Split functionality out into matrix and color passes

* Matricizers turn a hash into a matrix
* Colorizers turn a matrix into a colored matrix

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

colorhash/__main__.py

@@ -1,7 +1,9 @@
 import hashlib
 import sys
 
-from .hash_colorizer import PaletteColorizer
+from .colorizer import PaletteColorizer
+from .matricizer import NibbleMatricizer
+from .svg import gensvg
 
 
 # TODO - WASM compile for embedding directly in HTML
@@ -46,8 +48,8 @@ infile = sys.stdin.buffer
 
 if len(sys.argv) > 1:
     inpath = sys.argv[1]
-    if inpath != '-':
-        infile = open(inpath, 'rb')
+    if inpath != "-":
+        infile = open(inpath, "rb")
 
 
 hashdata = hashlib.file_digest(infile, hash_algo).digest()
@@ -62,4 +64,6 @@ colorizer = PaletteColorizer(palette)
 # pprint.pprint([[hex(c) for c in row] for row in colors])
 
 # Print SVG
-print(colorizer.hash_to_svg(hashdata, w, h, 32))
+matrix = NibbleMatricizer(w, h).hash_to_matrix(hashdata)
+colors = PaletteColorizer(palette).colorize(matrix)
+print(gensvg(colors, 32))

colorhash/colorizer.py

@@ -0,0 +1,24 @@
+import abc
+from typing import Sequence
+
+from .matricizer import Matrix
+
+
+class Colorizer(metaclass=abc.ABCMeta):
+    @abc.abstractmethod
+    def colorize(self, matrix: Matrix) -> Matrix:
+        """
+        Colorize a matrix.
+        """
+
+
+Palette = Sequence[str]
+
+
+class PaletteColorizer(Colorizer):
+    def __init__(self, palette: Palette) -> None:
+        assert len(palette) == 16, "palette must contain exactly 16 colors"
+        self.palette = palette
+
+    def colorize(self, matrix: Matrix) -> Matrix:
+        return [[self.palette[v] for v in row] for row in matrix]

colorhash/hash_colorizer.py

@@ -1,78 +0,0 @@
-import abc
-from typing import Sequence
-
-
-Matrix = Sequence[Sequence[int]]
-
-
-class HashColorizer(metaclass=abc.ABCMeta):
-    def hash_to_matrix(self, data: bytes, w: int, h: int) -> Matrix:
-        """
-        Convert a set of bytes to a list of rows of nibbles.
-        """
-
-        nibbles = []
-        for b in data:
-            top = (b & 0xF0) >> 4
-            bottom = b & 0x0F
-            nibbles += [top, bottom]
-
-        if len(nibbles) != w * h:
-            raise ValueError(
-                f"input data length ({len(nibbles)}) must match matrix dimensions ({w}x{h} = {w * h})"
-            )
-
-        cols = []
-        row = []
-        for b in nibbles:
-            row += [b]
-            if len(row) == w:
-                cols += [row]
-                row = []
-
-        return cols
-
-    @abc.abstractmethod
-    def colorize(self, matrix: Matrix) -> Matrix:
-        """
-        Colorize a matrix.
-        """
-
-    def gensvg(self, matrix: Matrix, square_size: int) -> str:
-        """
-        Generate an SVG based on a given matrix.
-        """
-        h = len(matrix)
-        w = len(matrix[0])
-
-        # Start SVG string
-        svg = f'<svg width="{w * square_size}" height="{h * square_size}" xmlns="http://www.w3.org/2000/svg">\n'
-
-        # Generate grid
-        for r in range(h):
-            for c in range(w):
-                x = c * square_size
-                y = r * square_size
-                color = matrix[r][c]
-                svg += f'  <rect x="{x}" y="{y}" width="{square_size}" height="{square_size}" fill="{color}" />\n'
-
-        # Close SVG string
-        svg += "</svg>"
-        return svg
-
-    def hash_to_svg(self, hash: bytes, w: int, h: int, square_size: int) -> str:
-        matrix = self.hash_to_matrix(hash, w, h)
-        colors = self.colorize(matrix)
-        return self.gensvg(colors, square_size)
-
-
-Palette = list
-
-
-class PaletteColorizer(HashColorizer):
-    def __init__(self, palette: Palette) -> None:
-        assert len(palette) == 16, "palette must contain exactly 16 colors"
-        self.palette = palette
-
-    def colorize(self, matrix: Matrix) -> Matrix:
-        return [[self.palette[v] for v in row] for row in matrix]

colorhash/matricizer.py

@@ -0,0 +1,45 @@
+import abc
+from typing import Sequence
+
+
+Matrix = Sequence[Sequence[int]]
+
+
+class Matricizer(metaclass=abc.ABCMeta):
+    def __init__(self, w: int, h: int) -> None:
+        self.w = w
+        self.h = h
+
+    @abc.abstractmethod
+    def hash_to_matrix(self, data: bytes) -> Matrix:
+        """
+        Convert a hash to a matrix of given width and height.
+        """
+
+
+class NibbleMatricizer(Matricizer):
+    def hash_to_matrix(self, data: bytes) -> Matrix:
+        """
+        Convert a set of bytes to a list of rows of nibbles.
+        """
+
+        nibbles = []
+        for b in data:
+            top = (b & 0xF0) >> 4
+            bottom = b & 0x0F
+            nibbles += [top, bottom]
+
+        if len(nibbles) != self.w * self.h:
+            raise ValueError(
+                f"input data length ({len(nibbles)}) must match matrix dimensions ({self.w}x{self.h} = {self.w * self.h})"
+            )
+
+        cols = []
+        row = []
+        for b in nibbles:
+            row += [b]
+            if len(row) == self.w:
+                cols += [row]
+                row = []
+
+        return cols

colorhash/svg.py

@@ -0,0 +1,24 @@
+from .matricizer import Matrix
+
+
+def gensvg(matrix: Matrix, square_size: int) -> str:
+    """
+    Generate an SVG based on a given matrix.
+    """
+    h = len(matrix)
+    w = len(matrix[0])
+
+    # Start SVG string
+    svg = f'<svg width="{w * square_size}" height="{h * square_size}" xmlns="http://www.w3.org/2000/svg">\n'
+
+    # Generate grid
+    for r in range(h):
+        for c in range(w):
+            x = c * square_size
+            y = r * square_size
+            color = matrix[r][c]
+            svg += f'  <rect x="{x}" y="{y}" width="{square_size}" height="{square_size}" fill="{color}" />\n'
+
+    # Close SVG string
+    svg += "</svg>"
+    return svg