%PDF-
%PDF-
Mini Shell
Mini Shell
/**
* tng.js - png reader
* Copyright (c) 2015, Christopher Jeffrey (MIT License).
* https://github.com/chjj/tng
*/
var fs = require('fs')
, util = require('util')
, path = require('path')
, zlib = require('zlib')
, assert = require('assert')
, cp = require('child_process')
, exec = cp.execFileSync;
/**
* PNG
*/
function PNG(file, options) {
var buf
, chunks
, idat
, pixels;
if (!(this instanceof PNG)) {
return new PNG(file, options);
}
if (!file) throw new Error('no file');
this.options = options || {};
this.colors = options.colors || require('blessed/lib/colors');
this.optimization = this.options.optimization || 'mem';
this.speed = this.options.speed || 1;
if (Buffer.isBuffer(file)) {
this.file = this.options.filename || null;
buf = file;
} else {
this.options.filename = file;
this.file = path.resolve(process.cwd(), file);
buf = fs.readFileSync(this.file);
}
this.format = buf.readUInt32BE(0) === 0x89504e47 ? 'png'
: buf.slice(0, 3).toString('ascii') === 'GIF' ? 'gif'
: buf.readUInt16BE(0) === 0xffd8 ? 'jpg'
: path.extname(this.file).slice(1).toLowerCase() || 'png';
if (this.format !== 'png') {
try {
return this.toPNG(buf);
} catch (e) {
throw e;
}
}
chunks = this.parseRaw(buf);
idat = this.parseChunks(chunks);
pixels = this.parseLines(idat);
this.bmp = this.createBitmap(pixels);
this.cellmap = this.createCellmap(this.bmp);
this.frames = this.compileFrames(this.frames);
}
PNG.prototype.parseRaw = function(buf) {
var chunks = []
, index = 0
, i = 0
, buf
, len
, type
, name
, data
, crc
, check
, critical
, public_
, conforming
, copysafe
, pos;
this._debug(this.file);
if (buf.readUInt32BE(0) !== 0x89504e47
|| buf.readUInt32BE(4) !== 0x0d0a1a0a) {
throw new Error('bad header');
}
i += 8;
while (i < buf.length) {
try {
len = buf.readUInt32BE(i);
i += 4;
pos = i;
type = buf.slice(i, i + 4);
name = type.toString('ascii');
i += 4;
data = buf.slice(i, i + len);
i += len;
check = this.crc32(buf.slice(pos, i));
crc = buf.readInt32BE(i);
i += 4;
critical = !!(~type[0] & 32);
public_ = !!(~type[1] & 32);
conforming = !!(~type[2] & 32);
copysafe = !!(~type[3] & 32);
if (crc !== check) {
throw new Error(name + ': bad crc');
}
} catch (e) {
if (this.options.debug) throw e;
break;
}
chunks.push({
index: index++,
id: name.toLowerCase(),
len: len,
pos: pos,
end: i,
type: type,
name: name,
data: data,
crc: crc,
check: check,
raw: buf.slice(pos, i),
flags: {
critical: critical,
public_: public_,
conforming: conforming,
copysafe: copysafe
}
});
}
return chunks;
};
PNG.prototype.parseChunks = function(chunks) {
var i
, chunk
, name
, data
, p
, idat
, info;
for (i = 0; i < chunks.length; i++) {
chunk = chunks[i];
name = chunk.id;
data = chunk.data;
info = {};
switch (name) {
case 'ihdr': {
this.width = info.width = data.readUInt32BE(0);
this.height = info.height = data.readUInt32BE(4);
this.bitDepth = info.bitDepth = data.readUInt8(8);
this.colorType = info.colorType = data.readUInt8(9);
this.compression = info.compression = data.readUInt8(10);
this.filter = info.filter = data.readUInt8(11);
this.interlace = info.interlace = data.readUInt8(12);
switch (this.bitDepth) {
case 1: case 2: case 4: case 8: case 16: case 24: case 32: break;
default: throw new Error('bad bit depth: ' + this.bitDepth);
}
switch (this.colorType) {
case 0: case 2: case 3: case 4: case 6: break;
default: throw new Error('bad color: ' + this.colorType);
}
switch (this.compression) {
case 0: break;
default: throw new Error('bad compression: ' + this.compression);
}
switch (this.filter) {
case 0: case 1: case 2: case 3: case 4: break;
default: throw new Error('bad filter: ' + this.filter);
}
switch (this.interlace) {
case 0: case 1: break;
default: throw new Error('bad interlace: ' + this.interlace);
}
break;
}
case 'plte': {
this.palette = info.palette = [];
for (p = 0; p < data.length; p += 3) {
this.palette.push({
r: data[p + 0],
g: data[p + 1],
b: data[p + 2],
a: 255
});
}
break;
}
case 'idat': {
this.size = this.size || 0;
this.size += data.length;
this.idat = this.idat || [];
this.idat.push(data);
info.size = data.length;
break;
}
case 'iend': {
this.end = true;
break;
}
case 'trns': {
this.alpha = info.alpha = Array.prototype.slice.call(data);
if (this.palette) {
for (p = 0; p < data.length; p++) {
if (!this.palette[p]) break;
this.palette[p].a = data[p];
}
}
break;
}
