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Nominatim/nominatim/voronoi/VoronoiDiagramGenerator.cpp
Brian Quinion a98bc3fae8 nominatim refactoring
2010-10-25 10:50:52 +00:00

1277 lines
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/*
* The author of this software is Steven Fortune. Copyright (c) 1994 by AT&T
* Bell Laboratories.
* Permission to use, copy, modify, and distribute this software for any
* purpose without fee is hereby granted, provided that this entire notice
* is included in all copies of any software which is or includes a copy
* or modification of this software and in all copies of the supporting
* documentation for such software.
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR AT&T MAKE ANY
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
* OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
*/
/*
* This code was originally written by Stephan Fortune in C code. I, Shane O'Sullivan,
* have since modified it, encapsulating it in a C++ class and, fixing memory leaks and
* adding accessors to the Voronoi Edges.
* Permission to use, copy, modify, and distribute this software for any
* purpose without fee is hereby granted, provided that this entire notice
* is included in all copies of any software which is or includes a copy
* or modification of this software and in all copies of the supporting
* documentation for such software.
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR AT&T MAKE ANY
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
* OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
*/
#include "VoronoiDiagramGenerator.h"
#include <stdio.h>
#include <sys/mman.h>
VoronoiDiagramGenerator::VoronoiDiagramGenerator()
{
siteidx = 0;
sites = 0;
allMemoryList = new FreeNodeArrayList;
allMemoryList->memory = 0;
allMemoryList->next = 0;
currentMemoryBlock = allMemoryList;
allEdges = 0;
iteratorEdges = 0;
minDistanceBetweenSites = 0;
}
VoronoiDiagramGenerator::~VoronoiDiagramGenerator()
{
cleanup();
cleanupEdges();
if(allMemoryList != 0)
delete allMemoryList;
}
bool VoronoiDiagramGenerator::generateVoronoi(struct SourcePoint* srcPoints, int numPoints, float minX, float maxX, float minY, float maxY, float minDist)
{
cleanup();
cleanupEdges();
int i;
minDistanceBetweenSites = minDist;
nsites = numPoints;
plot = 0;
triangulate = 0;
debug = 1;
sorted = 0;
freeinit(&sfl, sizeof (Site));
sites = (struct Site *) myalloc(nsites * sizeof(*sites));
polygons = (struct Polygon *) myalloc(nsites * sizeof(*polygons));
if(sites == 0) return false;
xmin = srcPoints[0].x;
ymin = srcPoints[0].y;
xmax = srcPoints[0].x;
ymax = srcPoints[0].y;
for(i = 0; i < nsites; i++)
{
sites[i].coord.x = srcPoints[i].x;
sites[i].coord.y = srcPoints[i].y;
sites[i].weight = srcPoints[i].weight;
sites[i].sitenbr = i;
sites[i].refcnt = 0; // prevent reuse?
if(sites[i].coord.x < xmin)
xmin = sites[i].coord.x;
else if(sites[i].coord.x > xmax)
xmax = sites[i].coord.x;
if(sites[i].coord.y < ymin)
ymin = sites[i].coord.y;
else if(sites[i].coord.y > ymax)
ymax = sites[i].coord.y;
polygons[i].coord.x = sites[i].coord.x;
polygons[i].coord.y = sites[i].coord.y;
polygons[i].numpoints = 0;
polygons[i].pointlist = NULL;
polygons[i].boundary = 0;
//printf("\n%lf %lf\n", sites[i].coord.x, sites[i].coord.y);
}
qsort(sites, nsites, sizeof (*sites), scomp);
siteidx = 0;
geominit();
float temp = 0;
if(minX > maxX)
{
temp = minX;
minX = maxX;
maxX = temp;
}
if(minY > maxY)
{
temp = minY;
minY = maxY;
maxY = temp;
}
borderMinX = minX;
borderMinY = minY;
borderMaxX = maxX;
borderMaxY = maxY;
corners[0].x = borderMinX;
corners[0].y = borderMinY;
corners[1].x = borderMinX;
corners[1].y = borderMaxY;
corners[2].x = borderMaxX;
corners[2].y = borderMaxY;
corners[3].x = borderMaxX;
corners[3].y = borderMinY;
siteidx = 0;
voronoi(triangulate);
return true;
}
