=*i;
+        std::vector<Constraint*> *cs=in?&(v->in):&(v->out);
+        for (Cit j=cs->begin();j!=cs->end();++j) {
+            Constraint *c=*j;
+            c->timeStamp=blocks->blockTimeCtr;
+            if ( ((c->left->block != this) && in) || 
+                 ((c->right->block != this) && !in) )
+            {
+                h->insert(c);
+            }
+        }
+    }
+}    
+Block* Block::merge(Block* b, Constraint* c) {
+#ifdef LIBVPSC_LOGGING
+    ofstream f(LOGFILE,ios::app);
+    f<<"  merging on: "<<*c<<",c->left->offset="<<c->left->offset<<",c->right->offset="<<c->right->offset<<endl;
+#endif
+    double dist = c->right->offset - c->left->offset - c->gap;
+    Block *l=c->left->block;
+    Block *r=c->right->block;
+    if (l->vars->size() < r->vars->size()) {
+        r->merge(l,c,dist);
+    } else {
+               l->merge(r,c,-dist);
+    }
+    Block* mergeBlock=b->deleted?this:b;
+#ifdef LIBVPSC_LOGGING
+    f<<"  merged block="<<*mergeBlock<<endl;
+#endif
+    return mergeBlock;
+}
+/*
+ * Merges b into this block across c.  Can be either a
+ * right merge or a left merge
+ * @param b block to merge into this
+ * @param c constraint being merged
+ * @param distance separation required to satisfy c
+ */
+void Block::merge(Block *b, Constraint *c, double dist) {
+#ifdef LIBVPSC_LOGGING
+    ofstream f(LOGFILE,ios::app);
+    f<<"    merging: "<<*b<<"dist="<<dist<<endl;
+#endif
+    c->active=true;
+    //wposn+=b->wposn-dist*b->weight;
+    //weight+=b->weight;
+    for(Vit i=b->vars->begin();i!=b->vars->end();++i) {
+        Variable *v=*i;
+        //v->block=this;
+        //vars->push_back(v);
+        v->offset+=dist;
+        addVariable(v);
+    }
+#ifdef LIBVPSC_LOGGING
+    for(Vit i=vars->begin();i!=vars->end();++i) {
+        Variable *v=*i;
+        f<<"    v["<<v->id<<"]: d="<<v->desiredPosition
+            <<" a="<<v->scale<<" o="<<v->offset
+            <<endl;
+    }
+    f<<"  AD="<<ps.AD<<" AB="<<ps.AB<<" A2="<<ps.A2<<endl;
+#endif
+    //posn=wposn/weight;
+    //COLA_ASSERT(wposn==ps.AD - ps.AB);
+    posn=(ps.AD - ps.AB) / ps.A2;
+    COLA_ASSERT(__NOTNAN(posn));
+    b->deleted=true;
+}
+
+void Block::mergeIn(Block *b) {
+#ifdef LIBVPSC_LOGGING
+    ofstream f(LOGFILE,ios::app);
+    f<<"  merging constraint heaps... "<<endl;
+#endif
+    // We check the top of the heaps to remove possible internal constraints
+    findMinInConstraint();
+    b->findMinInConstraint();
+    in->merge(b->in);
+#ifdef LIBVPSC_LOGGING
+    f<<"  merged heap: "<<*in<<endl;
+#endif
+}
+void Block::mergeOut(Block *b) {    
+    findMinOutConstraint();
+    b->findMinOutConstraint();
+    out->merge(b->out);
+}
+Constraint *Block::findMinInConstraint() {
+    Constraint *v = nullptr;
+    std::vector<Constraint*> outOfDate;
+    while (!in->isEmpty()) {
+        v = in->findMin();
+        Block *lb=v->left->block;
+        Block *rb=v->right->block;
+        // rb may not be this if called between merge and mergeIn
+#ifdef LIBVPSC_LOGGING
+        ofstream f(LOGFILE,ios::app);
+        f<<"  checking constraint ... "<<*v;
+        f<<"    timestamps: left="<<lb->timeStamp<<" right="<<rb->timeStamp<<" constraint="<<v->timeStamp<<endl;
+#endif
+        if(lb == rb) {
+            // constraint has been merged into the same block
+#ifdef LIBVPSC_LOGGING
+            if(v->slack()<0) {
+                f<<"  violated internal constraint found! "<<*v<<endl;