// https://wiki.mozilla.org/APNG_Specification
case 'actl': {
this.actl = info = {};
this.frames = [];
this.actl.numFrames = data.readUInt32BE(0);
this.actl.numPlays = data.readUInt32BE(4);
break;
}
case 'fctl': {
// IDAT is the first frame depending on the order:
// IDAT is a frame: acTL->fcTL->IDAT->[fcTL]->fdAT
// IDAT is not a frame: acTL->IDAT->[fcTL]->fdAT
if (!this.idat) {
this.idat = [];
this.frames.push({
idat: true,
fctl: info,
fdat: this.idat
});
} else {
this.frames.push({
fctl: info,
fdat: []
});
}
info.sequenceNumber = data.readUInt32BE(0);
info.width = data.readUInt32BE(4);
info.height = data.readUInt32BE(8);
info.xOffset = data.readUInt32BE(12);
info.yOffset = data.readUInt32BE(16);
info.delayNum = data.readUInt16BE(20);
info.delayDen = data.readUInt16BE(22);
info.disposeOp = data.readUInt8(24);
info.blendOp = data.readUInt8(25);
break;
}
case 'fdat': {
info.sequenceNumber = data.readUInt32BE(0);
info.data = data.slice(4);
this.frames[this.frames.length - 1].fdat.push(info.data);
break;
}
}
chunk.info = info;
}
this._debug(chunks);
if (this.frames) {
this.frames = this.frames.map(function(frame, i) {
frame.fdat = this.decompress(frame.fdat);
if (!frame.fdat.length) throw new Error('no data');
return frame;
}, this);
}
idat = this.decompress(this.idat);
if (!idat.length) throw new Error('no data');
return idat;
};
PNG.prototype.parseLines = function(data) {
var pixels = []
, x
, p
, prior
, line
, filter
, samples
, pendingSamples
, ch
, shiftStart
, i
, toShift
, sample;
this.sampleDepth =
this.colorType === 0 ? 1
: this.colorType === 2 ? 3
: this.colorType === 3 ? 1
: this.colorType === 4 ? 2
: this.colorType === 6 ? 4
: 1;
this.bitsPerPixel = this.bitDepth * this.sampleDepth;
this.bytesPerPixel = Math.ceil(this.bitsPerPixel / 8);
this.wastedBits = ((this.width * this.bitsPerPixel) / 8) - ((this.width * this.bitsPerPixel / 8) | 0);
this.byteWidth = Math.ceil(this.width * (this.bitsPerPixel / 8));
this.shiftStart = ((this.bitDepth + (8 / this.bitDepth - this.bitDepth)) - 1) | 0;
this.shiftMult = this.bitDepth >= 8 ? 0 : this.bitDepth;
this.mask = this.bitDepth === 32 ? 0xffffffff : (1 << this.bitDepth) - 1;
if (this.interlace === 1) {
samples = this.sampleInterlacedLines(data);
for (i = 0; i < samples.length; i += this.sampleDepth) {
pixels.push(samples.slice(i, i + this.sampleDepth));
}
return pixels;
}
for (p = 0; p < data.length; p += this.byteWidth) {
prior = line || [];
filter = data[p++];
line = data.slice(p, p + this.byteWidth);
line = this.unfilterLine(filter, line, prior);
samples = this.sampleLine(line);
for (i = 0; i < samples.length; i += this.sampleDepth) {
pixels.push(samples.slice(i, i + this.sampleDepth));
}
}
return pixels;
};
PNG.prototype.unfilterLine = function(filter, line, prior) {
for (var x = 0; x < line.length; x++) {
if (filter === 0) {
break;
} else if (filter === 1) {
line[x] = this.filters.sub(x, line, prior, this.bytesPerPixel);
} else if (filter === 2) {
line[x] = this.filters.up(x, line, prior, this.bytesPerPixel);
} else if (filter === 3) {
line[x] = this.filters.average(x, line, prior, this.bytesPerPixel);
} else if (filter === 4) {
line[x] = this.filters.paeth(x, line, prior, this.bytesPerPixel);
}
}
return line;
};
PNG.prototype.sampleLine = function(line, width) {
var samples = []
, x = 0
, pendingSamples
, ch
, i
, sample
, shiftStart
, toShift;
while (x < line.length) {
pendingSamples = this.sampleDepth;
while (pendingSamples--) {
ch = line[x];
if (this.bitDepth === 16) {
ch = (ch << 8) | line[++x];
} else if (this.bitDepth === 24) {
ch = (ch << 16) | (line[++x] << 8) | line[++x];
} else if (this.bitDepth === 32) {
ch = (ch << 24) | (line[++x] << 16) | (line[++x] << 8) | line[++x];
} else if (this.bitDepth > 32) {
throw new Error('bitDepth ' + this.bitDepth + ' unsupported.');
}
shiftStart = this.shiftStart;
toShift = shiftStart - (x === line.length - 1 ? this.wastedBits : 0);
for (i = 0; i <= toShift; i++) {
sample = (ch >> (this.shiftMult * shiftStart)) & this.mask;
if (this.colorType !== 3) {
if (this.bitDepth < 8) { // <= 8 would work too, doesn't matter
// sample = sample * (0xff / this.mask) | 0; // would work too
sample *= 0xff / this.mask;
sample |= 0;
} else if (this.bitDepth > 8) {
sample = (sample / this.mask) * 255 | 0;
}
}
samples.push(sample);
shiftStart--;
}
x++;
}
}
// Needed for deinterlacing?
