From de981cd9ec80c12137ac156304d58011930a82a1 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Fri, 8 Jul 2016 12:18:07 +0100
Subject: [PATCH 01/15] docs tweak

---
 libvips/create/buildlut.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/libvips/create/buildlut.c b/libvips/create/buildlut.c
index 16ab774d..e6e41b17 100644
--- a/libvips/create/buildlut.c
+++ b/libvips/create/buildlut.c
@@ -278,7 +278,8 @@ vips_buildlut_init( VipsBuildlut *lut )
  *
  * This operation builds a lookup table from a set of points. Intermediate
  * values are generated by piecewise linear interpolation. The lookup table is
- * always of type %gdouble, use vips_cast() to change it to the type you need.
+ * always of type #VIPS_FORMAT_DOUBLE, use vips_cast() to change it to the 
+ * type you need.
  *
  * For example, consider this 2 x 2 matrix of (x, y) coordinates:
  *
@@ -331,7 +332,7 @@ vips_buildlut_init( VipsBuildlut *lut )
  * several Ys, each becomes a band in the output LUT. You don't need to
  * start at zero, any integer will do, including negatives.
  *
- * See also: vips_identity(), vips_invertlut().
+ * See also: vips_identity(), vips_invertlut(), vips_cast(), vips_maplut().
  *
  * Returns: 0 on success, -1 on error
  */

From 4c1e6dd02375a4736166caa8da98f26d07af0780 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sat, 9 Jul 2016 18:49:22 +0100
Subject: [PATCH 02/15] turn off chroma subsample for Q > 90

see https://github.com/jcupitt/libvips/issues/482
---
 libvips/foreign/jpegsave.c  |  3 ++-
 libvips/foreign/vips2jpeg.c | 21 +++++++++++++++------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/libvips/foreign/jpegsave.c b/libvips/foreign/jpegsave.c
index f8b3b454..5289f176 100644
--- a/libvips/foreign/jpegsave.c
+++ b/libvips/foreign/jpegsave.c
@@ -95,7 +95,8 @@ typedef struct _VipsForeignSaveJpeg {
 	 */
 	gboolean trellis_quant;
 
-	/* Apply overshooting to samples with extreme values e.g. 0 & 255 for 8-bit.
+	/* Apply overshooting to samples with extreme values e.g. 0 & 255 
+	 * for 8-bit.
 	 */
 	gboolean overshoot_deringing;
 
diff --git a/libvips/foreign/vips2jpeg.c b/libvips/foreign/vips2jpeg.c
index 91c703ed..dbf25447 100644
--- a/libvips/foreign/vips2jpeg.c
+++ b/libvips/foreign/vips2jpeg.c
@@ -78,6 +78,8 @@
  * 	- add quant_table
  * 26/5/16
  * 	- switch to new orientation tag
+ * 9/7/16
+ * 	- turn off chroma subsample for Q > 90
  */
 
 /*
@@ -1020,7 +1022,9 @@ write_vips( Write *write, int qfac, const char *profile,
 	 */
         g_assert( in->BandFmt == VIPS_FORMAT_UCHAR );
 	g_assert( in->Coding == VIPS_CODING_NONE );
-        g_assert( in->Bands == 1 || in->Bands == 3 || in->Bands == 4 );
+        g_assert( in->Bands == 1 || 
+		in->Bands == 3 || 
+		in->Bands == 4 );
 
         /* Check input image.
          */
@@ -1032,7 +1036,8 @@ write_vips( Write *write, int qfac, const char *profile,
         write->cinfo.image_width = in->Xsize;
         write->cinfo.image_height = in->Ysize;
 	write->cinfo.input_components = in->Bands;
-	if( in->Bands == 4 && in->Type == VIPS_INTERPRETATION_CMYK ) {
+	if( in->Bands == 4 && 
+		in->Type == VIPS_INTERPRETATION_CMYK ) {
 		space = JCS_CMYK;
 		/* IJG always sets an Adobe marker, so we should invert CMYK.
 		 */
@@ -1153,9 +1158,11 @@ write_vips( Write *write, int qfac, const char *profile,
 	if( progressive ) 
 		jpeg_simple_progression( &write->cinfo ); 
 
-	/* Turn off chroma subsampling.
+	/* Turn off chroma subsampling. Follow IM and do it automatically for
+	 * high Q. 
 	 */
-	if( no_subsample ) { 
+	if( no_subsample ||
+		Q > 90 ) { 
 		int i;
 
 		for( i = 0; i < in->Bands; i++ ) { 
@@ -1250,7 +1257,8 @@ vips__jpeg_write_file( VipsImage *in,
 	 */
 	if( write_vips( write, 
 		Q, profile, optimize_coding, progressive, strip, no_subsample,
-		trellis_quant, overshoot_deringing, optimize_scans, quant_table ) ) {
+		trellis_quant, overshoot_deringing, optimize_scans, 
+		quant_table ) ) {
 		write_destroy( write );
 		return( -1 );
 	}
@@ -1535,7 +1543,8 @@ vips__jpeg_write_buffer( VipsImage *in,
 	 */
 	if( write_vips( write, 
 		Q, profile, optimize_coding, progressive, strip, no_subsample,
-		trellis_quant, overshoot_deringing, optimize_scans, quant_table ) ) {
+		trellis_quant, overshoot_deringing, optimize_scans, 
+		quant_table ) ) {
 		write_destroy( write );
 
 		return( -1 );

From f294ec5d9b7c6bf0cddfb69d91303d6e4e3c5c53 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sat, 9 Jul 2016 19:10:17 +0100
Subject: [PATCH 03/15] oops

---
 libvips/foreign/vips2jpeg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libvips/foreign/vips2jpeg.c b/libvips/foreign/vips2jpeg.c
index dbf25447..9b2d52a8 100644
--- a/libvips/foreign/vips2jpeg.c
+++ b/libvips/foreign/vips2jpeg.c
@@ -1162,7 +1162,7 @@ write_vips( Write *write, int qfac, const char *profile,
 	 * high Q. 
 	 */
 	if( no_subsample ||
-		Q > 90 ) { 
+		qfac > 90 ) { 
 		int i;
 
 		for( i = 0; i < in->Bands; i++ ) { 

From 828b36dfe58707eb797e9785e2b61f4129b24ff6 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Mon, 11 Jul 2016 10:07:41 +0100
Subject: [PATCH 04/15] fix --fail option to jpegload

getting --fail on jpegload working means tilecache must terminate on tile
calc error

make openslideload not report tile calc errors, it might need a --fail
option too

see https://github.com/jcupitt/libvips/issues/474
---
 libvips/conversion/tilecache.c   | 19 ++++++++++-------
 libvips/foreign/jpeg2vips.c      | 35 +++++++++++++++++++++++---------
 libvips/foreign/openslide2vips.c | 14 ++++++++-----
 libvips/foreign/vips2jpeg.c      |  1 -
 4 files changed, 46 insertions(+), 23 deletions(-)

diff --git a/libvips/conversion/tilecache.c b/libvips/conversion/tilecache.c
index 75873485..39942b22 100644
--- a/libvips/conversion/tilecache.c
+++ b/libvips/conversion/tilecache.c
@@ -31,6 +31,8 @@
  * 	- cache minimisation is optional, see "persistent" flag
  * 26/8/14 Lovell
  * 	- free the hash table in _dispose()
+ * 11/7/16
+ * 	- terminate on tile calc error
  */
 
 /*
@@ -609,6 +611,9 @@ vips_tile_cache_gen( VipsRegion *or,
 	VipsTile *tile;
 	GSList *work;
 	GSList *p;
+	int result;
+
+	result = 0;
 
 	VIPS_GATE_START( "vips_tile_cache_gen: wait1" );
 
@@ -658,8 +663,6 @@ vips_tile_cache_gen( VipsRegion *or,
 			tile = (VipsTile *) p->data;
 
 			if( tile->state == VIPS_TILE_STATE_PEND ) {
-				int result;
-
 				tile->state = VIPS_TILE_STATE_CALC;
 
 				VIPS_DEBUG_MSG_RED( "vips_tile_cache_gen: "
@@ -688,11 +691,11 @@ vips_tile_cache_gen( VipsRegion *or,
 				}
 
 				/* If there was an error calculating this
-				 * tile, just warn and carry on.
+				 * tile, black it out and terminate
+				 * calculation. We have to stop so we can
+				 * support things like --fail on jpegload.
 				 *
-				 * This can happen with things like reading
-				 * .scn files via openslide. We don't want the
-				 * read to fail because of one broken tile.
+				 * Don't return early, we'd deadlock. 
 				 */
 				if( result ) {
 					VIPS_DEBUG_MSG_RED( 
@@ -707,6 +710,8 @@ vips_tile_cache_gen( VipsRegion *or,
 					vips_error_clear();
 
 					vips_region_black( tile->region );
+
+					*stop = TRUE;
 				}
 
 				tile->state = VIPS_TILE_STATE_DATA;
@@ -749,7 +754,7 @@ vips_tile_cache_gen( VipsRegion *or,
 
 	g_mutex_unlock( cache->lock );
 
-	return( 0 );
+	return( result );
 }
 
 static int
diff --git a/libvips/foreign/jpeg2vips.c b/libvips/foreign/jpeg2vips.c
index afb57af5..1a1e42df 100644
--- a/libvips/foreign/jpeg2vips.c
+++ b/libvips/foreign/jpeg2vips.c
@@ -74,6 +74,8 @@
  * 	  memory for progressive jpg files
  * 26/5/16
  * 	- switch to new orientation tag
+ * 11/7/16
+ * 	- new --fail handling
  */
 
 /*
@@ -186,16 +188,10 @@ readjpeg_free( ReadJpeg *jpeg )
 	result = 0;
 
 	if( jpeg->eman.pub.num_warnings != 0 ) {
-		if( jpeg->fail ) {
-			vips_error( "VipsJpeg", "%s", vips_error_buffer() );
-			result = -1;
-		}
-		else {
-			vips_warn( "VipsJpeg", 
-				_( "read gave %ld warnings" ), 
-				jpeg->eman.pub.num_warnings );
-			vips_warn( NULL, "%s", vips_error_buffer() );
-		}
+		vips_warn( "VipsJpeg", 
+			_( "read gave %ld warnings" ), 
+			jpeg->eman.pub.num_warnings );
+		vips_warn( NULL, "%s", vips_error_buffer() );
 
 		/* Make the message only appear once.
 		 */
@@ -991,6 +987,25 @@ read_jpeg_generate( VipsRegion *or,
 	if( setjmp( jpeg->eman.jmp ) ) 
 		return( -1 );
 
+	/* If --fail is set, we make read fail on any warnings. This will stop
+	 * on any errors from the previous jpeg_read_scanlines().
+	 */
+	if( jpeg->eman.pub.num_warnings > 0 &&
+		jpeg->fail ) {
+		vips_error( "VipsJpeg", 
+			_( "read gave %ld warnings" ), 
+			jpeg->eman.pub.num_warnings );
+		vips_error( NULL, "%s", vips_error_buffer() );
+
+		/* Make the message only appear once.
+		 */
+		jpeg->eman.pub.num_warnings = 0;
+
+		*stop = TRUE;
+
+		return( -1 );
+	}
+
 	for( y = 0; y < r->height; y++ ) {
 		JSAMPROW row_pointer[1];
 
diff --git a/libvips/foreign/openslide2vips.c b/libvips/foreign/openslide2vips.c
index 4df9e2b1..93b05a6b 100644
--- a/libvips/foreign/openslide2vips.c
+++ b/libvips/foreign/openslide2vips.c
@@ -47,6 +47,8 @@
  * 	- do argb -> rgba for associated as well 
  * 27/1/15
  * 	- unpremultiplication speedups for fully opaque/transparent pixels
+ * 11/7/16
+ * 	- just warn on tile read error
  */
 
