add a direct path to flood for labelregions

TODO

@@ -1,3 +1,10 @@
+- add a direct route to flood for label_regions, delay speeding up operation
+  dispatch for now, seems like a large job
+
+  a direct path can also avoid things like vector_to_ink, which involve
+  running a pipeline to generate a single pixel
+
+  almost working
 
 - it was quick ..
 

libvips/draw/draw_flood.c

@@ -518,6 +518,68 @@ vips_draw_flood_init( VipsDrawFlood *draw_flood )
 {
 }
 
+/* Direct path to flood for vips_labelregions(). We need to avoid the function
+ * dispatch system for speed.
+ *
+ * Equivalent to:
+ *
+ * vips_draw_flood1( image, serial, x, y,
+ *       "test", test,
+ *       "equal", TRUE,
+ *       NULL )
+ *
+ * image must be 1-band int. 
+ */
+int
+vips__draw_flood_direct( VipsImage *image, VipsImage *test, 
+	int serial, int x, int y )
+{
+	VipsDrawFlood *flood = (VipsDrawFlood *) 
+		vips_operation_new( "draw_flood" );
+	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( flood ); 
+
+	if( vips_check_format( class->nickname, image, VIPS_FORMAT_INT ) ||
+		vips_check_mono( class->nickname, image ) ||
+		vips_check_coding_known( class->nickname, test ) ||
+		vips_check_size_same( class->nickname, test, image ) ||
+		vips_image_wio_input( test ) ) { 
+		g_object_unref( flood );
+		return( -1 );
+	}
+
+	((VipsDraw *) flood)->image = image;
+
+	if( !(((VipsDrawink *) flood)->pixel_ink = VIPS_ARRAY( flood, 
+		VIPS_IMAGE_SIZEOF_PEL( image ), VipsPel )) ) {
+		g_object_unref( flood );
+		return( -1 ); 
+	}
+	*((int *) (((VipsDrawink *) flood)->pixel_ink)) = serial; 
+
+	flood->test = test;
+	flood->tsize = VIPS_IMAGE_SIZEOF_PEL( test );
+	flood->left = flood->x;
+	flood->top = flood->y;
+	flood->right = flood->x;
+	flood->bottom = flood->y;
+	flood->in = buffer_build();
+	flood->out = buffer_build();
+
+	if( !(flood->edge = 
+		(VipsPel *) im_malloc( flood, flood->tsize )) ) {
+		g_object_unref( flood );
+		return( -1 );
+	}
+	memcpy( flood->edge, 
+		VIPS_IMAGE_ADDR( test, x, y ), flood->tsize );
+
+	vips_draw_flood_all( flood );
+
+	g_object_unref( flood );
+
+	return( 0 ); 
+}
+
 static int
 vips_draw_floodv( VipsImage *image, 
 	double *ink, int n, int x, int y, va_list ap )

libvips/include/vips/internal.h

@@ -259,7 +259,7 @@ int *im_offsets45( int size );
 int im_conv_f_raw( VipsImage *in, VipsImage *out, DOUBLEMASK *mask );
 int im_convsep_f_raw( VipsImage *in, VipsImage *out, DOUBLEMASK *mask );
 
-/* inplace
+/* draw
  */
 
 VipsPel *vips__vector_to_ink( const char *domain, 
@@ -269,8 +269,9 @@ double *vips__ink_to_vector( const char *domain,
 
 VipsPel *im__vector_to_ink( const char *domain, 
 	VipsImage *im, int n, double *vec );
-VipsImage *im__inplace_base( const char *domain, 
+
-	VipsImage *main, VipsImage *sub, VipsImage *out );
+int vips__draw_flood_direct( VipsImage *image, VipsImage *test, 
+	int serial, int x, int y );
 
 /* Register base vips interpolators, called during startup.
  */

libvips/morphology/labelregions.c

@@ -41,6 +41,7 @@
 #include <stdio.h>
 
 #include <vips/vips.h>
+#include <vips/internal.h>
 
 #include "pmorphology.h"
 
@@ -87,11 +88,16 @@ vips_labelregions_build( VipsObject *object )
 	for( y = 0; y < t[1]->Ysize; y++ ) {
 		for( x = 0; x < t[1]->Xsize; x++ ) {
 			if( !m[x] ) {
+				/*
 				if( vips_draw_flood1( t[1], serial, x, y,
 					"test", in,
 					"equal", TRUE,
 					NULL ) )
 					return( -1 ); 
+				 */
+				if( vips__draw_flood_direct( t[1], in, 
+					serial, x, y ) )
+					return( -1 ); 
 
 				serial += 1;
 			}