Expose 'density' attribute for magickload

Allows control of vector format resolution

libvips/deprecated/im_magick2vips.c

@@ -50,7 +50,7 @@ im_magick2vips( const char *filename, IMAGE *out )
 #ifdef HAVE_MAGICK
 	/* Old behaviour was always to read all frames.
 	 */
-	return( vips__magick_read( filename, out, TRUE ) ); 
+	return( vips__magick_read( filename, out, TRUE, NULL ) );
 #else
 	vips_error( "im_magick2vips", 
 		"%s", _( "no libMagick support in your libvips" ) ); 

libvips/foreign/foreign.c

@@ -1631,6 +1631,7 @@ vips_foreign_operation_init( void )
  * Optional arguments:
  *
  * @all_frames: load all frames in sequence
+ * @density: canvas resolution for rendering vector formats like SVG
  *
  * Read in an image using libMagick, the ImageMagick library. This library can
  * read more than 80 file formats, including SVG, BMP, EPS, DICOM and many 
@@ -1645,6 +1646,9 @@ vips_foreign_operation_init( void )
  * Normally it will only load the first image in a many-image sequence (such
  * as a GIF). Set @all_frames to true to read the whole image sequence. 
  *
+ * @density is "WxH" in DPI, e.g. "600x300" or "600" (default is "72x72")
+ * http://www.imagemagick.org/script/command-line-options.php#density
+ *
  * See also: vips_image_new_from_file().
  *
  * Returns: 0 on success, -1 on error.

libvips/foreign/magick.h

@@ -36,9 +36,9 @@ extern "C" {
 #endif /*__cplusplus*/
 
 int vips__magick_read( const char *filename, 
-	VipsImage *out, gboolean all_frames );
+	VipsImage *out, gboolean all_frames, const char* density );
 int vips__magick_read_header( const char *filename, 
-	VipsImage *out, gboolean all_frames );
+	VipsImage *out, gboolean all_frames, const char* density );
 
 #ifdef __cplusplus
 }

libvips/foreign/magick2vips.c

@@ -141,7 +141,8 @@ read_destroy( VipsImage *im, Read *read )
 }
 
 static Read *
-read_new( const char *filename, VipsImage *im, gboolean all_frames )
+read_new( const char *filename, VipsImage *im, gboolean all_frames,
+	const char* density )
 {
 	Read *read;
 	static int inited = 0;
@@ -175,6 +176,10 @@ read_new( const char *filename, VipsImage *im, gboolean all_frames )
 
 	vips_strncpy( read->image_info->filename, filename, MaxTextExtent );
 
+	/* Canvas resolution for rendering vector formats like SVG
+	 */
+	VIPS_SETSTR( read->image_info->density, density );
+
 #ifdef DEBUG
 	printf( "magick2vips: read_new: %s\n", read->filename );
 #endif /*DEBUG*/
@@ -647,7 +652,8 @@ magick_fill_region( VipsRegion *out,
 }
 
 int
-vips__magick_read( const char *filename, VipsImage *out, gboolean all_frames )
+vips__magick_read( const char *filename, VipsImage *out, gboolean all_frames,
+	const char *density )
 {
 	Read *read;
 
@@ -655,7 +661,7 @@ vips__magick_read( const char *filename, VipsImage *out, gboolean all_frames )
 	printf( "magick2vips: vips__magick_read: %s\n", filename );
 #endif /*DEBUG*/
 
-	if( !(read = read_new( filename, out, all_frames )) )
+	if( !(read = read_new( filename, out, all_frames, density )) )
 		return( -1 );
 
 #ifdef HAVE_SETIMAGEOPTION
@@ -697,7 +703,7 @@ vips__magick_read( const char *filename, VipsImage *out, gboolean all_frames )
  */
 int
 vips__magick_read_header( const char *filename, VipsImage *im, 
-	gboolean all_frames )
+	gboolean all_frames, const char *density )
 {
 	Read *read;
 
@@ -705,7 +711,7 @@ vips__magick_read_header( const char *filename, VipsImage *im,
 	printf( "vips__magick_read_header: %s\n", filename );
 #endif /*DEBUG*/
 
-	if( !(read = read_new( filename, im, all_frames )) )
+	if( !(read = read_new( filename, im, all_frames, density )) )
 		return( -1 );
 
 #ifdef DEBUG

libvips/foreign/magickload.c

@@ -61,6 +61,7 @@ typedef struct _VipsForeignLoadMagick {
 
 	char *filename; 
 	gboolean all_frames;
+	char *density;
 
 } VipsForeignLoadMagick;
 
@@ -77,7 +78,7 @@ ismagick( const char *filename )
 
 	t = vips_image_new();
 	vips_error_freeze();
-	result = vips__magick_read_header( filename, t, FALSE );
+	result = vips__magick_read_header( filename, t, FALSE, NULL );
 	g_object_unref( t );
 	vips_error_thaw();
 
@@ -113,7 +114,7 @@ vips_foreign_load_magick_header( VipsForeignLoad *load )
 	VipsForeignLoadMagick *magick = (VipsForeignLoadMagick *) load;
 
 	if( vips__magick_read( magick->filename, 
-		load->out, magick->all_frames ) ) 
+		load->out, magick->all_frames, magick->density ) )
 		return( -1 );
 
 	VIPS_SETSTR( load->out->filename, magick->filename );
@@ -160,6 +161,13 @@ vips_foreign_load_magick_class_init( VipsForeignLoadMagickClass *class )
 		VIPS_ARGUMENT_OPTIONAL_INPUT,
 		G_STRUCT_OFFSET( VipsForeignLoadMagick, all_frames ),
 		FALSE );
+
+	VIPS_ARG_STRING( class, "density", 4,
+		_( "Density" ),
+		_( "Canvas resolution for rendering vector formats like SVG" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsForeignLoadMagick, density ),
+		NULL );
 }
 
 static void