add ThreadCatalog and palette matching

3 files changed, 75 insertions, 0 deletions

diff --git a/embroider_print.py b/embroider_print.py
index cbdaeb09..7ab24876 100644
--- a/embroider_print.py
+++ b/embroider_print.py
@@ -21,6 +21,7 @@ from inkstitch.extensions import InkstitchExtension
 from inkstitch.stitch_plan import patches_to_stitch_plan
 from inkstitch.svg import render_stitch_plan
 from inkstitch.utils import save_stderr, restore_stderr
+from inkstitch.threads import ThreadCatalog
 
 from jinja2 import Environment, FileSystemLoader, select_autoescape
 from datetime import date
@@ -290,6 +291,7 @@ class Print(InkstitchExtension):
 
         patches = self.elements_to_patches(self.elements)
         stitch_plan = patches_to_stitch_plan(patches)
+        ThreadCatalog().match_and_apply_palette(stitch_plan)
         render_stitch_plan(self.document.getroot(), stitch_plan)
 
         self.strip_namespaces()
diff --git a/inkstitch/threads/__init__.py b/inkstitch/threads/__init__.py
index fec82ced..03cd777b 100644
--- a/inkstitch/threads/__init__.py
+++ b/inkstitch/threads/__init__.py
@@ -1,2 +1,3 @@
 from color import ThreadColor
 from palette import ThreadPalette
+from catalog import ThreadCatalog
diff --git a/inkstitch/threads/catalog.py b/inkstitch/threads/catalog.py
new file mode 100644
index 00000000..0f959a52
--- /dev/null
+++ b/inkstitch/threads/catalog.py
@@ -0,0 +1,72 @@
+import os
+from os.path import dirname, realpath
+import sys
+from glob import glob
+from collections import Sequence
+from .palette import ThreadPalette
+
+class _ThreadCatalog(Sequence):
+    """Holds a set of ThreadPalettes."""
+
+    def __init__(self):
+        self.palettes = []
+        self.load_palettes(self.get_palettes_path())
+
+    def get_palettes_path(self):
+        if getattr(sys, 'frozen', None) is not None:
+            path = sys._MEIPASS
+        else:
+            path = dirname(dirname(dirname(realpath(__file__))))
+
+        return os.path.join(path, 'palettes')
+
+    def load_palettes(self, path):
+        for palette_file in glob(os.path.join(path, '*.gpl')):
+            self.palettes.append(ThreadPalette(palette_file))
+
+    def __getitem__(self, item):
+        return self.palettes[item]
+
+    def __len__(self):
+        return len(self.palettes)
+
+    def match_and_apply_palette(self, stitch_plan):
+        """Figure out which color palette was used and set thread names.
+
+        Scans the catalog of color palettes and chooses one that seems most
+        likely to be the one that the user used.  A palette will only be
+        chosen if more tha 80% of the thread colors in the stitch plan are
+        exact matches for threads in the palette.  All other threads will be
+        matched to the closest thread in the palette.
+        """
+
+        threads = [color_block.color for color_block in stitch_plan]
+
+        for palette in self:
+            num_matched = sum(1 for thread in threads if thread in palette)
+            if num_matched > (0.8 * len(threads)):
+                # Pick this one.
+                break
+        else:
+            # This block will only get run if we ran off the end of the loop
+            # without breaking.  No palette had enough colors that exactly
+            # matched, so just do nothing.
+            return
+
+        for thread in threads:
+            nearest = palette.find_nearest(thread)
+
+            thread.name = nearest.name
+            thread.number = nearest.number
+            thread.manufacturer = nearest.manufacturer
+
+_catalog = None
+
+def ThreadCatalog():
+    """Singleton _ThreadCatalog factory"""
+
+    global _catalog
+    if _catalog is None:
+        _catalog = _ThreadCatalog()
+
+    return _catalog