Implement handling of the clip-rule property. Partially based on

a patch by Andrew Lutomirski.

Fixed bugs:
  - https://launchpad.net/bugs/171243

(bzr r10347.1.8)

6 files changed, 71 insertions, 10 deletions

diff --git a/src/display/nr-arena-glyphs.cpp b/src/display/nr-arena-glyphs.cpp
index 185551d31..b76e87a78 100644
--- a/src/display/nr-arena-glyphs.cpp
+++ b/src/display/nr-arena-glyphs.cpp
@@ -360,6 +360,14 @@ static unsigned int nr_arena_glyphs_group_clip(cairo_t *ct, NRArenaItem *item, N
     NRArenaGroup *ggroup = NR_ARENA_GLYPHS_GROUP(item);
 
     cairo_save(ct);
+    // handle clip-rule
+    if (ggroup->style) {
+        if (ggroup->style->clip_rule.computed == SP_WIND_RULE_EVENODD) {
+            cairo_set_fill_rule(ct, CAIRO_FILL_RULE_EVEN_ODD);
+        } else {
+            cairo_set_fill_rule(ct, CAIRO_FILL_RULE_WINDING);
+        }
+    }
     ink_cairo_transform(ct, ggroup->ctm);
 
     for (NRArenaItem *child = ggroup->children; child != NULL; child = child->next) {
@@ -369,9 +377,9 @@ static unsigned int nr_arena_glyphs_group_clip(cairo_t *ct, NRArenaItem *item, N
         cairo_save(ct);
         ink_cairo_transform(ct, g->g_transform);
         feed_pathvector_to_cairo(ct, pathv);
-        cairo_fill(ct);
         cairo_restore(ct);
     }
+    cairo_fill(ct);
     cairo_restore(ct);
 
     return item->state;
diff --git a/src/display/nr-arena-group.cpp b/src/display/nr-arena-group.cpp
index 5f11c1a6b..714c4ecff 100644
--- a/src/display/nr-arena-group.cpp
+++ b/src/display/nr-arena-group.cpp
@@ -12,6 +12,7 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
+#include "display/canvas-bpath.h"
 #include "display/nr-arena-group.h"
 #include "display/nr-filter.h"
 #include "display/nr-filter-types.h"
@@ -234,14 +235,25 @@ static unsigned int
 nr_arena_group_clip (cairo_t *ct, NRArenaItem *item, NRRectL *area)
 {
     NRArenaGroup *group = NR_ARENA_GROUP (item);
-
     unsigned int ret = item->state;
 
+    cairo_save(ct);
+
+    // handle clip-rule
+    if (group->style) {
+        if (group->style->clip_rule.computed == SP_WIND_RULE_EVENODD) {
+            cairo_set_fill_rule(ct, CAIRO_FILL_RULE_EVEN_ODD);
+        } else {
+            cairo_set_fill_rule(ct, CAIRO_FILL_RULE_WINDING);
+        }
+    }
+
     for (NRArenaItem *child = group->children; child != NULL; child = child->next) {
         ret = nr_arena_item_invoke_clip (ct, child, area);
         if (ret & NR_ARENA_ITEM_STATE_INVALID) break;
     }
 
+    cairo_restore(ct);
     return ret;
 }
 
diff --git a/src/display/nr-arena-shape.cpp b/src/display/nr-arena-shape.cpp
index 9bece05b5..6d65611bf 100644
--- a/src/display/nr-arena-shape.cpp
+++ b/src/display/nr-arena-shape.cpp
@@ -21,6 +21,7 @@
 #include <2geom/svg-path-parser.h>
 #include "display/cairo-utils.h"
 #include "display/canvas-arena.h"
+#include "display/canvas-bpath.h"
 #include "display/curve.h"
 #include "display/nr-arena.h"
 #include "display/nr-arena-shape.h"
@@ -401,10 +402,15 @@ static guint nr_arena_shape_clip(cairo_t *ct, NRArenaItem *item, NRRectL * /*are
         return item->state;
     }
 
-    // TODO: Handling of the clip-rule property / CSS attribute.
-    // Once the required bits are in SPStyle, this is as trivial as adding a single
-    // call to cairo_set_fill_rule() before cairo_fill().
     cairo_save(ct);
+    // handle clip-rule
+    if (shape->style) {
+        if (shape->style->clip_rule.computed == SP_WIND_RULE_EVENODD) {
+            cairo_set_fill_rule(ct, CAIRO_FILL_RULE_EVEN_ODD);
+        } else {
+            cairo_set_fill_rule(ct, CAIRO_FILL_RULE_WINDING);
+        }
+    }
     ink_cairo_transform(ct, shape->ctm);
     feed_pathvector_to_cairo(ct, shape->curve->get_pathvector());
     cairo_fill(ct);
diff --git a/src/sp-clippath.cpp b/src/sp-clippath.cpp
index 147ece167..48e466628 100644
--- a/src/sp-clippath.cpp
+++ b/src/sp-clippath.cpp
@@ -89,6 +89,7 @@ void SPClipPath::build(SPObject *object, SPDocument *document, Inkscape::XML::No
     if (((SPObjectClass *) SPClipPathClass::static_parent_class)->build)
         ((SPObjectClass *) SPClipPathClass::static_parent_class)->build(object, document, repr);
 
+    object->readAttr( "style" );
     object->readAttr( "clipPathUnits" );
 