 /*
@@ -471,14 +473,16 @@ vips__openslide_generate( VipsRegion *out,
 		rslide->level,
 		r->width, r->height ); 
 
+	/* Only warn on error: we don't want to make the whole image unreadable
+	 * because of one broken tile.
+	 *
+	 * FIXME ... add a --fail option like jpegload
+	 */
 	error = openslide_get_error( rslide->osr );
-	if( error ) {
-		vips_error( "openslide2vips", 
+	if( error ) 
+		vips_warn( "openslide2vips", 
 			_( "reading region: %s" ), error );
 
-		return( -1 );
-	}
-
 	/* Since we are inside a cache, we know buf must be continuous.
 	 */
 	argb2rgba( buf, n, bg );
diff --git a/libvips/foreign/vips2jpeg.c b/libvips/foreign/vips2jpeg.c
index 9b2d52a8..04ec6aa6 100644
--- a/libvips/foreign/vips2jpeg.c
+++ b/libvips/foreign/vips2jpeg.c
@@ -227,7 +227,6 @@ write_new( VipsImage *in )
         write->cinfo.err = jpeg_std_error( &write->eman.pub );
 	write->eman.pub.error_exit = vips__new_error_exit;
 	write->eman.pub.output_message = vips__new_output_message;
-	write->eman.pub.output_message = vips__new_output_message;
 	write->eman.fp = NULL;
 	write->profile_bytes = NULL;
 	write->profile_length = 0;

From 097ecd07c111cd380a3e371c528fb25ecdd82f6c Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Wed, 13 Jul 2016 07:06:43 +0100
Subject: [PATCH 05/15] doc improvements

---
 libvips/resample/affine.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/libvips/resample/affine.c b/libvips/resample/affine.c
index d67c184b..34ae4144 100644
--- a/libvips/resample/affine.c
+++ b/libvips/resample/affine.c
@@ -623,12 +623,12 @@ vips_affine_init( VipsAffine *affine )
  *
  * Optional arguments:
  *
- * * @interpolate: interpolate pixels with this
- * * @oarea: output rectangle
- * * @idx: input horizontal offset
- * * @idy: input vertical offset
- * * @odx: output horizontal offset
- * * @ody: output vertical offset
+ * * @interpolate: #VipsInterpolate, interpolate pixels with this
+ * * @oarea: #VipsArrayInt, output rectangle
+ * * @idx: %gdouble, input horizontal offset
+ * * @idy: %gdouble, input vertical offset
+ * * @odx: %gdouble, output horizontal offset
+ * * @ody: %gdouble, output vertical offset
  *
  * This operator performs an affine transform on an image using @interpolate.
  *

From 23d9bad5811e73ff8672b98bb95b685a81d8dfcf Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Wed, 13 Jul 2016 09:24:41 +0100
Subject: [PATCH 06/15] doc improvements

---
 configure.ac                   |  1 +
 libvips/Makefile.am            |  4 +---
 libvips/colour/Lab2XYZ.c       |  4 ++--
 libvips/colour/XYZ2Lab.c       |  4 ++--
 libvips/conversion/arrayjoin.c | 15 ++++++++-------
 libvips/conversion/autorot.c   |  4 ++--
 libvips/iofuncs/image.c        |  2 ++
 libvips/resample/reduce.c      | 19 ++++++++++++++++---
 8 files changed, 34 insertions(+), 19 deletions(-)

diff --git a/configure.ac b/configure.ac
index 7adf1160..0c4fed37 100644
--- a/configure.ac
+++ b/configure.ac
@@ -112,6 +112,7 @@ headers="\
 	draw.h \
 	morphology.h \
 	type.h \
+	rect.h \
 	memory.h \
 	region.h"
 
diff --git a/libvips/Makefile.am b/libvips/Makefile.am
index 4b378df1..b2178c5d 100644
--- a/libvips/Makefile.am
+++ b/libvips/Makefile.am
@@ -98,10 +98,8 @@ Vips_8_0_gir_LIBS = libvips.la
 Vips_8_0_gir_FILES = $(introspection_sources)
 INTROSPECTION_GIRS += Vips-8.0.gir
 
-# don't use --warn-all --verbose 
-# we have an unusual markup with optional args and we don't want to see all
-# those warnings
 Vips_8_0_gir_SCANNERFLAGS = \
+			--warn-all --verbose  \
 			    --program=./introspect \
 			    --identifier-prefix=Vips \
 			    --identifier-prefix=vips \
diff --git a/libvips/colour/Lab2XYZ.c b/libvips/colour/Lab2XYZ.c
index d24f0d52..417983e7 100644
--- a/libvips/colour/Lab2XYZ.c
+++ b/libvips/colour/Lab2XYZ.c
@@ -197,9 +197,9 @@ vips_Lab2XYZ_init( VipsLab2XYZ *Lab2XYZ )
  * @out: output image
  * @...: %NULL-terminated list of optional named arguments
  *
- * optional arguments:
+ * Optional arguments:
  *
- * @temp: colour temperature
+ * * @temp: #VipsArrayDouble, colour temperature
  *
  * Turn Lab to XYZ. The colour temperature defaults to D65, but can be 
  * specified with @temp.
diff --git a/libvips/colour/XYZ2Lab.c b/libvips/colour/XYZ2Lab.c
index 97d9af1d..6d96b46a 100644
--- a/libvips/colour/XYZ2Lab.c
+++ b/libvips/colour/XYZ2Lab.c
@@ -250,9 +250,9 @@ vips_XYZ2Lab_init( VipsXYZ2Lab *XYZ2Lab )
  * @out: output image
  * @...: %NULL-terminated list of optional named arguments
  *
- * optional arguments:
+ * Optional arguments:
  *
- * @temp: colour temperature
+ * * @temp: #VipsArrayDouble, colour temperature
  *
  * Turn XYZ to Lab, optionally specifying the colour temperature. @temp
  * defaults to D65. 
diff --git a/libvips/conversion/arrayjoin.c b/libvips/conversion/arrayjoin.c
index 227c28b4..a4536a43 100644
--- a/libvips/conversion/arrayjoin.c
+++ b/libvips/conversion/arrayjoin.c
@@ -394,16 +394,17 @@ vips_arrayjoinv( VipsImage **in, VipsImage **out, int n, va_list ap )
  * @in: (array length=n) (transfer none): array of input images
  * @out: output image
  * @n: number of input images
+ * @...: %NULL-terminated list of optional named arguments
  *
  * Optional arguments:
  *
- * * @across: number of images per row
- * * @shim: space between images, in pixels
- * * @background: background ink colour
- * * @halign: low, centre or high alignment
- * * @valign: low, centre or high alignment
- * * @hspacing: horizontal distance between images
- * * @vspacing: vertical distance between images
+ * * @across: %gint, number of images per row
+ * * @shim: %gint, space between images, in pixels
+ * * @background: #VipsArrayDouble, background ink colour
+ * * @halign: #VipsAlign, low, centre or high alignment
+ * * @valign: #VipsAlign, low, centre or high alignment
+ * * @hspacing: %gint, horizontal distance between images
+ * * @vspacing: %gint, vertical distance between images
  *
  * Lay out the images in @in in a grid. The grid is @across images across and
  * however high is necessary to use up all of @in. Images are set down
diff --git a/libvips/conversion/autorot.c b/libvips/conversion/autorot.c
index 0a700010..c693dbeb 100644
--- a/libvips/conversion/autorot.c
+++ b/libvips/conversion/autorot.c
@@ -126,9 +126,9 @@ vips_autorot_remove_angle_sub( VipsImage *image,
 
 /**
  * vips_autorot_remove_angle:
- * @im: image to remove orientation from
+ * @image: image to remove orientation from
  *
- * Remove the orientation tag on @im. Also remove any exif orientation tags. 
+ * Remove the orientation tag on @image. Also remove any exif orientation tags. 
  *
  * See also: vips_autorot_get_angle(). 
  */
diff --git a/libvips/iofuncs/image.c b/libvips/iofuncs/image.c
index a7c441a1..a296f1e3 100644
--- a/libvips/iofuncs/image.c
+++ b/libvips/iofuncs/image.c
@@ -2997,6 +2997,8 @@ vips_image_rewind_output( VipsImage *image )
  * have made it yourself), use vips_image_wio_input() instead.
  *
  * See also: vips_image_wio_input().
+ *
+ * Returns: (transfer full): the new #VipsImage, or %NULL on error.
  */
 VipsImage *
 vips_image_copy_memory( VipsImage *image )
diff --git a/libvips/resample/reduce.c b/libvips/resample/reduce.c
index 1304e609..27e7661d 100644
--- a/libvips/resample/reduce.c
+++ b/libvips/resample/reduce.c
@@ -50,6 +50,19 @@
 
 #include "presample.h"
 
+/**
+ * VipsKernel: 
+ * @VIPS_KERNEL_NEAREST: The nearest pixel to the point.
+ * @VIPS_KERNEL_LINEAR: Calculate a pixel value using linear interpolation.
+ * @VIPS_KERNEL_CUBIC: Calculate using a 4-element cubic kernel.
+ * @VIPS_KERNEL_LANCZOS2: Calculate with a two-lobe Lanczos kernel.
+ * @VIPS_KERNEL_LANCZOS3: Calculate with a three-lobe Lanczos kernel.
+ *
+ * The resampling kernels vips supports. See vips_reduce(), for example.  
+ *
+ * The Lanczos kernels vary in size with the downsampling ratio. 
+ */
+
 typedef struct _VipsReduce {
 	VipsResample parent_instance;
 
@@ -141,15 +154,15 @@ vips_reduce_init( VipsReduce *reduce )
  * @in: input image
  * @out: output image
  * @xshrink: horizontal shrink
- * @shrinke: vertical shrink
+ * @yshrink: vertical shrink
  * @...: %NULL-terminated list of optional named arguments
  *
  * Optional arguments:
  *
  * * @kernel: #VipsKernel to use to interpolate (default: lanczos3)
  *
- * Reduce @in by a pair of factors with a pair of 1D interpolators. This 
- * will not work well for shrink factors greater than two.
+ * Reduce @in by a pair of factors with a pair of 1D kernels. This 
+ * will not work well for shrink factors greater than three.
  *
  * This is a very low-level operation: see vips_resize() for a more
  * convenient way to resize images. 

