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Overview
| Comment: | Add the geopoly_svg() SQL function. |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | geojson |
| Files: | files | file ages | folders |
| SHA3-256: |
318ba5f0c52596fc5ceed23a2b7b1ca1 |
| User & Date: | drh 2018-05-12 21:09:31.743 |
Context
|
2018-05-12
| ||
| 23:31 | Resolve issues with floating-point round-off error in the geopoly_overlap() routine. (check-in: a3c6696f2f user: drh tags: geojson) | |
| 21:09 | Add the geopoly_svg() SQL function. (check-in: 318ba5f0c5 user: drh tags: geojson) | |
| 20:28 | Preliminary tests show geopoly_overlap() is working. (check-in: 77bb7b7d72 user: drh tags: geojson) | |
Changes
Changes to ext/misc/geopoly.c.
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}
sqlite3_str_appendf(x, "[%!g,%!g]]", p->a[0], p->a[1]);
sqlite3_result_text(context, sqlite3_str_finish(x), -1, sqlite3_free);
sqlite3_free(p);
}
}
/*
** Implementation of the geopoly_area(X) function.
**
** If the input is a well-formed Geopoly BLOB then return the area
** enclosed by the polygon. If the polygon circulates clockwise instead
** of counterclockwise (as it should) then return the negative of the
| > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 |
}
sqlite3_str_appendf(x, "[%!g,%!g]]", p->a[0], p->a[1]);
sqlite3_result_text(context, sqlite3_str_finish(x), -1, sqlite3_free);
sqlite3_free(p);
}
}
/*
** SQL function: geopoly_svg(X, ....)
**
** Interpret X as a polygon and render it as a SVG <polyline>.
** Additional arguments are added as attributes to the <polyline>.
*/
static void geopolySvgFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
GeoPoly *p = geopolyFuncParam(context, argv[0]);
if( p ){
sqlite3 *db = sqlite3_context_db_handle(context);
sqlite3_str *x = sqlite3_str_new(db);
int i;
char cSep = '\'';
sqlite3_str_appendf(x, "<polyline points=");
for(i=0; i<p->nVertex; i++){
sqlite3_str_appendf(x, "%c%g,%g", cSep, p->a[i*2], p->a[i*2+1]);
cSep = ' ';
}
sqlite3_str_appendf(x, " %g,%g'", p->a[0], p->a[1]);
for(i=1; i<argc; i++){
const char *z = (const char*)sqlite3_value_text(argv[i]);
if( z && z[0] ){
sqlite3_str_appendf(x, " %s", z);
}
}
sqlite3_str_appendf(x, "></polyline>");
sqlite3_result_text(context, sqlite3_str_finish(x), -1, sqlite3_free);
sqlite3_free(p);
}
}
/*
** Implementation of the geopoly_area(X) function.
**
** If the input is a well-formed Geopoly BLOB then return the area
** enclosed by the polygon. If the polygon circulates clockwise instead
** of counterclockwise (as it should) then return the negative of the
|
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void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
int nArg;
const char *zName;
} aFunc[] = {
{ geopolyAreaFunc, 1, "geopoly_area" },
{ geopolyBlobFunc, 1, "geopoly_blob" },
{ geopolyJsonFunc, 1, "geopoly_json" },
{ geopolyWithinFunc, 3, "geopoly_within" },
{ geopolyOverlapFunc, 2, "geopoly_overlap" },
{ geopolyDebugFunc, 1, "geopoly_debug" },
};
int i;
SQLITE_EXTENSION_INIT2(pApi);
(void)pzErrMsg; /* Unused parameter */
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void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
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" },
};
int i;
SQLITE_EXTENSION_INIT2(pApi);
(void)pzErrMsg; /* Unused parameter */
|
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