if (width != null) {
samples = samples.slice(0, width * this.sampleDepth);
}
return samples;
};
// http://www.w3.org/TR/PNG-Filters.html
PNG.prototype.filters = {
sub: function Sub(x, line, prior, bpp) {
if (x < bpp) return line[x];
return (line[x] + line[x - bpp]) % 256;
},
up: function Up(x, line, prior, bpp) {
return (line[x] + (prior[x] || 0)) % 256;
},
average: function Average(x, line, prior, bpp) {
if (x < bpp) return Math.floor((prior[x] || 0) / 2);
// if (x < bpp) return (prior[x] || 0) >> 1;
return (line[x]
+ Math.floor((line[x - bpp] + prior[x]) / 2)
// + ((line[x - bpp] + prior[x]) >> 1)
) % 256;
},
paeth: function Paeth(x, line, prior, bpp) {
if (x < bpp) return prior[x] || 0;
return (line[x] + this._predictor(
line[x - bpp], prior[x] || 0, prior[x - bpp] || 0
)) % 256;
},
_predictor: function PaethPredictor(a, b, c) {
// a = left, b = above, c = upper left
var p = a + b - c
, pa = Math.abs(p - a)
, pb = Math.abs(p - b)
, pc = Math.abs(p - c);
if (pa <= pb && pa <= pc) return a;
if (pb <= pc) return b;
return c;
}
};
/**
* Adam7 deinterlacing ported to javascript from PyPNG:
* pypng - Pure Python library for PNG image encoding/decoding
* Copyright (c) 2009-2015, David Jones (MIT License).
* https://github.com/drj11/pypng
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
PNG.prototype.sampleInterlacedLines = function(raw) {
var psize
, vpr
, samples
, source_offset
, i
, pass
, xstart
, ystart
, xstep
, ystep
, recon
, ppr
, row_size
, y
, filter_type
, scanline
, flat
, offset
, k
, end_offset
, skip
, j
, k
, f;
var adam7 = [
[0, 0, 8, 8],
[4, 0, 8, 8],
[0, 4, 4, 8],
[2, 0, 4, 4],
[0, 2, 2, 4],
[1, 0, 2, 2],
[0, 1, 1, 2]
];
// Fractional bytes per pixel
psize = (this.bitDepth / 8) * this.sampleDepth;
// Values per row (of the target image)
vpr = this.width * this.sampleDepth;
// Make a result array, and make it big enough. Interleaving
// writes to the output array randomly (well, not quite), so the
// entire output array must be in memory.
samples = new Buffer(vpr * this.height);
samples.fill(0);
source_offset = 0;
for (i = 0; i < adam7.length; i++) {
pass = adam7[i];
xstart = pass[0];
ystart = pass[1];
xstep = pass[2];
ystep = pass[3];
if (xstart >= this.width) continue;
// The previous (reconstructed) scanline. Empty array at the
// beginning of a pass to indicate that there is no previous
// line.
recon = [];
// Pixels per row (reduced pass image)
ppr = Math.ceil((this.width - xstart) / xstep);
// Row size in bytes for this pass.
row_size = Math.ceil(psize * ppr);
for (y = ystart; y < this.height; y += ystep) {
filter_type = raw[source_offset];
source_offset += 1;
scanline = raw.slice(source_offset, source_offset + row_size);
source_offset += row_size;
recon = this.unfilterLine(filter_type, scanline, recon);
// Convert so that there is one element per pixel value
flat = this.sampleLine(recon, ppr);
if (xstep === 1) {
assert.equal(xstart, 0);
offset = y * vpr;
for (k = offset, f = 0; k < offset + vpr; k++, f++) {
samples[k] = flat[f];
}
} else {
offset = y * vpr + xstart * this.sampleDepth;
end_offset = (y + 1) * vpr;
skip = this.sampleDepth * xstep;
for (j = 0; j < this.sampleDepth; j++) {
for (k = offset + j, f = j; k < end_offset; k += skip, f += this.sampleDepth) {
samples[k] = flat[f];
}
}
}
}
}
return samples;
};
PNG.prototype.createBitmap = function(pixels) {
var bmp = []
, i;
if (this.colorType === 0) {
pixels = pixels.map(function(sample) {
return { r: sample[0], g: sample[0], b: sample[0], a: 255 };
});
} else if (this.colorType === 2) {
pixels = pixels.map(function(sample) {
return { r: sample[0], g: sample[1], b: sample[2], a: 255 };
});
} else if (this.colorType === 3) {
pixels = pixels.map(function(sample) {
if (!this.palette[sample[0]]) throw new Error('bad palette index');
return this.palette[sample[0]];
}, this);
} else if (this.colorType === 4) {
pixels = pixels.map(function(sample) {
return { r: sample[0], g: sample[0], b: sample[0], a: sample[1] };
});