bool VoronoiDiagramGenerator::ELinitialize()
{
int i;
freeinit(&hfl, sizeof **ELhash);
ELhashsize = 2 * sqrt_nsites;
ELhash = (struct Halfedge **) myalloc ( sizeof *ELhash * ELhashsize);
if(ELhash == 0)
return false;
for(i=0; i<ELhashsize; i +=1) ELhash[i] = (struct Halfedge *)NULL;
ELleftend = HEcreate( (struct Edge *)NULL, 0);
ELrightend = HEcreate( (struct Edge *)NULL, 0);
ELleftend -> ELleft = (struct Halfedge *)NULL;
ELleftend -> ELright = ELrightend;
ELrightend -> ELleft = ELleftend;
ELrightend -> ELright = (struct Halfedge *)NULL;
ELhash[0] = ELleftend;
ELhash[ELhashsize-1] = ELrightend;
return true;
}
struct Halfedge* VoronoiDiagramGenerator::HEcreate(struct Edge *e,int pm)
{
struct Halfedge *answer;
answer = (struct Halfedge *) getfree(&hfl);
answer -> ELedge = e;
answer -> ELpm = pm;
answer -> PQnext = (struct Halfedge *) NULL;
answer -> vertex = (struct Site *) NULL;
answer -> ELrefcnt = 0;
return(answer);
}
void VoronoiDiagramGenerator::ELinsert(struct Halfedge *lb, struct Halfedge *newHe)
{
newHe -> ELleft = lb;
newHe -> ELright = lb -> ELright;
(lb -> ELright) -> ELleft = newHe;
lb -> ELright = newHe;
}
/* Get entry from hash table, pruning any deleted nodes */
struct Halfedge * VoronoiDiagramGenerator::ELgethash(int b)
{
struct Halfedge *he;
if(b<0 || b>=ELhashsize)
return((struct Halfedge *) NULL);
he = ELhash[b];
if (he == (struct Halfedge *) NULL || he->ELedge != (struct Edge *) DELETED )
return (he);
/* Hash table points to deleted half edge. Patch as necessary. */
ELhash[b] = (struct Halfedge *) NULL;
if ((he -> ELrefcnt -= 1) == 0)
makefree((Freenode*)he, &hfl);
return ((struct Halfedge *) NULL);
}
struct Halfedge * VoronoiDiagramGenerator::ELleftbnd(struct Point *p)
{
int i, bucket;
struct Halfedge *he;
/* Use hash table to get close to desired halfedge */
bucket = (int)((p->x - xmin)/deltax * ELhashsize); //use the hash function to find the place in the hash map that this HalfEdge should be
if(bucket<0) bucket =0; //make sure that the bucket position in within the range of the hash array
if(bucket>=ELhashsize) bucket = ELhashsize - 1;
he = ELgethash(bucket);
if(he == (struct Halfedge *) NULL) //if the HE isn't found, search backwards and forwards in the hash map for the first non-null entry
{
for(i=1; 1 ; i += 1)
{
if ((he=ELgethash(bucket-i)) != (struct Halfedge *) NULL)
break;
if ((he=ELgethash(bucket+i)) != (struct Halfedge *) NULL)
break;
};
totalsearch += i;
};
ntry += 1;
/* Now search linear list of halfedges for the correct one */
if (he==ELleftend || (he != ELrightend && right_of(he,p)))
{
do
{
he = he -> ELright;
} while (he!=ELrightend && right_of(he,p)); //keep going right on the list until either the end is reached, or you find the 1st edge which the point
he = he -> ELleft; //isn't to the right of
}
else //if the point is to the left of the HalfEdge, then search left for the HE just to the left of the point
do
{
he = he -> ELleft;
} while (he!=ELleftend && !right_of(he,p));
/* Update hash table and reference counts */
if(bucket > 0 && bucket <ELhashsize-1)
{
if(ELhash[bucket] != (struct Halfedge *) NULL)
{
ELhash[bucket] -> ELrefcnt -= 1;
}
ELhash[bucket] = he;
ELhash[bucket] -> ELrefcnt += 1;
};
return (he);
}
/* This delete routine can't reclaim node, since pointers from hash
table may be present. */
void VoronoiDiagramGenerator::ELdelete(struct Halfedge *he)
{
(he -> ELleft) -> ELright = he -> ELright;
(he -> ELright) -> ELleft = he -> ELleft;
he -> ELedge = (struct Edge *)DELETED;
}
struct Halfedge * VoronoiDiagramGenerator::ELright(struct Halfedge *he)
{
return (he -> ELright);
}
struct Halfedge * VoronoiDiagramGenerator::ELleft(struct Halfedge *he)
{
return (he -> ELleft);
}
struct Site * VoronoiDiagramGenerator::leftreg(struct Halfedge *he)
{
if(he -> ELedge == (struct Edge *)NULL)
return(bottomsite);
return( he -> ELpm == le ?