From b814baa78c98af12f3741e47c1065e50dcaddfde Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Wed, 13 Jul 2016 17:07:26 +0100
Subject: [PATCH 07/15] fix various small doc problems

---
 libvips/include/vips/object.h | 8 ++------
 libvips/iofuncs/object.c      | 6 +++---
 libvips/iofuncs/rect.c        | 4 ++--
 3 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/libvips/include/vips/object.h b/libvips/include/vips/object.h
index 4123a526..53e16397 100644
--- a/libvips/include/vips/object.h
+++ b/libvips/include/vips/object.h
@@ -296,11 +296,6 @@ typedef struct _VipsArgumentInstance {
  */
 typedef GHashTable VipsArgumentTable;
 
-VipsArgumentInstance *vips__argument_get_instance( 
-	VipsArgumentClass *argument_class,
-	VipsObject *object );
-VipsArgument *vips__argument_table_lookup( VipsArgumentTable *argument_class, 
-	GParamSpec *pspec );
 void vips__object_set_member( VipsObject *object, GParamSpec *pspec,
 	GObject **member, GObject *argument );
 typedef void *(*VipsArgumentMapFn)( VipsObject *object, GParamSpec *pspec,
@@ -622,7 +617,8 @@ GType vips_type_find( const char *basename, const char *nickname );
 const char *vips_nickname_find( GType type );
 
 void *vips_class_map_all( GType type, VipsClassMapFn fn, void *a );
-VipsObjectClass *vips_class_find( const char *basename, const char *nickname );
+const VipsObjectClass *vips_class_find( const char *basename, 
+	const char *nickname );
 
 VipsObject **vips_object_local_array( VipsObject *parent, int n );
 
diff --git a/libvips/iofuncs/object.c b/libvips/iofuncs/object.c
index 5e410bfa..77841dcc 100644
--- a/libvips/iofuncs/object.c
+++ b/libvips/iofuncs/object.c
@@ -2691,9 +2691,9 @@ test_name( VipsObjectClass *class, const char *nickname )
  *
  * See also: vips_type_find()
  *
- * Returns: the found class.
+ * Returns: (transfer none): the found class.
  */
-VipsObjectClass *
+const VipsObjectClass *
 vips_class_find( const char *basename, const char *nickname )
 {
 	const char *classname = basename ? basename : "VipsObject";
@@ -2802,7 +2802,7 @@ vips_type_find( const char *basename, const char *nickname )
 		g_type_is_a( hit->type, base ) ) 
 		type = hit->type;
 	else {
-		VipsObjectClass *class;
+		const VipsObjectClass *class;
 
 		if( !(class = vips_class_find( basename, nickname )) )
 			return( 0 );
diff --git a/libvips/iofuncs/rect.c b/libvips/iofuncs/rect.c
index 05eec762..a2f4ec15 100644
--- a/libvips/iofuncs/rect.c
+++ b/libvips/iofuncs/rect.c
@@ -203,12 +203,12 @@ vips_rect_unionrect( const VipsRect *r1, const VipsRect *r2, VipsRect *out )
 }
 
 /**
- * vips_rect_dup:
+ * vips_rect_dup: (skip)
  * @r: rectangle to duplicate
  *
  * Duplicate a rect to the heap. You need to free the result with vips_free().
  *
- * Returns: a pointer to copy of @r allocated on the heap.
+ * Returns: (transfer full): a pointer to copy of @r allocated on the heap.
  */
 VipsRect *
 vips_rect_dup( const VipsRect *r )

From 9c18f1b4d54e1036c00a1032a9b62b6b86ac7753 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Wed, 13 Jul 2016 22:39:16 +0100
Subject: [PATCH 08/15] yet mmore doc fixes

classes are working again in gtk-doc, yay
---
 libvips/foreign/foreign.c          |  6 +++---
 libvips/include/vips/foreign.h     | 12 +++++++++---
 libvips/include/vips/image.h       |  6 ++++--
 libvips/include/vips/interpolate.h |  4 +++-
 libvips/include/vips/object.h      |  6 ++++--
 libvips/include/vips/operation.h   |  4 +++-
 libvips/include/vips/region.h      |  4 +++-
 libvips/include/vips/threadpool.h  |  5 ++++-
 libvips/include/vips/type.h        | 16 ++++++++--------
 9 files changed, 41 insertions(+), 22 deletions(-)

diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index 04fd4551..707a1ed9 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -609,7 +609,7 @@ vips_foreign_find_load_buffer( const void *data, size_t size )
 gboolean 
 vips_foreign_is_a( const char *loader, const char *filename )
 {
-	VipsObjectClass *class;
+	const VipsObjectClass *class;
 	VipsForeignLoadClass *load_class;
 
 	if( !(class = vips_class_find( "VipsForeignLoad", loader )) ) 
@@ -636,7 +636,7 @@ vips_foreign_is_a( const char *loader, const char *filename )
 gboolean
 vips_foreign_is_a_buffer( const char *loader, const void *data, size_t size )
 {
-	VipsObjectClass *class;
+	const VipsObjectClass *class;
 	VipsForeignLoadClass *load_class;
 
 	if( !(class = vips_class_find( "VipsForeignLoad", loader )) )
@@ -662,7 +662,7 @@ vips_foreign_is_a_buffer( const char *loader, const void *data, size_t size )
 VipsForeignFlags 
 vips_foreign_flags( const char *loader, const char *filename )
 {
-	VipsObjectClass *class;
+	const VipsObjectClass *class;
 
 	if( (class = vips_class_find( "VipsForeignLoad", loader )) ) {
 		VipsForeignLoadClass *load_class = 
diff --git a/libvips/include/vips/foreign.h b/libvips/include/vips/foreign.h
index 14d9a824..2245167b 100644
--- a/libvips/include/vips/foreign.h
+++ b/libvips/include/vips/foreign.h
@@ -77,7 +77,9 @@ typedef struct _VipsForeignClass {
 
 } VipsForeignClass;
 
-GType vips_foreign_get_type( void );
+/* Don't put spaces around void here, it breaks gtk-doc.
+ */
+GType vips_foreign_get_type(void);
 
 /* Map over and find formats. This uses type introspection to loop over
  * subclasses of VipsForeign.
@@ -211,7 +213,9 @@ typedef struct _VipsForeignLoadClass {
 	int (*load)( VipsForeignLoad *load );
 } VipsForeignLoadClass;
 
-GType vips_foreign_load_get_type( void );
+/* Don't put spaces around void here, it breaks gtk-doc.
+ */
+GType vips_foreign_load_get_type(void);
 
 const char *vips_foreign_find_load( const char *filename );
 const char *vips_foreign_find_load_buffer( const void *data, size_t size );
@@ -313,7 +317,9 @@ typedef struct _VipsForeignSaveClass {
 	gboolean coding[VIPS_CODING_LAST];
 } VipsForeignSaveClass;
 
-GType vips_foreign_save_get_type( void );
+/* Don't put spaces around void here, it breaks gtk-doc.
+ */
+GType vips_foreign_save_get_type(void);
 
 const char *vips_foreign_find_save( const char *filename );
 const char *vips_foreign_find_save_buffer( const char *suffix );
diff --git a/libvips/include/vips/image.h b/libvips/include/vips/image.h
index ee8d7a6b..3fedba71 100644
--- a/libvips/include/vips/image.h
+++ b/libvips/include/vips/image.h
@@ -173,7 +173,7 @@ typedef struct _VipsProgress {
 	VIPS_TYPE_IMAGE, VipsImageClass ))
 
 typedef struct _VipsImage {
-	VipsObject parent_object;
+	VipsObject parent_instance;
 
 	/*< private >*/
 
@@ -356,7 +356,9 @@ typedef struct _VipsImageClass {
 
 } VipsImageClass;
 
-GType vips_image_get_type( void );
+/* Don't put spaces around void here, it breaks gtk-doc.
+ */
+GType vips_image_get_type(void);
 
 /* Has to be guint64 and not size_t/off_t since we have to be able to address
  * huge images on platforms with 32-bit files.
diff --git a/libvips/include/vips/interpolate.h b/libvips/include/vips/interpolate.h
index a872fb89..930e400e 100644
--- a/libvips/include/vips/interpolate.h
+++ b/libvips/include/vips/interpolate.h
@@ -87,7 +87,9 @@ typedef struct _VipsInterpolateClass {
 	int window_offset;
 } VipsInterpolateClass;
 
-GType vips_interpolate_get_type( void );
+/* Don't put spaces around void here, it breaks gtk-doc.
+ */
+GType vips_interpolate_get_type(void);
 void vips_interpolate( VipsInterpolate *interpolate,
 	void *out, VipsRegion *in, double x, double y );
 VipsInterpolateMethod vips_interpolate_get_method( VipsInterpolate *interpolate );
diff --git a/libvips/include/vips/object.h b/libvips/include/vips/object.h
index 53e16397..1da024fd 100644
--- a/libvips/include/vips/object.h
+++ b/libvips/include/vips/object.h
@@ -406,7 +406,7 @@ int vips_object_get_argument_priority( VipsObject *object, const char *name );
 	(G_TYPE_INSTANCE_GET_CLASS( (obj), VIPS_TYPE_OBJECT, VipsObjectClass ))
 
 struct _VipsObject {
-	GObject parent_object;
+	GObject parent_instance;
 
 	/* Set after ->build() has run succesfully: construct is fully done
 	 * and checked.
@@ -579,7 +579,9 @@ void vips_object_print_name( VipsObject *object );
 
 gboolean vips_object_sanity( VipsObject *object );
 
-GType vips_object_get_type( void );
+/* Don't put spaces around void here, it breaks gtk-doc.
+ */
+GType vips_object_get_type(void);
 
 void vips_object_class_install_argument( VipsObjectClass *cls, 
 	GParamSpec *pspec, VipsArgumentFlags flags, 
diff --git a/libvips/include/vips/operation.h b/libvips/include/vips/operation.h
index 3b732f6e..d76abdaa 100644
--- a/libvips/include/vips/operation.h
+++ b/libvips/include/vips/operation.h
@@ -92,7 +92,9 @@ typedef struct _VipsOperationClass {
 	void (*invalidate)( VipsOperation *operation );
 } VipsOperationClass;
 
-GType vips_operation_get_type( void );
+/* Don't put spaces around void here, it breaks gtk-doc.
+ */
+GType vips_operation_get_type(void);
 
 VipsOperationFlags vips_operation_get_flags( VipsOperation *operation );
 void vips_operation_class_print_usage( VipsOperationClass *operation_class );
diff --git a/libvips/include/vips/region.h b/libvips/include/vips/region.h
index 5c9439d4..ce171a39 100644
--- a/libvips/include/vips/region.h
+++ b/libvips/include/vips/region.h
@@ -98,7 +98,9 @@ typedef struct _VipsRegionClass {
 
 } VipsRegionClass;
 
-GType vips_region_get_type( void );
+/* Don't put spaces around void here, it breaks gtk-doc.
+ */
+GType vips_region_get_type(void);
 
 VipsRegion *vips_region_new( VipsImage *image );
 
diff --git a/libvips/include/vips/threadpool.h b/libvips/include/vips/threadpool.h
index 2352bc44..d1e49ce4 100644
--- a/libvips/include/vips/threadpool.h
+++ b/libvips/include/vips/threadpool.h
@@ -97,7 +97,10 @@ typedef struct _VipsThreadStateClass {
 } VipsThreadStateClass;
 
 void *vips_thread_state_set( VipsObject *object, void *a, void *b );
-GType vips_thread_state_get_type( void );
+
+/* Don't put spaces around void here, it breaks gtk-doc.
+ */
+GType vips_thread_state_get_type(void);
 
 VipsThreadState *vips_thread_state_new( VipsImage *im, void *a );
 
diff --git a/libvips/include/vips/type.h b/libvips/include/vips/type.h
index 37ed6b3c..88b44c88 100644
--- a/libvips/include/vips/type.h
+++ b/libvips/include/vips/type.h
@@ -50,7 +50,7 @@ typedef struct _VipsThing {
  * The #GType for a #VipsThing.
  */
 #define VIPS_TYPE_THING (vips_thing_get_type())
-GType vips_thing_get_type( void );
+GType vips_thing_get_type(void);
 VipsThing *vips_thing_new( int i );
 
 /* A ref-counted area of memory. Can hold arrays of things as well.
@@ -119,7 +119,7 @@ void *vips_area_get_data( VipsArea *area,
  */
 #define VIPS_TYPE_AREA (vips_area_get_type())
 #define VIPS_AREA( X ) ((VipsArea *) (X))
-GType vips_area_get_type( void );
+GType vips_area_get_type(void);
 
 /**
  * VIPS_TYPE_SAVE_STRING:
@@ -127,7 +127,7 @@ GType vips_area_get_type( void );
  * The #GType for a #VipsSaveString.
  */
 #define VIPS_TYPE_SAVE_STRING (vips_save_string_get_type())
-GType vips_save_string_get_type( void );
+GType vips_save_string_get_type(void);
 
 /**
  * VIPS_TYPE_REF_STRING:
@@ -142,7 +142,7 @@ typedef struct _VipsRefString {
 
 VipsRefString *vips_ref_string_new( const char *str );
 const char *vips_ref_string_get( VipsRefString *refstr, size_t *length );
-GType vips_ref_string_get_type( void );
+GType vips_ref_string_get_type(void);
 
