kind-of working

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

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

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)

libvips/create/Makefile.am

@@ -1,6 +1,7 @@
 noinst_LTLIBRARIES = libcreate.la
 
 libcreate_la_SOURCES = \
+	worley.c \
 	create.c \
 	pcreate.h \
 	gaussmat.c \

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(); 
 }
 

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 );
+}
+

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*/