+                f<<"     lb="<<*lb<<endl;
+                f<<"     rb="<<*rb<<endl;
+            }
+#endif
+            in->deleteMin();
+#ifdef LIBVPSC_LOGGING
+            f<<" ... skipping internal constraint"<<endl;
+#endif
+        } else if(v->timeStamp < lb->timeStamp) {
+            // block at other end of constraint has been moved since this
+            in->deleteMin();
+            outOfDate.push_back(v);
+#ifdef LIBVPSC_LOGGING
+            f<<"    reinserting out of date (reinsert later)"<<endl;
+#endif
+        } else {
+            break;
+        }
+    }
+    for(Cit i=outOfDate.begin();i!=outOfDate.end();++i) {
+        v=*i;
+        v->timeStamp=blocks->blockTimeCtr;
+        in->insert(v);
+    }
+    if(in->isEmpty()) {
+        v=nullptr;
+    } else {
+        v=in->findMin();
+    }
+    return v;
+}
+Constraint *Block::findMinOutConstraint() {
+    if(out->isEmpty()) return nullptr;
+    Constraint *v = out->findMin();
+    while (v->left->block == v->right->block) {
+        out->deleteMin();
+        if(out->isEmpty()) return nullptr;
+        v = out->findMin();
+    }
+    return v;
+}
+void Block::deleteMinInConstraint() {
+    in->deleteMin();
+#ifdef LIBVPSC_LOGGING
+    ofstream f(LOGFILE,ios::app);
+    f<<"deleteMinInConstraint... "<<endl;
+    f<<"  result: "<<*in<<endl;
+#endif
+}
+void Block::deleteMinOutConstraint() {
+    out->deleteMin();
+}
+inline bool Block::canFollowLeft(Constraint const* c, Variable const* last) const {
+    return c->left->block==this && c->active && last!=c->left;
+}
+inline bool Block::canFollowRight(Constraint const* c, Variable const* last) const {
+    return c->right->block==this && c->active && last!=c->right;
+}
+
+// computes the derivative of v and the lagrange multipliers
+// of v's out constraints (as the recursive sum of those below.
+// Does not backtrack over u.
+// also records the constraint with minimum lagrange multiplier
+// in min_lm
+double Block::compute_dfdv(Variable* const v, Variable* const u,
+               Constraint *&min_lm) {
+    double dfdv=v->dfdv();
+    for(Cit it=v->out.begin();it!=v->out.end();++it) {
+        Constraint *c=*it;
+        if(canFollowRight(c,u)) {
+            c->lm=compute_dfdv(c->right,v,min_lm);
+            dfdv+=c->lm*c->left->scale;
+            if(!c->equality&&(min_lm==nullptr||c->lm<min_lm->lm)) min_lm=c;
+        }
+    }
+    for(Cit it=v->in.begin();it!=v->in.end();++it) {
+        Constraint *c=*it;
+        if(canFollowLeft(c,u)) {
+            c->lm=-compute_dfdv(c->left,v,min_lm);
+            dfdv-=c->lm*c->right->scale;
+            if(!c->equality&&(min_lm==nullptr||c->lm<min_lm->lm)) min_lm=c;
+        }
+    }
+    return dfdv/v->scale;
+}
+double Block::compute_dfdv(Variable* const v, Variable* const u) {
+    double dfdv = v->dfdv();
+    for(Cit it = v->out.begin(); it != v->out.end(); ++it) {
+        Constraint *c = *it;
+        if(canFollowRight(c,u)) {
+            c->lm =   compute_dfdv(c->right,v);
+            dfdv += c->lm * c->left->scale;
+        }
+    }
+    for(Cit it=v->in.begin();it!=v->in.end();++it) {
+        Constraint *c = *it;
+        if(canFollowLeft(c,u)) {
+            c->lm = - compute_dfdv(c->left,v);
+            dfdv -= c->lm * c->right->scale;
+        }
+    }
+    return dfdv/v->scale;
+}
+
+// The top level v and r are variables between which we want to find the
+// constraint with the smallest lm.  
