fixes #1249

NAMESPACE

@@ -1,7 +1,7 @@
 useDynLib(terra, .registration=TRUE)
 import(methods, Rcpp)
 exportClasses(SpatExtent, SpatRaster, SpatRasterDataset, SpatRasterCollection, SpatVector, SpatVectorProxy, SpatVectorCollection)
-exportMethods("[", "[[", "!", "%in%", activeCat, "activeCat<-", "add<-", addCats, adjacent, all.equal, aggregate, allNA, align, animate, anyNA, app, area, Arith, approximate, as.bool, as.int, as.contour, as.lines, as.points, as.polygons, as.raster, as.array, as.data.frame, as.factor, as.list, as.logical, as.matrix, as.numeric, atan2, atan_2, autocor, barplot, blocks, boundaries, boxplot, buffer, cartogram, categories, cats, catalyze, clamp, clamp_ts, classify, clearance, cellSize, cells, cellFromXY, cellFromRowCol, cellFromRowColCombine, centroids, click, colFromX, colFromCell, colorize, coltab, "coltab<-", combineGeoms, compare, concats, Compare, compareGeom, contour, convHull, countNA, costDist, crds, cover, crop, crosstab, crs, "crs<-", datatype, deepcopy, delaunay, densify, density, depth, "depth<-", describe, diff, disagg, direction, distance, dots, draw, droplevels, elongate, emptyGeoms, erase, extend, ext, "ext<-", extract, expanse, fillHoles, fillTime, flip, focal, focal3D, focalCor, focalPairs, focalReg, focalCpp, focalValues, freq, gaps, geom, geomtype, global, gridDist, gridDistance, has.colors, has.RGB, hasMinMax, hasValues, hist, head, ifel, impose, init, image, inext, interpIDW, interpNear, inMemory, inset, interpolate, intersect, is.bool, is.int, is.lonlat, is.rotated, isTRUE, isFALSE, is.factor, is.lines, is.points, is.polygons, is.related, is.valid, lapp, layerCor, levels, linearUnits, lines, Logic, varnames, "varnames<-", logic, longnames, "longnames<-", makeValid, mask, match, math, Math, Math2, mean, median, meta, merge, mergeLines, mergeTime, minmax, minRect, modal, mosaic, na.omit, not.na, NAflag, "NAflag<-", nearby, nearest, ncell, ncol, "ncol<-", nlyr, "nlyr<-", noNA, normalize.longitude, nrow, "nrow<-", nsrc, origin, "origin<-", pairs, panel, patches, perim, persp, plot, plotRGB, plet, RGB, "RGB<-", polys, points, predict, project, quantile, query, rangeFill, rapp, rast, rasterize, rasterizeGeom, rasterizeWin,readStart, readStop, readValues, rectify, regress, relate, removeDupNodes, res, "res<-", resample, rescale, rev, rcl, roll, rotate, rowFromY, rowColCombine, rowColFromCell, rowFromCell, sapp, scale, scoff, "scoff<-", sds, sort, sprc, sel, selectRange, setMinMax, setValues, segregate, selectHighest, set.cats, set.crs, set.ext, set.names, set.RGB, set.values, size, sharedPaths, shift, sieve, simplifyGeom, snap, sources, spatSample, split, spin, stdev, stretch, subset, subst, summary, Summary, svc, symdif, t, tail, tapp, terrain, tighten, makeNodes, makeTiles, time, timeInfo, "time<-", text, trans, trim, units, union, "units<-", unique, unwrap, update, vect, values, "values<-", viewshed, voronoi, vrt, weighted.mean, where.min, where.max, which.lyr, which.min, which.max, which.lyr, width, window, "window<-", writeCDF, writeRaster, wrap, wrapCache, writeStart, writeStop, writeVector, writeValues, xmin, xmax, "xmin<-", "xmax<-", xres, xFromCol, xyFromCell, xFromCell, ymin, ymax, "ymin<-", "ymax<-", yres, yFromCell, yFromRow, zonal, zoom, cbind2, readRDS, saveRDS, unserialize, serialize)