 /**
  * VIPS_TYPE_BLOB:
@@ -159,7 +159,7 @@ VipsBlob *vips_blob_new( VipsCallbackFn free_fn,
 	const void *data, size_t size );
 VipsBlob *vips_blob_copy( const void *data, size_t size );
 const void *vips_blob_get( VipsBlob *blob, size_t *size );
-GType vips_blob_get_type( void );
+GType vips_blob_get_type(void);
 
 /**
  * VIPS_TYPE_ARRAY_DOUBLE:
@@ -175,7 +175,7 @@ typedef struct _VipsArrayDouble {
 VipsArrayDouble *vips_array_double_new( const double *array, int n );
 VipsArrayDouble *vips_array_double_newv( int n, ... );
 double *vips_array_double_get( VipsArrayDouble *array, int *n );
-GType vips_array_double_get_type( void );
+GType vips_array_double_get_type(void);
 
 /**
  * VIPS_TYPE_ARRAY_INT:
@@ -191,7 +191,7 @@ typedef struct _VipsArrayInt {
 VipsArrayInt *vips_array_int_new( const int *array, int n );
 VipsArrayInt *vips_array_int_newv( int n, ... );
 int *vips_array_int_get( VipsArrayInt *array, int *n );
-GType vips_array_int_get_type( void );
+GType vips_array_int_get_type(void);
 
 /**
  * VIPS_TYPE_ARRAY_IMAGE:
@@ -207,7 +207,7 @@ typedef struct _VipsArrayImage {
 /* See image.h for vips_array_image_new() etc., they need to be declared after
  * VipsImage.
  */
-GType vips_array_image_get_type( void );
+GType vips_array_image_get_type(void);
 
 void vips_value_set_area( GValue *value, VipsCallbackFn free_fn, void *data );
 void *vips_value_get_area( const GValue *value, size_t *length );

From dac671439c99ca5d776c713792f4922a1cb736d0 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Tue, 19 Jul 2016 10:57:21 +0100
Subject: [PATCH 09/15] kind-of working

---
 ChangeLog                     |   1 +
 TODO                          |   2 +
 libvips/Makefile.am           |  12 +-
 libvips/create/Makefile.am    |   1 +
 libvips/create/create.c       |   2 +
 libvips/create/worley.c       | 383 ++++++++++++++++++++++++++++++++++
 libvips/include/vips/create.h |   3 +
 7 files changed, 399 insertions(+), 5 deletions(-)
 create mode 100644 libvips/create/worley.c

diff --git a/ChangeLog b/ChangeLog
index 3c0a33a7..55cfc0c3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -27,6 +27,7 @@
 - better quality for vips_resize() with linear/cubic kernels 
 - pyvips8 can create new metadata
 - better upsizing with vips_resize()
+- added vips_worley(), generate worley noise
 
 18/5/16 started 8.3.2
 - more robust vips image reading
diff --git a/TODO b/TODO
index 4ead5e91..85383097 100644
--- a/TODO
+++ b/TODO
@@ -1,3 +1,5 @@
+- add perlin and worley noise generators
+
 - add more webp tests to py suite
 
 - try moving some more of the CLI tests to py
diff --git a/libvips/Makefile.am b/libvips/Makefile.am
index b2178c5d..015ac722 100644
--- a/libvips/Makefile.am
+++ b/libvips/Makefile.am
@@ -98,12 +98,14 @@ Vips_8_0_gir_LIBS = libvips.la
 Vips_8_0_gir_FILES = $(introspection_sources)
 INTROSPECTION_GIRS += Vips-8.0.gir
 
+# don't use 
+#   --warn-all --verbose 
+# too annoying
 Vips_8_0_gir_SCANNERFLAGS = \
-			--warn-all --verbose  \
-			    --program=./introspect \
-			    --identifier-prefix=Vips \
-			    --identifier-prefix=vips \
-			    --symbol-prefix=vips 
+	--program=./introspect \
+	--identifier-prefix=Vips \
+	--identifier-prefix=vips \
+	--symbol-prefix=vips 
 
 girdir = $(datadir)/gir-1.0
 gir_DATA = $(INTROSPECTION_GIRS)
diff --git a/libvips/create/Makefile.am b/libvips/create/Makefile.am
index 7f27218e..e56a9566 100644
--- a/libvips/create/Makefile.am
+++ b/libvips/create/Makefile.am
@@ -1,6 +1,7 @@
 noinst_LTLIBRARIES = libcreate.la
 
 libcreate_la_SOURCES = \
+	worley.c \
 	create.c \
 	pcreate.h \
 	gaussmat.c \
diff --git a/libvips/create/create.c b/libvips/create/create.c
index 77ef0ccc..cc2613a7 100644
--- a/libvips/create/create.c
+++ b/libvips/create/create.c
@@ -139,6 +139,7 @@ vips_create_operation_init( void )
 	extern GType vips_mask_ideal_band_get_type( void ); 
 	extern GType vips_mask_fractal_get_type( void ); 
 	extern GType vips_fractsurf_get_type( void ); 
+	extern GType vips_worley_get_type( void ); 
 
 	vips_black_get_type();
 	vips_gaussmat_get_type();
@@ -167,5 +168,6 @@ vips_create_operation_init( void )
 	vips_mask_gaussian_band_get_type(); 
 	vips_mask_fractal_get_type(); 
 	vips_fractsurf_get_type(); 
+	vips_worley_get_type(); 
 }
 
diff --git a/libvips/create/worley.c b/libvips/create/worley.c
new file mode 100644
index 00000000..2360bba7
--- /dev/null
+++ b/libvips/create/worley.c
@@ -0,0 +1,383 @@
+/* Worley noise generator
+ *
+ * 13/6/13
+ */
+
+/*
+
+    This file is part of VIPS.
+    
+    VIPS is free software; you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+    02110-1301  USA
+
+ */
+
+/*
+
+    These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
+
+ */
+
+/*
+#define VIPS_DEBUG
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif /*HAVE_CONFIG_H*/
+#include <vips/intl.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <math.h>
+
+#include <vips/vips.h>
+
+#include "pcreate.h"
+
+typedef struct _VipsWorley {
+	VipsCreate parent_instance;
+
+	int width;
+	int height;
+	int cell_size;
+
+	int cells_across;
+	int cells_down;
+
+	/* Use this to seed this call of our rng.
+	 */
+	int seed;
+} VipsWorley;
+
+typedef struct _VipsWorleyClass {
+	VipsCreateClass parent_class;
+
+} VipsWorleyClass;
+
+G_DEFINE_TYPE( VipsWorley, vips_worley, VIPS_TYPE_CREATE );
+
+#define MAX_FEATURES (10)
+
+/* Round N down to P boundary. 
+ */
+#define ROUND_DOWN( N, P ) ((N) - ((N) % P)) 
+
+/* Round N up to P boundary. 
+ */
+#define ROUND_UP( N, P ) (ROUND_DOWN( (N) + (P) - 1, (P) ))
+
+typedef struct _Cell {
+	/* Cell position, in number of cells. Scale by cell_size to get
+	 * absolute image cods.
+	 */
+	int cell_x;
+	int cell_y;
+
+	/* A cell contains 1 to n features.
+	 */
+	int n_features;
+
+	/* Feature coordinates, in absolute image space.
+	 */
+	int feature_x[MAX_FEATURES];
+	int feature_y[MAX_FEATURES];
+} Cell;
+
+typedef struct _Sequence {
+	VipsWorley *worley;
+
+	/* The position of the last cell we were in. Use this to avoid
+	 * regenerating cells on every pixel lookup.
+	 */
+	int cell_x;
+	int cell_y;
+
+	/* The 3 x 3 grid of cells around the current point.
+	 */
+	Cell cells[9];
+
+} Sequence;
+
+/* A very simple random number generator.
+ */
+static int
+vips_worley_random( int previous )
+{
+	return( ((guint64) 1103515245 * previous + 12345) & 0xffffff );
+}
+
+/* Generate a 3 x 3 grid of cells around a point.
+ */
+static void
+vips_worley_create_cells( VipsWorley *worley, 
+	Cell cells[9], int cell_x, int cell_y )
+{
+	int x, y;
+
+	for( y = 0; y < 3; y++ ) 
+		for( x = 0; x < 3; x++ ) {
+			Cell *cell = &cells[x + y * 3];
+
+			int seed;
+			int j;
+
+			/* We wrap cells around, so that out output will
+			 * tesselate.
+			 */
+			cell->cell_x = cell_x + x - 1;
+			if( cell->cell_x >= worley->cells_across )
+				cell->cell_x = 0;
+			if( cell->cell_x < 0 )
+				cell->cell_x = worley->cells_across - 1;
+			cell->cell_y = cell_y + y - 1;
+			if( cell->cell_y >= worley->cells_down )
+				cell->cell_y = 0;
+			if( cell->cell_y < 0 )
+				cell->cell_y = worley->cells_down - 1;
+
+			/* Seed our rng.
+			 */
+			seed = worley->seed + 
+				(cell->cell_x << 16) + cell->cell_y;
+
+			/* [1, MAX_FEATURES)
+			 */
+			seed = vips_worley_random( seed ); 
+			cell->n_features = (seed % (MAX_FEATURES - 1)) + 1;
+
+			for( j = 0; j < cell->n_features; j++ ) {
+				seed = vips_worley_random( seed ); 
+				cell->feature_x[j] = 
+					cell->cell_y * worley->cell_size + 
+					seed % worley->cell_size;
+				seed = vips_worley_random( seed ); 
+				cell->feature_y[j] = 
+					cell->cell_y * worley->cell_size + 
+					seed % worley->cell_size;
+			}
+		}
+}
+
+static int
+vips_worley_stop( void *vseq, void *a, void *b )
+{
+	Sequence *seq = (Sequence *) vseq;
+
+	VIPS_FREE( seq );
+
+	return( 0 );
+}
+
+static void *
+vips_worley_start( VipsImage *out, void *a, void *b )
+{
+	VipsWorley *worley = (VipsWorley *) b;
+
+	Sequence *seq;
+
+	if( !(seq = VIPS_NEW( NULL, Sequence )) )
+		return( NULL );
+
+	seq->worley = worley;
+	seq->cell_x = -1;
+	seq->cell_y = -1;
+
+	return( seq );
+}
+
+static int
+vips_hypot( int x, int y )
+{
+	int result;
+
+#ifdef HAVE_HYPOT
+	result = hypot( x, y ); 
+#else
+	result = sqrt( x * x + y * y );
+#endif
+
+	return( result );
+}
+
+static int
+vips_worley_distance( VipsWorley *worley, Cell cells[9], int x, int y )
+{
+	int distance;
+
+	int i, j;
+
+	distance = worley->cell_size * 1.5;
+
+	for( i = 0; i < 9; i++ ) {
+		Cell *cell = &cells[i];
+
+		for( j = 0; j < cell->n_features; j++ ) {
+			int d = vips_hypot( 
+				x - cell->feature_x[j], 
+				y - cell->feature_y[j] );
+
+			distance = VIPS_MIN( d, distance );
+		}
+	}
+
+	return( distance );
+}
+
+static int
+vips_worley_gen( VipsRegion *or, void *vseq, void *a, void *b,
+	gboolean *stop )
+{
+	VipsWorley *worley = (VipsWorley *) a;
+	VipsRect *r = &or->valid;
+	Sequence *seq = (Sequence *) vseq;
+
+	int x, y;
+
+	for( y = 0; y < r->height; y++ ) {
+		int *q = (int *) VIPS_REGION_ADDR( or, r->left, r->top + y );
+
+		for( x = 0; x < r->width; x++ ) {
+			int cell_x = (r->left + x) % worley->cell_size;
+			int cell_y = (r->top + y) % worley->cell_size;
+
+			if( cell_x != seq->cell_x ||
+				cell_y != seq->cell_y ) {
+				vips_worley_create_cells( worley, 
+					seq->cells, cell_x, cell_y );
+				seq->cell_x = cell_x;
+				seq->cell_y = cell_y;
+			}
+
+			q[x] = vips_worley_distance( worley, seq->cells, 
+				r->left + x, r->top + y );
+		}
+	}
+
+	return( 0 );
+}
+
+static int
+vips_worley_build( VipsObject *object )
+{
+	VipsCreate *create = VIPS_CREATE( object );
+	VipsWorley *worley = (VipsWorley *) object;
+
+	if( VIPS_OBJECT_CLASS( vips_worley_parent_class )->build( object ) )
+		return( -1 );
+
+	/* Be careful if width is a multiple of cell_size.
+	 */
+	worley->cells_across = ROUND_UP( worley->width, worley->cell_size ) / 
+		worley->cell_size;
+	worley->cells_down = ROUND_UP( worley->height, worley->cell_size ) / 
+		worley->cell_size;
+
+	worley->seed = g_random_double() * 0xffffff;
+
+	vips_image_init_fields( create->out,
+		worley->width, worley->height, 1,
+		VIPS_FORMAT_INT, VIPS_CODING_NONE, VIPS_INTERPRETATION_B_W,
+		1.0, 1.0 );
+	vips_image_pipelinev( create->out,
+		VIPS_DEMAND_STYLE_ANY, NULL );
+	if( vips_image_generate( create->out,
+		vips_worley_start, vips_worley_gen, vips_worley_stop, 
+		worley, NULL ) )
+		return( -1 );
+
+	return( 0 );
+}
+
+static void
+vips_worley_class_init( VipsWorleyClass *class )
+{
+	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
+	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
+
+	gobject_class->set_property = vips_object_set_property;
+	gobject_class->get_property = vips_object_get_property;
+
+	vobject_class->nickname = "worley";
+	vobject_class->description = _( "make a worley image" );
+	vobject_class->build = vips_worley_build;
+
+	VIPS_ARG_INT( class, "width", 2, 
+		_( "Width" ), 
+		_( "Image width in pixels" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsWorley, width ),
+		1, VIPS_MAX_COORD, 1 );
+
+	VIPS_ARG_INT( class, "height", 3, 
+		_( "Height" ), 
+		_( "Image height in pixels" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsWorley, height ),
+		1, VIPS_MAX_COORD, 1 );
+
+	VIPS_ARG_INT( class, "cell_size", 3, 
+		_( "Cell size" ), 
+		_( "Size of Worley cells" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsWorley, cell_size ),
+		1, VIPS_MAX_COORD, 256 );
+
+}
+
+static void
+vips_worley_init( VipsWorley *worley )
+{
+	worley->cell_size = 256;
+}
+
+/**
+ * vips_worley:
+ * @out: output image
+ * @width: horizontal size
+ * @height: vertical size
+ * @...: %NULL-terminated list of optional named arguments
+ *
+ * Optional arguments:
+ *
+ * * @cell_size: %gint, size of Worley cells
+ *
+ * Create a one-band int image of Worley noise. See:
+ *
+ * https://en.wikipedia.org/wiki/Worley_noise
+ *
+ * Use @cell_size to set the size of the cells from which the image is
+ * constructed. The default is 256 x 256.
+ *
+ * If @width and @height are mutiples of @cell_size, the image will tessellate.
+ *
+ * See also: vips_gaussnoise().
+ *
+ * Returns: 0 on success, -1 on error
+ */
+int
+vips_worley( VipsImage **out, int width, int height, ... )
+{
+	va_list ap;
+	int result;
+
+	va_start( ap, height );
+	result = vips_call_split( "worley", ap, out, width, height );
+	va_end( ap );
+
+	return( result );
+}
+
diff --git a/libvips/include/vips/create.h b/libvips/include/vips/create.h
index b7f96c4f..8567fb82 100644
--- a/libvips/include/vips/create.h
+++ b/libvips/include/vips/create.h
@@ -114,6 +114,9 @@ int vips_fractsurf( VipsImage **out,
 	int width, int height, double fractal_dimension, ... )
 	__attribute__((sentinel));
 