he -> ELedge -> reg[le] : he -> ELedge -> reg[re]);
}
struct Site * VoronoiDiagramGenerator::rightreg(struct Halfedge *he)
{
if(he -> ELedge == (struct Edge *)NULL) //if this halfedge has no edge, return the bottom site (whatever that is)
return(bottomsite);
//if the ELpm field is zero, return the site 0 that this edge bisects, otherwise return site number 1
return( he -> ELpm == le ? he -> ELedge -> reg[re] : he -> ELedge -> reg[le]);
}
void VoronoiDiagramGenerator::geominit()
{
float sn;
freeinit(&efl, sizeof(Edge));
nvertices = 0;
nedges = 0;
sn = (float)nsites+4;
sqrt_nsites = (int)sqrt(sn);
deltay = ymax - ymin;
deltax = xmax - xmin;
}
struct Edge * VoronoiDiagramGenerator::bisect(struct Site *s1,struct Site *s2)
{
float dx,dy,adx,ady;
struct Edge *newedge;
newedge = (struct Edge *) getfree(&efl);
newedge -> reg[0] = s1; //store the sites that this edge is bisecting
newedge -> reg[1] = s2;
ref(s1);
ref(s2);
newedge -> ep[0] = (struct Site *) NULL; //to begin with, there are no endpoints on the bisector - it goes to infinity
newedge -> ep[1] = (struct Site *) NULL;
dx = s2->coord.x - s1->coord.x; //get the difference in x dist between the sites
dy = s2->coord.y - s1->coord.y;
adx = dx>0 ? dx : -dx; //make sure that the difference in positive
ady = dy>0 ? dy : -dy;
newedge -> c = (float)(s1->coord.x * dx + s1->coord.y * dy + (dx*dx + dy*dy)*0.5);//get the slope of the line
if (adx>ady)
{
newedge -> a = 1.0; newedge -> b = dy/dx; newedge -> c /= dx;//set formula of line, with x fixed to 1
}
else
{
newedge -> b = 1.0; newedge -> a = dx/dy; newedge -> c /= dy;//set formula of line, with y fixed to 1
};
newedge -> edgenbr = nedges;
//printf("\nbisect(%d) ((%f,%f) and (%f,%f)",nedges,s1->coord.x,s1->coord.y,s2->coord.x,s2->coord.y);
nedges += 1;
return(newedge);
}
//create a new site where the HalfEdges el1 and el2 intersect - note that the Point in the argument list is not used, don't know why it's there
struct Site * VoronoiDiagramGenerator::intersect(struct Halfedge *el1, struct Halfedge *el2, struct Point *p)
{
struct Edge *e1,*e2, *e;
struct Halfedge *el;
float d, xint, yint;
int right_of_site;
struct Site *v;
e1 = el1 -> ELedge;
e2 = el2 -> ELedge;
if(e1 == (struct Edge*)NULL || e2 == (struct Edge*)NULL)
return ((struct Site *) NULL);
//if the two edges bisect the same parent, return null
if (e1->reg[1] == e2->reg[1])
return ((struct Site *) NULL);
d = e1->a * e2->b - e1->b * e2->a;
if (-1.0e-10<d && d<1.0e-10)
return ((struct Site *) NULL);
xint = (e1->c*e2->b - e2->c*e1->b)/d;
yint = (e2->c*e1->a - e1->c*e2->a)/d;
if( (e1->reg[1]->coord.y < e2->reg[1]->coord.y) ||
(e1->reg[1]->coord.y == e2->reg[1]->coord.y &&
e1->reg[1]->coord.x < e2->reg[1]->coord.x) )
{
el = el1;
e = e1;
}
else
{
el = el2;
e = e2;
};
right_of_site = xint >= e -> reg[1] -> coord.x;
if ((right_of_site && el -> ELpm == le) || (!right_of_site && el -> ELpm == re))
return ((struct Site *) NULL);
//create a new site at the point of intersection - this is a new vector event waiting to happen
v = (struct Site *) getfree(&sfl);
v -> refcnt = 0;
v -> coord.x = xint;
v -> coord.y = yint;
return(v);
}
/* returns 1 if p is to right of halfedge e */
int VoronoiDiagramGenerator::right_of(struct Halfedge *el,struct Point *p)
{
struct Edge *e;
struct Site *topsite;
int right_of_site, above, fast;
float dxp, dyp, dxs, t1, t2, t3, yl;
e = el -> ELedge;
topsite = e -> reg[1];
right_of_site = p -> x > topsite -> coord.x;
if(right_of_site && el -> ELpm == le) return(1);
if(!right_of_site && el -> ELpm == re) return (0);
if (e->a == 1.0)
{
dyp = p->y - topsite->coord.y;
dxp = p->x - topsite->coord.x;
fast = 0;
if ((!right_of_site & (e->b<0.0)) | (right_of_site & (e->b>=0.0)) )
{
above = dyp>= e->b*dxp;
fast = above;
}
else
{
above = p->x + p->y*e->b > e-> c;
if(e->b<0.0) above = !above;
if (!above) fast = 1;
}
if (!fast)
{
dxs = topsite->coord.x - (e->reg[0])->coord.x;
