From 0baf1f76888dc112f86c074dd6f19aa5e755a9cb Mon Sep 17 00:00:00 2001
From: Alek Ratzloff <alekratz@gmail.com>
Date: Fri, 24 May 2024 22:18:50 -0700
Subject: [PATCH] Palettes are selected by matricizer

Matricizers select color palettes now. This is motivated by the fact
that the gradient palettes don't really look good for openssh randomart
based art, and rainbows do look good.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>
---
 colorhash/__main__.py   | 16 ++++++++--------
 colorhash/matricizer.py | 16 +++++++++++++++-
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/colorhash/__main__.py b/colorhash/__main__.py
index 81b8a82..56dee97 100644
--- a/colorhash/__main__.py
+++ b/colorhash/__main__.py
@@ -154,13 +154,6 @@ def main() -> None:
         case _:
             assert False, f"unknown input type {args.input_type}"
 
-    # Choose the palette
-    palette: list[str]
-    if args.palette == "auto":
-        palette = list(DEFAULT_PALETTES.values())[sum(hashdata) % len(DEFAULT_PALETTES)]
-    else:
-        palette = PALETTES[args.palette]
-
     # Choose the dimensions and the matricizer
     matricizer: Matricizer
     match args.matrix:
@@ -170,10 +163,17 @@ def main() -> None:
         case "randomart":
             # 17x9 is what openssh uses
             # TODO - allow configuring dimensions, maybe
-            matricizer = RandomartMatricizer(17, 9)
+            matricizer = RandomartMatricizer(11, 6)
         case _:
             assert False, f"invalid args.matrix: {args.matrix}"
 
+    # Choose the palette
+    palette: list[str]
+    if args.palette == "auto":
+        palette = matricizer.choose_palette(hashdata, PALETTES)
+    else:
+        palette = PALETTES[args.palette]
+
     # Choose the colorizer
     colorizer = PaletteColorizer(palette)
 
diff --git a/colorhash/matricizer.py b/colorhash/matricizer.py
index 657503c..111e758 100644
--- a/colorhash/matricizer.py
+++ b/colorhash/matricizer.py
@@ -1,6 +1,8 @@
 "All things that turn a hash into a matrix."
 import abc
-from typing import Sequence
+from typing import Mapping, Sequence
+
+from .palettes import Palette, DEFAULT_PALETTES
 
 
 Matrix = Sequence[Sequence[int]]
@@ -33,6 +35,12 @@ class Matricizer(metaclass=abc.ABCMeta):
         :returns: the matrix converted from the hash data.
         """
 
+    @abc.abstractmethod
+    def choose_palette(self, data: bytes, palettes: Mapping[str, Palette]) -> Palette:
+        """
+        Choose a palette based on the give data and palettes.
+        """
+
 
 class NibbleMatricizer(Matricizer):
     """
@@ -81,6 +89,9 @@ class NibbleMatricizer(Matricizer):
 
         return cols
 
+    def choose_palette(self, data: bytes, palettes: Mapping[str, Palette]) -> Palette:
+        return list(palettes.values())[sum(data) % len(palettes)]
+
 
 class RandomartMatricizer(Matricizer):
     """
@@ -127,3 +138,6 @@ class RandomartMatricizer(Matricizer):
                 if rows[r][c] < 0xF:
                     rows[r][c] += 1
         return rows
+
+    def choose_palette(self, _data: bytes, _palettes: Mapping[str, Palette]) -> Palette:
+        return DEFAULT_PALETTES['rainbow']