vips_sink_screen() now invalidates for you

clients no longer need to call vips_image_invalidate_all()

TODO

@@ -1,13 +1,3 @@
-- try:
-
-	$ vips falsecolour k2.jpg x.jpg
-  	vips warning: VipsJpeg: read gave 896 warnings
-	vips warning: VipsJpeg: Application transferred too many scanlines
-
-  seems to read twice?
-
-  problem in 7.38 too
-
 - vips_colourspace() needs an option from_space param,?
 
 - check_uncoded() left to do:

libvips/include/vips/region.h

@@ -120,6 +120,8 @@ int vips_region_prepare_to( VipsRegion *reg,
 	VipsRegion *dest, VipsRect *r, int x, int y );
 int vips_region_prepare_many( VipsRegion **reg, VipsRect *r );
 
+void vips_region_invalidate( VipsRegion *reg );
+
 void vips_region_dump_all( void );
 
 /* Macros on VipsRegion.

libvips/iofuncs/image.c

@@ -953,9 +953,9 @@ vips_image_build( VipsObject *object )
 }
 
 static void *
-vips_region_invalidate( VipsRegion *reg )
+vips_image_real_invalidate_cb( VipsRegion *reg )
 {
-	reg->invalid = TRUE;
+	vips_region_invalidate( reg );
 
 	return( NULL );
 }
@@ -972,7 +972,7 @@ vips_image_real_invalidate( VipsImage *image )
 	VIPS_GATE_STOP( "vips_image_real_invalidate: wait" );
 
 	(void) vips_slist_map2( image->regions,
-		(VipsSListMap2Fn) vips_region_invalidate, NULL, NULL );
+		(VipsSListMap2Fn) vips_image_real_invalidate_cb, NULL, NULL );
 
 	g_mutex_unlock( image->sslock );
 }
@@ -1274,6 +1274,8 @@ vips_image_invalidate_all_cb( VipsImage *image )
  * is, images which depend on this image. 
  *
  * The "invalidate" callback is triggered for all invalidated images.
+ *
+ * See also: vips_region_invalidate().
  */
 void
 vips_image_invalidate_all( VipsImage *image )

libvips/iofuncs/region.c

@@ -1375,6 +1375,25 @@ vips_region_prepare_many( VipsRegion **reg, VipsRect *r )
 	return( 0 );
 }
 
+/** 
+ * vips_region_invalidate: 
+ * @reg: region to invalidate
+ *
+ * Mark a region as containing invalid pixels. Calling this function means
+ * that the next time vips_region_prepare() is called, the region will be
+ * recalculated.
+ *
+ * This is faster than calling vips_image_invalidate_all(), but obviously only
+ * affects a single region. 
+ *
+ * See also: vips_image_invalidate_all(), vips_region_prepare().
+ */
+void 
+vips_region_invalidate( VipsRegion *reg )
+{
+	reg->invalid = TRUE;
+}
+
 #ifdef VIPS_DEBUG
 static void *
 vips_region_dump_all_cb( VipsRegion *region, size_t *alive )

libvips/iofuncs/sinkscreen.c

@@ -424,6 +424,11 @@ render_work( VipsThreadState *state, void *a )
 	}
 	tile->painted = TRUE;
 
+	/* All downstream images must drop caches, since we've (effectively)
+	 * modified render->out. 
+	 */
+	vips_image_invalidate_all( render->out ); 
+
 	/* Now clients can update.
 	 */
 	if( render->notify )