database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-07-29 08:01:23 +03:00
Code Activity

Provide the two-argument geopoly_within(P1,P2) routine that determines if

Browse Source 
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.

FossilOrigin-Name: 6eb5d09b7f9d9bf8edbf993dccc2e2f702b95ba96cf68445609feb0ccc3ac0f7
This commit is contained in:
drh
2018-08-25 19:51:49 +00:00
parent 95327f539b
commit 27d62540e5
4 changed files with 125 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

56
ext/rtree/geopoly.c
View File

@ -579,34 +579,45 @@ static int pointBeneathLine(
return 0;
}
/* Forward declaration */
static int geopolyOverlap(GeoPoly *p1, GeoPoly *p2);
/*
** SQL function: geopoly_within(P,X,Y)
** 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 *p = geopolyFuncParam(context, argv[0], 0);
double x0 = sqlite3_value_double(argv[1]);
double y0 = sqlite3_value_double(argv[2]);
if( p ){
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<p->nVertex-1; ii++){
v = pointBeneathLine(x0,y0,p->a[ii*2],p->a[ii*2+1],
p->a[ii*2+2],p->a[ii*2+3]);
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,p->a[ii*2],p->a[ii*2+1],
p->a[0],p->a[1]);
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);
@ -615,8 +626,20 @@ static void geopolyWithinFunc(
}else{
sqlite3_result_int(context, 2);
}
sqlite3_free(p);
}
}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. */
@ -1219,6 +1242,7 @@ static int geopolyBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
if( iRowidTerm>=0 ){
pIdxInfo->idxNum = 1;
pIdxInfo->idxStr = "rowid";
pIdxInfo->aConstraintUsage[iRowidTerm].argvIndex = 1;
pIdxInfo->aConstraintUsage[iRowidTerm].omit = 1;
pIdxInfo->estimatedCost = 30.0;
@ -1228,6 +1252,7 @@ static int geopolyBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
}
if( iFuncTerm>=0 ){
pIdxInfo->idxNum = 2;
pIdxInfo->idxStr = "rtree";
pIdxInfo->aConstraintUsage[iFuncTerm].argvIndex = 1;
pIdxInfo->aConstraintUsage[iFuncTerm].omit = 0;
pIdxInfo->estimatedCost = 300.0;
@ -1235,6 +1260,7 @@ static int geopolyBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
return SQLITE_OK;
}
pIdxInfo->idxNum = 3;
pIdxInfo->idxStr = "fullscan";
pIdxInfo->estimatedCost = 3000000.0;
pIdxInfo->estimatedRows = 100000;
return SQLITE_OK;
@ -1432,6 +1458,11 @@ static int geopolyFindFunction(
*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;
}
@ -1473,6 +1504,7 @@ static int sqlite3_geopoly_init(sqlite3 *db){
{ 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" },