above = e->b * (dxp*dxp - dyp*dyp) <
dxs*dyp*(1.0+2.0*dxp/dxs + e->b*e->b);
if(e->b<0.0) above = !above;
}
}
else /*e->b==1.0 */
{
yl = e->c - e->a*p->x;
t1 = p->y - yl;
t2 = p->x - topsite->coord.x;
t3 = yl - topsite->coord.y;
above = t1*t1 > t2*t2 + t3*t3;
}
return (el->ELpm==le ? above : !above);
}
void VoronoiDiagramGenerator::endpoint(struct Edge *e,int lr,struct Site * s)
{
e -> ep[lr] = s;
ref(s);
return;
if(e -> ep[re-lr]== (struct Site *) NULL)
return;
clip_line(e);
deref(e->reg[le]);
deref(e->reg[re]);
makefree((Freenode*)e, &efl);
}
void VoronoiDiagramGenerator::endpoint(struct Edge *e1,int lr,struct Site * s, struct Edge *e2, struct Edge *e3)
{
e1 -> ep[lr] = s;
ref(s);
s->coordout.x = s->coord.x;
s->coordout.y = s->coord.y;
if(e1 -> ep[le] != (struct Site *) NULL && e1 -> ep[re] != (struct Site *) NULL)
{
clip_line(e1);
deref(e1->reg[le]);
deref(e1->reg[re]);
makefree((Freenode*)e1, &efl);
}
if(e2 -> ep[le] != (struct Site *) NULL && e2 -> ep[re] != (struct Site *) NULL)
{
clip_line(e2);
deref(e2->reg[le]);
deref(e2->reg[re]);
makefree((Freenode*)e2, &efl);
}
if(e3 -> ep[le] != (struct Site *) NULL && e3 -> ep[re] != (struct Site *) NULL)
{
clip_line(e3);
deref(e3->reg[le]);
deref(e3->reg[re]);
makefree((Freenode*)e3, &efl);
}
return;
}
float VoronoiDiagramGenerator::dist(struct Site *s,struct Site *t)
{
float dx,dy;
dx = s->coord.x - t->coord.x;
dy = s->coord.y - t->coord.y;
return (float)(sqrt(dx*dx + dy*dy));
}
void VoronoiDiagramGenerator::makevertex(struct Site *v)
{
v -> sitenbr = nvertices;
nvertices += 1;
out_vertex(v);
}
void VoronoiDiagramGenerator::deref(struct Site *v)
{
v -> refcnt -= 1;
if (v -> refcnt == 0 )
makefree((Freenode*)v, &sfl);
}
void VoronoiDiagramGenerator::ref(struct Site *v)
{
v -> refcnt += 1;
}
//push the HalfEdge into the ordered linked list of vertices
void VoronoiDiagramGenerator::PQinsert(struct Halfedge *he,struct Site * v, float offset)
{
struct Halfedge *last, *next;
he -> vertex = v;
ref(v);
he -> ystar = (float)(v -> coord.y + offset);
last = &PQhash[PQbucket(he)];
while ((next = last -> PQnext) != (struct Halfedge *) NULL &&
(he -> ystar > next -> ystar ||
(he -> ystar == next -> ystar && v -> coord.x > next->vertex->coord.x)))
{
last = next;
}
he -> PQnext = last -> PQnext;
last -> PQnext = he;
PQcount += 1;
}
//remove the HalfEdge from the list of vertices
void VoronoiDiagramGenerator::PQdelete(struct Halfedge *he)
{
struct Halfedge *last;
if(he -> vertex != (struct Site *) NULL)
{
last = &PQhash[PQbucket(he)];
while (last -> PQnext != he)
last = last -> PQnext;
last -> PQnext = he -> PQnext;
PQcount -= 1;
deref(he -> vertex);
he -> vertex = (struct Site *) NULL;
};
}
int VoronoiDiagramGenerator::PQbucket(struct Halfedge *he)
{
int bucket;
bucket = (int)((he->ystar - ymin)/deltay * PQhashsize);
if (bucket<0) bucket = 0;
if (bucket>=PQhashsize) bucket = PQhashsize-1 ;
if (bucket < PQmin) PQmin = bucket;
return(bucket);
}
int VoronoiDiagramGenerator::PQempty()
{
return(PQcount==0);
}
struct Point VoronoiDiagramGenerator::PQ_min()
{
struct Point answer;
while(PQhash[PQmin].PQnext == (struct Halfedge *)NULL) {PQmin += 1;};
answer.x = PQhash[PQmin].PQnext -> vertex -> coord.x;
answer.y = PQhash[PQmin].PQnext -> ystar;
return (answer);
}
struct Halfedge * VoronoiDiagramGenerator::PQextractmin()
{
struct Halfedge *curr;
curr = PQhash[PQmin].PQnext;
PQhash[PQmin].PQnext = curr -> PQnext;
PQcount -= 1;
return(curr);
}
bool VoronoiDiagramGenerator::PQinitialize()
{
int i;
PQcount = 0;
PQmin = 0;
PQhashsize = 4 * sqrt_nsites;
PQhash = (struct Halfedge *) myalloc(PQhashsize * sizeof *PQhash);
if(PQhash == 0)
return false;
for(i=0; i<PQhashsize; i+=1) PQhash[i].PQnext = (struct Halfedge *)NULL;
return true;
}
void VoronoiDiagramGenerator::freeinit(struct Freelist *fl,int size)
{
fl -> head = (struct Freenode *) NULL;
fl -> nodesize = size;
}
char * VoronoiDiagramGenerator::getfree(struct Freelist *fl)
