From 9e06823fedd36c568a31df43f5bcc419cd0a125c Mon Sep 17 00:00:00 2001
From: Constantin Gierczak--Galle <git.cst1@mailbox.org>
Date: Sat, 9 Dec 2023 17:49:51 +0100
Subject: [PATCH] Add procedure to blend a list of colors to a 16-length list
 for LED bars

---
 pyjecteur/common.py | 87 +++++++++++++++++++++++++++++++++++++++++++++
 shell.nix           |  1 +
 2 files changed, 88 insertions(+)
 create mode 100644 pyjecteur/common.py

diff --git a/pyjecteur/common.py b/pyjecteur/common.py
new file mode 100644
index 0000000..3a989bd
--- /dev/null
+++ b/pyjecteur/common.py
@@ -0,0 +1,87 @@
+import logging
+from colour import Color
+from typing import List, Callable, Optional, Union, Tuple
+from enum import Enum
+
+LedBarLen = 16
+
+def remove_duplicates(colors: List[Color]) -> Tuple[List[Color], List[int]]:
+    if len(colors) == 0:
+        return ([], [])
+    colors_res = [colors[0]]
+    res_nb = [1]
+    for i in range(1, len(colors)):
+        if colors[i] != colors_res[-1]:
+            colors_res.append(colors[i])
+            res_nb.append(1)
+        else:
+            res_nb[-1] += 1
+    return (colors_res, res_nb)
+
+def reduplicate(colors: List[Color], repetitions: List[int]) -> List[Color]:
+    """
+    Re-duplicates a list. Takes in a list of elements and a list of numbers of
+    repetitions. Concatetantes the repeted elements.
+
+    Requires both lists to have the same length
+    """
+
+    res = []
+    for i in range(len(colors)):
+        for _ in range(repetitions[i]):
+            res.append(colors[i])
+
+    return res
+    
+class InterpType(Enum):
+    """
+    Interpolation algorithm
+    """
+    
+    NEAREST = 1
+    LINEAR = 2
+
+class Filling(Enum):
+
+    VOID = 1
+    EXTREMA = 2
+    GREATEST = 3
+
+def blendLedBar(colors: List[Color], 
+                blending: Optional[InterpType] = InterpType.NEAREST,
+                filling: Optional[Filling] = Filling.GREATEST,
+                void_color: Optional[Color] = Color("black")) -> List[Color]:
+    total_len = len(colors)
+    (deduped, rep_nb) = remove_duplicates(colors)
+    if len(deduped) > LedBarLen:
+        # After dedup, there are still too many colors. Only show the first ones
+        logging.warning(f"LED bar interpolation: More than {LedBarLen} colors. Dropping colors")
+        return deduped[:LedBarLen]
+
+    if len(colors) > LedBarLen:
+        # TODO: Try and dedup some colors to save space
+        return colors[:LedBarLen]
+
+    if blending == InterpType.NEAREST:
+        factor = LedBarLen // total_len
+
+        # First pass
+        for i in range(len(rep_nb)):
+            rep_nb[i] *= factor
+
+        gap = LedBarLen - total_len * factor
+
+        # TODO: Add GREATEST
+        # The idea is to first add a repetition to the already longest
+        # repetition to hurt the color ratio as little as possible
+        if gap == 0:
+            return reduplicate(deduped, rep_nb)
+        # If there is still
+        elif filling == Filling.VOID:
+            return (reduplicate(deduped, rep_nb) + ([void_color] * gap))
+        elif filling == Filling.EXTREMA:
+            bot_gap = gap // 2
+            top_gap = gap - bot_gap
+            return (([deduped[0]] * top_gap) + reduplicate(deduped, rep_nb) +
+                    ([deduped[-1]] * bot_gap))
+
diff --git a/shell.nix b/shell.nix
index c3efeff..d021efa 100644
--- a/shell.nix
+++ b/shell.nix
@@ -21,6 +21,7 @@ in
         ps.black
         ps.pylint
         ps.ipython
+        ps.python-lsp-server
       ]))
       pkgs.pyright
     ];