ciallorize/paint.js

Ciallorize your bundled js into ascii art.

const sharp = require('sharp');
const compareAST = require('./compare_ast');

module.exports = async (sequence, mask_path, options = {
    fontWidthToHeightRatio: 16/40,
    characterCompensation: 0.95
}) => {
    const image = await sharp(mask_path)
        .grayscale()
        .raw()
        .toBuffer({ resolveWithObject: true });
    const width = image.info.width;
    const height = image.info.height;

    let black_pixels = 0;
    let white_pixels = 0;

    const threshold = 0xFF / 2;
    for(let i of image.data){
        if(i < threshold){
            black_pixels++;
        }else{
            white_pixels++;
        }
    }

    // console.log(`Black pixels: ${black_pixels}`);
    // console.log(`White pixels: ${white_pixels}`);

    const fontConstant = options.fontWidthToHeightRatio;   // 英文字符的宽:高
    const characterCount = Math.round(sequence.join('').length * options.characterCompensation);
    const k = Math.sqrt(black_pixels / characterCount * fontConstant);
    const targetWidth = Math.floor(width / k);
    const targetHeight = Math.floor(height / k * fontConstant);

    // console.log(`characterCount: ${characterCount}`);
    
    const resizedImage = await sharp(image.data, {
        raw: {
            width: width,
            height: height,
            channels: 1
        }
    })
        .resize(targetWidth, targetHeight, {fit:'fill'})
        .grayscale()
        .raw()
        .toBuffer({ resolveWithObject: true })
    // console.log(resizedImage);
    
    

    const lines = []
    for(let row=0;row<resizedImage.info.height;row++){
        let line = []
        for(let col=0;col<resizedImage.info.width;col++){
            let pixel = resizedImage.data[row*resizedImage.info.width+col]
            if(pixel < threshold){
                line.push(1)
            }else{
                line.push(0)
            }
        }
        lines.push(line)
    }

    function getTokenWidth(token){
        return token.length
    }
    
    function consumeLine(previousLines, line, sequence, seqIdx){
        let rowIdx = 0

        let code = ''

        while(rowIdx<line.length){
            if(seqIdx==sequence.length){
                break
            }
            if(line[rowIdx]==0){
                code += ' '
                rowIdx++
            }else{
                code += sequence[seqIdx]
                rowIdx+= getTokenWidth(sequence[seqIdx])
                seqIdx++
            }
        }

        function validate(){
            const crrCode = previousLines.join('\n') +
                         '\n' + code +
                         '\n' + sequence.slice(seqIdx).join('')
            try{
                return compareAST(crrCode, sequence.join(''))
            }catch{
                return false
            }
        }

        while(!validate()){
            code += sequence[seqIdx]
            seqIdx++
        }

        return {code, seqIdx}
    }

    const resultLines = []
    let seqIdx = 0
    for(let row=0;row<lines.length;row++){
        let line = lines[row]
        let {code, seqIdx: nextSeqIdx} = consumeLine(resultLines, line, sequence, seqIdx)
        resultLines.push(code)
        seqIdx = nextSeqIdx
    }
    
    return resultLines.join('\n')+sequence.slice(seqIdx).join('')
}