textual-paint/src/textual_paint/repack_font.py

#!/usr/bin/env python3

import os
from PIL import Image

block_char_lookup = {
    0x0: ' ',
    0x1: '▘',
    0x2: '▝',
    0x3: '▀',
    0x4: '▖',
    0x5: '▌',
    0x6: '▞',
    0x7: '▛',
    0x8: '▗',
    0x9: '▚',
    0xA: '▐',
    0xB: '▜',
    0xC: '▄',
    0xD: '▙',
    0xE: '▟',
    0xF: '█',
}

def spacePad(num: int) -> str:
    return ' ' * num

def blankLines(num: int, width: int) -> str:
    lines = [spacePad(width) for _ in range(num)]
    return '\n'.join(lines)

class FIGletFontWriter:
    """Used to write FIGlet fonts.
    
    createFigFileData() returns a string that can be written to a .flf file.

    It can automatically fix some common problems with FIGlet fonts, such as
    incorrect character widths/heights, and missing lowercase characters.
    """

    charOrder: list[int] = [ii for ii in range(32, 127)] + [196, 214, 220, 228, 246, 252, 223]
    R"""Character codes that are required to be in any FIGlet font.
    
    Printable portion of the ASCII character set:
32 (blank/space) 64 @             96  `
33 !             65 A             97  a
34 "             66 B             98  b
35 #             67 C             99  c
36 $             68 D             100 d
37 %             69 E             101 e
38 &             70 F             102 f
39 '             71 G             103 g
40 (             72 H             104 h
41 )             73 I             105 i
42 *             74 J             106 j
43 +             75 K             107 k
44 ,             76 L             108 l
45 -             77 M             109 m
46 .             78 N             110 n
47 /             79 O             111 o
48 0             80 P             112 p
49 1             81 Q             113 q
50 2             82 R             114 r
51 3             83 S             115 s
52 4             84 T             116 t
53 5             85 U             117 u
54 6             86 V             118 v
55 7             87 W             119 w
56 8             88 X             120 x
57 9             89 Y             121 y
58 :             90 Z             122 z
59 ;             91 [             123 {
60 <             92 \             124 |
61 =             93 ]             125 }
62 >             94 ^             126 ~
63 ?             95 _
Additional required Deutsch FIGcharacters, in order:
196 Ä (umlauted "A" -- two dots over letter "A")
214 Ö (umlauted "O" -- two dots over letter "O")
220 Ü (umlauted "U" -- two dots over letter "U")
228 ä (umlauted "a" -- two dots over letter "a")
246 ö (umlauted "o" -- two dots over letter "o")
252 ü (umlauted "u" -- two dots over letter "u")
223 ß ("ess-zed" -- see FIGcharacter illustration below)
                              ___
                             / _ \
                            | |/ /
          Ess-zed >>--->    | |\ \
                            | ||_/
                            |_|

Additional characters must use code tagged characters, which are not yet supported.
"""

    def __init__(
        self,
        figChars: dict[int, str] = {},
        height: int | None = None,
        baseline: int | None = None,
        maxLength: int | None = None,
        commentLines: list[str] = [],
        rightToLeft: bool = False,
        horizontalLayout: str = 'Universal Smushing',
        verticalLayout: str = 'Universal Smushing',
        codeTagCount: int = 0,
        hardBlank: str = "$",
        endMark: str = "@",
        caseInsensitive: bool = False,
    ):
        self.figChars: dict[int, str] = figChars
        """Dictionary that maps character codes to FIGcharacter strings."""
        self.height = height
        """Height of a FIGcharacter, in characters."""
        self.baseline = baseline
        """Distance from the top of the character to the baseline. If not specified, defaults to height."""
        self.maxLength = maxLength
        """Maximum length of a line INCLUDING two endMark characters."""
        self.commentLines: list[str] = commentLines
        """List of comment lines to be included in the header. It's recommended to include at least the name of the font and the name of the author."""
        self.rightToLeft = rightToLeft
        """Indicates RTL writing direction (or LTR if False)."""
        self.codeTagCount = codeTagCount
        """Number of extra characters included in the font (in addition to the required 102 untagged characters). Outputting tagged characters is not yet supported."""
        self.hardBlank = hardBlank
        """Invisible character used to prevent smushing."""
        self.endMark = endMark
        """Denotes the end of a line. Two of these characters in a row denotes the end of a FIGcharacter."""
        self.horizontalLayout = horizontalLayout
        """One of 'Full', 'Fitted', 'Universal Smushing', or 'Controlled Smushing'"""
        self.verticalLayout = verticalLayout
        """One of 'Full', 'Fitted', 'Universal Smushing', or 'Controlled Smushing'"""
        self.hRule = [False] * 7
        """Horizontal Smushing Rules, 1-6 (0 is not used, so that indices correspond with the names of the parameters). horizontalLayout must be 'Controlled Smushing' for these to take effect."""
        self.vRule = [False] * 6
        """Vertical Smushing Rules, 1-5 (0 is not used, so that indices correspond with the names of the parameters). verticalLayout must be 'Controlled Smushing' for these to take effect."""
        self.caseInsensitive = caseInsensitive
        """Makes lowercase same as uppercase. Note that this is one-way overwrite. It doesn't check if a character already exists, and it won't fill in uppercase using lowercase."""

