1 files changed, 153 insertions, 0 deletions
diff --git a/lib/elements/stroke.py b/lib/elements/stroke.py
new file mode 100644
index 00000000..5239f978
--- /dev/null
+++ b/lib/elements/stroke.py
@@ -0,0 +1,153 @@
+import sys
+
+from .element import param, EmbroideryElement, Patch
+from ..i18n import _
+from ..utils import cache, Point
+from ..stitches import running_stitch
+
+warned_about_legacy_running_stitch = False
+
+
+class Stroke(EmbroideryElement):
+    element_name = "Stroke"
+
+    @property
+    @param('satin_column', _('Satin stitch along paths'), type='toggle', inverse=True)
+    def satin_column(self):
+        return self.get_boolean_param("satin_column")
+
+    @property
+    def color(self):
+        return self.get_style("stroke")
+
+    @property
+    def dashed(self):
+        return self.get_style("stroke-dasharray") is not None
+
+    @property
+    @param('running_stitch_length_mm', _('Running stitch length'), unit='mm', type='float', default=1.5)
+    def running_stitch_length(self):
+        return max(self.get_float_param("running_stitch_length_mm", 1.5), 0.01)
+
+    @property
+    @param('zigzag_spacing_mm', _('Zig-zag spacing (peak-to-peak)'), unit='mm', type='float', default=0.4)
+    @cache
+    def zigzag_spacing(self):
+        return max(self.get_float_param("zigzag_spacing_mm", 0.4), 0.01)
+
+    @property
+    @param('repeats', _('Repeats'), type='int', default="1")
+    def repeats(self):
+        return self.get_int_param("repeats", 1)
+
+    @property
+    def paths(self):
+        path = self.parse_path()
+
+        if self.manual_stitch_mode:
+            return [self.strip_control_points(subpath) for subpath in path]
+        else:
+            return self.flatten(path)
+
+    @property
+    @param('manual_stitch', _('Manual stitch placement'), tooltip=_("Stitch every node in the path.  Stitch length and zig-zag spacing are ignored."), type='boolean', default=False)
+    def manual_stitch_mode(self):
+        return self.get_boolean_param('manual_stitch')
+
+    def is_running_stitch(self):
+        # using stroke width <= 0.5 pixels to indicate running stitch is deprecated in favor of dashed lines
+
+        stroke_width = float(self.get_style("stroke-width", 1))
+
+        if self.dashed:
+            return True
+        elif stroke_width <= 0.5 and self.get_float_param('running_stitch_length_mm', None) is not None:
+            # if they use a stroke width less than 0.5 AND they specifically set a running stitch
+            # length, then assume they intend to use the deprecated <= 0.5 method to set running
+            # stitch.
+            #
+            # Note that we use self.get_style("stroke_width") _not_ self.stroke_width above.  We
+            # explicitly want the stroke width in "user units" ("document units") -- that is, what
+            # the user sees in inkscape's stroke settings.
+            #
+            # Also note that we don't use self.running_stitch_length_mm above.  This is because we
+            # want to see if they set a running stitch length at all, and the property will apply
+            # a default value.
+            #
+            # Thsi is so tricky, and and intricate that's a major reason that we deprecated the
+            # 0.5 units rule.
+
+            # Warn them the first time.
+            global warned_about_legacy_running_stitch
+            if not warned_about_legacy_running_stitch:
+                warned_about_legacy_running_stitch = True
+                print >> sys.stderr, _("Legacy running stitch setting detected!\n\nIt looks like you're using a stroke " + \
+                    "smaller than 0.5 units to indicate a running stitch, which is deprecated.  Instead, please set " + \
+                    "your stroke to be dashed to indicate running stitch.  Any kind of dash will work.")
+
+            # still allow the deprecated setting to work in order to support old files
+            return True
+        else:
+            return False
+
+    def simple_satin(self, path, zigzag_spacing, stroke_width):
+        "zig-zag along the path at the specified spacing and wdith"
+
+        # `self.zigzag_spacing` is the length for a zig and a zag
+        # together (a V shape).  Start with running stitch at half
+        # that length:
+        patch = self.running_stitch(path, zigzag_spacing / 2.0)
+
+        # Now move the points left and right.  Consider each pair
+        # of points in turn, and move perpendicular to them,
+        # alternating left and right.
+
+        offset = stroke_width / 2.0
+
+        for i in xrange(len(patch) - 1):
+            start = patch.stitches[i]
+            end = patch.stitches[i + 1]
+            segment_direction = (end - start).unit()
+            zigzag_direction = segment_direction.rotate_left()
+
+            if i % 2 == 1:
+                zigzag_direction *= -1
+
+            patch.stitches[i] += zigzag_direction * offset
+
+        return patch
+
+    def running_stitch(self, path, stitch_length):
+        repeated_path = []
+
+        # go back and forth along the path as specified by self.repeats
+        for i in xrange(self.repeats):
+            if i % 2 == 1:
+                # reverse every other pass
+                this_path = path[::-1]
+            else:
+                this_path = path[:]
+
+            repeated_path.extend(this_path)
+
+        stitches = running_stitch(repeated_path, stitch_length)
+
+        return Patch(self.color, stitches)
+
+
+    def to_patches(self, last_patch):
+        patches = []
+
+        for path in self.paths:
+            path = [Point(x, y) for x, y in path]
+            if self.manual_stitch_mode:
+                patch = Patch(color=self.color, stitches=path, stitch_as_is=True)
+            elif self.is_running_stitch():
+                patch = self.running_stitch(path, self.running_stitch_length)
+            else:
+                patch = self.simple_satin(path, self.zigzag_spacing, self.stroke_width)
+
+            if patch:
+                patches.append(patch)
+
+        return patches