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Overview
| Comment: | Provide the two-argument geopoly_within(P1,P2) routine that determines if polygon P2 is contained within polygon P1. Make this function available to the query planner for optimized rtree lookups. Update the visual01.txt script to verify that the new functionality actually works. |
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| Timelines: | family | ancestors | descendants | both | rtree-geopoly |
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| SHA3-256: |
6eb5d09b7f9d9bf8edbf993dccc2e2f7 |
| User & Date: | drh 2018-08-25 19:51:49.457 |
Context
|
2018-08-25
| ||
| 23:03 | Enhance the geopoly virtual table so that it does a better job of optimizing geopoly_within() queries. (check-in: 1f71738534 user: drh tags: rtree-geopoly) | |
| 19:51 | Provide the two-argument geopoly_within(P1,P2) routine that determines if polygon P2 is contained within polygon P1. Make this function available to the query planner for optimized rtree lookups. Update the visual01.txt script to verify that the new functionality actually works. (check-in: 6eb5d09b7f user: drh tags: rtree-geopoly) | |
| 18:57 | Fix a harmless compiler warning. (check-in: d49be9838d user: drh tags: rtree-geopoly) | |
Changes
Changes to ext/rtree/geopoly.c.
| ︙ | ︙ | |||
575 576 577 578 579 580 581 582 | } y = y1 + (y2-y1)*(x0-x1)/(x2-x1); if( y0==y ) return 2; if( y0<y ) return 1; return 0; } /* | > > > | > > > > > > > | > > | | < | | | | | > > > > > > > > > > | | > > | 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 |
}
y = y1 + (y2-y1)*(x0-x1)/(x2-x1);
if( y0==y ) return 2;
if( y0<y ) return 1;
return 0;
}
/* Forward declaration */
static int geopolyOverlap(GeoPoly *p1, GeoPoly *p2);
/*
** SQL function: geopoly_within(P,X,Y) -- 3-argument form
**
** Return +2 if point X,Y is within polygon P.
** Return +1 if point X,Y is on the polygon boundary.
** Return 0 if point X,Y is outside the polygon
**
** SQL function: geopoly_within(P1,P2) -- 2-argument form
**
** Return +2 if P1 and P2 are the same polygon
** Return +1 if P2 is contained within P1
** Return 0 if any part of P2 is on the outside of P1
**
*/
static void geopolyWithinFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
GeoPoly *p1 = geopolyFuncParam(context, argv[0], 0);
if( p1==0 ) return;
if( argc==3 ){
double x0 = sqlite3_value_double(argv[1]);
double y0 = sqlite3_value_double(argv[2]);
int v = 0;
int cnt = 0;
int ii;
for(ii=0; ii<p1->nVertex-1; ii++){
v = pointBeneathLine(x0,y0,p1->a[ii*2],p1->a[ii*2+1],
p1->a[ii*2+2],p1->a[ii*2+3]);
if( v==2 ) break;
cnt += v;
}
if( v!=2 ){
v = pointBeneathLine(x0,y0,p1->a[ii*2],p1->a[ii*2+1],
p1->a[0],p1->a[1]);
}
if( v==2 ){
sqlite3_result_int(context, 1);
}else if( ((v+cnt)&1)==0 ){
sqlite3_result_int(context, 0);
}else{
sqlite3_result_int(context, 2);
}
}else{
assert( argc==2 );
GeoPoly *p2 = geopolyFuncParam(context, argv[1], 0);
if( p2 ){
int x = geopolyOverlap(p1, p2);
if( x<0 ){
sqlite3_result_error_nomem(context);
}else{
sqlite3_result_int(context, x==2 ? 1 : x==4 ? 2 : 0);
}
sqlite3_free(p2);
}
}
sqlite3_free(p1);
}
/* Objects used by the overlap algorihm. */
typedef struct GeoEvent GeoEvent;
typedef struct GeoSegment GeoSegment;
typedef struct GeoOverlap GeoOverlap;
struct GeoEvent {
|
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1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 |
