Merge pull request #153 from boosh/black

Add black

vips/create.c

@@ -5,3 +5,8 @@
 int xyz(VipsImage **out, int width, int height){
 	return vips_xyz(out, width, height, NULL);
 }
+
+// http://libvips.github.io/libvips/API/current/libvips-create.html#vips-black
+int black(VipsImage **out, int width, int height) {
+	return vips_black(out, width, height, NULL);
+}

vips/create.go

@@ -14,3 +14,14 @@ func vipsXYZ(width int, height int) (*C.VipsImage, error) {
 
 	return out, nil
 }
+
+// http://libvips.github.io/libvips/API/current/libvips-create.html#vips-black
+func vipsBlack(width int, height int) (*C.VipsImage, error) {
+	var out *C.VipsImage
+
+	if err := C.black(&out, C.int(width), C.int(height)); err != 0 {
+		return nil, handleImageError(out)
+	}
+
+	return out, nil
+}

vips/create.h

@@ -5,3 +5,4 @@
 #include <vips/foreign.h>
 
 int xyz(VipsImage **out, int width, int height);
+int black(VipsImage **out, int width, int height);

vips/image.go

@@ -162,6 +162,12 @@ func XYZ(width, height int) (*ImageRef, error) {
 	return &ImageRef{image: image}, err
 }
 
+// Black creates a new black image of the specified size
+func Black(width, height int) (*ImageRef, error) {
+	image, err := vipsBlack(width, height)
+	return &ImageRef{image: image}, err
+}
+
 func newImageRef(vipsImage *C.VipsImage, format ImageType, buf []byte) *ImageRef {
 	image := &ImageRef{
 		image:  vipsImage,

vips/image_golden_test.go

@@ -526,6 +526,16 @@ func TestImage_Tiff(t *testing.T) {
 	}, nil, nil)
 }
 
+func TestImage_Black(t *testing.T) {
+	Startup(nil)
+	i, err := Black(10, 20)
+	require.NoError(t, err)
+	buf, metadata, err := i.Export(nil)
+	require.NoError(t, err)
+
+	assertGoldenMatch(t, resources+"jpg-24bit.jpg", buf, metadata.Format)
+}
+
 func goldenTest(t *testing.T, file string, exec func(img *ImageRef) error, validate func(img *ImageRef), params *ExportParams) []byte {
 	Startup(nil)