+int vips_worley( VipsImage **out, int width, int height, ... )
+	__attribute__((sentinel));
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus*/

From e14c97359ab03142a7a2b7404e3c412ea2cf7db4 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Tue, 19 Jul 2016 11:53:56 +0100
Subject: [PATCH 10/15] done!

perlin next I guess
---
 libvips/create/worley.c | 60 ++++++++++++++++++++---------------------
 1 file changed, 30 insertions(+), 30 deletions(-)

diff --git a/libvips/create/worley.c b/libvips/create/worley.c
index 2360bba7..8d364001 100644
--- a/libvips/create/worley.c
+++ b/libvips/create/worley.c
@@ -1,6 +1,6 @@
-/* Worley noise generator
+/* Worley noise generator.
  *
- * 13/6/13
+ * 19/7/16
  */
 
 /*
@@ -120,7 +120,7 @@ vips_worley_random( int previous )
 	return( ((guint64) 1103515245 * previous + 12345) & 0xffffff );
 }
 
-/* Generate a 3 x 3 grid of cells around a point.
+/* Generate a 3 x 3 grid of cells around a point. 
  */
 static void
 vips_worley_create_cells( VipsWorley *worley, 
@@ -135,24 +135,29 @@ vips_worley_create_cells( VipsWorley *worley,
 			int seed;
 			int j;
 
-			/* We wrap cells around, so that out output will
-			 * tesselate.
+			/* Can go <0 and >width for edges.
 			 */
 			cell->cell_x = cell_x + x - 1;
-			if( cell->cell_x >= worley->cells_across )
-				cell->cell_x = 0;
-			if( cell->cell_x < 0 )
-				cell->cell_x = worley->cells_across - 1;
 			cell->cell_y = cell_y + y - 1;
-			if( cell->cell_y >= worley->cells_down )
-				cell->cell_y = 0;
-			if( cell->cell_y < 0 )
-				cell->cell_y = worley->cells_down - 1;
 
-			/* Seed our rng.
+			seed = worley->seed;
+
+			/* When we calculate the seed for this cell, we wrap
+			 * around so that our output will tesselate.
 			 */
-			seed = worley->seed + 
-				(cell->cell_x << 16) + cell->cell_y;
+			if( cell->cell_x >= worley->cells_across )
+				seed ^= 0;
+			else if( cell->cell_x < 0 )
+				seed ^= worley->cells_across - 1;
+			else 
+				seed ^= cell->cell_x;
+
+			if( cell->cell_y >= worley->cells_down )
+				seed ^= 0;
+			else if( cell->cell_y < 0 )
+				seed ^= worley->cells_down - 1;
+			else 
+				seed ^= cell->cell_y;
 
 			/* [1, MAX_FEATURES)
 			 */
@@ -162,8 +167,9 @@ vips_worley_create_cells( VipsWorley *worley,
 			for( j = 0; j < cell->n_features; j++ ) {
 				seed = vips_worley_random( seed ); 
 				cell->feature_x[j] = 
-					cell->cell_y * worley->cell_size + 
+					cell->cell_x * worley->cell_size + 
 					seed % worley->cell_size;
+
 				seed = vips_worley_random( seed ); 
 				cell->feature_y[j] = 
 					cell->cell_y * worley->cell_size + 
@@ -202,15 +208,9 @@ vips_worley_start( VipsImage *out, void *a, void *b )
 static int
 vips_hypot( int x, int y )
 {
-	int result;
-
-#ifdef HAVE_HYPOT
-	result = hypot( x, y ); 
-#else
-	result = sqrt( x * x + y * y );
-#endif
-
-	return( result );
+	/* Faster than hypot() for int args.
+	 */
+	return( sqrt( x * x + y * y ) );
 }
 
 static int
@@ -230,7 +230,7 @@ vips_worley_distance( VipsWorley *worley, Cell cells[9], int x, int y )
 				x - cell->feature_x[j], 
 				y - cell->feature_y[j] );
 
-			distance = VIPS_MIN( d, distance );
+			distance = VIPS_MIN( distance, d );
 		}
 	}
 
@@ -251,8 +251,8 @@ vips_worley_gen( VipsRegion *or, void *vseq, void *a, void *b,
 		int *q = (int *) VIPS_REGION_ADDR( or, r->left, r->top + y );
 
 		for( x = 0; x < r->width; x++ ) {
-			int cell_x = (r->left + x) % worley->cell_size;
-			int cell_y = (r->top + y) % worley->cell_size;
+			int cell_x = (r->left + x) / worley->cell_size;
+			int cell_y = (r->top + y) / worley->cell_size;
 
 			if( cell_x != seq->cell_x ||
 				cell_y != seq->cell_y ) {
@@ -362,7 +362,7 @@ vips_worley_init( VipsWorley *worley )
  * Use @cell_size to set the size of the cells from which the image is
  * constructed. The default is 256 x 256.
  *
- * If @width and @height are mutiples of @cell_size, the image will tessellate.
+ * If @width and @height are multiples of @cell_size, the image will tessellate.
  *
  * See also: vips_gaussnoise().
  *

From 99766dbd830b7d9099d60cb2ed3d90c3c8306784 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Tue, 19 Jul 2016 12:29:36 +0100
Subject: [PATCH 11/15] better hash for worley

---
 libvips/create/worley.c | 36 +++++++++++++++++++++++-------------
 1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/libvips/create/worley.c b/libvips/create/worley.c
index 8d364001..2187a7be 100644
--- a/libvips/create/worley.c
+++ b/libvips/create/worley.c
@@ -60,7 +60,7 @@ typedef struct _VipsWorley {
 
 	/* Use this to seed this call of our rng.
 	 */
-	int seed;
+	guint32 seed;
 } VipsWorley;
 
 typedef struct _VipsWorleyClass {
@@ -112,12 +112,19 @@ typedef struct _Sequence {
 
 } Sequence;
 
-/* A very simple random number generator.
+/* A very simple random number generator. See:
+ * http://isthe.com/chongo/tech/comp/fnv/#FNV-source
  */
-static int
-vips_worley_random( int previous )
+static guint32
+vips_worley_random( guint32 seed )
 {
-	return( ((guint64) 1103515245 * previous + 12345) & 0xffffff );
+	return( 1103515245u * seed + 12345 );
+}
+
+static guint32 
+vips_worley_seed_add( guint32 seed, int value )
+{
+	return( ((2166136261u ^ seed) * 16777619u) ^ value );
 }
 
 /* Generate a 3 x 3 grid of cells around a point. 
@@ -132,7 +139,8 @@ vips_worley_create_cells( VipsWorley *worley,
 		for( x = 0; x < 3; x++ ) {
 			Cell *cell = &cells[x + y * 3];
 
-			int seed;
+			guint32 seed;
+			int value;
 			int j;
 
 			/* Can go <0 and >width for edges.
@@ -146,18 +154,20 @@ vips_worley_create_cells( VipsWorley *worley,
 			 * around so that our output will tesselate.
 			 */
 			if( cell->cell_x >= worley->cells_across )
-				seed ^= 0;
+				value = 0;
 			else if( cell->cell_x < 0 )
-				seed ^= worley->cells_across - 1;
+				value = worley->cells_across - 1;
 			else 
-				seed ^= cell->cell_x;
+				value = cell->cell_x;
+			seed = vips_worley_seed_add( seed, value );
 
 			if( cell->cell_y >= worley->cells_down )
-				seed ^= 0;
+				value = 0;
 			else if( cell->cell_y < 0 )
-				seed ^= worley->cells_down - 1;
+				value = worley->cells_down - 1;
 			else 
-				seed ^= cell->cell_y;
+				value = cell->cell_y;
+			seed = vips_worley_seed_add( seed, value );
 