     /* Register ourselves */
@@ -132,8 +133,13 @@ void SPClipPath::set(SPObject *object, unsigned int key, gchar const *value)
             object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
             break;
         default:
-            if (((SPObjectClass *) SPClipPathClass::static_parent_class)->set) {
-                ((SPObjectClass *) SPClipPathClass::static_parent_class)->set(object, key, value);
+            if (SP_ATTRIBUTE_IS_CSS(key)) {
+                sp_style_read_from_object(object->style, object);
+                object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_STYLE_MODIFIED_FLAG);
+            } else {
+                if (((SPObjectClass *) SPClipPathClass::static_parent_class)->set) {
+                    ((SPObjectClass *) SPClipPathClass::static_parent_class)->set(object, key, value);
+                }
             }
             break;
     }
@@ -258,6 +264,7 @@ NRArenaItem *SPClipPath::show(NRArena *arena, unsigned int key)
         t[5] = display->bbox.y0;
         nr_arena_group_set_child_transform(NR_ARENA_GROUP(ai), &t);
     }
+    nr_arena_group_set_style(NR_ARENA_GROUP(ai), this->style);
 
     return ai;
 }
diff --git a/src/style.cpp b/src/style.cpp
index 37a784e2a..e66c15494 100644
--- a/src/style.cpp
+++ b/src/style.cpp
@@ -335,6 +335,12 @@ static SPStyleEnum const enum_enable_background[] = {
     {NULL, -1}
 };
 
+static SPStyleEnum const enum_clip_rule[] = {
+    {"nonzero", SP_WIND_RULE_NONZERO},
+    {"evenodd", SP_WIND_RULE_EVENODD},
+    {NULL, -1}
+};
+
 /**
  * Release callback.
  */
@@ -767,6 +773,9 @@ sp_style_read(SPStyle *style, SPObject *object, Inkscape::XML::Node *repr)
     SPS_READ_PENUM_IF_UNSET(&style->enable_background, repr,
                             "enable-background", enum_enable_background, true);
 
+    /* clip-rule */
+    SPS_READ_PENUM_IF_UNSET(&style->clip_rule, repr, "clip-rule", enum_clip_rule, true);
+
     /* 3. Merge from parent */
     if (object) {
         if (object->parent) {
@@ -1020,7 +1029,9 @@ sp_style_merge_property(SPStyle *style, gint id, gchar const *val)
             style->object->getRepr()->setAttribute("clip-path", val);
             break;
         case SP_PROP_CLIP_RULE:
-            g_warning("Unimplemented style property SP_PROP_CLIP_RULE: value: %s", val);
+            if (!style->clip_rule.set) {
+                sp_style_read_ienum(&style->clip_rule, val, enum_clip_rule, true);
+            }
             break;
         case SP_PROP_MASK:
             /** \todo
@@ -1645,6 +1656,11 @@ sp_style_merge_from_parent(SPStyle *const style, SPStyle const *const parent)
     if(style->enable_background.inherit) {
         style->enable_background.value = parent->enable_background.value;
     }
+
+    /* Clipping */
+    if (!style->clip_rule.set || style->clip_rule.inherit) {
+        style->clip_rule.computed = parent->clip_rule.computed;
+    }
 }
 
 template <typename T>
@@ -1906,7 +1922,7 @@ sp_style_merge_from_dying_parent(SPStyle *const style, SPStyle const *const pare
     /* Enum values that don't have any relative settings (other than `inherit'). */
     {
         SPIEnum SPStyle::*const fields[] = {
-            //nyi: SPStyle::clip_rule,
+            &SPStyle::clip_rule,
             //nyi: SPStyle::color_interpolation,
             //nyi: SPStyle::color_interpolation_filters,
             //nyi: SPStyle::color_rendering,
@@ -2446,6 +2462,9 @@ sp_style_write_string(SPStyle const *const style, guint const flags)
 
     p += sp_style_write_ienum(p, c + BMAX - p, "enable-background", enum_enable_background, &style->enable_background, NULL, flags);
 
+    /* clipping */
+    p += sp_style_write_ienum(p, c + BMAX - p, "clip-rule", enum_clip_rule, &style->clip_rule, NULL, flags);
+
     /* fixme: */
     p += sp_text_style_write(p, c + BMAX - p, style->text, flags);
 
@@ -2592,6 +2611,8 @@ sp_style_write_difference(SPStyle const *const from, SPStyle const *const to)
 
     p += sp_text_style_write(p, c + BMAX - p, from->text, SP_STYLE_FLAG_IFDIFF);
 
+    p += sp_style_write_ienum(p, c + BMAX - p, "clip-rule", enum_clip_rule, &from->clip_rule, &to->clip_rule, SP_STYLE_FLAG_IFDIFF);
+
     /** \todo
      * The reason we use IFSET rather than IFDIFF is the belief that the IFDIFF
      * flag is mainly only for attributes that don't handle explicit unset well.
@@ -2783,6 +2804,8 @@ sp_style_clear(SPStyle *style)
     style->enable_background.value = SP_CSS_BACKGROUND_ACCUMULATE;
     style->enable_background.set = false;
     style->enable_background.inherit = false;
+
+    style->clip_rule.value = style->clip_rule.computed = SP_WIND_RULE_NONZERO;
 }
 
 
@@ -4178,6 +4201,9 @@ sp_style_unset_property_attrs(SPObject *o)
     if (style->enable_background.set) {
         repr->setAttribute("enable-background", NULL);
     }
+    if (style->clip_rule.set) {
+        repr->setAttribute("clip-rule", NULL);
+    }
 }
 
 /**
diff --git a/src/style.h b/src/style.h
index a12db388a..3ca1d4dbc 100644
--- a/src/style.h
+++ b/src/style.h
@@ -327,9 +327,11 @@ struct SPStyle {
     unsigned cursor_set : 1;
     unsigned overflow_set : 1;
     unsigned clip_path_set : 1;
-    unsigned clip_rule_set : 1;
     unsigned mask_set : 1;
 
+    /** clip-rule: 0 nonzero, 1 evenodd */
+    SPIEnum clip_rule;
+
     /** display */
     SPIEnum display;