add a direct path for draw_mask

and get draw_circle ready for draw-along-circle

TODO

@@ -1,3 +1,7 @@
+- test draw_mask on labq images
+
+  we probably need to unpack the ink back to double before blending
+
 - vips_draw_image() might need a direct mode? see vips_flood_direct()
 
 - need call operation along a circle, see line draw

libvips/deprecated/vips7compat.c

@@ -4576,15 +4576,11 @@ im_draw_line_user( VipsImage *image,
 }
 
 int
-im_draw_mask( VipsImage *image, VipsImage *mask_im, int x, int y, VipsPel *ink )
+im_draw_mask( VipsImage *image, VipsImage *mask, int x, int y, VipsPel *ink )
 {
-	double *vec;
+	/* Direct call, since this has to be very quick.
-	int n;
+	 */
-
+	return( vips__draw_mask_direct( image, mask, ink, x, y ) ); 
-	if( !(vec = vips__ink_to_vector( "im_draw_mask", image, ink, &n )) )
-		return( -1 ); 
-
-	return( vips_draw_mask( image, vec, n, mask_im, x, y, NULL ) ); 
 }
 
 int

libvips/draw/draw_circle.c

@@ -67,53 +67,72 @@ typedef struct _VipsDrawCircle {
 	int radius;
 	gboolean fill;
 
-	VipsPel *centre;
+	VipsDrawPoint draw_point;
+	VipsDrawScanline draw_scanline;
 } VipsDrawCircle;
 
-typedef VipsDrawinkClass VipsDrawCircleClass;
+typedef struct _VipsDrawCircleClass {
+	VipsDrawinkClass parent_class;
+
+} VipsDrawCircleClass; 
 
 G_DEFINE_TYPE( VipsDrawCircle, vips_draw_circle, VIPS_TYPE_DRAWINK );
 
 static void
 vips_draw_circle_octants( VipsDrawCircle *circle, int x, int y )
 {
-	VipsDraw *draw = VIPS_DRAW( circle );
 	VipsDrawink *drawink = VIPS_DRAWINK( circle );
+	VipsDrawPoint draw_point = circle->draw_point; 
+	VipsDrawScanline draw_scanline = circle->draw_scanline; 
 	const int cx = circle->cx;
 	const int cy = circle->cy;
 
 	if( circle->fill ) {
-		vips__drawink_scanline( drawink, cy + y, cx - x, cx + x );
+		draw_scanline( drawink, cy + y, cx - x, cx + x );
-		vips__drawink_scanline( drawink, cy - y, cx - x, cx + x );
+		draw_scanline( drawink, cy - y, cx - x, cx + x );
-		vips__drawink_scanline( drawink, cy + x, cx - y, cx + y );
+		draw_scanline( drawink, cy + x, cx - y, cx + y );
-		vips__drawink_scanline( drawink, cy - x, cx - y, cx + y );
+		draw_scanline( drawink, cy - x, cx - y, cx + y );
-	}
-	else if( draw->noclip ) {
-		const size_t lsize = draw->lsize;
-		const size_t psize = draw->psize;
-		VipsPel *centre = circle->centre;
-
-		vips__drawink_pel( drawink, centre + lsize * y - psize * x );
-		vips__drawink_pel( drawink, centre + lsize * y + psize * x );
-		vips__drawink_pel( drawink, centre - lsize * y - psize * x );
-		vips__drawink_pel( drawink, centre - lsize * y + psize * x );
-		vips__drawink_pel( drawink, centre + lsize * x - psize * y );
-		vips__drawink_pel( drawink, centre + lsize * x + psize * y );
-		vips__drawink_pel( drawink, centre - lsize * x - psize * y );
-		vips__drawink_pel( drawink, centre - lsize * x + psize * y );
 	}
 	else {
-		vips__drawink_pel_clip( drawink, cx + y, cy - x );
+		draw_point( drawink, cx + y, cy - x );
-		vips__drawink_pel_clip( drawink, cx + y, cy + x );
+		draw_point( drawink, cx + y, cy + x );
-		vips__drawink_pel_clip( drawink, cx - y, cy - x );
+		draw_point( drawink, cx - y, cy - x );
-		vips__drawink_pel_clip( drawink, cx - y, cy + x );
+		draw_point( drawink, cx - y, cy + x );
-		vips__drawink_pel_clip( drawink, cx + x, cy - y );
+		draw_point( drawink, cx + x, cy - y );
-		vips__drawink_pel_clip( drawink, cx + x, cy + y );
+		draw_point( drawink, cx + x, cy + y );
-		vips__drawink_pel_clip( drawink, cx - x, cy - y );
+		draw_point( drawink, cx - x, cy - y );
-		vips__drawink_pel_clip( drawink, cx - x, cy + y );
+		draw_point( drawink, cx - x, cy + y );
 	}
 }
 
