1 files changed, 121 insertions, 0 deletions
diff --git a/lib/sew_stack/stitch_layers/mixins/randomization.py b/lib/sew_stack/stitch_layers/mixins/randomization.py
new file mode 100644
index 00000000..5414731c
--- /dev/null
+++ b/lib/sew_stack/stitch_layers/mixins/randomization.py
@@ -0,0 +1,121 @@
+import os
+from secrets import randbelow
+from typing import TYPE_CHECKING
+
+import wx.propgrid
+
+from ..stitch_layer_editor import Category, Property
+from ....i18n import _
+from ....svg import PIXELS_PER_MM
+from ....utils import DotDict, get_resource_dir, prng
+
+if TYPE_CHECKING:
+    from ... import SewStack
+
+
+editor_instance = None
+
+
+class RandomSeedEditor(wx.propgrid.PGTextCtrlAndButtonEditor):
+    def CreateControls(self, property_grid, property, position, size):
+        if wx.SystemSettings().GetAppearance().IsDark():
+            randomize_icon_file = 'randomize_20x20_dark.png'
+        else:
+            randomize_icon_file = 'randomize_20x20.png'
+        randomize_icon = wx.Image(os.path.join(get_resource_dir("icons"), randomize_icon_file)).ConvertToBitmap()
+        # button = wx.Button(property_grid, wx.ID_ANY, _("Re-roll"))
+        # button.SetBitmap(randomize_icon)
+
+        window_list = super().CreateControls(property_grid, property, position, size)
+        button = window_list.GetSecondary()
+        button.SetBitmap(randomize_icon)
+        button.SetLabel("")
+        button.SetToolTip(_("Re-roll"))
+        return window_list
+
+
+class RandomSeedProperty(wx.propgrid.IntProperty):
+    def DoGetEditorClass(self):
+        return wx.propgrid.PropertyGridInterface.GetEditorByName("RandomSeedEditor")
+
+    def OnEvent(self, propgrid, primaryEditor, event):
+        if event.GetEventType() == wx.wxEVT_COMMAND_BUTTON_CLICKED:
+            self.SetValueInEvent(randbelow(int(1e8)))
+            return True
+        return False
+
+
+class RandomizationPropertiesMixin:
+    @classmethod
+    def randomization_properties(cls):
+        # We have to register the editor class once. We have to save a reference
+        # to the editor to avoid letting it get garbage collected.
+        global editor_instance
+        if editor_instance is None:
+            editor_instance = RandomSeedEditor()
+            wx.propgrid.PropertyGrid.DoRegisterEditorClass(editor_instance, "RandomSeedEditor")
+
+        return Category(_("Randomization")).children(
+            Property("random_seed", _("Random seed"), type=RandomSeedProperty,
+                     # Wow, it's really hard to explain the concept of a random seed to non-programmers...
+                     help=_("The random seed is used when handling randomization settings.  " +
+                            "Click the button to choose a new random seed, which will generate random features differently. " +
+                            "Alternatively, you can enter your own random seed.  If you reuse a random seed, random features " +
+                            "will look the same.")),
+            Property("random_stitch_offset", _("Offset stitches"), unit="mm", prefix="±",
+                     help=_("Move stitches randomly by up to this many millimeters in any direction.")),
+            Property("random_stitch_path_offset", _("Offset stitch path"), unit="mm", prefix="±",
+                     help=_("Move stitches randomly by up to this many millimeters perpendicular to the stitch path.\n\n" +
+                            "If <b>Offset stitches</b> is also specified, then this one is processed first.")),
+        )
+
+
+class RandomizationMixin:
+    config: DotDict
+    element: "SewStack"
+
+    @classmethod
+    def randomization_defaults(cls):
+        return dict(
+            random_seed=None,
+            random_stitch_offset=0.0,
+            random_stitch_path_offset=0.0,
+        )
+
+    def get_random_seed(self):
+        seed = self.config.get('random_seed')
+        if seed is None:
+            return self.element.get_default_random_seed()
+        else:
+            return seed
+
+    def offset_stitches(self, stitches):
+        """Randomly move stitches by modifying a list of stitches in-place."""
+
+        if not stitches:
+            return
+
+        if 'random_stitch_path_offset' in self.config and self.config.random_stitch_path_offset:
+            offset = self.config.random_stitch_path_offset * PIXELS_PER_MM
+            rand_iter = iter(prng.iter_uniform_floats(self.get_random_seed(), "random_stitch_path_offset"))
+
+            last_stitch = stitches[0]
+            for stitch in stitches[1:]:
+                try:
+                    direction = (stitch - last_stitch).unit().rotate_left()
+                except ZeroDivisionError:
+                    continue
+
+                last_stitch = stitch
+                distance = next(rand_iter) * 2 * offset - offset
+                result = stitch + direction * distance
+                stitch.x = result.x
+                stitch.y = result.y
+
+        if 'random_stitch_offset' in self.config and self.config.random_stitch_offset:
+            offset = self.config.random_stitch_offset * PIXELS_PER_MM
+            rand_iter = iter(prng.iter_uniform_floats(self.get_random_seed(), "random_stitch_offset"))
+
+            for stitch in stitches:
+                stitch.x += next(rand_iter) * 2 * offset - offset
+                stitch.y += next(rand_iter) * 2 * offset - offset