+// Similarly, m is initially nullptr and is only assigned a value if the next
+// variable to be visited is r or if a possible min constraint is returned from
+// a nested call (rather than nullptr).
+// Then, the search for the m with minimum lm occurs as we return from
+// the recursion (checking only constraints traversed left-to-right 
+// in order to avoid creating any new violations).
+// We also do not consider equality constraints as potential split points
+bool Block::split_path(
+    Variable* r, 
+    Variable* const v, 
+    Variable* const u, 
+    Constraint* &m,
+    bool desperation=false
+    ) 
+{
+    for(Cit it(v->in.begin());it!=v->in.end();++it) {
+        Constraint *c=*it;
+        if(canFollowLeft(c,u)) {
+#ifdef LIBVPSC_LOGGING
+    ofstream f(LOGFILE,ios::app);
+    f<<"  left split path: "<<*c<<endl;
+#endif
+            if(c->left==r) {
+                if(desperation&&!c->equality) m=c;
+                return true;
+            } else {
+                if(split_path(r,c->left,v,m)) {
+                    if(desperation && !c->equality && (!m||c->lm<m->lm)) {
+                               m=c;
+                    }
+                    return true;
+                }
+            }
+        }
+    }
+    for(Cit it(v->out.begin());it!=v->out.end();++it) {
+        Constraint *c=*it;
+        if(canFollowRight(c,u)) {
+#ifdef LIBVPSC_LOGGING
+    ofstream f(LOGFILE,ios::app);
+    f<<"  right split path: "<<*c<<endl;
+#endif
+            if(c->right==r) {
+                if(!c->equality) m=c;
+                return true;
+            } else {
+                if(split_path(r,c->right,v,m)) {
+                    if(!c->equality && (!m||c->lm<m->lm))
+                               m=c;
+                    return true;
+                }
+            }
+        }
+    }
+    return false;
+}
+/*
+Block::Pair Block::compute_dfdv_between(
+        Variable* r, Variable* const v, Variable* const u, 
+        const Direction dir = NONE, bool changedDirection = false) {
+    double dfdv=v->weight*(v->position() - v->desiredPosition);
+    Constraint *m=nullptr;
+    for(Cit it(v->in.begin());it!=v->in.end();++it) {
+        Constraint *c=*it;
+        if(canFollowLeft(c,u)) {
+            if(dir==RIGHT) { 
+                changedDirection = true; 
+            }
+            if(c->left==r) {
+                       r=nullptr;
+                    if(!c->equality) m=c; 
+            }
+            Pair p=compute_dfdv_between(r,c->left,v,
+                    LEFT,changedDirection);
+            dfdv -= c->lm = -p.first;
+            if(r && p.second) 
+                m = p.second;
+        }
+    }
+    for(Cit it(v->out.begin());it!=v->out.end();++it) {
+        Constraint *c=*it;
+        if(canFollowRight(c,u)) {
+            if(dir==LEFT) { 
+                changedDirection = true; 
+            }
+            if(c->right==r) {