{
int i;
struct Freenode *t;
if(fl->head == (struct Freenode *) NULL)
{
t = (struct Freenode *) myalloc(sqrt_nsites * fl->nodesize);
if(t == 0)
return 0;
currentMemoryBlock->next = new FreeNodeArrayList;
currentMemoryBlock = currentMemoryBlock->next;
currentMemoryBlock->memory = t;
currentMemoryBlock->next = 0;
for(i=0; i<sqrt_nsites; i+=1)
makefree((struct Freenode *)((char *)t+i*fl->nodesize), fl);
};
t = fl -> head;
fl -> head = (fl -> head) -> nextfree;
return((char *)t);
}
void VoronoiDiagramGenerator::makefree(struct Freenode *curr,struct Freelist *fl)
{
curr -> nextfree = fl -> head;
fl -> head = curr;
}
void VoronoiDiagramGenerator::cleanup()
{
if(sites != 0)
{
free(sites);
sites = 0;
}
FreeNodeArrayList* current=0, *prev = 0;
current = prev = allMemoryList;
while(current->next != 0)
{
prev = current;
current = current->next;
free(prev->memory);
delete prev;
prev = 0;
}
if(current != 0 && current->memory != 0)
{
free(current->memory);
delete current;
}
allMemoryList = new FreeNodeArrayList;
allMemoryList->next = 0;
allMemoryList->memory = 0;
currentMemoryBlock = allMemoryList;
}
void VoronoiDiagramGenerator::cleanupEdges()
{
GraphEdge* geCurrent = 0, *gePrev = 0;
geCurrent = gePrev = allEdges;
while(geCurrent != 0 && geCurrent->next != 0)
{
gePrev = geCurrent;
geCurrent = geCurrent->next;
delete gePrev;
}
allEdges = 0;
}
void VoronoiDiagramGenerator::pushGraphEdge(float x1, float y1, float x2, float y2)
{
GraphEdge* newEdge = new GraphEdge;
newEdge->next = allEdges;
allEdges = newEdge;
newEdge->x1 = x1;
newEdge->y1 = y1;
newEdge->x2 = x2;
newEdge->y2 = y2;
}
char * VoronoiDiagramGenerator::myalloc(unsigned n)
{
char *t=0;
t=(char*)malloc(n);
total_alloc += n;
return(t);
}
/* for those who don't have Cherry's plot */
/* #include <plot.h> */
void VoronoiDiagramGenerator::openpl(){}
void VoronoiDiagramGenerator::line(float x1, float y1, float x2, float y2)
{
pushGraphEdge(x1,y1,x2,y2);
}
void VoronoiDiagramGenerator::circle(float x, float y, float radius){}
void VoronoiDiagramGenerator::range(float minX, float minY, float maxX, float maxY){}
void VoronoiDiagramGenerator::out_bisector(struct Edge *e)
{
}
void VoronoiDiagramGenerator::out_ep(struct Edge *e)
{
}
void VoronoiDiagramGenerator::out_vertex(struct Site *v)
{
}
void VoronoiDiagramGenerator::out_site(struct Site *s)
{
if(!triangulate & plot & !debug)
circle (s->coord.x, s->coord.y, cradius);
}
void VoronoiDiagramGenerator::out_triple(struct Site *s1, struct Site *s2,struct Site * s3)
{
}
void VoronoiDiagramGenerator::plotinit()
{
float dx,dy,d;
dy = ymax - ymin;
dx = xmax - xmin;
d = (float)(( dx > dy ? dx : dy) * 1.1);
pxmin = (float)(xmin - (d-dx)/2.0);
pxmax = (float)(xmax + (d-dx)/2.0);
pymin = (float)(ymin - (d-dy)/2.0);
pymax = (float)(ymax + (d-dy)/2.0);
cradius = (float)((pxmax - pxmin)/350.0);
openpl();
range(pxmin, pymin, pxmax, pymax);
}
void VoronoiDiagramGenerator::pushpoint(int sitenbr, double x, double y, int boundary)
{
Polygon *s;
s = &polygons[sitenbr];
if (s->numpoints == 0)
{
s->pointlist = (PolygonPoint *)malloc(sizeof(struct PolygonPoint)*(s->numpoints+10));
if (!s->pointlist)
{
printf("Out of mem\n");
}
}
else if (s->numpoints % 10 == 0)
{
s->pointlist = (PolygonPoint *)realloc(s->pointlist, sizeof(struct PolygonPoint)*(s->numpoints+10));
if (!s->pointlist)
{
printf("Out of remem\n");
}
}
s->pointlist[s->numpoints].coord.x = x;
s->pointlist[s->numpoints].coord.y = y;
s->pointlist[s->numpoints].angle = atan2f(x-s->coord.x, y-s->coord.y);
s->pointlist[s->numpoints].boundary = boundary;
if (boundary) s->boundary = 1;
//printf("point #%d in %d (%lf, %lf) [%d] (%lf, %lf): %lf\n", s->numpoints, sitenbr, s->coord.x, s->coord.y, boundary, x, y, (s->pointlist[s->numpoints].angle/M_PI)*180);
s->numpoints++;
}
int VoronoiDiagramGenerator::ccw( Point p0, Point p1, Point p2 )
{
double dx1, dx2, dy1, dy2;
dx1 = p1.x - p0.x; dy1 = p1.y - p0.y;
