neoboxels/js/save_load.js

/*
    Code for saving and loading data.

    Features a somewhat efficient compression algorithm.
*/

function downloadFile(data, filename) {
    // ONLY works with ascii/latin1 characters. if you'd like to be able to download UTF-16 data (for compression, etc), please find a base64-encoding library for UTF-16, and replace "btoa".
    
    let a = document.createElement("a");
    a.href = "data:text/plain;base64,"+(btoa(data));
    a.setAttribute("download", filename);
    a.click();
    a.remove();
    
}

function uploadFile(options = {}) {
    base64_output = Boolean(options.useBase64);
    textEncoding = options.textEncoding ? options.textEncoding : "UTF-8";
    
    return new Promise(function(res) {
        var input = document.createElement('input');
        input.type = 'file';
        
        input.onchange = e => { 
            var file = e.target.files[0];
            var reader = new FileReader();
            reader.onload = readerEvent => {
                
                res(readerEvent.target.result); // this is the content!
                input.remove();
                
            }
            
            if(base64_output)
                reader.readAsDataURL(file);
            else
                reader.readAsText(file, textEncoding);
            
            
        }
        
        input.click();
    });
}

function save() {
    let jason = {
        'pal': [],
        'data': [],
        'width': canvas.width,
        'height': canvas.height
    };

    for (let item of mainTiles.tiles) {
        jason.pal.push([
            item.namespace,
            item.id
        ])
    }

    let json = jason.data;

    for (let i = 0; i < canvas.blocks.length; i += 128) {
        let arr = canvas.blocks.slice(i, i + 128);

        let pal = Object.values(arr.filter((v, i, a) => a.findIndex(v2 => (v2 === v)) === i).sort());
        let otherArray;
        if (pal.length < 9 && pal.length > 1) {
            otherArray = new Uint8Array(64);

            for (let i in otherArray) {
                otherArray[i] = (((pal.indexOf(arr[i*2]) * 8) + pal.indexOf(arr[i*2+1])) + 'A'.charCodeAt()) % 128;
            }

        } else if (pal.length > 8) {
            otherArray = new Uint8Array(128);

            for (let i in otherArray) {
                otherArray[i] = (pal.indexOf(arr[i]) + 'A'.charCodeAt()) % 128;
            }

        }


        json[i / 128] = {
            'pal': pal,
            'dat': otherArray ? new TextDecoder('ascii').decode(otherArray) : undefined
        };
    }
    
    downloadFile(JSON.stringify(jason), "game-data.json");
}

function loadFile(text_data) {
    let jason = JSON.parse(text_data);

    let json = jason.data;

    canvas.width = jason.width;
    canvas.height = jason.height;
    canvas.resize();
    
    let mainPal = jason.pal.map(x => mainTiles.resolveID(x[0],x[1]));

    console.log(mainPal);

    for (let i in json) {
        let data = json[i];
        let pal = data.pal;
        let dat = new TextEncoder('ascii').encode(data.dat);

        let otherArray = new Uint16Array(128);

        if (pal.length < 2) {
            for (let i in otherArray) {
                otherArray[i] =  mainPal[(pal[0])];
            }
            
        } else if (pal.length < 9) {
            for (let i in dat) {
                otherArray[i*2] = mainPal[pal[((dat[i] - 'A'.charCodeAt()) & 0x38) / 8]];
                otherArray[i*2+1] =  mainPal[pal[(dat[i] - 'A'.charCodeAt()) & 0x7]];
            }
            
        } else {
            for (let i in dat) {
                otherArray[i] =  mainPal[pal[(dat[i] - 'A'.charCodeAt()) & 0x7F]];
            }
        }

        canvas.blocks.set(otherArray,Math.min(i*128,canvas.blocks.length - 128));
    }

    for (let i in canvas.temp) {
        canvas.temp[i] = mainTiles.tiles[canvas.blocks[i]].attributes.temperature;
    }
}

function load() {
    uploadFile().then((text_data) => {
        try {
            loadFile(text_data);
        } catch(err) {
            alert("This save file is invalid! Please provide a JSON file, with Altboxels save data.")
        }
    })
}

var loc3 = new URL(window.location).searchParams;
let loc = loc3.get("embed");
if (loc3.get('oops') == 'true') {
    alert('Oh no!');
}
var loc2;

if (loc) {
    (async function() {
        loadFile(await fetch(loc).then(x => x.text()));
        load();
        loc2 = loc3;
    })()
}