port MaxPos and MinPos

vips/arithmetic.c

@@ -28,14 +28,13 @@ int average(VipsImage *in, double *out) {
 	return vips_avg(in, out, NULL);
 }
 
-int maxpos(VipsImage *in, double *out) {
-  return vips_max(in, out, NULL);
+int maxpos(VipsImage *in, double *out, int *x, int *y) {
+  return vips_max(in, out, "x", x, "y", y, NULL);
 }
 
-int minpos(VipsImage *in, double *out) {
-  return vips_min(in, out, NULL);
+int minpos(VipsImage *in, double *out, int *x, int *y) {
+  return vips_min(in, out, "x", x, "y", y, NULL);
 }
-
 int find_trim(VipsImage *in, int *left, int *top, int *width, int *height,
               double threshold, double r, double g, double b) {
 

vips/arithmetic.go

@@ -152,27 +152,29 @@ func vipsHistFindNdim(in *C.VipsImage, bins int) (*C.VipsImage, error) {
 }
 
 // https://www.libvips.org/API/current/libvips-arithmetic.html#vips-max
-func vipsMax(in *C.VipsImage) (float64, error) {
+func vipsMax(in *C.VipsImage) (int, int, error) {
 	incOpCounter("max")
 	var out C.double
+	var x, y C.int
 
-	if err := C.maxpos(in, &out); err != 0 {
-		return 0, handleVipsError()
+	if err := C.maxpos(in, &out, &x, &y); err != 0 {
+		return -1, -1, handleVipsError()
 	}
 
-	return float64(out), nil
+	return int(x), int(y), nil
 }
 
 // https://www.libvips.org/API/current/libvips-arithmetic.html#vips-min
-func vipsMin(in *C.VipsImage) (float64, error) {
+func vipsMin(in *C.VipsImage) (int, int, error) {
 	incOpCounter("min")
 	var out C.double
+	var x, y C.int
 
-	if err := C.minpos(in, &out); err != 0 {
-		return 0, handleVipsError()
+	if err := C.maxpos(in, &out, &x, &y); err != 0 {
+		return -1, -1, handleVipsError()
 	}
 
-	return float64(out), nil
+	return int(x), int(y), nil
 }
 
 // https://www.libvips.org/API/current/libvips-histogram.html#vips-hist-norm

vips/arithmetic.h

@@ -14,8 +14,8 @@ int find_trim(VipsImage *in, int *left, int *top, int *width, int *height,
               double threshold, double r, double g, double b);
 int getpoint(VipsImage *in, double **vector, int n, int x, int y);
 int stats(VipsImage *in, VipsImage **out);
-int maxpos(VipsImage *in, double *out);
-int minpos(VipsImage *in, double *out);
+int maxpos(VipsImage *in, double *out, int *x, int *y);
+int minpos(VipsImage *in, double *out, int *x, int *y);
 int hist_find(VipsImage *in, VipsImage **out);
 int hist_find_ndim(VipsImage *in, VipsImage **out, int bins);
 int hist_cum(VipsImage *in, VipsImage **out);

vips/image.go

@@ -1730,11 +1730,13 @@ func (r *ImageRef) HistogramFindNdim(bins int) error {
 	return nil
 }
 
-func (r *ImageRef) MaxPos() (float64, error) {
+// This operation finds the maximum value in an image.
+func (r *ImageRef) MaxPos() (x, y int, err error) {
 	return vipsMax(r.image)
 }
 
-func (r *ImageRef) MinPos() (float64, error) {
+// This operation finds the maximum value in an image.
+func (r *ImageRef) MinPos() (x, y int, err error) {
 	return vipsMin(r.image)
 }