New freehand curve drawing tool

- Access with Shift-LMB or from the 'Create' toolbar tab.
- Uses curve fitting for bezier curves, with error and corner angle options.
- Optional tablet pressure to curve radius mapping.
- Depth can use the cursor or optionally draw onto the surface,
  for the entire stroke or using the stroke start.
- Stroke plane can optionally be perpendicular to, or aligned to the surface normal.
- Optional radius tapering and for start/end points.
- Supports operator redo and calling from Python.

release/scripts/startup/bl_ui/space_view3d_toolbar.py

@@ -136,6 +136,7 @@ class VIEW3D_PT_tools_add_object(View3DPanel, Panel):
 
     @staticmethod
     def draw_add_curve(layout, label=False):
+
         if label:
             layout.label(text="Bezier:")
         layout.operator("curve.primitive_bezier_curve_add", text="Bezier", icon='CURVE_BEZCURVE')
@@ -149,6 +150,10 @@ class VIEW3D_PT_tools_add_object(View3DPanel, Panel):
         layout.operator("curve.primitive_nurbs_circle_add", text="Nurbs Circle", icon='CURVE_NCIRCLE')
         layout.operator("curve.primitive_nurbs_path_add", text="Path", icon='CURVE_PATH')
 
+        layout.separator()
+
+        layout.operator("curve.draw", icon='LINE_DATA')
+
     @staticmethod
     def draw_add_surface(layout):
         layout.operator("surface.primitive_nurbs_surface_curve_add", text="Nurbs Curve", icon='SURFACE_NCURVE')
@@ -546,8 +551,61 @@ class VIEW3D_PT_tools_add_curve_edit(View3DPanel, Panel):
 
         VIEW3D_PT_tools_add_object.draw_add_curve(col, label=True)
 
-# ********** default tools for editmode_surface ****************
 
+class VIEW3D_PT_tools_curveedit_options_stroke(View3DPanel, Panel):
+    bl_category = "Options"
+    bl_context = "curve_edit"
+    bl_label = "Curve Stroke"
+
+    def draw(self, context):
+        layout = self.layout
+
+        tool_settings = context.tool_settings
+        cps = tool_settings.curve_paint_settings
+
+        col = layout.column()
+
+        col.prop(cps, "curve_type")
+
+        if cps.curve_type == 'BEZIER':
+            col.label("Bezier Options:")
+            col.prop(cps, "error_threshold")
+            col.prop(cps, "use_corners_detect")
+
+            col = layout.column()
+            col.active = cps.use_corners_detect
+            col.prop(cps, "corner_angle")
+
+        col.label("Pressure Radius:")
+        row = layout.row(align=True)
+        rowsub = row.row(align=True)
+        rowsub.prop(cps, "radius_min", text="Min")
+        rowsub.prop(cps, "radius_max", text="Max")
+
+        row.prop(cps, "use_pressure_radius", text="", icon_only=True)
+
+        col = layout.column()
+        col.label("Taper Radius:")
+        row = layout.row(align=True)
+        row.prop(cps, "radius_taper_start", text="Start")
+        row.prop(cps, "radius_taper_end", text="End")
+
+        col = layout.column()
+        col.label("Projection Depth:")
+        row = layout.row(align=True)
+        row.prop(cps, "depth_mode", expand=True)
+
+        col = layout.column()
+        if cps.depth_mode == 'SURFACE':
+            col.prop(cps, "use_stroke_endpoints")
+            if cps.use_stroke_endpoints:
+                colsub = layout.column(align=True)
+                colsub.prop(cps, "surface_plane", expand=True)
+            else:
+                col.prop(cps, "radius_offset")
+
+
+# ********** default tools for editmode_surface ****************
 
 class VIEW3D_PT_tools_transform_surface(View3DPanel, Panel):
     bl_category = "Tools"