+                       r=nullptr; 
+                    if(!c->equality) m=c; 
+            }
+            Pair p=compute_dfdv_between(r,c->right,v,
+                    RIGHT,changedDirection);
+            dfdv += c->lm = p.first;
+            if(r && p.second) 
+                m = changedDirection && !c->equality && c->lm < p.second->lm 
+                    ? c 
+                    : p.second;
+        }
+    }
+    return Pair(dfdv,m);
+}
+*/
+
+// resets LMs for all active constraints to 0 by
+// traversing active constraint tree starting from v,
+// not back tracking over u
+void Block::reset_active_lm(Variable* const v, Variable* const u) {
+    for(Cit it=v->out.begin();it!=v->out.end();++it) {
+        Constraint *c=*it;
+        if(canFollowRight(c,u)) {
+            c->lm=0;
+            reset_active_lm(c->right,v);
+        }
+    }
+    for(Cit it=v->in.begin();it!=v->in.end();++it) {
+        Constraint *c=*it;
+        if(canFollowLeft(c,u)) {
+            c->lm=0;
+            reset_active_lm(c->left,v);
+        }
+    }
+}
+void Block::list_active(Variable* const v, Variable* const u) {
+    for(Cit it=v->out.begin();it!=v->out.end();++it) {
+        Constraint *c=*it;
+        if(canFollowRight(c,u)) {
+#ifdef LIBVPSC_LOGGING
+    ofstream f(LOGFILE,ios::app);
+    f<<"  "<<*c<<endl;
+#endif
+            list_active(c->right,v);
+        }
+    }
+    for(Cit it=v->in.begin();it!=v->in.end();++it) {
+        Constraint *c=*it;
+        if(canFollowLeft(c,u)) {
+#ifdef LIBVPSC_LOGGING
+    ofstream f(LOGFILE,ios::app);
+    f<<"  "<<*c<<endl;
+#endif
+            list_active(c->left,v);
+        }
+    }
+}
+/*
+ * finds the constraint with the minimum lagrange multiplier, that is, the constraint
+ * that most wants to split
+ */
+Constraint *Block::findMinLM() {
+    Constraint *min_lm=nullptr;
+    reset_active_lm(vars->front(),nullptr);
+    compute_dfdv(vars->front(),nullptr,min_lm);
+#ifdef LIBVPSC_LOGGING
+    ofstream f(LOGFILE,ios::app);
+    f<<"  langrangians: "<<endl;
+    list_active(vars->front(),nullptr);
+#endif
+    return min_lm;
+}
+Constraint *Block::findMinLMBetween(Variable* const lv, Variable* const rv) {
+    reset_active_lm(vars->front(),nullptr);
+    compute_dfdv(vars->front(),nullptr);
+    Constraint *min_lm=nullptr;
+    split_path(rv,lv,nullptr,min_lm);
+#if 0
+    if(min_lm==nullptr) {
+        split_path(rv,lv,nullptr,min_lm,true);
+    }
+#else
+    if(min_lm==nullptr) {
+#ifdef LIBVPSC_DEBUG
+        fprintf(stderr,"Couldn't find split point!\n");
+#endif
+        UnsatisfiableException e;
+        getActivePathBetween(e.path,lv,rv,nullptr);
+        throw e;
+    }
+    COLA_ASSERT(min_lm!=nullptr);
+#endif
+    return min_lm;
+}
+
+// populates block b by traversing the active constraint tree adding variables as they're 
+// visited.  Starts from variable v and does not backtrack over variable u.