dx2 = p2.x - p0.x; dy2 = p2.y - p0.y;
if (dx1*dy2 > dy1*dx2)
return +1;
if (dx1*dy2 < dy1*dx2)
return -1;
if ((dx1*dx2 < 0) || (dy1*dy2 < 0))
return -1;
if ((dx1*dx1 + dy1*dy1) < (dx2*dx2 + dy2*dy2))
return +1;
return 0;
}
void VoronoiDiagramGenerator::getSitePoints(int sitenbr, int* numpoints, PolygonPoint** pS)
{
int i, j, c, any, centrevalue, cornerinpolygon[4];
if (polygons[sitenbr].numpoints == 0)
{
for(c = 0; c < 4; c++)
{
pushpoint(sitenbr, corners[c].x, corners[c].y, 0);
}
}
qsort(polygons[sitenbr].pointlist, polygons[sitenbr].numpoints, sizeof(PolygonPoint), anglecomp);
if (polygons[sitenbr].boundary)
{
// printf("\nsite %d is boundary intersection\n", sitenbr);
for(c = 0; c < 4; c++) cornerinpolygon[c] = 1;
for(i = 0; i < polygons[sitenbr].numpoints; i++)
{
// printf("Point (%lf,%lf) %d\n", polygons[sitenbr].pointlist[i].coord.x,polygons[sitenbr].pointlist[i].coord.y,polygons[sitenbr].pointlist[i].boundary);
j = i > 0?i-1:polygons[sitenbr].numpoints-1;
if ( (!polygons[sitenbr].pointlist[i].boundary || !polygons[sitenbr].pointlist[j].boundary) &&
(polygons[sitenbr].pointlist[i].coord.x != polygons[sitenbr].pointlist[j].coord.x ||
polygons[sitenbr].pointlist[i].coord.y != polygons[sitenbr].pointlist[j].coord.y))
{
// printf("line side test (%lf,%lf) => (%lf,%lf)\n",polygons[sitenbr].pointlist[i].coord.x,polygons[sitenbr].pointlist[i].coord.y,polygons[sitenbr].pointlist[j].coord.x,polygons[sitenbr].pointlist[j].coord.y);
any = 0;
centrevalue = ccw(polygons[sitenbr].pointlist[i].coord, polygons[sitenbr].pointlist[j].coord, polygons[sitenbr].coord);
//printf(" test against centre (%lf,%lf) %d\n", polygons[sitenbr].coord.x, polygons[sitenbr].coord.y, centrevalue);
for(c = 0; c < 4; c++)
{
if (cornerinpolygon[c])
{
//printf(" test against corner (%lf,%lf) %d\n", corners[c].x, corners[c].y, ccw(polygons[sitenbr].pointlist[i].coord, polygons[sitenbr].pointlist[j].coord, corners[c]));
if (centrevalue == ccw(polygons[sitenbr].pointlist[i].coord, polygons[sitenbr].pointlist[j].coord, corners[c]))
{
any = 1;
}
else
{
cornerinpolygon[c] = 0;
}
}
}
if (!any) break;
}
}
if (any)
{
for(c = 0; c < 4; c++)
{
if (cornerinpolygon[c])
{
// printf("adding corger (%lf,%lf) to %d\n", corners[c].x, corners[c].y, sitenbr);
pushpoint(sitenbr, corners[c].x, corners[c].y, 0);
}
}
}
qsort(polygons[sitenbr].pointlist, polygons[sitenbr].numpoints, sizeof(PolygonPoint), anglecomp);
polygons[sitenbr].boundary = 0;
}
*numpoints = polygons[sitenbr].numpoints;
*pS = polygons[sitenbr].pointlist;
}
void VoronoiDiagramGenerator::clip_line(struct Edge *e)
{
struct Site *s1, *s2, *ts1, *ts2;
float x1=0,x2=0,y1=0,y2=0, temp = 0;
int boundary1 = 0, boundary2 = 0;
x1 = e->reg[0]->coord.x;
x2 = e->reg[1]->coord.x;
y1 = e->reg[0]->coord.y;
y2 = e->reg[1]->coord.y;
if(sqrt(((x2 - x1) * (x2 - x1)) + ((y2 - y1) * (y2 - y1))) == 0)
{
return;
}
pxmin = borderMinX;
pxmax = borderMaxX;
pymin = borderMinY;
pymax = borderMaxY;
if(e -> a == 1.0 && e ->b >= 0.0)
{
s1 = e -> ep[1];
s2 = e -> ep[0];
ts1 = e -> reg[1];
ts2 = e -> reg[0];
}
else
{
s1 = e -> ep[0];
s2 = e -> ep[1];
ts1 = e -> reg[0];
ts2 = e -> reg[1];
};
if(e -> a == 1.0)
{
if ( s1!=(struct Site *)NULL
&& s1->coordout.y > pymin && s1->coordout.y < pymax
&& s1->coordout.x > pxmin && s1->coordout.x < pxmax)
{
x1 = s1->coordout.x;
y1 = s1->coordout.y;
}
else
{
boundary1 = 1;
y1 = pymin;
if (s1!=(struct Site *)NULL && s1->coord.y > pymin)
{
y1 = s1->coord.y;
}
if(y1>pymax)
{
y1 = pymax;
}
x1 = e -> c - e -> b * y1;
}
if ( s2!=(struct Site *)NULL
&& s2->coordout.y > pymin && s2->coordout.y < pymax
&& s2->coordout.x > pxmin && s2->coordout.x < pxmax)
{
x2 = s2->coordout.x;
y2 = s2->coordout.y;
}
else
{
boundary2 = 1;
y2 = pymax;
if (s2!=(struct Site *)NULL && s2->coord.y < pymax)
y2 = s2->coord.y;
if(y2<pymin)
{
y2 = pymin;
}
x2 = (e->c) - (e->b) * y2;
}
if (((x1> pxmax) & (x2>pxmax)) | ((x1<pxmin)&(x2<pxmin)))
{