 			/* [1, MAX_FEATURES)
 			 */
@@ -286,7 +296,7 @@ vips_worley_build( VipsObject *object )
 	worley->cells_down = ROUND_UP( worley->height, worley->cell_size ) / 
 		worley->cell_size;
 
-	worley->seed = g_random_double() * 0xffffff;
+	worley->seed = g_random_double() * 0xffffffffu;
 
 	vips_image_init_fields( create->out,
 		worley->width, worley->height, 1,

From 3efee94e19cdcb5c3b7a3ec399f8e10408bfb3c7 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Thu, 21 Jul 2016 07:40:33 +0100
Subject: [PATCH 12/15] fix possible out of bounds read in tiff2vips

reading a malformed tiff file from a buffer could trigger out of bounds
read

thanks Matt Richards
---
 ChangeLog                   |  1 +
 libvips/foreign/tiff2vips.c | 15 +++++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 600f20f9..d7981499 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,6 @@
 18/5/16 started 8.3.2
 - more robust vips image reading
+- more robust tiff read [Matt Richards]
 
 15/4/16 started 8.3.1
 - rename vips wrapper script, it was still vips-8.2, thanks Benjamin
diff --git a/libvips/foreign/tiff2vips.c b/libvips/foreign/tiff2vips.c
index 1c58bd61..2c2bf39c 100644
--- a/libvips/foreign/tiff2vips.c
+++ b/libvips/foreign/tiff2vips.c
@@ -1832,9 +1832,17 @@ my_tiff_read( thandle_t st, tdata_t buffer, tsize_t size )
 {
 	ReadTiff *rtiff = (ReadTiff *) st;
 
-	size_t available = rtiff->len - rtiff->pos;
-	size_t copy = VIPS_MIN( size, available );
+	size_t available;
+	size_t copy;
 
+	if( rtiff->pos > rtiff->len ) {
+		vips_error( "tiff2vips", 
+			"%s", _( "read beyond end of buffer" ) );
+		return( 0 );
+	}
+
+	available = rtiff->len - rtiff->pos;
+	copy = VIPS_MIN( size, available );
 	memcpy( buffer, (unsigned char *) rtiff->buf + rtiff->pos, copy );
 	rtiff->pos += copy;
 
@@ -1855,6 +1863,9 @@ my_tiff_close( thandle_t st )
 	return 0;
 }
 
+/* After calling this, ->pos is not bound by the size of the buffer, it can 
+ * have any positive value.
+ */
 static toff_t 
 my_tiff_seek( thandle_t st, toff_t pos, int whence )
 {

From c469bb398394bc98edede29c4fb2168a2733cf46 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sun, 24 Jul 2016 11:46:42 +0100
Subject: [PATCH 13/15] perlin sort-of works

---
 ChangeLog                     |   3 +-
 TODO                          |   4 +-
 libvips/create/Makefile.am    |   1 +
 libvips/create/create.c       |   2 +
 libvips/create/perlin.c       | 360 ++++++++++++++++++++++++++++++++++
 libvips/create/worley.c       |   4 +-
 libvips/include/vips/create.h |   2 +
 7 files changed, 372 insertions(+), 4 deletions(-)
 create mode 100644 libvips/create/perlin.c

diff --git a/ChangeLog b/ChangeLog
index 55cfc0c3..86a9c497 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -27,7 +27,8 @@
 - better quality for vips_resize() with linear/cubic kernels 
 - pyvips8 can create new metadata
 - better upsizing with vips_resize()
-- added vips_worley(), generate worley noise
+- added vips_worley(), generate Worley noise
+- added vips_perlin(), generate Perlin noise
 
 18/5/16 started 8.3.2
 - more robust vips image reading
diff --git a/TODO b/TODO
index 85383097..eed2e9f1 100644
--- a/TODO
+++ b/TODO
@@ -1,4 +1,6 @@
-- add perlin and worley noise generators
+- need better interpolation in the perlin generator?
+
+- add tests for perlin and worley noise generators
 
 - add more webp tests to py suite
 
diff --git a/libvips/create/Makefile.am b/libvips/create/Makefile.am
index e56a9566..8b5c11e4 100644
--- a/libvips/create/Makefile.am
+++ b/libvips/create/Makefile.am
@@ -1,6 +1,7 @@
 noinst_LTLIBRARIES = libcreate.la
 
 libcreate_la_SOURCES = \
+	perlin.c \
 	worley.c \
 	create.c \
 	pcreate.h \
diff --git a/libvips/create/create.c b/libvips/create/create.c
index cc2613a7..93c35796 100644
--- a/libvips/create/create.c
+++ b/libvips/create/create.c
@@ -140,6 +140,7 @@ vips_create_operation_init( void )
 	extern GType vips_mask_fractal_get_type( void ); 
 	extern GType vips_fractsurf_get_type( void ); 
 	extern GType vips_worley_get_type( void ); 
+	extern GType vips_perlin_get_type( void ); 
 
 	vips_black_get_type();
 	vips_gaussmat_get_type();
@@ -169,5 +170,6 @@ vips_create_operation_init( void )
 	vips_mask_fractal_get_type(); 
 	vips_fractsurf_get_type(); 
 	vips_worley_get_type(); 
+	vips_perlin_get_type(); 
 }
 
diff --git a/libvips/create/perlin.c b/libvips/create/perlin.c
new file mode 100644
index 00000000..fdb9ae57
--- /dev/null
+++ b/libvips/create/perlin.c
@@ -0,0 +1,360 @@
+/* Perlin noise generator.
+ *
+ * 24/7/16
+ */
+
+/*
+
+    This file is part of VIPS.
+    
+    VIPS is free software; you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+    02110-1301  USA
+
+ */
+
+/*
+
+    These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
+
+ */
+
+/*
+#define VIPS_DEBUG
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif /*HAVE_CONFIG_H*/
+#include <vips/intl.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <math.h>
+
+#include <vips/vips.h>
+
+#include "pcreate.h"
+
+typedef struct _VipsPerlin {
+	VipsCreate parent_instance;
+
+	int width;
+	int height;
+	int cell_size;
+
+	int cells_across;
+	int cells_down;
+
+	/* Use this to seed this call of our rng.
+	 */
+	guint32 seed;
+} VipsPerlin;
+
+typedef struct _VipsPerlinClass {
+	VipsCreateClass parent_class;
+
+} VipsPerlinClass;
+
+G_DEFINE_TYPE( VipsPerlin, vips_perlin, VIPS_TYPE_CREATE );
+
+/* Round N down to P boundary. 
+ */
+#define ROUND_DOWN( N, P ) ((N) - ((N) % P)) 
+
+/* Round N up to P boundary. 
+ */
+#define ROUND_UP( N, P ) (ROUND_DOWN( (N) + (P) - 1, (P) ))
+
+/* cos and sin from an angle in 0 - 255.
+ */
+float vips_perlin_cos[256];
+float vips_perlin_sin[256];
+
+typedef struct _Sequence {
+	VipsPerlin *perlin;
+
+	/* The position of the last cell we were in. Use this to avoid
+	 * regenerating vectors on every pixel lookup.
+	 */
+	int cell_x;
+	int cell_y;
+
+	/* The 2 x 2 grid of unit vectors, with cell_x/cell_y as the top left.
+	 */
+	float gx[4];
+	float gy[4];
+
+} Sequence;
+
+/* A very simple random number generator. See:
+ * http://isthe.com/chongo/tech/comp/fnv/#FNV-source
+ */
+static guint32
+vips_perlin_random( guint32 seed )
+{
+	return( 1103515245u * seed + 12345 );
+}
+
+static guint32 
+vips_perlin_seed_add( guint32 seed, int value )
+{
+	return( ((2166136261u ^ seed) * 16777619u) ^ value );
+}
+
+/* Generate a 3 x 3 grid of cells around a point. 
+ */
+static void
+vips_perlin_create_cells( VipsPerlin *perlin, 
+	float gx[4], float gy[4], int cell_x, int cell_y )
+{
+	int x, y;
+
+	for( y = 0; y < 2; y++ ) 
+		for( x = 0; x < 2; x++ ) {
+			int ci = x + y * 2;
+
+			guint32 seed;
+			int cx;
+			int cy;
+			int angle;
+
+			seed = perlin->seed;
+
+			cx = cell_x + x;
+			cy = cell_y + y;
+
+			/* When we calculate the seed for this cell, we wrap
+			 * around so that our output will tesselate.
+			 */
+			if( cx >= perlin->cells_across )
+				cx = 0;
+			seed = vips_perlin_seed_add( seed, cx );
+
+			if( cy >= perlin->cells_down )
+				cy = 0;
+			seed = vips_perlin_seed_add( seed, cy );
+
+			seed = vips_perlin_random( seed ); 
+			angle = seed & 0xff;
+
+			gx[ci] = vips_perlin_cos[angle];
+			gy[ci] = vips_perlin_sin[angle];
+		}
+}
+
+static int
+vips_perlin_stop( void *vseq, void *a, void *b )
+{
+	Sequence *seq = (Sequence *) vseq;
+
+	VIPS_FREE( seq );
+
+	return( 0 );
+}
+
+static void *
+vips_perlin_start( VipsImage *out, void *a, void *b )
+{
+	VipsPerlin *perlin = (VipsPerlin *) b;
+
+	Sequence *seq;
+
+	if( !(seq = VIPS_NEW( NULL, Sequence )) )
+		return( NULL );
+
+	seq->perlin = perlin;
+	seq->cell_x = -1;
+	seq->cell_y = -1;
+
+	return( seq );
+}
+
+static int
+vips_perlin_gen( VipsRegion *or, void *vseq, void *a, void *b,
+	gboolean *stop )
+{
+	VipsPerlin *perlin = (VipsPerlin *) a;
+	VipsRect *r = &or->valid;
+	Sequence *seq = (Sequence *) vseq;
+
+	int x, y;
+
+	for( y = 0; y < r->height; y++ ) {
+		float *q = (float *) VIPS_REGION_ADDR( or, r->left, r->top + y );
+
+		for( x = 0; x < r->width; x++ ) {
+			int cs = perlin->cell_size;
+			int cell_x = (r->left + x) / cs;
+			int cell_y = (r->top + y) / cs;
+			float dx = (x + r->left - cell_x * cs) / (float) cs;
+			float dy = (y + r->top - cell_y * cs) / (float) cs;
+
+			float n0, n1;
+			float ix0, ix1;
+
+			if( cell_x != seq->cell_x ||
+				cell_y != seq->cell_y ) {
+				vips_perlin_create_cells( perlin, 
+					seq->gx, seq->gy, cell_x, cell_y );
+				seq->cell_x = cell_x;
+				seq->cell_y = cell_y;
+			}
+
+			n0 = -dx * seq->gx[0] + -dy * seq->gy[0];
+			n1 = (1 - dx) * seq->gx[1] + -dy * seq->gy[1];
+			ix0 = (1 - dx) * n0 + dx * n1;
+
+			n0 = -dx * seq->gx[2] + (1 - dy) * seq->gy[2];
+			n1 = (1 - dx) * seq->gx[3] + (1 - dy) * seq->gy[3];
+			ix1 = (1 - dx) * n0 + dx * n1;
+
+			q[x] = (1 - dy) * ix0 + dy * ix1; 
+		}
+	}
+
+	return( 0 );
+}
+
+static int
+vips_perlin_build( VipsObject *object )
+{
+	VipsCreate *create = VIPS_CREATE( object );
+	VipsPerlin *perlin = (VipsPerlin *) object;
+
+	if( VIPS_OBJECT_CLASS( vips_perlin_parent_class )->build( object ) )
+		return( -1 );
+
+	/* Be careful if width is a multiple of cell_size.
+	 */
+	perlin->cells_across = ROUND_UP( perlin->width, perlin->cell_size ) / 
+		perlin->cell_size;
+	perlin->cells_down = ROUND_UP( perlin->height, perlin->cell_size ) / 
+		perlin->cell_size;
+
+	perlin->seed = g_random_double() * 0xffffffffu;
+
+	vips_image_init_fields( create->out,
+		perlin->width, perlin->height, 1,
+		VIPS_FORMAT_FLOAT, VIPS_CODING_NONE, VIPS_INTERPRETATION_B_W,
+		1.0, 1.0 );
+	vips_image_pipelinev( create->out,
+		VIPS_DEMAND_STYLE_ANY, NULL );
+	if( vips_image_generate( create->out,
+		vips_perlin_start, vips_perlin_gen, vips_perlin_stop, 
+		perlin, NULL ) )
+		return( -1 );
+
+	return( 0 );
+}
+
+static void *
+vips_perlin_make_tables( void *client )
+{
+	int i;
+
+	for( i = 0; i < 256; i++ ) {
+		double angle = 2 * M_PI * i / 256.0;
+
+		vips_perlin_cos[i] = cos( angle );
+		vips_perlin_sin[i] = sin( angle );
+	}
+
+	return( NULL );
+}
+
+static void
+vips_perlin_class_init( VipsPerlinClass *class )
+{
+	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
+	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
+
+	static GOnce once = G_ONCE_INIT;
+
+	(void) g_once( &once, vips_perlin_make_tables, NULL );
+
+	gobject_class->set_property = vips_object_set_property;
+	gobject_class->get_property = vips_object_get_property;
+
+	vobject_class->nickname = "perlin";
+	vobject_class->description = _( "make a perlin noise image" );
+	vobject_class->build = vips_perlin_build;
+
+	VIPS_ARG_INT( class, "width", 2, 
+		_( "Width" ), 
+		_( "Image width in pixels" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsPerlin, width ),
+		1, VIPS_MAX_COORD, 1 );
+
+	VIPS_ARG_INT( class, "height", 3, 
+		_( "Height" ), 
+		_( "Image height in pixels" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsPerlin, height ),
+		1, VIPS_MAX_COORD, 1 );
+
+	VIPS_ARG_INT( class, "cell_size", 3, 
+		_( "Cell size" ), 
+		_( "Size of Perlin cells" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsPerlin, cell_size ),
+		1, VIPS_MAX_COORD, 256 );
+
+}
+
+static void
+vips_perlin_init( VipsPerlin *perlin )
+{
+	perlin->cell_size = 256;
+}
+
+/**
+ * vips_perlin:
+ * @out: output image
+ * @width: horizontal size
+ * @height: vertical size
+ * @...: %NULL-terminated list of optional named arguments
+ *
+ * Optional arguments:
+ *
+ * * @cell_size: %gint, size of Perlin cells
+ *
+ * Create a one-band float image of Perlin noise. See:
+ *
+ * https://en.wikipedia.org/wiki/Perlin_noise
+ *
+ * Use @cell_size to set the size of the cells from which the image is
+ * constructed. The default is 256 x 256.
+ *
+ * If @width and @height are multiples of @cell_size, the image will tessellate.
+ *
+ * See also: vips_worley(), vips_fractsurf(), vips_gaussnoise().
+ *
+ * Returns: 0 on success, -1 on error
+ */
+int
+vips_perlin( VipsImage **out, int width, int height, ... )
+{
+	va_list ap;
+	int result;
+
+	va_start( ap, height );
+	result = vips_call_split( "perlin", ap, out, width, height );
+	va_end( ap );
+
+	return( result );
+}
+
diff --git a/libvips/create/worley.c b/libvips/create/worley.c
index 2187a7be..dc509731 100644
--- a/libvips/create/worley.c
+++ b/libvips/create/worley.c
@@ -322,7 +322,7 @@ vips_worley_class_init( VipsWorleyClass *class )
 	gobject_class->get_property = vips_object_get_property;
 
