improve scaling of SVG images

We were not scaling images with fixed absolute dimensions.

libvips/foreign/svgload.c

@@ -377,8 +377,8 @@ svg_css_length_to_pixels( RsvgLength length, double dpi )
 			value = dpi * value / 6;
 			break;
 		default:
-			/* Probably RSVG_UNIT_PERCENT. We can't know what the pixel
+			/* Probably RSVG_UNIT_PERCENT. We can't know what the 
-			 * value is without more information.
+			 * pixel value is without more information.
 			 */
 			value = 0;
 	}
@@ -397,6 +397,7 @@ vips_foreign_load_svg_get_natural_size( VipsForeignLoadSvg *svg,
 	double height;
 
 #if LIBRSVG_CHECK_VERSION( 2, 52, 0 )
+
 	if( !rsvg_handle_get_intrinsic_size_in_pixels( svg->page, 
 		&width, &height ) ) {
 		RsvgRectangle zero_rect, viewbox;
@@ -412,11 +413,11 @@ vips_foreign_load_svg_get_natural_size( VipsForeignLoadSvg *svg,
 			&has_height, &iheight,
 			&has_viewbox, &viewbox );
 
-		/* After librsvg 2.54.0, the `has_width` and `has_height` arguments
-		 * always returns `TRUE`, since with SVG2 all documents *have* a
-		 * default width and height of `100%`.
-		 */
 #if LIBRSVG_CHECK_VERSION( 2, 54, 0 )
+		/* After librsvg 2.54.0, the `has_width` and `has_height` 
+		 * arguments always returns `TRUE`, since with SVG2 all 
+		 * documents *have* a default width and height of `100%`.
+		 */
 		width = svg_css_length_to_pixels( iwidth, svg->dpi );
 		height = svg_css_length_to_pixels( iheight, svg->dpi );
 
@@ -424,7 +425,8 @@ vips_foreign_load_svg_get_natural_size( VipsForeignLoadSvg *svg,
 		has_height = height > 0.0;
 
 		if( has_width && has_height ) {
-			/* Success! Taking the viewbox into account is not needed.
+			/* Success! Taking the viewbox into account is not 
+			 * needed.
 			 */
 		}
 		else if( has_width && has_viewbox ) {
@@ -460,8 +462,8 @@ vips_foreign_load_svg_get_natural_size( VipsForeignLoadSvg *svg,
 
 		if( width <= 0.0 ||
 			height <= 0.0 ) {
-			/* We haven't found a usable set of sizes, so try working out
+			/* We haven't found a usable set of sizes, so try 
-			 * the visible area.
+			 * working out the visible area.
 			 */
 			rsvg_handle_get_geometry_for_layer( svg->page, NULL,
 				&zero_rect, &viewbox, NULL, NULL );
@@ -469,7 +471,9 @@ vips_foreign_load_svg_get_natural_size( VipsForeignLoadSvg *svg,
 			height = viewbox.y + viewbox.height;
 		}
 	}
+
 #else /*!LIBRSVG_CHECK_VERSION( 2, 52, 0 )*/
+
 {
 	RsvgDimensionData dimensions;
 
@@ -477,6 +481,7 @@ vips_foreign_load_svg_get_natural_size( VipsForeignLoadSvg *svg,
 	width = dimensions.width;
 	height = dimensions.height;
 }
+
 #endif /*LIBRSVG_CHECK_VERSION( 2, 52, 0 )*/
 
 	/* width or height below 0.5 can't be rounded to 1.
@@ -499,7 +504,6 @@ vips_foreign_load_svg_get_scaled_size( VipsForeignLoadSvg *svg,
 {
 	double width;
 	double height;
-	double scale;
 
 	/* Get dimensions with the default dpi.
 	 */
@@ -507,36 +511,12 @@ vips_foreign_load_svg_get_scaled_size( VipsForeignLoadSvg *svg,
 	if( vips_foreign_load_svg_get_natural_size( svg, &width, &height ) )
 		return( -1 );
 
