From 5160010edacfb0a76957b16623b09a39c523dc9e Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sun, 25 Oct 2015 17:15:45 +0000
Subject: [PATCH] add vips_array_image_empty()/_append()

to help bindings without init from array
---
 libvips/include/vips/image.h |  3 ++
 libvips/iofuncs/type.c       | 57 ++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

diff --git a/libvips/include/vips/image.h b/libvips/include/vips/image.h
index f47982cc..48fc8068 100644
--- a/libvips/include/vips/image.h
+++ b/libvips/include/vips/image.h
@@ -482,6 +482,9 @@ int vips_system( const char *cmd_format, ... )
  */
 VipsArrayImage *vips_array_image_new( VipsImage **array, int n );
 VipsArrayImage *vips_array_image_newv( int n, ... );
+VipsArrayImage *vips_array_image_empty( void );
+VipsArrayImage *vips_array_image_append( VipsArrayImage *array, 
+	VipsImage *image );
 VipsImage **vips_array_image_get( VipsArrayImage *array, int *n );
 VipsImage **vips_value_get_array_image( const GValue *value, int *n );
 void vips_value_set_array_image( GValue *value, int n );
diff --git a/libvips/iofuncs/type.c b/libvips/iofuncs/type.c
index 6106734e..ee76916f 100644
--- a/libvips/iofuncs/type.c
+++ b/libvips/iofuncs/type.c
@@ -1205,6 +1205,63 @@ vips_array_image_newv( int n, ... )
 	return( (VipsArrayImage *) area );
 }
 
+/**
+ * vips_array_image_empty:
+ *
+ * Make an empty image array. 
+ * Handy with vips_array_image_add() for bindings
+ * which can't handle object array arguments.
+ *
+ * See also: vips_array_image_add().
+ *
+ * Returns: (transfer full): A new #VipsArrayImage.
+ */
+VipsArrayImage *
+vips_array_image_empty( void )
+{
+	return( vips_array_image_new( NULL, 0 ) ); 
+}
+
+/**
+ * vips_array_image_append:
+ * @array: (transfer none): append to this
+ * @image: add this
+ *
+ * Make a new #VipsArrayImage, one larger than @array, with @image appended 
+ * to the end.
+ * Handy with vips_array_image_empty() for bindings
+ * which can't handle object array arguments.
+ *
+ * See also: vips_array_image_empty().
+ *
+ * Returns: (transfer full): A new #VipsArrayImage.
+ */
+VipsArrayImage *
+vips_array_image_append( VipsArrayImage *array, VipsImage *image )
+{
+	VipsArea *old_area = VIPS_AREA( array );
+	int n = old_area->n;
+
+	VipsArea *new_area;
+	VipsImage **old_vector;
+	VipsImage **new_vector;
+	int i;
+
+	new_area = vips_area_new_array_object( n + 1 );
+	new_area->type = VIPS_TYPE_IMAGE;
+
+	old_vector = vips_area_get_data( old_area, NULL, NULL, NULL, NULL );
+	new_vector = vips_area_get_data( new_area, NULL, NULL, NULL, NULL );
+	for( i = 0; i < n; i++ ) {
+		new_vector[i] = (VipsImage *) old_vector[i]; 
+		g_object_ref( new_vector[i] ); 
+	}
+	new_vector[i] = image;
+	g_object_ref( new_vector[i] ); 
+
+	return( (VipsArrayImage *) new_area );
+}
+
 /**
  * vips_array_image_get:
  * @array: the #VipsArrayImage to fetch from