    def _getOldLayoutValue(self) -> int:
        val = 0
        if self.horizontalLayout == 'Full':
            return -1
        elif self.horizontalLayout == 'Fitted':
            return 0
        elif self.horizontalLayout == 'Universal Smushing':
            return 0
        else:
            val += 1 if self.hRule[1] else 0
            val += 2 if self.hRule[2] else 0
            val += 4 if self.hRule[3] else 0
            val += 8 if self.hRule[4] else 0
            val += 16 if self.hRule[5] else 0
            val += 32 if self.hRule[6] else 0
        return val

    def _getFullLayoutValue(self) -> int:
        val = 0

        # horizontal rules
        if self.horizontalLayout == 'Full':
            val += 0
        elif self.horizontalLayout == 'Fitted':
            val += 64
        elif self.horizontalLayout == 'Universal Smushing':
            val += 128
        else:
            val += 128
            val += 1 if self.hRule[1] else 0
            val += 2 if self.hRule[2] else 0
            val += 4 if self.hRule[3] else 0
            val += 8 if self.hRule[4] else 0
            val += 16 if self.hRule[5] else 0
            val += 32 if self.hRule[6] else 0

        # vertical rules
        if self.verticalLayout == 'Full':
            val += 0
        elif self.verticalLayout == 'Fitted':
            val += 8192
        elif self.verticalLayout == 'Universal Smushing':
            val += 16384
        else:
            val += 16384
            val += 256 if self.vRule[1] else 0
            val += 512 if self.vRule[2] else 0
            val += 1024 if self.vRule[3] else 0
            val += 2048 if self.vRule[4] else 0
            val += 4096 if self.vRule[5] else 0

        return val

    def generateFigFontHeader(self) -> str:
        header: list[str] = []
        baseline = self.baseline

        if self.height is None:
            raise ValueError("Height must be specified, or should be automatically determined.")
        if baseline is None:
            baseline = self.height
        baseline = int(baseline)
        if baseline <= 0 or baseline > self.height:
            baseline = self.height

        header.append('flf2a' + self.hardBlank)
        header.append(str(self.height))
        header.append(str(baseline))
        header.append(str(self.maxLength))
        header.append(str(self._getOldLayoutValue()))
        header.append(str(len(self.commentLines)))
        header.append("1" if self.rightToLeft else "0")
        header.append(str(self._getFullLayoutValue()))
        header.append(str(self.codeTagCount))

        return ' '.join(header)

    def _fixFigChars(self):
        height = 0
        charWidth: dict[int, int] = {}
        maxWidth = 0

        # Fix case insensitivity
        if self.caseInsensitive is True:
            for ii in range(97, 123):
                self.figChars[ii] = self.figChars[ii - 32]

        # Calculate max height and ensure consistent width for each character
        for idx in self.figChars:
            figChar = self.figChars[idx].replace('\r\n', '\n').split('\n')
            height = max(height, len(figChar))
            charWidth[idx] = 0

            for line in figChar:
                charWidth[idx] = max(charWidth[idx], len(line))

            for i in range(len(figChar)):
                if len(figChar[i]) < charWidth[idx]:
                    figChar[i] += spacePad(charWidth[idx] - len(figChar[i]))

                maxWidth = max(maxWidth, charWidth[idx])

            self.figChars[idx] = '\n'.join(figChar)

        # Fix any height issues
        for idx in self.figChars:
            figChar = self.figChars[idx].replace('\r\n', '\n').split('\n')
            if len(figChar) < height:
                self.figChars[idx] = '\n'.join(figChar) + '\n' + blankLines(height - len(figChar), charWidth[idx])

        self.height = height
        self.maxLength = maxWidth + 2

    def createFigFileData(self) -> str:
        """Generates the FIGlet file data for the current font."""
        output = ''
        self._fixFigChars()

        output = self.generateFigFontHeader() + '\n'
        output += "\n".join(self.commentLines) + '\n'

        for char in self.charOrder:
            figChar = self.figChars.get(char)
            if figChar is None:
                raise Exception(f"Character {char} missing from figChars")
            output += (self.endMark + '\n').join(figChar.split('\n'))
            output += self.endMark + self.endMark + '\n'

        return output

def extract_textures(image_path: str):
    """Removes the border around glyphs in an image, creates a new image without the border, and converts the image into FIGlet format font files."""