 	vobject_class->nickname = "worley";
-	vobject_class->description = _( "make a worley image" );
+	vobject_class->description = _( "make a worley noise image" );
 	vobject_class->build = vips_worley_build;
 
 	VIPS_ARG_INT( class, "width", 2, 
@@ -374,7 +374,7 @@ vips_worley_init( VipsWorley *worley )
  *
  * If @width and @height are multiples of @cell_size, the image will tessellate.
  *
- * See also: vips_gaussnoise().
+ * See also: vips_perlin(), vips_fractsurf(), vips_gaussnoise().
  *
  * Returns: 0 on success, -1 on error
  */
diff --git a/libvips/include/vips/create.h b/libvips/include/vips/create.h
index 8567fb82..f04752d4 100644
--- a/libvips/include/vips/create.h
+++ b/libvips/include/vips/create.h
@@ -116,6 +116,8 @@ int vips_fractsurf( VipsImage **out,
 
 int vips_worley( VipsImage **out, int width, int height, ... )
 	__attribute__((sentinel));
+int vips_perlin( VipsImage **out, int width, int height, ... )
+	__attribute__((sentinel));
 
 #ifdef __cplusplus
 }

From 6db9a2fdf9e7c11d13349322dbb8c59051794bbe Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sun, 24 Jul 2016 12:58:45 +0100
Subject: [PATCH 14/15] better smoothing for perlin

---
 TODO                    |  2 --
 libvips/create/perlin.c | 43 ++++++++++++++++++++++++++++++++++++-----
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/TODO b/TODO
index eed2e9f1..a173d5b7 100644
--- a/TODO
+++ b/TODO
@@ -1,5 +1,3 @@
-- need better interpolation in the perlin generator?
-
 - add tests for perlin and worley noise generators
 
 - add more webp tests to py suite
diff --git a/libvips/create/perlin.c b/libvips/create/perlin.c
index fdb9ae57..d01e3a79 100644
--- a/libvips/create/perlin.c
+++ b/libvips/create/perlin.c
@@ -54,6 +54,7 @@ typedef struct _VipsPerlin {
 	int width;
 	int height;
 	int cell_size;
+	gboolean uchar;
 
 	int cells_across;
 	int cells_down;
@@ -182,6 +183,16 @@ vips_perlin_start( VipsImage *out, void *a, void *b )
 	return( seq );
 }
 
+/* Smooth linear interpolation, 0 <= x <= 1.
+ *
+ * https://en.wikipedia.org/wiki/Smoothstep
+ */
+static float 
+smootherstep( float x )
+{
+    return( x * x * x * (x * (x * 6 - 15) + 10) );
+}
+
 static int
 vips_perlin_gen( VipsRegion *or, void *vseq, void *a, void *b,
 	gboolean *stop )
@@ -193,7 +204,9 @@ vips_perlin_gen( VipsRegion *or, void *vseq, void *a, void *b,
 	int x, y;
 
 	for( y = 0; y < r->height; y++ ) {
-		float *q = (float *) VIPS_REGION_ADDR( or, r->left, r->top + y );
+		float *fq = (float *) 
+			VIPS_REGION_ADDR( or, r->left, r->top + y );
+		VipsPel *q = (VipsPel *) fq;
 
 		for( x = 0; x < r->width; x++ ) {
 			int cs = perlin->cell_size;
@@ -201,9 +214,12 @@ vips_perlin_gen( VipsRegion *or, void *vseq, void *a, void *b,
 			int cell_y = (r->top + y) / cs;
 			float dx = (x + r->left - cell_x * cs) / (float) cs;
 			float dy = (y + r->top - cell_y * cs) / (float) cs;
+			float sx = smootherstep( dx );
+			float sy = smootherstep( dy );
 
 			float n0, n1;
 			float ix0, ix1;
+			float p;
 
 			if( cell_x != seq->cell_x ||
 				cell_y != seq->cell_y ) {
@@ -215,13 +231,18 @@ vips_perlin_gen( VipsRegion *or, void *vseq, void *a, void *b,
 
 			n0 = -dx * seq->gx[0] + -dy * seq->gy[0];
 			n1 = (1 - dx) * seq->gx[1] + -dy * seq->gy[1];
-			ix0 = (1 - dx) * n0 + dx * n1;
+			ix0 = n0 + sx * (n1 - n0);
 
 			n0 = -dx * seq->gx[2] + (1 - dy) * seq->gy[2];
 			n1 = (1 - dx) * seq->gx[3] + (1 - dy) * seq->gy[3];
-			ix1 = (1 - dx) * n0 + dx * n1;
+			ix1 = n0 + sx * (n1 - n0);
 
-			q[x] = (1 - dy) * ix0 + dy * ix1; 
+			p = ix0 + sy * (ix1 - ix0);
+
+			if( perlin->uchar )
+				q[x] = 128 * p + 128;
+			else
+				fq[x] = p;
 		}
 	}
 
@@ -248,7 +269,8 @@ vips_perlin_build( VipsObject *object )
 
 	vips_image_init_fields( create->out,
 		perlin->width, perlin->height, 1,
-		VIPS_FORMAT_FLOAT, VIPS_CODING_NONE, VIPS_INTERPRETATION_B_W,
+		perlin->uchar ? VIPS_FORMAT_UCHAR : VIPS_FORMAT_FLOAT, 
+		VIPS_CODING_NONE, VIPS_INTERPRETATION_B_W,
 		1.0, 1.0 );
 	vips_image_pipelinev( create->out,
 		VIPS_DEMAND_STYLE_ANY, NULL );
@@ -313,6 +335,13 @@ vips_perlin_class_init( VipsPerlinClass *class )
 		G_STRUCT_OFFSET( VipsPerlin, cell_size ),
 		1, VIPS_MAX_COORD, 256 );
 
+	VIPS_ARG_BOOL( class, "uchar", 4, 
+		_( "Uchar" ), 
+		_( "Output an unsigned char image" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsPerlin, uchar ),
+		FALSE );
+
 }
 
 static void
@@ -331,6 +360,7 @@ vips_perlin_init( VipsPerlin *perlin )
  * Optional arguments:
  *
  * * @cell_size: %gint, size of Perlin cells
+ * * @uchar: output a uchar image
  *
  * Create a one-band float image of Perlin noise. See:
  *
@@ -341,6 +371,9 @@ vips_perlin_init( VipsPerlin *perlin )
  *
  * If @width and @height are multiples of @cell_size, the image will tessellate.
  *
+ * Normally, output pixels are #VIPS_FORMAT_FLOAT in the range [-1, +1]. Set 
+ * @uchar to output a uchar image with pixels in [0, 255]. 
+ *
  * See also: vips_worley(), vips_fractsurf(), vips_gaussnoise().
  *
  * Returns: 0 on success, -1 on error

From 2dc43198e49e36fa62800eda9acf3f1f4e91624b Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sun, 24 Jul 2016 14:47:22 +0100
Subject: [PATCH 15/15] final fixups

---
 TODO                                      |   2 -
 cplusplus/gen-operators.py                |   2 +
 cplusplus/include/vips/gen-operators-h.py |   2 +
 cplusplus/include/vips/vips-operators.h   |  18 ++--
 cplusplus/vips-operators.cpp              | 126 +++++++++++++---------
 libvips/create/perlin.c                   |   9 +-
 python/find_class_methods.py              |   2 +
 python/packages/gi/overrides/Vips.py      |   2 +
 test/test_create.py                       |  14 +++
 9 files changed, 109 insertions(+), 68 deletions(-)

diff --git a/TODO b/TODO
index a173d5b7..4ead5e91 100644
--- a/TODO
+++ b/TODO
@@ -1,5 +1,3 @@
-- add tests for perlin and worley noise generators
-
 - add more webp tests to py suite
 
 - try moving some more of the CLI tests to py
diff --git a/cplusplus/gen-operators.py b/cplusplus/gen-operators.py
index c64d1bf3..9be011fb 100755
--- a/cplusplus/gen-operators.py
+++ b/cplusplus/gen-operators.py
@@ -22,6 +22,8 @@ import re
 import logging
 #logging.basicConfig(level = logging.DEBUG)
 