} else if (this.colorType === 6) {
pixels = pixels.map(function(sample) {
return { r: sample[0], g: sample[1], b: sample[2], a: sample[3] };
});
}
for (i = 0; i < pixels.length; i += this.width) {
bmp.push(pixels.slice(i, i + this.width));
}
return bmp;
};
PNG.prototype.createCellmap = function(bmp, options) {
var bmp = bmp || this.bmp
, options = options || this.options
, cellmap = []
, scale = options.scale || 0.20
, height = bmp.length
, width = bmp[0].length
, cmwidth = options.width
, cmheight = options.height
, line
, x
, y
, xx
, yy
, scale
, xs
, ys;
if (cmwidth) {
scale = cmwidth / width;
} else if (cmheight) {
scale = cmheight / height;
}
if (!cmheight) {
cmheight = Math.round(height * scale);
}
if (!cmwidth) {
cmwidth = Math.round(width * scale);
}
ys = height / cmheight;
xs = width / cmwidth;
for (y = 0; y < bmp.length; y += ys) {
line = [];
yy = Math.round(y);
if (!bmp[yy]) break;
for (x = 0; x < bmp[yy].length; x += xs) {
xx = Math.round(x);
if (!bmp[yy][xx]) break;
line.push(bmp[yy][xx]);
}
cellmap.push(line);
}
return cellmap;
};
PNG.prototype.renderANSI = function(bmp) {
var self = this
, out = '';
bmp.forEach(function(line, y) {
line.forEach(function(pixel, x) {
var outch = self.getOutch(x, y, line, pixel);
out += self.pixelToSGR(pixel, outch);
});
out += '\n';
});
return out;
};
PNG.prototype.renderContent = function(bmp, el) {
var self = this
, out = '';
bmp.forEach(function(line, y) {
line.forEach(function(pixel, x) {
var outch = self.getOutch(x, y, line, pixel);
out += self.pixelToTags(pixel, outch);
});
out += '\n';
});
el.setContent(out);
return out;
};
PNG.prototype.renderScreen = function(bmp, screen, xi, xl, yi, yl) {
var self = this
, lines = screen.lines
, cellLines
, y
, yy
, x
, xx
, alpha
, attr
, ch;
cellLines = bmp.reduce(function(cellLines, line, y) {
var cellLine = [];
line.forEach(function(pixel, x) {
var outch = self.getOutch(x, y, line, pixel)
, cell = self.pixelToCell(pixel, outch);
cellLine.push(cell);
});
cellLines.push(cellLine);
return cellLines;
}, []);
for (y = yi; y < yl; y++) {
yy = y - yi;
for (x = xi; x < xl; x++) {
xx = x - xi;
if (lines[y] && lines[y][x] && cellLines[yy] && cellLines[yy][xx]) {
alpha = cellLines[yy][xx].pop();
// completely transparent
if (alpha === 0.0) {
continue;
}
// translucency / blending
if (alpha < 1.0) {
attr = cellLines[yy][xx][0];
ch = cellLines[yy][xx][1];
lines[y][x][0] = this.colors.blend(lines[y][x][0], attr, alpha);
if (ch !== ' ') lines[y][x][1] = ch;
lines[y].dirty = true;
continue;
}
// completely opaque
lines[y][x] = cellLines[yy][xx];
lines[y].dirty = true;
}
}
}
};
PNG.prototype.renderElement = function(bmp, el) {
var xi = el.aleft + el.ileft
, xl = el.aleft + el.width - el.iright
, yi = el.atop + el.itop
, yl = el.atop + el.height - el.ibottom;
return this.renderScreen(bmp, el.screen, xi, xl, yi, yl);
};
PNG.prototype.pixelToSGR = function(pixel, ch) {
var bga = 1.0
, fga = 0.5
, a = pixel.a / 255
, bg
, fg;
bg = this.colors.match(
pixel.r * a * bga | 0,
pixel.g * a * bga | 0,
pixel.b * a * bga | 0);
if (ch && this.options.ascii) {
fg = this.colors.match(
pixel.r * a * fga | 0,
pixel.g * a * fga | 0,
pixel.b * a * fga | 0);
if (a === 0) {
return '\x1b[38;5;' + fg + 'm' + ch + '\x1b[m';
}
return '\x1b[38;5;' + fg + 'm\x1b[48;5;' + bg + 'm' + ch + '\x1b[m';
}
if (a === 0) return ' ';
return '\x1b[48;5;' + bg + 'm \x1b[m';
};
PNG.prototype.pixelToTags = function(pixel, ch) {
var bga = 1.0
, fga = 0.5
, a = pixel.a / 255
, bg
, fg;
bg = this.colors.RGBtoHex(
pixel.r * a * bga | 0,
pixel.g * a * bga | 0,
pixel.b * a * bga | 0);
if (ch && this.options.ascii) {
fg = this.colors.RGBtoHex(
pixel.r * a * fga | 0,
pixel.g * a * fga | 0,
pixel.b * a * fga | 0);
if (a === 0) {
return '{' + fg + '-fg}' + ch + '{/}';
}
return '{' + fg + '-fg}{' + bg + '-bg}' + ch + '{/}';
}
if (a === 0) return ' ';
return '{' + bg + '-bg} {/' + bg + '-bg}';
};
PNG.prototype.pixelToCell = function(pixel, ch) {
var bga = 1.0
, fga = 0.5
, a = pixel.a / 255