+/* Paint a point, with clip.
+ */
+static inline void 
+vips_draw_circle_draw_point_clip( VipsDrawink *drawink, int x, int y )
+{
+	VipsDraw *draw = (VipsDraw *) drawink;
+
+	if( x < 0 || 
+		x >= draw->image->Xsize )
+		return;
+	if( y < 0 || 
+		y >= draw->image->Ysize )
+		return;
+
+	vips__drawink_pel( drawink, VIPS_IMAGE_ADDR( draw->image, x, y ) );
+}
+
+/* Paint a point, no clipping needed.
+ */
+static inline int 
+vips_draw_circle_draw_point( VipsDrawink *drawink, int x, int y )
+{
+	VipsDraw *draw = (VipsDraw *) drawink;
+
+	return( vips__drawink_pel( drawink, 
+		VIPS_IMAGE_ADDR( draw->image, x, y ) ) ); 
+}
+
 static int
 vips_draw_circle_build( VipsObject *object )
 {
@@ -126,13 +145,15 @@ vips_draw_circle_build( VipsObject *object )
 		build( object ) )
 		return( -1 );
 
-	circle->centre = VIPS_IMAGE_ADDR( draw->image, circle->cx, circle->cy );
+	circle->draw_scanline = vips__drawink_scanline;
 
 	if( circle->cx - circle->radius >= 0 && 
 		circle->cx + circle->radius < draw->image->Xsize &&
 		circle->cy - circle->radius >= 0 && 
 		circle->cy + circle->radius < draw->image->Ysize )
-		draw->noclip = TRUE;
+		circle->draw_point = vips_draw_circle_draw_point; 
+		else
+		circle->draw_point = vips__drawink_pel_clip; 
 
 	y = circle->radius;
 	d = 3 - 2 * circle->radius;

libvips/draw/draw_image.c

@@ -100,12 +100,7 @@ G_DEFINE_TYPE( VipsDrawImage, vips_draw_image, VIPS_TYPE_DRAW );
 		\
 		v = pt[x] + qt[x]; \
 		\
-		if( v > MAX ) \
+		qt[x] = VIPS_CLIP( MIN, v, MAX ); \
-			v = MAX; \
-		else if( v < MIN ) \
-			v = MIN; \
-		\
-		qt[x] = v; \
 	} \
 }
 

libvips/draw/draw_line.c

@@ -18,7 +18,7 @@
  * 	- gtk-doc
  * 	- use draw.c base class
  * 	- do pointwise clipping
- * 	- rename as im_draw_draw_line() for consistency
+ * 	- rename as im_draw_line() for consistency
  * 	- cleanups!
  * 6/2/14
  * 	- redo as a class
@@ -68,8 +68,9 @@ G_DEFINE_TYPE( VipsDrawLine, vips_draw_line, VIPS_TYPE_DRAWINK );
 static int
 vips_draw_line_draw( VipsDrawLine *line )
 {
+	VipsDrawink *drawink = VIPS_DRAWINK( line );
 	VipsDrawLineClass *class = VIPS_DRAW_LINE_GET_CLASS( line );
-	VipsDrawLinePlotPoint plot_point = class->plot_point; 
+	VipsDrawPoint draw_point = class->draw_point; 
 
 	int x, y, err;
 
