Added new line style options for sketchy chaining of feature edges.

The default chaining option is now called "Natural", while the new chaining options
are "Sketchy: Topology Preserved" and "Sketchy: Topology broken".  The latter two
options allow for generating chains of feature edges with a sketchy multiple touch.
The "Sketchy: Topology Preserved" option takes account of the topology of objects
in the view map, while the "Sketchy: Topology broken" ignores the edge topology.
The "rounds" option specifies the number of rounds in sketchy strokes.

5 files changed, 42 insertions, 5 deletions

diff --git a/release/scripts/freestyle/style_modules/parameter_editor.py b/release/scripts/freestyle/style_modules/parameter_editor.py
index 45c242fec8e..0324586b135 100644
--- a/release/scripts/freestyle/style_modules/parameter_editor.py
+++ b/release/scripts/freestyle/style_modules/parameter_editor.py
@@ -881,10 +881,15 @@ def process(layer_name, lineset_name):
         upred = TrueUP1D()
     Operators.select(upred)
     # join feature edges to form chains
-    bpred = AngleLargerThanBP1D(1.0) # XXX temporary fix for occasional unexpected long lines
-    if linestyle.same_object:
-        bpred = AndBP1D(bpred, SameShapeIdBP1D())
-    Operators.bidirectionalChain(ChainPredicateIterator(upred, bpred), NotUP1D(upred))
+    if linestyle.chaining == "NATURAL":
+        bpred = AngleLargerThanBP1D(1.0) # XXX temporary fix for occasional unexpected long lines
+        if linestyle.same_object:
+            bpred = AndBP1D(bpred, SameShapeIdBP1D())
+        Operators.bidirectionalChain(ChainPredicateIterator(upred, bpred), NotUP1D(upred))
+    elif linestyle.chaining == "SKETCHY_TOPOLOGY_PRESERVED":
+        Operators.bidirectionalChain(pySketchyChainSilhouetteIterator(linestyle.rounds))
+    elif linestyle.chaining == "SKETCHY_TOPOLOGY_BROKEN":
+        Operators.bidirectionalChain(pySketchyChainingIterator(linestyle.rounds))
     # split chains
     if linestyle.material_boundary:
         Operators.sequentialSplit(MaterialBoundaryUP0D())
diff --git a/release/scripts/startup/bl_ui/properties_render.py b/release/scripts/startup/bl_ui/properties_render.py
index f471ffc65e5..8d72fc95cf1 100644
--- a/release/scripts/startup/bl_ui/properties_render.py
+++ b/release/scripts/startup/bl_ui/properties_render.py
@@ -514,7 +514,13 @@ class RENDER_PT_freestyle_linestyle(RenderButtonsPanel, Panel):
             # Chaining
             col = layout.column()
             col.label(text="Chaining:")
-            col.prop(linestyle, "same_object")
+            col.prop(linestyle, "chaining", text="")
+            if linestyle.chaining == "NATURAL":
+                col.prop(linestyle, "same_object")
+            elif linestyle.chaining == "SKETCHY_TOPOLOGY_PRESERVED":
+                col.prop(linestyle, "rounds")
+            elif linestyle.chaining == "SKETCHY_TOPOLOGY_BROKEN":
+                col.prop(linestyle, "rounds")
             # Splitting
             col = layout.column()
             col.label(text="Splitting:")
diff --git a/source/blender/blenkernel/intern/linestyle.c b/source/blender/blenkernel/intern/linestyle.c
index 86ea80cb89e..167f440ffd0 100644
--- a/source/blender/blenkernel/intern/linestyle.c
+++ b/source/blender/blenkernel/intern/linestyle.c
@@ -69,6 +69,8 @@ static void default_linestyle_settings(FreestyleLineStyle *linestyle)
 	linestyle->r = linestyle->g = linestyle->b = 0.0;
 	linestyle->alpha = 1.0;
 	linestyle->thickness = 1.0;
+	linestyle->chaining = LS_CHAINING_NATURAL;
+	linestyle->rounds = 3;
 	linestyle->min_length = 0.0f;
 	linestyle->max_length = 10000.0f;
 
diff --git a/source/blender/makesdna/DNA_linestyle_types.h b/source/blender/makesdna/DNA_linestyle_types.h
index 85468ce6657..d3536da2336 100644
--- a/source/blender/makesdna/DNA_linestyle_types.h
+++ b/source/blender/makesdna/DNA_linestyle_types.h
@@ -322,6 +322,11 @@ typedef struct LineStyleThicknessModifier_Calligraphy {
 #define LS_MIN_2D_LENGTH      16
 #define LS_MAX_2D_LENGTH      32
 