// Line completely outside clipbox
//printf("\nClipLine jumping out(3), x1 = %f, pxmin = %f, pxmax = %f",x1,pxmin,pxmax);
return;
}
if(x1 > pxmax)
{
x1 = pxmax;
y1 = (e -> c - x1)/e -> b;
}
if(x1 < pxmin)
{
x1 = pxmin;
y1 = (e -> c - x1)/e -> b;
}
if(x2 > pxmax)
{
x2 = pxmax;
y2 = (e -> c - x2)/e -> b;
}
if(x2 < pxmin)
{
x2 = pxmin;
y2 = (e -> c - x2)/e -> b;
}
}
else
{
if ( s1!=(struct Site *)NULL
&& s1->coordout.y > pymin && s1->coordout.y < pymax
&& s1->coordout.x > pxmin && s1->coordout.x < pxmax)
{
x1 = s1->coordout.x;
y1 = s1->coordout.y;
}
else
{
boundary1 = 1;
x1 = pxmin;
if (s1!=(struct Site *)NULL && s1->coord.x > pxmin)
x1 = s1->coord.x;
if(x1>pxmax)
{
//printf("\nClipped (3) x1 = %f to %f",x1,pxmin);
//return;
x1 = pxmax;
}
y1 = e -> c - e -> a * x1;
}
if ( s2!=(struct Site *)NULL
&& s2->coordout.y > pymin && s2->coordout.y < pymax
&& s2->coordout.x > pxmin && s2->coordout.x < pxmax)
{
x2 = s2->coordout.x;
y2 = s2->coordout.y;
}
else
{
boundary2 = 1;
x2 = pxmax;
if (s2!=(struct Site *)NULL && s2->coord.x < pxmax)
x2 = s2->coord.x;
if(x2<pxmin)
{
//printf("\nClipped (4) x2 = %f to %f",x2,pxmin);
//return;
x2 = pxmin;
}
y2 = e -> c - e -> a * x2;
}
if (((y1> pymax) & (y2>pymax)) | ((y1<pymin)&(y2<pymin)))
{
//printf("\nClipLine jumping out(6), y1 = %f, pymin = %f, pymax = %f",y2,pymin,pymax);
return;
}
if(y1 > pymax)
{ y1 = pymax; x1 = (e -> c - y1)/e -> a;};
if(y1 < pymin)
{ y1 = pymin; x1 = (e -> c - y1)/e -> a;};
if(y2 > pymax)
{ y2 = pymax; x2 = (e -> c - y2)/e -> a;};
if(y2 < pymin)
{ y2 = pymin; x2 = (e -> c - y2)/e -> a;};
};
if(sqrt(((x2 - x1) * (x2 - x1)) + ((y2 - y1) * (y2 - y1))) == 0)
{
return;
}
pushpoint(ts1->sitenbr, x1, y1, boundary1);
pushpoint(ts2->sitenbr, x2, y2, boundary2);
pushpoint(ts1->sitenbr, x2, y2, boundary2);
pushpoint(ts2->sitenbr, x1, y1, boundary1);
}
/* implicit parameters: nsites, sqrt_nsites, xmin, xmax, ymin, ymax,
deltax, deltay (can all be estimates).
Performance suffers if they are wrong; better to make nsites,
deltax, and deltay too big than too small. (?) */
bool VoronoiDiagramGenerator::voronoi(int triangulate)
{
struct Site *newsite, *bot, *top, *temp, *p;
struct Site *v;
struct Point newintstar;
int pm;
struct Halfedge *lbnd, *rbnd, *llbnd, *rrbnd, *bisector;
struct Edge *e, *e2, *e3;
PQinitialize();
bottomsite = nextone();
out_site(bottomsite);
bool retval = ELinitialize();
if(!retval)
return false;
newsite = nextone();
while(1)
{
if(!PQempty())
newintstar = PQ_min();
//if the lowest site has a smaller y value than the lowest vector intersection, process the site
//otherwise process the vector intersection
if (newsite != (struct Site *)NULL && (PQempty() || newsite -> coord.y < newintstar.y
|| (newsite->coord.y == newintstar.y && newsite->coord.x < newintstar.x)))
{/* new site is smallest - this is a site event*/
out_site(newsite); //output the site
lbnd = ELleftbnd(&(newsite->coord)); //get the first HalfEdge to the LEFT of the new site
rbnd = ELright(lbnd); //get the first HalfEdge to the RIGHT of the new site
bot = rightreg(lbnd); //if this halfedge has no edge, , bot = bottom site (whatever that is)
e = bisect(bot, newsite); //create a new edge that bisects
bisector = HEcreate(e, le); //create a new HalfEdge, setting its ELpm field to 0
ELinsert(lbnd, bisector); //insert this new bisector edge between the left and right vectors in a linked list
if ((p = intersect(lbnd, bisector)) != (struct Site *) NULL) //if the new bisector intersects with the left edge, remove the left edge's vertex, and put in the new one
{
PQdelete(lbnd);
PQinsert(lbnd, p, dist(p,newsite));
};
lbnd = bisector;
bisector = HEcreate(e, re); //create a new HalfEdge, setting its ELpm field to 1
ELinsert(lbnd, bisector); //insert the new HE to the right of the original bisector earlier in the IF stmt
if ((p = intersect(bisector, rbnd)) != (struct Site *) NULL) //if this new bisector intersects with the