@@ -82,7 +83,7 @@ vips_draw_line_draw( VipsDrawLine *line )
 	 */
 	if( line->dx == 0 && 
 		line->dy == 0 ) {
-		if( plot_point( line, x, y ) ) 
+		if( draw_point( drawink, x, y ) ) 
 			return( -1 );
 	}
 	/* Special case vertical and horizontal lines for speed.
@@ -91,7 +92,7 @@ vips_draw_line_draw( VipsDrawLine *line )
 		/* Vertical line going down.
 		 */
 		for( ; y <= line->y2; y++ ) {
-			if( plot_point( line, x, y ) )
+			if( draw_point( drawink, x, y ) )
 				return( -1 );
 		}
 	}
@@ -99,7 +100,7 @@ vips_draw_line_draw( VipsDrawLine *line )
 		/* Horizontal line to the right.
 		 */
 		for( ; x <= line->x2; x++ ) {
-			if( plot_point( line, x, y ) )
+			if( draw_point( drawink, x, y ) )
 				return( -1 );
 		}
 	}
@@ -110,7 +111,7 @@ vips_draw_line_draw( VipsDrawLine *line )
 		/* Diagonal line going down and right.
 		 */
 		for( ; x <= line->x2; x++, y++ ) {
-			if( plot_point( line, x, y ) )
+			if( draw_point( drawink, x, y ) )
 				return( -1 );
 		}
 	}
@@ -119,7 +120,7 @@ vips_draw_line_draw( VipsDrawLine *line )
 		/* Diagonal line going up and right.
 		 */
 		for( ; x <= line->x2; x++, y-- ) {
-			if( plot_point( line, x, y ) )
+			if( draw_point( drawink, x, y ) )
 				return( -1 );
 		}
 	}
@@ -128,7 +129,7 @@ vips_draw_line_draw( VipsDrawLine *line )
 		/* Between -45 and 0 degrees.
 		 */
 		for( err = 0; x <= line->x2; x++ ) {
-			if( plot_point( line, x, y ) )
+			if( draw_point( drawink, x, y ) )
 				return( -1 );
 
 			err += line->dy;
@@ -143,7 +144,7 @@ vips_draw_line_draw( VipsDrawLine *line )
 		/* Between 0 and 45 degrees.
 		 */
 		for( err = 0; x <= line->x2; x++ ) {
-			if( plot_point( line, x, y ) )
+			if( draw_point( drawink, x, y ) )
 				return( -1 );
 
 			err -= line->dy;
@@ -158,7 +159,7 @@ vips_draw_line_draw( VipsDrawLine *line )
 		/* Between -45 and -90 degrees.
 		 */
 		for( err = 0; y <= line->y2; y++ ) {
-			if( plot_point( line, x, y ) )
+			if( draw_point( drawink, x, y ) )
 				return( -1 );
 
 			err += line->dx;
@@ -173,7 +174,7 @@ vips_draw_line_draw( VipsDrawLine *line )
 		/* Between -90 and -135 degrees.
 		 */
 		for( err = 0; y <= line->y2; y++ ) {
-			if( plot_point( line, x, y ) )
+			if( draw_point( drawink, x, y ) )
 				return( -1 );
 
 			err -= line->dx;
@@ -244,10 +245,9 @@ vips_draw_line_build( VipsObject *object )
 }
 
 static int
-vips_draw_line_plot_point( VipsDrawLine *line, int x, int y ) 
+vips_draw_line_draw_point( VipsDrawink *drawink, int x, int y ) 
 {
-	VipsDraw *draw = (VipsDraw *) line;
+	VipsDraw *draw = (VipsDraw *) drawink;
-	VipsDrawink *drawink = (VipsDrawink *) line;
 
 	if( draw->noclip )
 		vips__drawink_pel( drawink, 
@@ -271,7 +271,7 @@ vips_draw_line_class_init( VipsDrawLineClass *class )
 	vobject_class->description = _( "draw a draw_line on an image" );
 	vobject_class->build = vips_draw_line_build;
 
-	class->plot_point = vips_draw_line_plot_point; 
+	class->draw_point = vips_draw_line_draw_point; 
 
 	VIPS_ARG_INT( class, "x1", 3, 
 		_( "x1" ), 

libvips/draw/draw_line.h

@@ -68,11 +68,9 @@ typedef struct _VipsDrawLine {
 typedef struct _VipsDrawLineClass {
 	VipsDrawinkClass parent_class;
 