if( p->iColumn==0 && p->op==SQLITE_INDEX_CONSTRAINT_FUNCTION ){
iFuncTerm = ii;
}
}
if( iRowidTerm>=0 ){
pIdxInfo->idxNum = 1;
pIdxInfo->aConstraintUsage[iRowidTerm].argvIndex = 1;
pIdxInfo->aConstraintUsage[iRowidTerm].omit = 1;
pIdxInfo->estimatedCost = 30.0;
pIdxInfo->estimatedRows = 1;
pIdxInfo->idxFlags = SQLITE_INDEX_SCAN_UNIQUE;
return SQLITE_OK;
}
if( iFuncTerm>=0 ){
pIdxInfo->idxNum = 2;
pIdxInfo->aConstraintUsage[iFuncTerm].argvIndex = 1;
pIdxInfo->aConstraintUsage[iFuncTerm].omit = 0;
pIdxInfo->estimatedCost = 300.0;
pIdxInfo->estimatedRows = 10;
return SQLITE_OK;
}
pIdxInfo->idxNum = 3;
pIdxInfo->estimatedCost = 3000000.0;
pIdxInfo->estimatedRows = 100000;
return SQLITE_OK;
}
/*
| > > > | 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 |
if( p->iColumn==0 && p->op==SQLITE_INDEX_CONSTRAINT_FUNCTION ){
iFuncTerm = ii;
}
}
if( iRowidTerm>=0 ){
pIdxInfo->idxNum = 1;
pIdxInfo->idxStr = "rowid";
pIdxInfo->aConstraintUsage[iRowidTerm].argvIndex = 1;
pIdxInfo->aConstraintUsage[iRowidTerm].omit = 1;
pIdxInfo->estimatedCost = 30.0;
pIdxInfo->estimatedRows = 1;
pIdxInfo->idxFlags = SQLITE_INDEX_SCAN_UNIQUE;
return SQLITE_OK;
}
if( iFuncTerm>=0 ){
pIdxInfo->idxNum = 2;
pIdxInfo->idxStr = "rtree";
pIdxInfo->aConstraintUsage[iFuncTerm].argvIndex = 1;
pIdxInfo->aConstraintUsage[iFuncTerm].omit = 0;
pIdxInfo->estimatedCost = 300.0;
pIdxInfo->estimatedRows = 10;
return SQLITE_OK;
}
pIdxInfo->idxNum = 3;
pIdxInfo->idxStr = "fullscan";
pIdxInfo->estimatedCost = 3000000.0;
pIdxInfo->estimatedRows = 100000;
return SQLITE_OK;
}
/*
|
| ︙ | ︙ | |||
1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 |
void **ppArg
){
if( sqlite3_stricmp(zName, "geopoly_overlap")==0 ){
*pxFunc = geopolyOverlapFunc;
*ppArg = 0;
return SQLITE_INDEX_CONSTRAINT_FUNCTION;
}
return 0;
}
static sqlite3_module geopolyModule = {
2, /* iVersion */
geopolyCreate, /* xCreate - create a table */
| > > > > > | 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 |
void **ppArg
){
if( sqlite3_stricmp(zName, "geopoly_overlap")==0 ){
*pxFunc = geopolyOverlapFunc;
*ppArg = 0;
return SQLITE_INDEX_CONSTRAINT_FUNCTION;
}
if( nArg==2 && sqlite3_stricmp(zName, "geopoly_within")==0 ){
*pxFunc = geopolyWithinFunc;
*ppArg = 0;
return SQLITE_INDEX_CONSTRAINT_FUNCTION;
}
return 0;
}
static sqlite3_module geopolyModule = {
2, /* iVersion */
geopolyCreate, /* xCreate - create a table */
|
| ︙ | ︙ | |||
1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 |
int nArg;
const char *zName;
} aFunc[] = {
{ geopolyAreaFunc, 1, "geopoly_area" },
{ geopolyBlobFunc, 1, "geopoly_blob" },
{ geopolyJsonFunc, 1, "geopoly_json" },
{ geopolySvgFunc, -1, "geopoly_svg" },
{ geopolyWithinFunc, 3, "geopoly_within" },
{ geopolyOverlapFunc, 2, "geopoly_overlap" },
{ geopolyDebugFunc, 1, "geopoly_debug" },
{ geopolyBBoxFunc, 1, "geopoly_bbox" },
{ geopolyXformFunc, 7, "geopoly_xform" },
};
int i;
| > | 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 |
int nArg;
const char *zName;
} aFunc[] = {
{ geopolyAreaFunc, 1, "geopoly_area" },
{ geopolyBlobFunc, 1, "geopoly_blob" },
{ geopolyJsonFunc, 1, "geopoly_json" },
{ geopolySvgFunc, -1, "geopoly_svg" },
{ geopolyWithinFunc, 2, "geopoly_within" },
{ geopolyWithinFunc, 3, "geopoly_within" },
{ geopolyOverlapFunc, 2, "geopoly_overlap" },
{ geopolyDebugFunc, 1, "geopoly_debug" },
{ geopolyBBoxFunc, 1, "geopoly_bbox" },
{ geopolyXformFunc, 7, "geopoly_xform" },
};
int i;
|
| ︙ | ︙ |
Changes to ext/rtree/visual01.txt.