    # Open the image
    image = Image.open(image_path)

    # Calculate the texture size and border width
    width, height = image.size
    texture_width = 4
    texture_height = 4
    border_width = 1

    # Calculate the number of textures in each dimension
    num_textures_x = (width - border_width) // (texture_width + border_width)
    num_textures_y = (height - border_width) // (texture_height + border_width)

    # Create a new image to store the extracted textures
    extracted_image = Image.new('RGB', (num_textures_x * texture_width, num_textures_y * texture_height))
    
    half_size_meta_glyphs: dict[int, str] = {}
    full_size_meta_glyphs: dict[int, str] = {}

    # Extract textures
    for row in range(num_textures_y):
        for col in range(num_textures_x):
            # Calculate the coordinates for the current texture
            left = col * (texture_width + border_width) + border_width
            upper = row * (texture_height + border_width) + border_width
            right = left + texture_width
            lower = upper + texture_height

            # Crop the texture from the original image
            texture = image.crop((left, upper, right, lower))

            # Calculate the paste coordinates on the extracted image
            paste_x = col * texture_width
            paste_y = row * texture_height

            # Paste the texture onto the extracted image
            extracted_image.paste(texture, (paste_x, paste_y))

            # Calculate the ordinal of the character
            ordinal = row * num_textures_x + col
            ordinal -= 2
            
            # Extract as half-size FIGlet font
            extracted_text_half = ""
            for y in range(0, texture_height, 2):
                for x in range(0, texture_width, 2):
                    # Get the four pixels that make up a character
                    fg_palette_index = 1
                    aa = texture.getpixel((x, y)) == fg_palette_index
                    ab = texture.getpixel((x, y + 1)) == fg_palette_index
                    ba = texture.getpixel((x + 1, y)) == fg_palette_index
                    bb = texture.getpixel((x + 1, y + 1)) == fg_palette_index

                    # Convert the pixel to a character
                    # char = block_char_lookup[(aa << 3) | (ab << 2) | (ba << 1) | bb]
                    char = block_char_lookup[(bb << 3) | (ab << 2) | (ba << 1) | aa]

                    # Add the character to the extracted text
                    extracted_text_half += char

                # Add a newline after each row
                extracted_text_half += '\n'
            
            half_size_meta_glyphs[ordinal] = extracted_text_half
            
            # Extract as full-size FIGlet font
            extracted_text_full = ""
            for y in range(texture_height):
                for x in range(texture_width):
                    # Get the pixel
                    fg_palette_index = 1
                    pixel = texture.getpixel((x, y)) == fg_palette_index

                    # Convert the pixel to a character
                    char = '█' if pixel else ' '

                    # Add the character to the extracted text
                    extracted_text_full += char

                # Add a newline after each row
                extracted_text_full += '\n'
            
            full_size_meta_glyphs[ordinal] = extracted_text_full
    
    for figChars in [half_size_meta_glyphs, full_size_meta_glyphs]:
        # Fill in the space characters with hard blanks
        # figChars[32] = figChars[32].replace(' ', '$')
        # Or just half of the max width of the FIGcharacters
        figChars[32] = '\n'.join(['$' * (len(row) // 2) for row in figChars[32].split('\n')])
        # Add hard blanks to the end of non-whitespace of each row of each FIGcharacter
        # With the "Full" layout, this will ensure a space between rendered FIGcharacters.
        # The fixup code (_fixFigChars) will handle the ragged right edge.
        for ordinal in figChars:
            figChars[ordinal] = '\n'.join([row.rstrip() + '$' for row in figChars[ordinal].split('\n')])

    half_size_font = FIGletFontWriter(
        figChars=half_size_meta_glyphs,
        baseline=2,
        commentLines=[
            "NanoTiny 2x2 (version 14)",
            "by Isaiah Odhner",
        ],
        horizontalLayout="Full",
        verticalLayout="Full",
    )
    full_size_font = FIGletFontWriter(
        figChars=full_size_meta_glyphs,
        baseline=4,
        commentLines=[
            "NanoTiny 4x4 (version 14)",
            "by Isaiah Odhner",
        ],
        horizontalLayout="Full",
        verticalLayout="Full",
    )

    return extracted_image, half_size_font.createFigFileData(), full_size_font.createFigFileData()

repo_folder = os.path.abspath(os.path.join(os.path.dirname(__file__), '../..'))
font_folder = os.path.join(repo_folder, 'fonts/NanoTiny')
image_input_path = os.path.join(font_folder, 'NanoTiny_v14.png')
image_output_path = os.path.join(font_folder, 'NanoTiny_v14_no_border.png')
half_size_flf_output_path = os.path.join(font_folder, 'NanoTiny_v14_2x2.flf')
full_size_flf_output_path = os.path.join(font_folder, 'NanoTiny_v14_4x4.flf')

extracted_image, extracted_text_half, extracted_text_full = extract_textures(image_input_path)
extracted_image.save(image_output_path)
print(f'Wrote extracted textures to {image_output_path}')
with open(full_size_flf_output_path, 'w') as f:
    f.write(extracted_text_full)
print(f'Wrote FIGlet font {full_size_flf_output_path}')
with open(half_size_flf_output_path, 'w') as f:
    f.write(extracted_text_half)
print(f'Wrote FIGlet font {half_size_flf_output_path}')