-	int (*plot_point)( VipsDrawLine *, int x, int y ); 
+	VipsDrawPoint draw_point; 
 } VipsDrawLineClass; 
 
-typedef int (*VipsDrawLinePlotPoint)( VipsDrawLine *draw_line, int x, int y ); 
-
 GType vips_draw_line_get_type( void );
 
 #ifdef __cplusplus

libvips/draw/draw_line_mask.c

@@ -74,11 +74,10 @@ typedef VipsDrawLineClass VipsDrawLineMaskClass;
 G_DEFINE_TYPE( VipsDrawLineMask, vips_draw_line_mask, VIPS_TYPE_DRAW_LINE );
 
 static int
-vips_draw_line_mask_plot_point( VipsDrawLine *line, int x, int y ) 
+vips_draw_line_mask_draw_point( VipsDrawink *drawink, int x, int y ) 
 {
-	VipsDraw *draw = (VipsDraw *) line;
+	VipsDraw *draw = (VipsDraw *) drawink;
-	VipsDrawink *drawink = (VipsDrawink *) line;
+	VipsDrawLineMask *mask = (VipsDrawLineMask *) drawink;
-	VipsDrawLineMask *mask = (VipsDrawLineMask *) line;
 
 	return( vips_draw_mask( draw->image, 
 		drawink->ink->data, drawink->ink->n, 
@@ -97,7 +96,7 @@ vips_draw_line_mask_class_init( VipsDrawLineMaskClass *class )
 	vobject_class->nickname = "draw_line_mask";
 	vobject_class->description = _( "draw a mask along a line" );
 
-	class->plot_point = vips_draw_line_mask_plot_point; 
+	class->draw_point = vips_draw_line_mask_draw_point; 
 
 	VIPS_ARG_IMAGE( class, "mask", 7, 
 		_( "Mask" ), 

libvips/draw/draw_line_user.c

@@ -80,10 +80,10 @@ typedef VipsDrawLineClass VipsDrawLineUserClass;
 G_DEFINE_TYPE( VipsDrawLineUser, vips_draw_line_user, VIPS_TYPE_DRAW_LINE );
 
 static int
-vips_draw_line_user_plot_point( VipsDrawLine *line, int x, int y ) 
+vips_draw_line_user_draw_point( VipsDrawink *drawink, int x, int y ) 
 {
-	VipsDraw *draw = (VipsDraw *) line;
+	VipsDraw *draw = (VipsDraw *) drawink;
-	VipsDrawLineUser *user = (VipsDrawLineUser *) line;
+	VipsDrawLineUser *user = (VipsDrawLineUser *) drawink;
 
 	return( user->plot_fn( draw->image, x, y, user->a, user->b, user->c ) );
 }
@@ -103,7 +103,7 @@ vips_draw_line_user_class_init( VipsDrawLineUserClass *class )
 
 	operation_class->flags = VIPS_OPERATION_DEPRECATED;
 
-	class->plot_point = vips_draw_line_user_plot_point; 
+	class->draw_point = vips_draw_line_user_draw_point; 
 
 	VIPS_ARG_POINTER( class, "plot_fn", 7, 
 		_( "Plot" ), 

libvips/draw/draw_mask.c

@@ -131,13 +131,12 @@ G_DEFINE_TYPE( VipsDrawMask, vips_draw_mask, VIPS_TYPE_DRAWINK );
 }
 
 static int
-vips_draw_mask_draw_labq( VipsDrawMask *mask )
+vips_draw_mask_draw_labq( VipsImage *image, VipsImage *mask, VipsPel *ink, 
+	VipsRect *image_clip, VipsRect *mask_clip )
 {
-	VipsDraw *draw = VIPS_DRAW( mask );
+	int width = image_clip->width;
-	VipsDrawink *drawink = VIPS_DRAWINK( mask );
+	int height = image_clip->height;
-	int width = mask->image_clip.width;
+	int bands = image->Bands; 
-	int height = mask->image_clip.height;
-	int bands = draw->image->Bands; 
 
 	float *lab_buffer;
 	int y;
@@ -146,15 +145,15 @@ vips_draw_mask_draw_labq( VipsDrawMask *mask )
 		return( -1 );
 