+exportMethods("[", "[[", "!", "%in%", activeCat, "activeCat<-", "add<-", addCats, adjacent, all.equal, aggregate, allNA, align, animate, anyNA, app, area, Arith, approximate, as.bool, as.int, as.contour, as.lines, as.points, as.polygons, as.raster, as.array, as.data.frame, as.factor, as.list, as.logical, as.matrix, as.numeric, atan2, atan_2, autocor, barplot, blocks, boundaries, boxplot, buffer, cartogram, categories, cats, catalyze, clamp, clamp_ts, classify, clearance, cellSize, cells, cellFromXY, cellFromRowCol, cellFromRowColCombine, centroids, click, colFromX, colFromCell, colorize, coltab, "coltab<-", combineGeoms, compare, concats, Compare, compareGeom, contour, convHull, countNA, costDist, crds, cover, crop, crosstab, crs, "crs<-", datatype, deepcopy, delaunay, densify, density, depth, "depth<-", describe, diff, disagg, direction, distance, dots, draw, droplevels, elongate, emptyGeoms, erase, extend, ext, "ext<-", extract, expanse, fillHoles, fillTime, flip, focal, focal3D, focalCor, focalPairs, focalReg, focalCpp, focalValues, forceCCW, freq, gaps, geom, geomtype, global, gridDist, gridDistance, has.colors, has.RGB, hasMinMax, hasValues, hist, head, ifel, impose, init, image, inext, interpIDW, interpNear, inMemory, inset, interpolate, intersect, is.bool, is.int, is.lonlat, is.rotated, isTRUE, isFALSE, is.factor, is.lines, is.points, is.polygons, is.related, is.valid, lapp, layerCor, levels, linearUnits, lines, Logic, varnames, "varnames<-", logic, longnames, "longnames<-", makeValid, mask, match, math, Math, Math2, mean, median, meta, merge, mergeLines, mergeTime, minmax, minRect, modal, mosaic, na.omit, not.na, NAflag, "NAflag<-", nearby, nearest, ncell, ncol, "ncol<-", nlyr, "nlyr<-", noNA, normalize.longitude, nrow, "nrow<-", nsrc, origin, "origin<-", pairs, panel, patches, perim, persp, plot, plotRGB, plet, RGB, "RGB<-", polys, points, predict, project, quantile, query, rangeFill, rapp, rast, rasterize, rasterizeGeom, rasterizeWin,readStart, readStop, readValues, rectify, regress, relate, removeDupNodes, res, "res<-", resample, rescale, rev, rcl, roll, rotate, rowFromY, rowColCombine, rowColFromCell, rowFromCell, sapp, scale, scoff, "scoff<-", sds, sort, sprc, sel, selectRange, setMinMax, setValues, segregate, selectHighest, set.cats, set.crs, set.ext, set.names, set.RGB, set.values, size, sharedPaths, shift, sieve, simplifyGeom, snap, sources, spatSample, split, spin, stdev, stretch, subset, subst, summary, Summary, svc, symdif, t, tail, tapp, terrain, tighten, makeNodes, makeTiles, time, timeInfo, "time<-", text, trans, trim, units, union, "units<-", unique, unwrap, update, vect, values, "values<-", viewshed, voronoi, vrt, weighted.mean, where.min, where.max, which.lyr, which.min, which.max, which.lyr, width, window, "window<-", writeCDF, writeRaster, wrap, wrapCache, writeStart, writeStop, writeVector, writeValues, xmin, xmax, "xmin<-", "xmax<-", xres, xFromCol, xyFromCell, xFromCell, ymin, ymax, "ymin<-", "ymax<-", yres, yFromCell, yFromRow, zonal, zoom, cbind2, readRDS, saveRDS, unserialize, serialize)
 
