const fs = require('fs').promises; const PNG = require("pngjs").PNG; const process = require('process'); const { Buffer } = require('buffer'); const StringBuilder = require('string-builder'); // Starting color index let startIndex = 0; let transparentColor = 0; let transparentIndex = -1; main(process.argv.slice(2)).then( () => process.exit(0), (e) => { console.error(e); process.exit(1); } ); function findColorIndex(png, pixel) { for (let i = 0; i < png.palette.length; i += 1) { const color = png.palette[i].slice(0, pixel.length); // Handle RGB or RGBA if (color.every((c, idx) => c === pixel[idx])) { return i + startIndex; } } return null; } function pngToIIgsBuff(png) { let i = 0; const buff = Buffer.alloc(png.height * (png.width / 2), 0); for (let y = 0; y < png.height; y += 1) { for (let x = 0; x < png.width; x += 1, i += 4) { const pixel = png.data.slice(i, i + 4); const index = findColorIndex(png, pixel); const j = y * (png.width / 2) + Math.floor(x / 2); if (index > 15) { console.warn('; Pixel index greater than 15. Skipping...'); continue; } if (x % 2 === 0) { buff[j] = 16 * index; } else { buff[j] = buff[j] | index; } } } return buff; } function shiftImage(src) { const { width, height, colorType, bitDepth } = src; const dst = new PNG({ width, height, colorType, bitDepth }); PNG.bitblt(src, dst, 1, 0, width - 1, height, 0, 0); PNG.bitblt(src, dst, 0, 0, 1, height, width - 1, 0); return dst; } function pngToIIgsBuffRepeat(png) { let i = 0; const buff = Buffer.alloc(png.height * png.width, 0); for (let y = 0; y < png.height; y += 1) { for (let x = 0; x < png.width; x += 1, i += 4) { const pixel = png.data.slice(i, i + 4); const index = findColorIndex(png, pixel); const j = y * png.width + Math.floor(x / 2); if (index > 15) { console.warn('; Pixel index greater than 15. Skipping...'); continue; } if (x % 2 === 0) { buff[j] = 16 * index; } else { buff[j] = buff[j] | index; } buff[j + (png.width / 2)] = buff[j]; } } return buff; } function paletteToIIgs(palette) { const r = Math.round(palette[0] / 17); const g = Math.round(palette[1] / 17); const b = Math.round(palette[2] / 17); return '0' + r.toString(16).toUpperCase() + g.toString(16).toUpperCase() + b.toString(16).toUpperCase(); } function getArg(argv, arg, fn, defaultValue) { for (let i = 0; i < argv.length; i += 1) { if (argv[i] === arg) { if (fn) { return fn(argv[i+1]); } return true; // Return true if the argument was found } } return defaultValue; } async function readPNG(filename) { const data = await fs.readFile(filename); const png = PNG.sync.read(data); if (png.colorType !== 3) { throw new Error('PNG must be in palette color type'); } if (png.palette.length > 16) { throw new Error(`Too many colors. Must be 16 or less. Found ${png.palette.length}`); } return png; } async function main(argv) { try { const png = await readPNG(argv[0]); startIndex = getArg(argv, '--start-index', x => parseInt(x, 10), 0); asTileData = getArg(argv, '--as-tile-data', null, 0); maxTiles = getArg(argv, '--max-tiles', x => parseInt(x, 10), 64); transparentColor = getArg(argv, '--transparent-color-index', x => parseInt(x, 10), -1); transparentIndex = transparentColor; console.info(`; startIndex = ${startIndex}`); if (png.colorType !== 3) { console.warn('; PNG must be in palette color type'); return; } if (png.palette.length > 16) { console.warn('; Too many colors. Must be 16 or less'); return; } // Dump the palette in IIgs hex format console.log('; Palette:'); const hexCodes = png.palette.map(c => '$' + paletteToIIgs(c)); console.log(';', hexCodes.join(',')); // Just convert a paletted PNG to IIgs memory format. We make sure that only a few widths // are supported let buff = null; if (png.width === 512) { console.log('; Converting to BG1 format...'); buff = pngToIIgsBuff(png); } if (png.width === 256) { console.log('; Converting to BG1 format w/repeat...'); buff = pngToIIgsBuffRepeat(png); } if (png.width === 328 || png.width == 320) { console.log('; Converting to BG0 format...'); buff = pngToIIgsBuff(png); } if (buff && argv[1]) { if (asTileData) { writeToTileDataSource(buff, png.width / 2, maxTiles); } else { console.log(`; Writing to output file ${argv[1]}`); await writeBinayOutput(argv[1], buff); } } } catch (e) { console.log(`; ${e}`); process.exit(1); } } function reverse(str) { return [...str].reverse().join(''); // use [...str] instead of split as it is unicode-aware. } function toHex(h) { return h.toString(16).padStart(2, '0'); } function swap(hex) { const high = hex & 0xF0; const low = hex & 0x0F; return (high >> 4) | (low << 4); } function toMask(hex, transparentIndex) { if (transparentIndex === -1) { return 0; } const indexHigh = (transparentIndex & 0xF) << 4; const indexLow = (transparentIndex & 0xF); let mask = 0; if ((hex & 0xF0) === indexHigh) { mask = mask | 0xF0; } if ((hex & 0x0F) === indexLow) { mask = mask | 0x0F; } return mask; } /** * Return all four 32 byte chunks of data for a single 8x8 tile */ function buildTile(buff, width, x, y, transparentIndex = -1) { const tile = { isSolid: true, normal: { data: [], mask: [] }, flipped: { data: [], mask: [] } }; const offset = y * width + x; for (dy = 0; dy < 8; dy += 1) { const hex0 = buff[offset + dy * width + 0]; const hex1 = buff[offset + dy * width + 1]; const hex2 = buff[offset + dy * width + 2]; const hex3 = buff[offset + dy * width + 3]; const raw = [hex0, hex1, hex2, hex3]; const mask = raw.map(h => toMask(h, transparentIndex)); const data = raw.map((h, i) => h & ~mask[i]); tile.normal.data.push(data); tile.normal.mask.push(mask); // If we run across any non-zero mask value, then the tile is not solid if (mask.some(h => h != 0)) { tile.isSolid = false; } } for (dy = 0; dy < 8; dy += 1) { const hex0 = swap(buff[offset + dy * width + 0]); const hex1 = swap(buff[offset + dy * width + 1]); const hex2 = swap(buff[offset + dy * width + 2]); const hex3 = swap(buff[offset + dy * width + 3]); const raw = [hex3, hex2, hex1, hex0]; const mask = raw.map(h => toMask(h, transparentIndex)); const data = raw.map((h, i) => h & ~mask[i]); tile.flipped.data.push(data); tile.flipped.mask.push(mask); } return tile; } function buildTiles(buff, width, transparentIndex = -1) { const tiles = []; const MAX_TILES = 240; let count = 0; for (let y = 0; ; y += 8) { for (let x = 0; x < width; x += 4, count += 1) { if (count >= MAX_TILES) { return tiles; } const tile = buildTile(buff, width, x, y, transparentIndex); // Tiled TileIDs start at 1 tile.tileId = count + 1; tiles.push(tile); } } } function writeTileToStream(stream, data) { // Output the tile data for (const row of data) { const hex = row.map(d => toHex(d)).join(''); stream.write(' hex ' + hex + '\n'); } } function writeTilesToStream(stream, tiles, label='tiledata') { stream.write(`${label} ENT\n`); stream.write(''); stream.write('; Reserved space (tile 0 is special...)\n'); stream.write(' ds 128\n'); const MAX_TILES = 511; let count = 0; for (const tile of tiles.slice(0, MAX_TILES)) { console.log(`Writing tile ${count + 1}`); stream.write(`; Tile ID ${count + 1}, isSolid: ${tile.isSolid}\n`); writeTileToStream(stream, tile.normal.data); writeTileToStream(stream, tile.normal.mask); writeTileToStream(stream, tile.flipped.data); writeTileToStream(stream, tile.flipped.mask); stream.write(''); count += 1; } } function buildMerlinCodeForTile(data) { const sb = new StringBuilder(); // Output the tile data for (const row of data) { const hex = row.map(d => toHex(d)).join(''); sb.appendLine(' hex ' + hex); } return sb.toString(); } function buildMerlinCodeForTiles(tiles, label='tiledata') { const sb = new StringBuilder(); sb.appendLine(`${label} ENT`); sb.appendLine(); sb.appendLine('; Reserved space (tile 0 is special...)'); sb.appendLine(' ds 128'); const MAX_TILES = 511; let count = 0; for (const tile of tiles.slice(0, MAX_TILES)) { console.log(`Writing tile ${count + 1}`); sb.appendLine(`; Tile ID ${count + 1}, isSolid: ${tile.isSolid}`); sb.append(buildMerlinCodeForTile(tile.normal.data)); sb.append(buildMerlinCodeForTile(tile.normal.mask)); sb.append(buildMerlinCodeForTile(tile.flipped.data)); sb.append(buildMerlinCodeForTile(tile.flipped.mask)); sb.appendLine(); count += 1; } return sb.toString(); } function writeToTileDataSource(buff, width, MAX_TILES = 64) { console.log('tiledata ENT'); console.log(); console.log('; Reserved space (tile 0 is special...'); console.log(' ds 128'); let count = 0; for (let y = 0; ; y += 8) { for (let x = 0; x < width; x += 4, count += 1) { if (count >= MAX_TILES) { return; } console.log('; Tile ID ' + (count + 1)); console.log('; From image coordinates ' + (x * 2) + ', ' + y); const tile = buildTile(buff, width, x, y, transparentIndex); // Output the tile data for (const row of tile.normal.data) { const hex = row.map(d => toHex(d)).join(''); console.log(' hex ' + hex); } console.log(); // Output the tile mask for (const row of tile.normal.mask) { const hex = row.map(d => toHex(d)).join(''); console.log(' hex ' + hex); } console.log(); // Output the flipped tile data for (const row of tile.flipped.data) { const hex = row.map(d => toHex(d)).join(''); console.log(' hex ' + hex); } console.log(); // Output the flipped tile data for (const row of tile.flipped.mask) { const hex = row.map(d => toHex(d)).join(''); console.log(' hex ' + hex); } console.log(); } } } async function writeBinayOutput(filename, buff) { // Write a small header. This is useful and avoids triggering a sparse file load // bug when the first block of the file on the GS/OS drive is sparse. // Put the ASCII text of "GTERAW" in the first 6 bytes const header = Buffer.alloc(8); header.write('GTERAW', 'latin1'); // Use the special value $A5A5 to identify no transparency if (typeof transparentColor !== 'number') { header.writeUInt16LE(0xA5A5); } else { header.writeUInt16LE(0x1111 * transparentColor, 6); } await fs.writeFile(filename, Buffer.concat([header, buff])); } module.exports = { buildTile, buildTiles, buildMerlinCodeForTiles, buildMerlinCodeForTile, findColorIndex, paletteToIIgs, pngToIIgsBuff, readPNG, toHex, writeBinayOutput, writeToTileDataSource, writeTilesToStream }