 	for( y = 0; y < height; y++ ) {
-		VipsPel *to = VIPS_IMAGE_ADDR( draw->image, 
+		VipsPel *to = VIPS_IMAGE_ADDR( image, 
-			mask->image_clip.left, 
+			image_clip->left, 
-			y + mask->image_clip.top );
+			y + image_clip->top );
-		VipsPel *m = VIPS_IMAGE_ADDR( mask->mask, 
+		VipsPel *m = VIPS_IMAGE_ADDR( mask, 
-			mask->mask_clip.left, 
+			mask_clip->left, 
-			y + mask->mask_clip.top );
+			y + mask_clip->top );
 
 		vips__LabQ2Lab_vec( lab_buffer, to, width );
-		DBLEND( float, lab_buffer, (double *) drawink->ink->data );
+		DBLEND( float, lab_buffer, (double *) ink );
 		vips__Lab2LabQ_vec( to, lab_buffer, width );
 	}
 
@@ -164,63 +163,60 @@ vips_draw_mask_draw_labq( VipsDrawMask *mask )
 }
 
 static int
-vips_draw_mask_draw( VipsDrawMask *mask )
+vips_draw_mask_draw( VipsImage *image, VipsImage *mask, VipsPel *ink, 
+	VipsRect *image_clip, VipsRect *mask_clip )
 {
-	VipsDraw *draw = VIPS_DRAW( mask );
+	int width = image_clip->width;
-	VipsDrawink *drawink = VIPS_DRAWINK( mask );
+	int height = image_clip->height;
-	int width = mask->image_clip.width;
+	int bands = image->Bands; 
-	int height = mask->image_clip.height;
-	int bands = draw->image->Bands; 
 
 	int y;
 
 	for( y = 0; y < height; y++ ) {
-		VipsPel *to = VIPS_IMAGE_ADDR( draw->image, 
+		VipsPel *to = VIPS_IMAGE_ADDR( image, 
-			mask->image_clip.left, 
+			image_clip->left, y + image_clip->top );
-			y + mask->image_clip.top );
+		VipsPel *m = VIPS_IMAGE_ADDR( mask, 
-		VipsPel *m = VIPS_IMAGE_ADDR( mask->mask, 
+			mask_clip->left, y + mask_clip->top );
-			mask->mask_clip.left, 
-			y + mask->mask_clip.top );
 
-		switch( draw->image->BandFmt ) {
+		switch( image->BandFmt ) {
 		case VIPS_FORMAT_UCHAR: 
-			IBLEND( unsigned char, to, drawink->pixel_ink );
+			IBLEND( unsigned char, to, ink );
 			break;
 
 		case VIPS_FORMAT_CHAR: 
-			IBLEND( signed char, to, drawink->pixel_ink );
+			IBLEND( signed char, to, ink );
 			break;
 
 		case VIPS_FORMAT_USHORT: 
-			IBLEND( unsigned short, to, drawink->pixel_ink );
+			IBLEND( unsigned short, to, ink );
 			break;
 
 		case VIPS_FORMAT_SHORT: 
-			IBLEND( signed short, to, drawink->pixel_ink );
+			IBLEND( signed short, to, ink );
 			break;
 
 		case VIPS_FORMAT_UINT: 
-			DBLEND( unsigned int, to, drawink->pixel_ink );
+			DBLEND( unsigned int, to, ink );
 			break;
 
 		case VIPS_FORMAT_INT: 
-			DBLEND( signed int, to, drawink->pixel_ink );
+			DBLEND( signed int, to, ink );
 			break;
 
 		case VIPS_FORMAT_FLOAT:  
-			DBLEND( float, to, drawink->pixel_ink );
+			DBLEND( float, to, ink );
 			break;
 
 		case VIPS_FORMAT_DOUBLE:
-			DBLEND( double, to, drawink->pixel_ink );
+			DBLEND( double, to, ink );
 			break;
 
 		case VIPS_FORMAT_COMPLEX:
-			CBLEND( float, to, drawink->pixel_ink );
+			CBLEND( float, to, ink );
 			break;
 
 		case VIPS_FORMAT_DPCOMPLEX:
-			CBLEND( double, to, drawink->pixel_ink );
+			CBLEND( double, to, ink );
 			break;
 
 		default:
@@ -231,11 +227,73 @@ vips_draw_mask_draw( VipsDrawMask *mask )
 	return( 0 );
 }
 