, bg
, fg;
bg = this.colors.match(
pixel.r * bga | 0,
pixel.g * bga | 0,
pixel.b * bga | 0);
if (ch && this.options.ascii) {
fg = this.colors.match(
pixel.r * fga | 0,
pixel.g * fga | 0,
pixel.b * fga | 0);
} else {
fg = 0x1ff;
ch = null;
}
// if (a === 0) bg = 0x1ff;
return [(0 << 18) | (fg << 9) | (bg << 0), ch || ' ', a];
};
// Taken from libcaca:
PNG.prototype.getOutch = (function() {
var dchars = '????8@8@#8@8##8#MKXWwz$&%x><\\/xo;+=|^-:i\'.`, `. ';
var luminance = function(pixel) {
var a = pixel.a / 255
, r = pixel.r * a
, g = pixel.g * a
, b = pixel.b * a
, l = 0.2126 * r + 0.7152 * g + 0.0722 * b;
return l / 255;
};
return function(x, y, line, pixel) {
var lumi = luminance(pixel)
, outch = dchars[lumi * (dchars.length - 1) | 0];
return outch;
};
})();
PNG.prototype.compileFrames = function(frames) {
return this.optimization === 'mem'
? this.compileFrames_lomem(frames)
: this.compileFrames_locpu(frames);
};
PNG.prototype.compileFrames_lomem = function(frames) {
if (!this.actl) return;
return frames.map(function(frame, i) {
this.width = frame.fctl.width;
this.height = frame.fctl.height;
var pixels = frame._pixels || this.parseLines(frame.fdat)
, bmp = frame._bmp || this.createBitmap(pixels)
, fc = frame.fctl;
return {
actl: this.actl,
fctl: frame.fctl,
delay: (fc.delayNum / (fc.delayDen || 100)) * 1000 | 0,
bmp: bmp
};
}, this);
};
PNG.prototype.compileFrames_locpu = function(frames) {
if (!this.actl) return;
this._curBmp = null;
this._lastBmp = null;
return frames.map(function(frame, i) {
this.width = frame.fctl.width;
this.height = frame.fctl.height;
var pixels = frame._pixels || this.parseLines(frame.fdat)
, bmp = frame._bmp || this.createBitmap(pixels)
, renderBmp = this.renderFrame(bmp, frame, i)
, cellmap = this.createCellmap(renderBmp)
, fc = frame.fctl;
return {
actl: this.actl,
fctl: frame.fctl,
delay: (fc.delayNum / (fc.delayDen || 100)) * 1000 | 0,
bmp: renderBmp,
cellmap: cellmap
};
}, this);
};
PNG.prototype.renderFrame = function(bmp, frame, i) {
var first = this.frames[0]
, last = this.frames[i - 1]
, fc = frame.fctl
, xo = fc.xOffset
, yo = fc.yOffset
, lxo
, lyo
, x
, y
, line
, p;
if (!this._curBmp) {
this._curBmp = [];
for (y = 0; y < first.fctl.height; y++) {
line = [];
for (x = 0; x < first.fctl.width; x++) {
p = bmp[y][x];
line.push({ r: p.r, g: p.g, b: p.b, a: p.a });
}
this._curBmp.push(line);
}
}
if (last && last.fctl.disposeOp !== 0) {
lxo = last.fctl.xOffset;
lyo = last.fctl.yOffset;
for (y = 0; y < last.fctl.height; y++) {
for (x = 0; x < last.fctl.width; x++) {
if (last.fctl.disposeOp === 0) {
// none / keep
} else if (last.fctl.disposeOp === 1) {
// background / clear
this._curBmp[lyo + y][lxo + x] = { r: 0, g: 0, b: 0, a: 0 };
} else if (last.fctl.disposeOp === 2) {
// previous / restore
p = this._lastBmp[y][x];
this._curBmp[lyo + y][lxo + x] = { r: p.r, g: p.g, b: p.b, a: p.a };
}
}
}
}
if (frame.fctl.disposeOp === 2) {
this._lastBmp = [];
for (y = 0; y < frame.fctl.height; y++) {
line = [];
for (x = 0; x < frame.fctl.width; x++) {
p = this._curBmp[yo + y][xo + x];
line.push({ r: p.r, g: p.g, b: p.b, a: p.a });
}
this._lastBmp.push(line);
}
} else {
this._lastBmp = null;
}
for (y = 0; y < frame.fctl.height; y++) {
for (x = 0; x < frame.fctl.width; x++) {
p = bmp[y][x];
if (fc.blendOp === 0) {
// source
this._curBmp[yo + y][xo + x] = { r: p.r, g: p.g, b: p.b, a: p.a };
} else if (fc.blendOp === 1) {
// over
if (p.a !== 0) {
this._curBmp[yo + y][xo + x] = { r: p.r, g: p.g, b: p.b, a: p.a };
}
}
}
}
return this._curBmp;
};
PNG.prototype._animate = function(callback) {
if (!this.frames) {
return callback(this.bmp, this.cellmap);
}
var self = this
, numPlays = this.actl.numPlays || Infinity
, running = 0
, i = -1;
this._curBmp = null;
this._lastBmp = null;
var next_lomem = function() {
if (!running) return;
var frame = self.frames[++i];
if (!frame) {
if (!--numPlays) return callback();
i = -1;
// XXX may be able to optimize by only setting the self._curBmp once???