+import gi
+gi.require_version('Vips', '8.0')
 from gi.repository import Vips, GObject
 
 vips_type_image = GObject.GType.from_name("VipsImage")
diff --git a/cplusplus/include/vips/gen-operators-h.py b/cplusplus/include/vips/gen-operators-h.py
index 6c76c257..aa0a96d0 100755
--- a/cplusplus/include/vips/gen-operators-h.py
+++ b/cplusplus/include/vips/gen-operators-h.py
@@ -12,6 +12,8 @@ import re
 import logging
 #logging.basicConfig(level = logging.DEBUG)
 
+import gi
+gi.require_version('Vips', '8.0')
 from gi.repository import Vips, GObject
 
 vips_type_image = GObject.GType.from_name("VipsImage")
diff --git a/cplusplus/include/vips/vips-operators.h b/cplusplus/include/vips/vips-operators.h
index 92b30b1f..620465a8 100644
--- a/cplusplus/include/vips/vips-operators.h
+++ b/cplusplus/include/vips/vips-operators.h
@@ -1,7 +1,3 @@
-// headers for vips operations
-// Fri Feb 12 20:04:03 GMT 2016
-// this file is generated automatically, do not edit!
-
 static void system( char * cmd_format , VOption *options = 0 );
 VImage add( VImage right , VOption *options = 0 );
 VImage subtract( VImage right , VOption *options = 0 );
@@ -103,13 +99,15 @@ VImage invertlut( VOption *options = 0 );
 static VImage tonelut( VOption *options = 0 );
 static VImage identity( VOption *options = 0 );
 static VImage fractsurf( int width , int height , double fractal_dimension , VOption *options = 0 );
-static VImage radload( char * filename , VOption *options = 0 );
-static VImage ppmload( char * filename , VOption *options = 0 );
+static VImage worley( int width , int height , VOption *options = 0 );
+static VImage perlin( int width , int height , VOption *options = 0 );
 static VImage csvload( char * filename , VOption *options = 0 );
 static VImage matrixload( char * filename , VOption *options = 0 );
-static VImage analyzeload( char * filename , VOption *options = 0 );
 static VImage rawload( char * filename , int width , int height , int bands , VOption *options = 0 );
 static VImage vipsload( char * filename , VOption *options = 0 );
+static VImage analyzeload( char * filename , VOption *options = 0 );
+static VImage ppmload( char * filename , VOption *options = 0 );
+static VImage radload( char * filename , VOption *options = 0 );
 static VImage pdfload( char * filename , VOption *options = 0 );
 static VImage pdfload_buffer( VipsBlob * buffer , VOption *options = 0 );
 static VImage svgload( char * filename , VOption *options = 0 );
@@ -130,15 +128,15 @@ static VImage magickload( char * filename , VOption *options = 0 );
 static VImage magickload_buffer( VipsBlob * buffer , VOption *options = 0 );
 static VImage fitsload( char * filename , VOption *options = 0 );
 static VImage openexrload( char * filename , VOption *options = 0 );
-void radsave( char * filename , VOption *options = 0 );
-VipsBlob * radsave_buffer( VOption *options = 0 );
-void ppmsave( char * filename , VOption *options = 0 );
 void csvsave( char * filename , VOption *options = 0 );
 void matrixsave( char * filename , VOption *options = 0 );
 void matrixprint( VOption *options = 0 );
 void rawsave( char * filename , VOption *options = 0 );
 void rawsave_fd( int fd , VOption *options = 0 );
 void vipssave( char * filename , VOption *options = 0 );
+void ppmsave( char * filename , VOption *options = 0 );
+void radsave( char * filename , VOption *options = 0 );
+VipsBlob * radsave_buffer( VOption *options = 0 );
 void dzsave( char * filename , VOption *options = 0 );
 void pngsave( char * filename , VOption *options = 0 );
 VipsBlob * pngsave_buffer( VOption *options = 0 );
diff --git a/cplusplus/vips-operators.cpp b/cplusplus/vips-operators.cpp
index ddbef979..1cb98e9f 100644
--- a/cplusplus/vips-operators.cpp
+++ b/cplusplus/vips-operators.cpp
@@ -1,7 +1,3 @@
-// bodies for vips operations
-// Fri Feb 12 20:03:53 GMT 2016
-// this file is generated automatically, do not edit!
-
 void VImage::system( char * cmd_format , VOption *options )
 {
     call( "system" ,
@@ -1321,26 +1317,28 @@ VImage VImage::fractsurf( int width , int height , double fractal_dimension , VO
     return( out );
 }
 
-VImage VImage::radload( char * filename , VOption *options )
+VImage VImage::worley( int width , int height , VOption *options )
 {
     VImage out;
 
-    call( "radload" ,
+    call( "worley" ,
         (options ? options : VImage::option()) ->
-            set( "filename", filename ) ->
-            set( "out", &out ) );
+            set( "out", &out ) ->
+            set( "width", width ) ->
+            set( "height", height ) );
 
     return( out );
 }
 
-VImage VImage::ppmload( char * filename , VOption *options )
+VImage VImage::perlin( int width , int height , VOption *options )
 {
     VImage out;
 
-    call( "ppmload" ,
+    call( "perlin" ,
         (options ? options : VImage::option()) ->
-            set( "filename", filename ) ->
-            set( "out", &out ) );
+            set( "out", &out ) ->
+            set( "width", width ) ->
+            set( "height", height ) );
 
     return( out );
 }
@@ -1369,18 +1367,6 @@ VImage VImage::matrixload( char * filename , VOption *options )
     return( out );
 }
 
-VImage VImage::analyzeload( char * filename , VOption *options )
-{
-    VImage out;
-
-    call( "analyzeload" ,
-        (options ? options : VImage::option()) ->
-            set( "filename", filename ) ->
-            set( "out", &out ) );
-
-    return( out );
-}
-
 VImage VImage::rawload( char * filename , int width , int height , int bands , VOption *options )
 {
     VImage out;
@@ -1408,6 +1394,42 @@ VImage VImage::vipsload( char * filename , VOption *options )
     return( out );
 }
 
+VImage VImage::analyzeload( char * filename , VOption *options )
+{
+    VImage out;
+
+    call( "analyzeload" ,
+        (options ? options : VImage::option()) ->
+            set( "filename", filename ) ->
+            set( "out", &out ) );
+
+    return( out );
+}
+
+VImage VImage::ppmload( char * filename , VOption *options )
+{
+    VImage out;
+
+    call( "ppmload" ,
+        (options ? options : VImage::option()) ->
+            set( "filename", filename ) ->
+            set( "out", &out ) );
+
+    return( out );
+}
+
+VImage VImage::radload( char * filename , VOption *options )
+{
+    VImage out;
+
+    call( "radload" ,
+        (options ? options : VImage::option()) ->
+            set( "filename", filename ) ->
+            set( "out", &out ) );
+
+    return( out );
+}
+
 VImage VImage::pdfload( char * filename , VOption *options )
 {
     VImage out;
@@ -1648,34 +1670,6 @@ VImage VImage::openexrload( char * filename , VOption *options )
     return( out );
 }
 
-void VImage::radsave( char * filename , VOption *options )
-{
-    call( "radsave" ,
-        (options ? options : VImage::option()) ->
-            set( "in", *this ) ->
-            set( "filename", filename ) );
-}
-
-VipsBlob * VImage::radsave_buffer( VOption *options )
-{
-    VipsBlob * buffer;
-
-    call( "radsave_buffer" ,
-        (options ? options : VImage::option()) ->
-            set( "in", *this ) ->
-            set( "buffer", &buffer ) );
-
-    return( buffer );
-}
-
-void VImage::ppmsave( char * filename , VOption *options )
-{
-    call( "ppmsave" ,
-        (options ? options : VImage::option()) ->
-            set( "in", *this ) ->
-            set( "filename", filename ) );
-}
-
 void VImage::csvsave( char * filename , VOption *options )
 {
     call( "csvsave" ,
@@ -1723,6 +1717,34 @@ void VImage::vipssave( char * filename , VOption *options )
             set( "filename", filename ) );
 }
 
+void VImage::ppmsave( char * filename , VOption *options )
+{
+    call( "ppmsave" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "filename", filename ) );
+}
+
+void VImage::radsave( char * filename , VOption *options )
+{
+    call( "radsave" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "filename", filename ) );
+}
+
+VipsBlob * VImage::radsave_buffer( VOption *options )
+{
+    VipsBlob * buffer;
+
+    call( "radsave_buffer" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "buffer", &buffer ) );
+
+    return( buffer );
+}
+
 void VImage::dzsave( char * filename , VOption *options )
 {
     call( "dzsave" ,
diff --git a/libvips/create/perlin.c b/libvips/create/perlin.c
index d01e3a79..e006a5a6 100644
--- a/libvips/create/perlin.c
+++ b/libvips/create/perlin.c
@@ -140,16 +140,17 @@ vips_perlin_create_cells( VipsPerlin *perlin,
 			/* When we calculate the seed for this cell, we wrap
 			 * around so that our output will tesselate.
 			 */
-			if( cx >= perlin->cells_across )
-				cx = 0;
-			seed = vips_perlin_seed_add( seed, cx );
 
 			if( cy >= perlin->cells_down )
 				cy = 0;
 			seed = vips_perlin_seed_add( seed, cy );
 
+			if( cx >= perlin->cells_across )
+				cx = 0;
+			seed = vips_perlin_seed_add( seed, cx );
+
 			seed = vips_perlin_random( seed ); 
-			angle = seed & 0xff;
+			angle = (seed ^ (seed >> 8) ^ (seed >> 16)) & 0xff;
 
 			gx[ci] = vips_perlin_cos[angle];
 			gy[ci] = vips_perlin_sin[angle];
diff --git a/python/find_class_methods.py b/python/find_class_methods.py
index 9fc31e3f..93c55159 100755
--- a/python/find_class_methods.py
+++ b/python/find_class_methods.py
@@ -5,6 +5,8 @@ import sys
 import logging
 #logging.basicConfig(level = logging.DEBUG)
 
+import gi
+gi.require_version('Vips', '8.0')
 from gi.repository import Vips, GObject
 
 # Search for all VipsOperation which don't have an input image object ... these
diff --git a/python/packages/gi/overrides/Vips.py b/python/packages/gi/overrides/Vips.py
index 0a78fbda..b015779e 100644
--- a/python/packages/gi/overrides/Vips.py
+++ b/python/packages/gi/overrides/Vips.py
@@ -1093,6 +1093,8 @@ class_methods = [
                     "mask_fractal",
                     "tonelut",
                     "identity",
+                    "perlin",
+                    "worley",
                     "fractsurf",
                     "radload",
                     "ppmload",
diff --git a/test/test_create.py b/test/test_create.py
index d0048625..861ee07d 100755
--- a/test/test_create.py
+++ b/test/test_create.py
@@ -441,5 +441,19 @@ class TestCreate(unittest.TestCase):
         self.assertEqual(im.bands, 1)
         self.assertEqual(im.format, Vips.BandFormat.FLOAT)
 
+    def test_worley(self):
+        im = Vips.Image.worley(512, 512)
+        self.assertEqual(im.width, 512)
+        self.assertEqual(im.height, 512)
+        self.assertEqual(im.bands, 1)
+        self.assertEqual(im.format, Vips.BandFormat.INT)
+
+    def test_perlin(self):
+        im = Vips.Image.perlin(512, 512)
+        self.assertEqual(im.width, 512)
+        self.assertEqual(im.height, 512)
+        self.assertEqual(im.bands, 1)
+        self.assertEqual(im.format, Vips.BandFormat.FLOAT)
+
 if __name__ == '__main__':
     unittest.main()