+/* Direct path for draw-mask-along-line or draw-mask-along-circle. We want to
+ * avoid function dispatch overhead.
+ *
+ * The vips7 im_draw_mask() wrapper calls this as well.
+ */
+int
+vips__draw_mask_direct( VipsImage *image, VipsImage *mask, 
+	VipsPel *ink, int x, int y )
+{
+	VipsRect image_rect;
+	VipsRect area_rect;
+	VipsRect image_clip;
+	VipsRect mask_clip;
+
+	if( vips_check_coding_noneorlabq( "draw_mask_direct", image ) ||
+		vips_image_wio_input( mask ) ||
+		vips_check_mono( "draw_mask_direct", mask ) ||
+		vips_check_uncoded( "draw_mask_direct", mask ) ||
+		vips_check_format( "draw_mask_direct", 
+			mask, VIPS_FORMAT_UCHAR ) )
+		return( -1 );
+
+	/* Find the area we draw on the image.
+	 */
+	area_rect.left = x;
+	area_rect.top = y;
+	area_rect.width = mask->Xsize;
+	area_rect.height = mask->Ysize;
+	image_rect.left = 0;
+	image_rect.top = 0;
+	image_rect.width = image->Xsize;
+	image_rect.height = image->Ysize;
+	vips_rect_intersectrect( &area_rect, &image_rect, &image_clip );
+
+	/* And the area of the mask image we use.
+	 */
+	mask_clip = image_clip;
+	mask_clip.left -= x;
+	mask_clip.top -= y;
+
+	if( !vips_rect_isempty( &image_clip ) ) 
+		switch( image->Coding ) {
+		case VIPS_CODING_LABQ:
+			if( vips_draw_mask_draw_labq( image, mask, ink, 
+				&image_clip, &mask_clip ) )
+				return( -1 );
+			break;
+
+		case VIPS_CODING_NONE:
+			if( vips_draw_mask_draw( image, mask, ink, 
+				&image_clip, &mask_clip ) )
+				return( -1 );
+			break;
+
+		default:
+			g_assert( 0 );
+		}
+
+	return( 0 );
+}
+
 static int
 vips_draw_mask_build( VipsObject *object )
 {
 	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object );
 	VipsDraw *draw = VIPS_DRAW( object );
+	VipsDrawink *drawink = VIPS_DRAWINK( object );
 	VipsDrawMask *mask = (VipsDrawMask *) object;
 
 	VipsRect area;
@@ -244,49 +302,9 @@ vips_draw_mask_build( VipsObject *object )
 	if( VIPS_OBJECT_CLASS( vips_draw_mask_parent_class )->build( object ) )
 		return( -1 );
 
-	if( vips_check_coding_noneorlabq( class->nickname, draw->image ) ||
+	if( vips__draw_mask_direct( draw->image, mask->mask, drawink->pixel_ink,
-		vips_image_wio_input( mask->mask ) ||
+		mask->x, mask->y  ) )
-		vips_check_mono( class->nickname, mask->mask ) ||
+		return( -1 ) ;
-		vips_check_uncoded( class->nickname, mask->mask ) ||
-		vips_check_format( class->nickname, 
-			mask->mask, VIPS_FORMAT_UCHAR ) )
-		return( -1 );
-
-	/* Find the area we draw on the image.
-	 */
-	area.left = mask->x;
-	area.top = mask->y;
-	area.width = mask->mask->Xsize;
-	area.height = mask->mask->Ysize;
-	image.left = 0;
-	image.top = 0;
-	image.width = draw->image->Xsize;
-	image.height = draw->image->Ysize;
-	vips_rect_intersectrect( &area, &image, &mask->image_clip );
-
-	/* And the area of the mask image we use.
-	 */
-	mask->mask_clip = mask->image_clip;
-	mask->mask_clip.left -= mask->x;
-	mask->mask_clip.top -= mask->y;
-
-	if( !vips_rect_isempty( &mask->image_clip ) ) 
-		/* Loop through image plotting where required.
-		 */
-		switch( draw->image->Coding ) {
-		case VIPS_CODING_LABQ:
-			if( vips_draw_mask_draw_labq( mask ) ) 
-				return( -1 );
-			break;
-
-		case VIPS_CODING_NONE:
-			if( vips_draw_mask_draw( mask ) ) 
-				return( -1 );
-			break;
-
-		default:
-			g_assert( 0 );
-		}
 