| ︙ | ︙ | |||
370 371 372 373 374 375 376 |
)
FROM geo1;
SELECT geopoly_svg(poly,
printf('style="fill:%s;fill-opacity:0.5;"',clr)
)
FROM querypoly;
.print '</svg>'
| > > | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 |
)
FROM geo1;
SELECT geopoly_svg(poly,
printf('style="fill:%s;fill-opacity:0.5;"',clr)
)
FROM querypoly;
.print '</svg>'
.print '<h1>Overlap Query</h1>'
.print '<pre>'
EXPLAIN QUERY PLAN
SELECT geopoly_svg(_shape,
printf('style="fill:none;stroke:%s;stroke-width:1"',geo1.clr)
)
FROM geo1, querypoly
WHERE geopoly_overlap(_shape, poly);
.print '</pre>'
.print '<svg width="1000" height="800" style="border:1px solid black">'
SELECT geopoly_svg(_shape,
printf('style="fill:none;stroke:%s;stroke-width:1"',geo1.clr)
)
FROM geo1, querypoly
WHERE geopoly_overlap(_shape, poly);
SELECT geopoly_svg(poly,
printf('style="fill:%s;fill-opacity:0.5;"',clr)
)
FROM querypoly;
.print '</svg>'
.print '<h1>Within Query</h1>'
.print '<pre>'
EXPLAIN QUERY PLAN
SELECT geopoly_svg(_shape,
printf('style="fill:none;stroke:%s;stroke-width:1"',geo1.clr)
)
FROM geo1, querypoly
WHERE geopoly_within(_shape, poly);
.print '</pre>'
.print '<svg width="1000" height="800" style="border:1px solid black">'
SELECT geopoly_svg(_shape,
printf('style="fill:none;stroke:%s;stroke-width:1"',geo1.clr)
)
FROM geo1, querypoly
WHERE geopoly_within(_shape, poly);
SELECT geopoly_svg(poly,
printf('style="fill:%s;fill-opacity:0.5;"',clr)
)
FROM querypoly;
.print '</svg>'
.print '<h1>Not Overlap Query</h1>'
.print '<pre>'
EXPLAIN QUERY PLAN
SELECT geopoly_svg(_shape,
printf('style="fill:none;stroke:%s;stroke-width:1"',geo1.clr)
)
FROM geo1, querypoly
WHERE NOT geopoly_overlap(_shape, poly);
.print '</pre>'
.print '<svg width="1000" height="800" style="border:1px solid black">'
SELECT geopoly_svg(_shape,
printf('style="fill:none;stroke:%s;stroke-width:1"',geo1.clr)
)
FROM geo1, querypoly
WHERE NOT geopoly_overlap(_shape, poly);
SELECT geopoly_svg(poly,
printf('style="fill:%s;fill-opacity:0.5;"',clr)
)
FROM querypoly;
.print '</svg>'
.print '<h1>Not Within Query</h1>'
.print '<pre>'
EXPLAIN QUERY PLAN
SELECT geopoly_svg(_shape,
printf('style="fill:none;stroke:%s;stroke-width:1"',geo1.clr)
)
FROM geo1, querypoly
WHERE NOT geopoly_within(_shape, poly);
.print '</pre>'
.print '<svg width="1000" height="800" style="border:1px solid black">'
SELECT geopoly_svg(_shape,
printf('style="fill:none;stroke:%s;stroke-width:1"',geo1.clr)
)
FROM geo1, querypoly
WHERE NOT geopoly_within(_shape, poly);
SELECT geopoly_svg(poly,
printf('style="fill:%s;fill-opacity:0.5;"',clr)
)
FROM querypoly;
.print '</svg>'
.print '</html>'
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