+void Block::populateSplitBlock(Block *b, Variable* v, Variable const* u) {
+    b->addVariable(v);
+    for (Cit c=v->in.begin();c!=v->in.end();++c) {
+        if (canFollowLeft(*c,u))
+            populateSplitBlock(b, (*c)->left, v);
+    }
+    for (Cit c=v->out.begin();c!=v->out.end();++c) {
+        if (canFollowRight(*c,u)) 
+            populateSplitBlock(b, (*c)->right, v);
+    }
+}
+/*
+ * Returns the active path between variables u and v... not back tracking over w
+ */
+bool Block::getActivePathBetween(Constraints& path, Variable const* u,
+               Variable const* v, Variable const *w) const {
+    if(u==v) return true;
+    for (Cit_const c=u->in.begin();c!=u->in.end();++c) {
+        if (canFollowLeft(*c,w)) {
+            if(getActivePathBetween(path, (*c)->left, v, u)) {
+                path.push_back(*c);
+                return true;
+            }
+        }
+    }
+    for (Cit_const c=u->out.begin();c!=u->out.end();++c) {
+        if (canFollowRight(*c,w)) {
+            if(getActivePathBetween(path, (*c)->right, v, u)) {
+                path.push_back(*c);
+                return true;
+            }
+        }
+    }
+    return false;
+}
+// Search active constraint tree from u to see if there is a directed path to v.
+// Returns true if path is found with all constraints in path having their visited flag
+// set true.
+bool Block::isActiveDirectedPathBetween(Variable const* u, Variable const* v) const {
+    if(u==v) return true;
+    for (Cit_const c=u->out.begin();c!=u->out.end();++c) {
+        if(canFollowRight(*c,nullptr)) {
+            if(isActiveDirectedPathBetween((*c)->right,v)) {
+                return true;
+            }
+        }
+    }
+    return false;
+}
+bool Block::getActiveDirectedPathBetween(
+        Constraints& path, Variable const* u, Variable const* v) const {
+    if(u==v) return true;
+    for (Cit_const c=u->out.begin();c!=u->out.end();++c) {
+        if(canFollowRight(*c,nullptr)) {
+            if(getActiveDirectedPathBetween(path,(*c)->right,v)) {
+                path.push_back(*c);
+                return true;
+            }
+        }
+    }
+    return false;
+}
+/*
+ * Block needs to be split because of a violated constraint between vl and vr.
+ * We need to search the active constraint tree between l and r and find the constraint
+ * with min lagrangrian multiplier and split at that point.
+ * Returns the split constraint
+ */
+Constraint* Block::splitBetween(Variable* const vl, Variable* const vr,
+               Block* &lb, Block* &rb) {
+#ifdef LIBVPSC_LOGGING
+    ofstream f(LOGFILE,ios::app);
+    f<<"  need to split between: "<<*vl<<" and "<<*vr<<endl;
+#endif
+    Constraint *c=findMinLMBetween(vl, vr);
+#ifdef LIBVPSC_LOGGING
+    f<<"  going to split on: "<<*c<<endl;
+#endif
+    if(c!=nullptr) {
+        split(lb,rb,c);
+        deleted = true;
+    }
+    return c;
+}
+
+/*
+ * Creates two new blocks, l and r, and splits this block across constraint c,
+ * placing the left subtree of constraints (and associated variables) into l
+ * and the right into r.
+ */
+void Block::split(Block* &l, Block* &r, Constraint* c) {
+    c->active=false;
+    l=new Block(blocks);
+    populateSplitBlock(l,c->left,c->right);
+    //COLA_ASSERT(l->weight>0);
+    r=new Block(blocks);
+    populateSplitBlock(r,c->right,c->left);
+    //COLA_ASSERT(r->weight>0);
+}
+
+/*
+ * Computes the cost (squared euclidean distance from desired positions) of the
+ * current positions for variables in this block
+ */
+double Block::cost() {
+    double c = 0;
+    for (Vit v=vars->begin();v!=vars->end();++v) {
+        double diff = (*v)->position() - (*v)->desiredPosition;
+        c += (*v)->weight * diff * diff;
+    }
+    return c;
+}
+std::ostream& operator <<(std::ostream &os, const Block& b)
+{
+    os<<"Block(posn="<<b.posn<<"):";
+    for(Block::Vit v=b.vars->begin();v!=b.vars->end();++v) {
+        os<<" "<<**v;
+    }
+    if(b.deleted) {
+        os<<" Deleted!";
+    }
+    return os;
+}
+
+}
+
-- 
cgit v1.2.3