self._curBmp = null;
self._lastBmp = null;
return setImmediate(next);
}
var bmp = frame.bmp
, renderBmp = self.renderFrame(bmp, frame, i)
, cellmap = self.createCellmap(renderBmp);
callback(renderBmp, cellmap);
return setTimeout(next, frame.delay / self.speed | 0);
};
var next_locpu = function() {
if (!running) return;
var frame = self.frames[++i];
if (!frame) {
if (!--numPlays) return callback();
i = -1;
return setImmediate(next);
}
callback(frame.bmp, frame.cellmap);
return setTimeout(next, frame.delay / self.speed | 0);
};
var next = this.optimization === 'mem'
? next_lomem
: next_locpu;
this._control = function(state) {
if (state === -1) {
i = -1;
self._curBmp = null;
self._lastBmp = null;
running = 0;
callback(self.frames[0].bmp,
self.frames[0].cellmap || self.createCellmap(self.frames[0].bmp));
return;
}
if (state === running) return;
running = state;
return next();
};
this._control(1);
};
PNG.prototype.play = function(callback) {
if (!this._control || callback) {
this.stop();
return this._animate(callback);
}
this._control(1);
};
PNG.prototype.pause = function() {
if (!this._control) return;
this._control(0);
};
PNG.prototype.stop = function() {
if (!this._control) return;
this._control(-1);
};
PNG.prototype.toPNG = function(input) {
var options = this.options
, file = this.file
, format = this.format
, buf
, img
, gif
, i
, control
, disposeOp;
if (format !== 'gif') {
buf = exec('convert', [format + ':-', 'png:-'],
{ stdio: ['pipe', 'pipe', 'ignore'], input: input });
img = PNG(buf, options);
img.file = file;
return img;
}
gif = GIF(input, options);
this.width = gif.width;
this.height = gif.height;
this.frames = [];
for (i = 0; i < gif.images.length; i++) {
img = gif.images[i];
// Convert from gif disposal to png disposal. See:
// http://www.w3.org/Graphics/GIF/spec-gif89a.txt
control = img.control || gif;
disposeOp = Math.max(0, (control.disposeMethod || 0) - 1);
if (disposeOp > 2) disposeOp = 0;
this.frames.push({
fctl: {
sequenceNumber: i,
width: img.width,
height: img.height,
xOffset: img.left,
yOffset: img.top,
delayNum: control.delay,
delayDen: 100,
disposeOp: disposeOp,
blendOp: 1
},
fdat: [],
_pixels: [],
_bmp: img.bmp
});
}
this.bmp = this.frames[0]._bmp;
this.cellmap = this.createCellmap(this.bmp);
if (this.frames.length > 1) {
this.actl = { numFrames: gif.images.length, numPlays: gif.numPlays || 0 };
this.frames = this.compileFrames(this.frames);
} else {
this.frames = undefined;
}
return this;
};
// Convert a gif to an apng using imagemagick. Unfortunately imagemagick
// doesn't support apngs, so we coalesce the gif frames into one image and then
// slice them into frames.
PNG.prototype.gifMagick = function(input) {
var options = this.options
, file = this.file
, format = this.format
, buf
, fmt
, img
, frames
, frame
, width
, height
, iwidth
, twidth
, i
, lines
, line
, x
, y;
buf = exec('convert',
[format + ':-', '-coalesce', '+append', 'png:-'],
{ stdio: ['pipe', 'pipe', 'ignore'], input: input });
fmt = '{"W":%W,"H":%H,"w":%w,"h":%h,"d":%T,"x":"%X","y":"%Y"},'
frames = exec('identify', ['-format', fmt, format + ':-'],
{ encoding: 'utf8', stdio: ['pipe', 'pipe', 'ignore'], input: input });
frames = JSON.parse('[' + frames.trim().slice(0, -1) + ']');
img = PNG(buf, options);
img.file = file;
Object.keys(img).forEach(function(key) {
this[key] = img[key];
}, this);
width = frames[0].W;
height = frames[0].H;
iwidth = 0;
twidth = 0;
this.width = width;
this.height = height;
this.frames = [];
for (i = 0; i < frames.length; i++) {
frame = frames[i];
frame.x = +frame.x;