+/* FreestyleLineStyle::chaining */
+#define LS_CHAINING_NATURAL                     1
+#define LS_CHAINING_SKETCHY_TOPOLOGY_PRESERVED  2
+#define LS_CHAINING_SKETCHY_TOPOLOGY_BROKEN     3
+
 /* FreestyleLineStyle::caps */
 #define LS_CAPS_BUTT    1
 #define LS_CAPS_ROUND   2
@@ -334,6 +339,8 @@ typedef struct FreestyleLineStyle {
 	float r, g, b, alpha;
 	float thickness;
 	int flag, caps;
+	int chaining;
+	unsigned int rounds;
 	float min_length, max_length;
 	unsigned short dash1, gap1, dash2, gap2, dash3, gap3;
 	int panel; /* for UI */
diff --git a/source/blender/makesrna/intern/rna_linestyle.c b/source/blender/makesrna/intern/rna_linestyle.c
index 389d3746671..415379b39d1 100644
--- a/source/blender/makesrna/intern/rna_linestyle.c
+++ b/source/blender/makesrna/intern/rna_linestyle.c
@@ -674,6 +674,11 @@ static void rna_def_linestyle(BlenderRNA *brna)
 		{LS_PANEL_GEOMETRY, "GEOMETRY", 0, "Geometry", "Show the panel for stroke geometry options."},
 		{LS_PANEL_MISC, "MISC", 0, "Misc", "Show the panel for miscellaneous options."},
 		{0, NULL, 0, NULL, NULL}};
+	static EnumPropertyItem chaining_items[] = {
+		{LS_CHAINING_NATURAL, "NATURAL", 0, "Natural", "Natural chaining."},
+		{LS_CHAINING_SKETCHY_TOPOLOGY_PRESERVED, "SKETCHY_TOPOLOGY_PRESERVED", 0, "Sketchy: Topology Preserved", "Natural chaining with a sketchy multiple touch."},
+		{LS_CHAINING_SKETCHY_TOPOLOGY_BROKEN, "SKETCHY_TOPOLOGY_BROKEN", 0, "Sketchy: Topology Broken", "Sketchy chaining with a broken topology of objects."},
+		{0, NULL, 0, NULL, NULL}};
 	static EnumPropertyItem cap_items[] = {
 		{LS_CAPS_BUTT, "BUTT", 0, "Butt", "Butt cap (flat)."},
 		{LS_CAPS_ROUND, "ROUND", 0, "Round", "Round cap (half-circle)."},
@@ -723,6 +728,18 @@ static void rna_def_linestyle(BlenderRNA *brna)
 	RNA_def_property_struct_type(prop, "LineStyleThicknessModifier");
 	RNA_def_property_ui_text(prop, "Thickness Modifiers", "List of line thickness modifiers.");
 
+	prop= RNA_def_property(srna, "chaining", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_sdna(prop, NULL, "chaining");
+	RNA_def_property_enum_items(prop, chaining_items);
+	RNA_def_property_ui_text(prop, "Chaining", "Select the way how feature edges are jointed to form chains.");
+	RNA_def_property_update(prop, NC_SCENE, NULL);
+
+	prop= RNA_def_property(srna, "rounds", PROP_INT, PROP_UNSIGNED);
+	RNA_def_property_int_sdna(prop, NULL, "rounds");
+	RNA_def_property_range(prop, 1, 1000);
+	RNA_def_property_ui_text(prop, "Rounds", "Number of rounds in a sketch multiple touch.");
+	RNA_def_property_update(prop, NC_SCENE, NULL);
+
 	prop= RNA_def_property(srna, "geometry_modifiers", PROP_COLLECTION, PROP_NONE);
 	RNA_def_property_collection_sdna(prop, NULL, "geometry_modifiers", NULL);
 	RNA_def_property_struct_type(prop, "LineStyleGeometryModifier");