-	/* Calculate dimensions at required dpi/scale.
+	/* We scale up with cairo --- scaling with rsvg_handle_set_dpi() will
+	 * fail for SVGs with absolute sizes.
 	 */
-	scale = svg->scale * svg->dpi / 72.0;
+	svg->cairo_scale = svg->scale * svg->dpi / 72.0;
-	if( scale != 1.0 ) {
+	width *= svg->cairo_scale;
-		double scaled_width;
+	height *= svg->cairo_scale;
-		double scaled_height;
-
-		rsvg_handle_set_dpi( svg->page, scale * 72.0 );
-		if( vips_foreign_load_svg_get_natural_size( svg, 
-			&scaled_width, &scaled_height ) )
-			return( -1 );
-
-		if( scaled_width == width &&
-			scaled_height == height ) {
-			/* SVG without width and height always reports the same 
-			 * dimensions regardless of dpi. Apply dpi/scale using 
-			 * cairo instead.
-			 */
-			svg->cairo_scale = scale;
-			width *= scale;
-			height *= scale;
-		} 
-		else {
-			/* SVG with width and height reports correctly scaled 
-			 * dimensions.
-			 */
-			width = scaled_width;
-			height = scaled_height;
-		}
-	}
 
 	*out_width = VIPS_ROUND_UINT( width );
 	*out_height = VIPS_ROUND_UINT( height );
@@ -563,7 +543,8 @@ vips_foreign_load_svg_parse( VipsForeignLoadSvg *svg, VipsImage *out )
 		4, VIPS_FORMAT_UCHAR,
 		VIPS_CODING_NONE, VIPS_INTERPRETATION_sRGB, res, res );
 
-	/* We render to a linecache, so fat strips work well.
+	/* We render to a cache with a couple of rows of tiles, so fat strips 
+	 * work well.
 	 */
         if( vips_image_pipelinev( out, VIPS_DEMAND_STYLE_FATSTRIP, NULL ) )
 		return( -1 );
@@ -613,10 +594,14 @@ vips_foreign_load_svg_generate( VipsRegion *or,
 	 * running inside a non-threaded tilecache.
 	 */
 #if LIBRSVG_CHECK_VERSION( 2, 46, 0 )
+
 {
 	RsvgRectangle viewport;
 	GError *error = NULL;
 
+	/* No need to scale -- we always set the viewport to the
+	 * whole image, and set the region to draw on the surface.
+	 */
 	cairo_translate( cr, -r->left, -r->top );
 	viewport.x = 0;
 	viewport.y = 0;
@@ -634,7 +619,9 @@ vips_foreign_load_svg_generate( VipsRegion *or,
 
 	cairo_destroy( cr );
 }
+
 #else /*!LIBRSVG_CHECK_VERSION( 2, 46, 0 )*/
+
 	cairo_scale( cr, svg->cairo_scale, svg->cairo_scale );
 	cairo_translate( cr, -r->left / svg->cairo_scale,
 		-r->top / svg->cairo_scale );
@@ -648,6 +635,7 @@ vips_foreign_load_svg_generate( VipsRegion *or,
 	}
 
 	cairo_destroy( cr );
+
 #endif /*LIBRSVG_CHECK_VERSION( 2, 46, 0 )*/
 
 	/* Cairo makes pre-multipled BRGA -- we must byteswap and unpremultiply.

libvips/iofuncs/ginputsource.c

@@ -99,7 +99,7 @@ vips_g_input_stream_finalize( GObject *object )
 {
 	VipsGInputStream *gstream = VIPS_G_INPUT_STREAM( object );
 
-	VIPS_FREEF( g_object_unref, gstream->source );
+	VIPS_UNREF( gstream->source );
 
 	G_OBJECT_CLASS( vips_g_input_stream_parent_class )->finalize( object );
 }
@@ -107,13 +107,13 @@ vips_g_input_stream_finalize( GObject *object )
 static goffset
 vips_g_input_stream_tell( GSeekable *seekable )
 {
-	VipsSource *source = VIPS_G_INPUT_STREAM( seekable )->source;
+	VipsGInputStream *gstream = VIPS_G_INPUT_STREAM( seekable );
 
 	goffset pos;
 
 	VIPS_DEBUG_MSG( "vips_g_input_stream_tell:\n" );
 
-	pos = vips_source_seek( source, 0, SEEK_CUR );
+	pos = vips_source_seek( gstream->source, 0, SEEK_CUR );
 	if( pos == -1 )
 		return( 0 );
 
@@ -123,12 +123,12 @@ vips_g_input_stream_tell( GSeekable *seekable )
 static gboolean
 vips_g_input_stream_can_seek( GSeekable *seekable )
 {
-	VipsSource *source = VIPS_G_INPUT_STREAM( seekable )->source;
+	VipsGInputStream *gstream = VIPS_G_INPUT_STREAM( seekable );
 