frame.y = +frame.y;
iwidth = twidth;
twidth += width;
lines = [];
for (y = frame.y; y < height; y++) {
line = [];
for (x = iwidth + frame.x; x < twidth; x++) {
line.push(img.bmp[y][x]);
}
lines.push(line);
}
this.frames.push({
fctl: {
sequenceNumber: i,
width: frame.w,
height: frame.h,
xOffset: frame.x,
yOffset: frame.y,
delayNum: frame.d,
delayDen: 100,
disposeOp: 0,
blendOp: 0
},
fdat: [],
_pixels: [],
_bmp: lines
});
}
this.bmp = this.frames[0]._bmp;
this.cellmap = this.createCellmap(this.bmp);
if (this.frames.length > 1) {
this.actl = { numFrames: frames.length, numPlays: 0 };
this.frames = this.compileFrames(this.frames);
} else {
this.frames = undefined;
}
return this;
};
PNG.prototype.decompress = function(buffers) {
return zlib.inflateSync(new Buffer(buffers.reduce(function(out, data) {
return out.concat(Array.prototype.slice.call(data));
}, [])));
};
/**
* node-crc
* https://github.com/alexgorbatchev/node-crc
* https://github.com/alexgorbatchev/node-crc/blob/master/LICENSE
*
* The MIT License (MIT)
*
* Copyright 2014 Alex Gorbatchev
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
PNG.prototype.crc32 = (function() {
var crcTable = [
0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
];
return function crc32(buf) {
//var crc = previous === 0 ? 0 : ~~previous ^ -1;
var crc = -1;
for (var i = 0, len = buf.length; i < len; i++) {
crc = crcTable[(crc ^ buf[i]) & 0xff] ^ (crc >>> 8);
}
return crc ^ -1;
};
})();
PNG.prototype._debug = function() {
if (!this.options.log) return;
return this.options.log.apply(null, arguments);
};
/**
* GIF
*/
function GIF(file, options) {
var self = this;
if (!(this instanceof GIF)) {
return new GIF(file, options);
}
var info = {}
, p = 0
, buf
, i
, total
, sig
, desc
, img
, ext
, label
, size;
if (!file) throw new Error('no file');
options = options || {};
this.options = options;
// XXX If the gif is not optimized enough
// it may OOM the process with too many frames.
// TODO: Implement in PNG reader.
this.pixelLimit = this.options.pixelLimit || 7622550;
this.totalPixels = 0;
if (Buffer.isBuffer(file)) {
buf = file;
file = null;
} else {
file = path.resolve(process.cwd(), file);
buf = fs.readFileSync(file);
}
sig = buf.slice(0, 6).toString('ascii');
if (sig !== 'GIF87a' && sig !== 'GIF89a') {
throw new Error('bad header: ' + sig);
}
this.width = buf.readUInt16LE(6);
this.height = buf.readUInt16LE(8);
this.flags = buf.readUInt8(10);
this.gct = !!(this.flags & 0x80);
this.gctsize = (this.flags & 0x07) + 1;
this.bgIndex = buf.readUInt8(11);
this.aspect = buf.readUInt8(12);
p += 13;
if (this.gct) {
this.colors = [];
total = 1 << this.gctsize;
for (i = 0; i < total; i++, p += 3) {
this.colors.push([buf[p], buf[p + 1], buf[p + 2], 255]);
}
}
this.images = [];
this.extensions = [];
try {
while (p < buf.length) {
desc = buf.readUInt8(p);
p += 1;
if (desc === 0x2c) {
img = {};
img.left = buf.readUInt16LE(p);
p += 2;
img.top = buf.readUInt16LE(p);
p += 2;
img.width = buf.readUInt16LE(p);
p += 2;
img.height = buf.readUInt16LE(p);
p += 2;
img.flags = buf.readUInt8(p);
p += 1;
img.lct = !!(img.flags & 0x80);
img.ilace = !!(img.flags & 0x40);
img.lctsize = (img.flags & 0x07) + 1;
if (img.lct) {
img.lcolors = [];
total = 1 << img.lctsize;
for (i = 0; i < total; i++, p += 3) {
img.lcolors.push([buf[p], buf[p + 1], buf[p + 2], 255]);
}
}
img.codeSize = buf.readUInt8(p);
p += 1;
img.size = buf.readUInt8(p);
p += 1;
img.lzw = [buf.slice(p, p + img.size)];
p += img.size;
while (buf[p] !== 0x00) {
// Some gifs screw up their size.
// XXX Same for all subblocks?