 	return( 0 );
 }

libvips/draw/drawink.c

@@ -104,7 +104,7 @@ vips_drawink_init( VipsDrawink *drawink )
 
 /* Fill a scanline between points x1 and x2 inclusive. x1 < x2.
  */
-void 
+int
 vips__drawink_scanline( VipsDrawink *drawink, int y, int x1, int x2 )
 {
 	VipsDraw *draw = (VipsDraw *) drawink;
@@ -117,13 +117,13 @@ vips__drawink_scanline( VipsDrawink *drawink, int y, int x1, int x2 )
 
 	if( y < 0 || 
 		y >= draw->image->Ysize )
-		return;
+		return( 0 );
 	if( x1 < 0 && 
 		x2 < 0 )
-		return;
+		return( 0 );
 	if( x1 >= draw->image->Xsize && 
 		x2 >= draw->image->Xsize )
-		return;
+		return( 0 );
 	x1 = VIPS_CLIP( 0, x1, draw->image->Xsize - 1 );
 	x2 = VIPS_CLIP( 0, x2, draw->image->Xsize - 1 );
 
@@ -134,6 +134,8 @@ vips__drawink_scanline( VipsDrawink *drawink, int y, int x1, int x2 )
 		vips__drawink_pel( drawink, mp );
 		mp += draw->psize;
 	}
+
+	return( 0 );
 }
 
 

libvips/draw/drawink.h

@@ -69,7 +69,10 @@ typedef struct _VipsDrawinkClass {
 
 GType vips_drawink_get_type( void );
 
-static inline void
+typedef int (*VipsDrawPoint)( VipsDrawink *drawink, int x, int y ); 
+typedef int (*VipsDrawScanline)( VipsDrawink *drawink, int y, int x1, int x2 );
+
+static inline int
 vips__drawink_pel( VipsDrawink *drawink, VipsPel *q )
 {
 	VipsDraw *draw = (VipsDraw *) drawink;
@@ -80,23 +83,27 @@ vips__drawink_pel( VipsDrawink *drawink, VipsPel *q )
 	 */
 	for( j = 0; j < draw->psize; j++ ) 
 		q[j] = drawink->pixel_ink[j];
+
+	return( 0 ); 
 }
 
 /* Paint, with clip.
  */
-static inline void 
+static inline int 
 vips__drawink_pel_clip( VipsDrawink *drawink, int x, int y )
 {
 	VipsDraw *draw = (VipsDraw *) drawink;
 
 	if( x < 0 || 
 		x >= draw->image->Xsize )
-		return;
+		return( 0 );
 	if( y < 0 || 
 		y >= draw->image->Ysize )
-		return;
+		return( 0 );
 
 	vips__drawink_pel( drawink, VIPS_IMAGE_ADDR( draw->image, x, y ) );
+
+	return( 0 ); 
 }
 
 /* Is p painted?
@@ -115,7 +122,7 @@ vips__drawink_painted( VipsDrawink *drawink, VipsPel *p )
 	return( j == draw->psize );
 }
 
-void vips__drawink_scanline( VipsDrawink *drawink, int y, int x1, int x2 );
+int vips__drawink_scanline( VipsDrawink *drawink, int y, int x1, int x2 );
 
 #ifdef __cplusplus
 }

libvips/include/vips/internal.h

@@ -271,6 +271,8 @@ VipsPel *im__vector_to_ink( const char *domain,
 
 int vips__draw_flood_direct( VipsImage *image, VipsImage *test, 
 	int serial, int x, int y );
+int vips__draw_mask_direct( VipsImage *image, VipsImage *mask, 
+	VipsPel *ink, int x, int y ); 
 
 /* Register base vips interpolators, called during startup.
  */