 	VIPS_DEBUG_MSG( "vips_g_input_stream_can_seek: %d\n", 
-		!source->is_pipe );
+		!gstream->source->is_pipe );
 
-	return( !source->is_pipe );
+	return( !gstream->source->is_pipe );
 }
 
 static int
@@ -149,12 +149,12 @@ static gboolean
 vips_g_input_stream_seek( GSeekable *seekable, goffset offset,
 	GSeekType type, GCancellable *cancellable, GError **error )
 {
-	VipsSource *source = VIPS_G_INPUT_STREAM( seekable )->source;
+	VipsGInputStream *gstream = VIPS_G_INPUT_STREAM( seekable );
 
 	VIPS_DEBUG_MSG( "vips_g_input_stream_seek: offset = %" G_GINT64_FORMAT
 		", type = %d\n", offset, type );
 
-	if( vips_source_seek( source, offset, 
+	if( vips_source_seek( gstream->source, offset, 
 		seek_type_to_lseek( type ) ) == -1 ) {
 		g_set_error( error, G_IO_ERROR,
 			G_IO_ERROR_FAILED,
@@ -189,17 +189,16 @@ static gssize
 vips_g_input_stream_read( GInputStream *stream, void *buffer, gsize count,
 	GCancellable *cancellable, GError **error )
 {
-	VipsSource *source;
+	VipsGInputStream *gstream = VIPS_G_INPUT_STREAM( stream );
-	gssize res;
 
-	source = VIPS_G_INPUT_STREAM( stream )->source;
+	gssize res;
 
 	VIPS_DEBUG_MSG( "vips_g_input_stream_read: count: %zd\n", count );
 
 	if( g_cancellable_set_error_if_cancelled( cancellable, error ) )
 		return( -1 );
 
-	if( (res = vips_source_read( source, buffer, count )) == -1 )
+	if( (res = vips_source_read( gstream->source, buffer, count )) == -1 )
 		g_set_error( error, G_IO_ERROR,
 			G_IO_ERROR_FAILED,
 			_( "Error while reading: %s" ),
@@ -212,17 +211,16 @@ static gssize
 vips_g_input_stream_skip( GInputStream *stream, gsize count,
 	GCancellable *cancellable, GError **error )
 {
-	VipsSource *source;
+	VipsGInputStream *gstream = VIPS_G_INPUT_STREAM( stream );
-	gssize position;
 
-	source = VIPS_G_INPUT_STREAM( stream )->source;
+	gssize position;
 
 	VIPS_DEBUG_MSG( "vips_g_input_stream_skip: count: %zd\n", count );
 
 	if( g_cancellable_set_error_if_cancelled( cancellable, error ) )
 		return( -1 );
 
-	position = vips_source_seek( source, count, SEEK_CUR );
+	position = vips_source_seek( gstream->source, count, SEEK_CUR );
 	if( position == -1 ) {
 		g_set_error( error, G_IO_ERROR,
 			G_IO_ERROR_FAILED,

libvips/iofuncs/init.c

@@ -742,21 +742,6 @@ vips_shutdown( void )
 
 	vips_cache_drop_all();
 
-	/* In dev releases, always show leaks. But not more than once, it's
-	 * annoying.
-	 */
-#ifndef DEBUG_LEAK
-	if( vips__leak ) 
-#endif /*DEBUG_LEAK*/
-	{
-		static gboolean done = FALSE;
-
-		if( !done ) {
-			done = TRUE;
-			vips_leak();
-		}
-	}
-
 #if ENABLE_DEPRECATED
 	im_close_plugins();
 #endif
@@ -787,6 +772,21 @@ vips_shutdown( void )
 	VIPS_FREE( vips__argv0 );
 	VIPS_FREE( vips__prgname );
 	VIPS_FREEF( g_timer_destroy, vips__global_timer );
+
+	/* In dev releases, always show leaks. But not more than once, it's
+	 * annoying.
+	 */
+#ifndef DEBUG_LEAK
+	if( vips__leak ) 
+#endif /*DEBUG_LEAK*/
+	{
+		static gboolean done = FALSE;
+
+		if( !done ) {
+			done = TRUE;
+			vips_leak();
+		}
+	}
 }
 
 static gboolean