for #1929

Author: rhijmans

R/distance.R

@@ -4,9 +4,9 @@
 # License GPL v3
 
 setMethod("buffer", signature(x="SpatRaster"),
-	function(x, width, background=0, filename="", ...) {
+	function(x, width, background=0, include=TRUE, filename="", ...) {
 		opt <- spatOptions(filename, ...)
-		x@pntr <- x@pntr$buffer(width, background, opt)
+		x@pntr <- x@pntr$buffer(width, background, include, opt)
 		messages(x, "buffer")
 	}
 )

man/buffer.Rd

@@ -16,7 +16,7 @@ Note that the distance unit of the buffer \code{width} parameter is meters if th
 }
 
 \usage{
-\S4method{buffer}{SpatRaster}(x, width, background=0, filename="", ...)
+\S4method{buffer}{SpatRaster}(x, width, background=0, include=TRUE, filename="", ...)
 
 \S4method{buffer}{SpatVector}(x, width, quadsegs=10, capstyle="round", 
 		joinstyle="round", mitrelimit=NA, singlesided=FALSE)
@@ -28,6 +28,7 @@ Note that the distance unit of the buffer \code{width} parameter is meters if th
   \item{filename}{character. Output filename}
   \item{...}{additional arguments for writing files as in \code{\link{writeRaster}}}
   \item{background}{numeric. value to assign to cells outside the buffer. If this value is zero or FALSE, a boolean SpatRaster is returned}  
+  \item{include}{logical. If \code{TRUE} the raster cells that are not \code{NA} are included in the buffer. Otherwise these cells get the background value}  
   \item{quadsegs}{positive integer. Number of line segments to use to draw a quart circle}  
   \item{capstyle}{character. One of "round", "square" or "flat". Ignored if \code{is.lonlat(x)}}
   \item{joinstyle}{character. One of "round", "mitre" or "bevel". Ignored if \code{is.lonlat(x)}}  

src/distRaster.cpp

@@ -1878,7 +1878,7 @@ SpatRaster SpatRaster::edges(bool classes, std::string type, unsigned directions
 
 
 
-SpatRaster SpatRaster::buffer(double d, double background, SpatOptions &opt) {
+SpatRaster SpatRaster::buffer(double d, double background, bool include, SpatOptions &opt) {
 
 	SpatRaster out = geometry(1);
 	if (!hasValues()) {
@@ -1908,7 +1908,7 @@ SpatRaster SpatRaster::buffer(double d, double background, SpatOptions &opt) {
 			std::vector<size_t> lyr = {i};
 			SpatRaster r = subset(lyr, ops);
 			ops.names = {nms[i]};
-			r = r.buffer(d, background, ops);
+			r = r.buffer(d, background, include, ops);
 			out.source[i] = r.source[0];
 		}
 		if (!opt.get_filename().empty()) {
@@ -1929,6 +1929,9 @@ SpatRaster SpatRaster::buffer(double d, double background, SpatOptions &opt) {
 		} else {
 			out = proximity(NAN, NAN, false, "", true, d, true, opt);
 		}
+		if (!include) {
+			out = out.mask(*this, true, NAN, NAN, opt);						
+		}
 	} else {
 		SpatRaster e = edges(false, "inner", 8, NAN, ops);
 		SpatVector p = e.as_points(false, true, false, ops);
@@ -1938,7 +1941,11 @@ SpatRaster SpatRaster::buffer(double d, double background, SpatOptions &opt) {
 		if (background == 0) {
 			out.setValueType(3);
 		}
-		out = out.mask(*this, true, NAN, 1, opt);
+		if (include) {
+			out = out.mask(*this, true, NAN, 1, opt);
+		} else {
+			out = out.mask(*this, true, NAN, NAN, opt);			
+		}
 		//out = out.disdir_vector_rasterize(p, false, true, false, false, NAN, NAN, "m", ops);
 		//out = out.arith(d, "<=", false, opt);
 	}

src/spatRaster.h

@@ -662,7 +662,7 @@ class SpatRaster {
 		std::vector<double> bilinearCells(const std::vector<double> &x, const std::vector<double> &y);
 		void fourCellsFromXY(std::vector<double> &out, const std::vector<double> &x, const std::vector<double> &y);
 
-		SpatRaster buffer(double d, double background, SpatOptions &opt);
+		SpatRaster buffer(double d, double background, bool include, SpatOptions &opt);
 		SpatRaster clamp(std::vector<double> low, std::vector<double> high, bool usevalue, SpatOptions &opt);
 		SpatRaster clamp_raster(SpatRaster &x, SpatRaster &y, std::vector<double> low, std::vector<double> high, bool usevalue, SpatOptions &opt);
 		SpatRaster clamp_ts(bool min, bool max, SpatOptions &opt);