{
PQinsert(bisector, p, dist(p,newsite)); //push the HE into the ordered linked list of vertices
};
newsite = nextone();
}
else if (!PQempty()) /* intersection is smallest - this is a vector event */
{
lbnd = PQextractmin(); //pop the HalfEdge with the lowest vector off the ordered list of vectors
llbnd = ELleft(lbnd); //get the HalfEdge to the left of the above HE
rbnd = ELright(lbnd); //get the HalfEdge to the right of the above HE
rrbnd = ELright(rbnd); //get the HalfEdge to the right of the HE to the right of the lowest HE
bot = leftreg(lbnd); //get the Site to the left of the left HE which it bisects
top = rightreg(rbnd); //get the Site to the right of the right HE which it bisects
out_triple(bot, top, rightreg(lbnd)); //output the triple of sites, stating that a circle goes through them
v = lbnd->vertex; //get the vertex that caused this event
makevertex(v); //set the vertex number - couldn't do this earlier since we didn't know when it would be processed
e2 = lbnd->ELedge;
e3 = rbnd->ELedge;
endpoint(lbnd->ELedge,lbnd->ELpm,v); //set the endpoint of the left HalfEdge to be this vector
endpoint(rbnd->ELedge,rbnd->ELpm,v); //set the endpoint of the right HalfEdge to be this vector
ELdelete(lbnd); //mark the lowest HE for deletion - can't delete yet because there might be pointers to it in Hash Map
PQdelete(rbnd); //remove all vertex events to do with the right HE
ELdelete(rbnd); //mark the right HE for deletion - can't delete yet because there might be pointers to it in Hash Map
pm = le; //set the pm variable to zero
if (bot->coord.y > top->coord.y) //if the site to the left of the event is higher than the Site
{ //to the right of it, then swap them and set the 'pm' variable to 1
temp = bot;
bot = top;
top = temp;
pm = re;
}
e = bisect(bot, top); //create an Edge (or line) that is between the two Sites. This creates
//the formula of the line, and assigns a line number to it
bisector = HEcreate(e, pm); //create a HE from the Edge 'e', and make it point to that edge with its ELedge field
ELinsert(llbnd, bisector); //insert the new bisector to the right of the left HE
endpoint(e, re-pm, v, e2, e3); //set one endpoint to the new edge to be the vector point 'v'.
//If the site to the left of this bisector is higher than the right
//Site, then this endpoint is put in position 0; otherwise in pos 1
deref(v); //delete the vector 'v'
//if left HE and the new bisector don't intersect, then delete the left HE, and reinsert it
if((p = intersect(llbnd, bisector)) != (struct Site *) NULL)
{
PQdelete(llbnd);
PQinsert(llbnd, p, dist(p,bot));
};
//if right HE and the new bisector don't intersect, then reinsert it
if ((p = intersect(bisector, rrbnd)) != (struct Site *) NULL)
{
PQinsert(bisector, p, dist(p,bot));
};
}
else break;
};
for(lbnd=ELright(ELleftend); lbnd != ELrightend; lbnd=ELright(lbnd))
{
e = lbnd -> ELedge;
clip_line(e);
};
cleanup();
return true;
}
int scomp(const void *p1,const void *p2)
{
struct Point *s1 = (Point*)p1, *s2=(Point*)p2;
if(s1 -> y < s2 -> y) return(-1);
if(s1 -> y > s2 -> y) return(1);
if(s1 -> x < s2 -> x) return(-1);
if(s1 -> x > s2 -> x) return(1);
return(0);
}
int spcomp(const void *p1,const void *p2)
{
struct SourcePoint *s1 = (SourcePoint*)p1, *s2=(SourcePoint*)p2;
if(s1 -> y < s2 -> y) return(-1);
if(s1 -> y > s2 -> y) return(1);
if(s1 -> x < s2 -> x) return(-1);
if(s1 -> x > s2 -> x) return(1);
return(0);
}
int anglecomp(const void * p1, const void * p2)
{
PolygonPoint * s1 = (PolygonPoint *)p1 ;
PolygonPoint * s2 = (PolygonPoint *)p2 ;
if (s1->angle < s2->angle) {
return (-1) ;
}
if (s1->angle > s2->angle) {
return (1) ;
}
return (0) ;
}
/* return a single in-storage site */
struct Site * VoronoiDiagramGenerator::nextone()
{
struct Site *s;
if(siteidx < nsites)
{
s = &sites[siteidx];
siteidx += 1;
return(s);
}
else
return( (struct Site *)NULL);
}
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