 S3method(cbind, SpatVector)
 S3method(rbind, SpatVector)

R/Agenerics.R

@@ -1,5 +1,6 @@
 #if (!isGeneric("#")) { setGeneric("#", function(x, ...) standardGeneric("#")) }
 
+if (!isGeneric("forceCCW")) {setGeneric("forceCCW", function(x, ...) standardGeneric("forceCCW"))}
 if (!isGeneric("addCats")) {setGeneric("addCats", function(x, ...) standardGeneric("addCats"))}
 if (!isGeneric("regress")) {setGeneric("regress", function(y, x, ...) standardGeneric("regress"))}
 

R/geom.R

@@ -655,3 +655,12 @@ setMethod("split", signature(x="SpatVector", f="SpatVector"),
 		intersect(x, p)
 	}
 )
+
+
+setMethod("forceCCW", signature(x="SpatVector"),
+	function(x) {
+		x <- deepcopy(x)
+		x@pnt$make_CCW()
+		x
+	}
+)

src/RcppModule.cpp

@@ -582,6 +582,7 @@ RCPP_MODULE(spat){
 
 		.method("densify", &SpatVector::densify)
 		.method("round", &SpatVector::round)
+		.method("make_CCW", &SpatVector::make_CCW)
 	;
 
 

src/geos_methods.cpp

@@ -3194,3 +3194,27 @@ SpatVector SpatVector::clearance() {
 }
 
 
+bool SpatPart::is_CCW() {
+#ifndef GEOS370
+	return true;
+#else
+
+	GEOSContextHandle_t hGEOSCtxt = geos_init();
+	GEOSCoordSequence *pseq;
+	size_t n = size();
+	pseq = GEOSCoordSeq_create_r(hGEOSCtxt, n, 2);
+	for (size_t i = 0; i < n; i++) {
+		GEOSCoordSeq_setX_r(hGEOSCtxt, pseq, i, x[i]);
+		GEOSCoordSeq_setY_r(hGEOSCtxt, pseq, i, y[i]);
+	}
+	char is_ccw;
+	bool success = GEOSCoordSeq_isCCW_r(hGEOSCtxt, pseq, &is_ccw);
+	geos_finish(hGEOSCtxt);
+	if (success) {
+		Rcpp::Rcout << is_ccw << std::endl;
+		return is_ccw != 0;
+	} else {
+		return true;
+	}
+#endif
+}

src/spatVector.cpp

@@ -1432,3 +1432,23 @@ std::vector<std::vector<std::vector<std::vector<double>>>> SpatVector::polygonsL
 }
 
 
+
+void SpatVector::make_CCW() {
+	size_t n = size();
+	if (n == 0) return;
+	if (geoms[0].gtype != polygons) return;
+	for (size_t i=0; i<n; i++) {
+		for (size_t j=0; j<geoms[i].parts.size(); j++) {
+			if (!geoms[i].parts[j].is_CCW()) {
+				std::reverse(geoms[i].parts[j].x.begin(), geoms[i].parts[j].x.end());
+				std::reverse(geoms[i].parts[j].y.begin(), geoms[i].parts[j].y.end());
+				for (size_t k=0; k<geoms[i].parts[j].nHoles(); k++) {
+					std::reverse(geoms[i].parts[j].holes[k].x.begin(), geoms[i].parts[j].holes[k].x.end());
+					std::reverse(geoms[i].parts[j].holes[k].y.begin(), geoms[i].parts[j].holes[k].y.end());
+				}
+			}
+		}
+	}
+}
+
+

src/spatVector.h

@@ -64,6 +64,7 @@ class SpatPart {
 		bool hasHoles() { return !holes.empty();}
 		unsigned nHoles() { return holes.size();}
 		size_t ncoords();
+		bool is_CCW();
 };
 
 
@@ -215,6 +216,8 @@ class SpatVector {
 		bool read(std::string fname, std::string layer, std::string query, std::vector<double> extent, SpatVector filter, bool as_proxy, std::string what);
 
 		bool write(std::string filename, std::string lyrname, std::string driver, bool append, bool overwrite, std::vector<std::string>);
+
+		void make_CCW();
 
 #ifdef useGDAL
 		GDALDataset* write_ogr(std::string filename, std::string lyrname, std::string driver, bool append, bool overwrite, std::vector<std::string> options);