Add ANSI color output, set that as the default

ANSI-based color output is available and now the default. Add a
-y / --output-type argument to select SVG or ANSI output. Also update
tools/genexamples.sh to use the SVG output type.

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

colorhash/cli.py

@@ -8,13 +8,13 @@ import textwrap
 from .colorizer import PaletteColorizer
 from .matricizer import Matricizer, NibbleMatricizer, RandomartMatricizer
 from .palettes import Palette, DEFAULT_PALETTES, PALETTES
-from .svg import gensvg
+from .writer import ANSIWriter, SVGWriter
 
 
 # TODO - WASM compile for embedding directly in HTML
 # TODO - option to add a caption based on the filename
 # TODO - load palettes from a file
-# TODO - ANSI 24-bit color output
+
 
 def cli_main() -> None:
     "Main function entrypoint."
@@ -49,7 +49,14 @@ def cli_main() -> None:
     INPUT_TYPE_HELP = "INPUT TYPE (-x, --input-type)\n" + "\n".join(
         [f"    {choice} - {desc}" for choice, desc in INPUT_TYPE_CHOICES.items()]
     )
-    EPILOGUE = "\n\n".join([MATRIX_HELP, PALETTE_HELP, INPUT_TYPE_HELP])
+    OUTPUT_TYPE_CHOICES = {
+        "ansi": "the output should be colored for ANSI terminals using 24 bit true color",
+        "svg": "the output should be an SVG format",
+    }
+    OUTPUT_TYPE_HELP = "OUTPUT TYPE (-y, --output-type)\n" + "\n".join(
+        [f"     {choice} - {desc}" for choice, desc in OUTPUT_TYPE_CHOICES.items()]
+    )
+    EPILOGUE = "\n\n".join([MATRIX_HELP, PALETTE_HELP, INPUT_TYPE_HELP, OUTPUT_TYPE_HELP])
 
     progname: str = sys.argv[0]
     if progname.endswith("__main__.py"):
@@ -102,12 +109,11 @@ def cli_main() -> None:
         help="Choose the hash algorithm. default: sha512",
     )
     ap.add_argument(
-        "-z",
-        "--square-size",
+        "--svg-square-size",
         metavar="PX",
         type=int,
         default=32,
-        help="Decide how big the output squares are, in pixels. default: 32",
+        help="For SVG outputs, decide how big the output squares are, in pixels. default: 32",
     )
     ap.add_argument(
         "-x",
@@ -116,6 +122,13 @@ def cli_main() -> None:
         choices=INPUT_TYPE_CHOICES.keys(),
         help="Determines how the input should be treated. default: path",
     )
+    ap.add_argument(
+        "-y",
+        "--output-type",
+        default="ansi",
+        choices=OUTPUT_TYPE_CHOICES.keys(),
+        help="Determines how the output should be generated. default: ansi",
+    )
     args = ap.parse_args()
 
     ############################################################################
@@ -182,9 +195,19 @@ def cli_main() -> None:
     # Print SVG
     matrix = matricizer.matricize(hashdata)
     colors = colorizer.colorize(matrix)
-    svg = gensvg(colors, args.square_size)
-    if str(args.out) == "-":
-        sys.stdout.write(svg)
-    else:
-        args.out.write_text(svg)
+
+    # Choose the output writer
+    writer: Writer
+    match args.output_type:
+        case "ansi":
+            writer = ANSIWriter()
+        case "svg":
+            writer = SVGWriter(args.svg_square_size)
+
+    output = writer.write(colors)
+
+    if str(args.out) == "-":
+        sys.stdout.write(output)
+    else:
+        args.out.write_text(output)
 

colorhash/svg.py

@@ -1,29 +0,0 @@
-"SVG-related functions."
-from .colorizer import ColorMatrix
-
-
-def gensvg(matrix: ColorMatrix, square_size: int) -> str:
-    """
-    Generate an SVG based on a given matrix.
-
-    :param matrix: the color matrix to generate the SVG for.
-    :param square_size: the size of the squares generated, in pixels.
-    :returns: the full generated SVG as a string.
-    """
-    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.to_html_color()}" />\n'
-
-    # Close SVG string
-    svg += "</svg>"
-    return svg

colorhash/writer.py

@@ -0,0 +1,71 @@
+import abc
+
+from .color import Color
+from .colorizer import ColorMatrix
+
+
+class Writer(metaclass=abc.ABCMeta):
+    """
+    Base writer class.
+
+    This is used to write an input colorized matrix to a string, which is then forwarded to the
+    appropriate output.
+    """
+
+    @abc.abstractmethod
+    def write(self, matrix: ColorMatrix) -> str:
+        "Write the color matrix to a string."
+
+
+class ANSIWriter(Writer):
+    def write(self, matrix: ColorMatrix) -> str:
+        ESC = '\x1b'
+        RESET = f"{ESC}[0m"
+        C = "██"
+        def ansi_color(c: Color) -> str:
+            c = c.to_rgb()
+            return f"{ESC}[38;2;{round(c.r)};{round(c.g)};{round(c.b)}m"
+        out = ''
+        for row in matrix:
+            for col in row:
+                out += ansi_color(col)
+                out += C
+            out += "\n"
+        out += RESET
+        return out
+
+
+class SVGWriter(Writer):
+    def __init__(self, square_size: int) -> None:
+        """
+        Create a new SVG writer that uses the given square size.
+
+        :param square_size: the size of the squares generated, in pixels.
+        """
+        self.square_size = square_size
+
+    def write(self, matrix: ColorMatrix) -> str:
+        """
+        Generate an SVG based on a given matrix.
+
+        :param matrix: the color matrix to generate the SVG for.
+        :returns: the full generated SVG as a string.
+        """
+        h = len(matrix)
+        w = len(matrix[0])
+
+        # Start SVG string
+        svg = f'<svg width="{w * self.square_size}" height="{h * self.square_size}" xmlns="http://www.w3.org/2000/svg">\n'
+
+        # Generate grid
+        for r in range(h):
+            for c in range(w):
+                x = c * self.square_size
+                y = r * self.square_size
+                color = matrix[r][c]
+                svg += f'  <rect x="{x}" y="{y}" width="{self.square_size}" height="{self.square_size}" fill="{color.to_html_color()}" />\n'
+
+        # Close SVG string
+        svg += "</svg>"
+        return svg
+

tools/genexamples.sh

@@ -11,9 +11,12 @@ find "examples" -type f -name '*.in' | \
 while read infile; do
     for hash in "${hashes[@]}"; do
         for matrix in "${matrices[@]}"; do
-            outfile="examples/$(basename -s .in "$infile")-$hash-$matrix.svg"
-            echo "Generating $outfile"
-            python3 -m colorhash "$infile" --out "$outfile" --hash "$hash" --matrix "$matrix"
+            svgfile="examples/$(basename -s .in "$infile")-$hash-$matrix.svg"
+            pngfile="examples/$(basename -s .in "$infile")-$hash-$matrix.png"
+            echo "Generating $svgfile"
+            python3 -m colorhash "$infile" --output-type svg --out "$svgfile" --hash "$hash" --matrix "$matrix"
+            echo "Generating $pngfile"
+            convert "$svgfile" "$pngfile"
         done
     done
 done