[lasem] filter: implementation of get_extents.

[Emmanuel Pacaud <emmanuel src gnome org>]

commit ea1c04dba67f80b220f8d284a13497649ffb1e85
Author: Emmanuel Pacaud <emmanuel gnome org>
Date:   Fri Oct 8 16:39:54 2010 +0200

    filter: implementation of get_extents.

 src/lsmsvgfilterelement.c |   40 ++++++++++++++++++++++++++++++++++++++++
 1 files changed, 40 insertions(+), 0 deletions(-)
---
diff --git a/src/lsmsvgfilterelement.c b/src/lsmsvgfilterelement.c
index 73f3c96..fbf3cfa 100644
--- a/src/lsmsvgfilterelement.c
+++ b/src/lsmsvgfilterelement.c
@@ -119,6 +119,45 @@ lsm_svg_filter_element_enable_rendering (LsmSvgElement *element)
 	LSM_SVG_FILTER_ELEMENT (element)->enable_rendering  = TRUE;
 }
 
+static void
+lsm_svg_filter_element_get_extents (LsmSvgElement *self, LsmSvgView *view, LsmExtents *extents)
+{
+	LsmSvgFilterElement *filter = LSM_SVG_FILTER_ELEMENT (self);
+	const LsmBox *source_extents;
+	double x, y;
+	double w, h;
+	gboolean is_object_bounding_box;
+
+	source_extents = lsm_svg_view_get_pattern_extents (view);
+
+	is_object_bounding_box = (filter->units.value == LSM_SVG_PATTERN_UNITS_OBJECT_BOUNDING_BOX);
+
+	if (is_object_bounding_box) {
+		LsmBox viewbox = {.x = 0.0, .y = .0, .width = 1.0, .height = 1.0};
+
+		lsm_svg_view_push_viewbox (view, &viewbox);
+	}
+
+	x = lsm_svg_view_normalize_length (view, &filter->x.length, LSM_SVG_LENGTH_DIRECTION_HORIZONTAL);
+	y = lsm_svg_view_normalize_length (view, &filter->y.length, LSM_SVG_LENGTH_DIRECTION_VERTICAL);
+	w  = lsm_svg_view_normalize_length (view, &filter->width.length, LSM_SVG_LENGTH_DIRECTION_HORIZONTAL);
+	h = lsm_svg_view_normalize_length (view, &filter->height.length, LSM_SVG_LENGTH_DIRECTION_VERTICAL);
+
+	if (is_object_bounding_box) {
+		lsm_svg_view_pop_viewbox (view);
+
+		x = x * source_extents->width + source_extents->x;
+		y = y * source_extents->height + source_extents->y;
+		w *= source_extents->width;
+		h *= source_extents->height;
+	}
+
+	extents->x1 = x;
+	extents->y1 = y;
+	extents->x2 = x + w;
+	extents->y2 = y + h;
+}
+
 /* LsmSvgGraphic implementation */
 
 /* LsmSvgFilterElement implementation */
@@ -209,6 +248,7 @@ lsm_svg_filter_element_class_init (LsmSvgFilterElementClass *s_rect_class)
 	s_element_class->category = LSM_SVG_ELEMENT_CATEGORY_NONE;
 
 	s_element_class->render = lsm_svg_filter_element_render;
+	s_element_class->get_extents = lsm_svg_filter_element_get_extents;
 	s_element_class->enable_rendering = lsm_svg_filter_element_enable_rendering;
 	s_element_class->attribute_manager = lsm_attribute_manager_duplicate (s_element_class->attribute_manager);