if (buf[p] === 0x3b && p === buf.length - 1) {
p--;
break;
}
size = buf.readUInt8(p);
p += 1;
img.lzw.push(buf.slice(p, p + size));
p += size;
}
assert.equal(buf.readUInt8(p), 0x00);
p += 1;
if (ext && ext.label === 0xf9) {
img.control = ext;
}
this.totalPixels += img.width * img.height;
this.images.push(img);
if (this.totalPixels >= this.pixelLimit) {
break;
}
} else if (desc === 0x21) {
// Extensions:
// http://www.w3.org/Graphics/GIF/spec-gif89a.txt
ext = {};
label = buf.readUInt8(p);
p += 1;
ext.label = label;
if (label === 0xf9) {
size = buf.readUInt8(p);
assert.equal(size, 0x04);
p += 1;
ext.fields = buf.readUInt8(p);
ext.disposeMethod = (ext.fields >> 2) & 0x07;
ext.useTransparent = !!(ext.fields & 0x01);
p += 1;
ext.delay = buf.readUInt16LE(p);
p += 2;
ext.transparentColor = buf.readUInt8(p);
p += 1;
while (buf[p] !== 0x00) {
size = buf.readUInt8(p);
p += 1;
p += size;
}
assert.equal(buf.readUInt8(p), 0x00);
p += 1;
this.delay = ext.delay;
this.transparentColor = ext.transparentColor;
this.disposeMethod = ext.disposeMethod;
this.useTransparent = ext.useTransparent;
} else if (label === 0xff) {
// https://wiki.whatwg.org/wiki/GIF#Specifications
size = buf.readUInt8(p);
p += 1;
ext.id = buf.slice(p, p + 8).toString('ascii');
p += 8;
ext.auth = buf.slice(p, p + 3).toString('ascii');
p += 3;
ext.data = [];
while (buf[p] !== 0x00) {
size = buf.readUInt8(p);
p += 1;
ext.data.push(buf.slice(p, p + size));
p += size;
}
ext.data = new Buffer(ext.data.reduce(function(out, data) {
return out.concat(Array.prototype.slice.call(data));
}, []));
// AnimExts looping extension (identical to netscape)
if (ext.id === 'ANIMEXTS' && ext.auth === '1.0') {
ext.id = 'NETSCAPE';
ext.auth = '2.0';
ext.animexts = true;
}
// Netscape extensions
if (ext.id === 'NETSCAPE' && ext.auth === '2.0') {
if (ext.data.readUInt8(0) === 0x01) {
// Netscape looping extension
// http://graphcomp.com/info/specs/ani_gif.html
ext.numPlays = ext.data.readUInt16LE(1);
this.numPlays = ext.numPlays;
} else if (ext.data.readUInt8(0) === 0x02) {
// Netscape buffering extension
this.minBuffer = ext.data;
}
}
// Adobe XMP extension
if (ext.id === 'XMP Data' && ext.auth === 'XMP') {
ext.xmp = ext.data.toString('utf8');
this.xmp = ext.xmp;
}
// ICC extension
if (ext.id === 'ICCRGBG1' && ext.auth === '012') {
// NOTE: Says size is 4 bytes, not 1? Maybe just buffer size?
this.icc = ext.data;
}
// fractint extension
if (ext.id === 'fractint' && /^00[1-7]$/.test(ext.auth)) {
// NOTE: Says size is 4 bytes, not 1? Maybe just buffer size?
// Size: '!\377\013' == [0x00, 0x15, 0xff, 0x0b]
this.fractint = ext.data;
}
assert.equal(buf.readUInt8(p), 0x00);
p += 1;
} else {
ext.data = [];
while (buf[p] !== 0x00) {
size = buf.readUInt8(p);
p += 1;
ext.data.push(buf.slice(p, p + size));
p += size;
}
assert.equal(buf.readUInt8(p), 0x00);
p += 1;
}
this.extensions.push(ext);
} else if (desc === 0x3b) {
break;
} else if (p === buf.length - 1) {
// } else if (desc === 0x00 && p === buf.length - 1) {
break;
} else {
throw new Error('unknown block');
}
}
} catch (e) {
if (options.debug) {
throw e;
}
}
this.images = this.images.map(function(img, imageIndex) {
var control = img.control || this;
img.lzw = new Buffer(img.lzw.reduce(function(out, data) {
return out.concat(Array.prototype.slice.call(data));
}, []));
try {
img.data = this.decompress(img.lzw, img.codeSize);
} catch (e) {
if (options.debug) throw e;
return;
}
var interlacing = [
[ 0, 8 ],
[ 4, 8 ],
[ 2, 4 ],
[ 1, 2 ],
[ 0, 0 ]
];
var table = img.lcolors || this.colors
, row = 0
, col = 0
, ilp = 0
, p = 0
, b
, idx
, i
, y
, x
, line
, pixel;
img.samples = [];
// Rewritten version of:
// https://github.com/lbv/ka-cs-programs/blob/master/lib/gif-reader.js
for (;;) {
b = img.data[p++];
if (b == null) break;
idx = (row * img.width + col) * 4;
if (!table[b]) {
if (options.debug) throw new Error('bad samples');
table[b] = [0, 0, 0, 0];
}
img.samples[idx] = table[b][0];
img.samples[idx + 1] = table[b][1];
img.samples[idx + 2] = table[b][2];
img.samples[idx + 3] = table[b][3];
if (control.useTransparent && b === control.transparentColor) {
img.samples[idx + 3] = 0;
}
if (++col >= img.width) {
col = 0;
if (img.ilace) {
row += interlacing[ilp][1];
if (row >= img.height) {
row = interlacing[++ilp][0];
}
} else {
row++;
}
}
}
img.pixels = [];
for (i = 0; i < img.samples.length; i += 4) {
img.pixels.push(img.samples.slice(i, i + 4));
}
img.bmp = [];
for (y = 0, p = 0; y < img.height; y++) {
line = [];
for (x = 0; x < img.width; x++) {
pixel = img.pixels[p++];
if (!pixel) {
if (options.debug) throw new Error('no pixel');
line.push({ r: 0, g: 0, b: 0, a: 0 });
continue;
}
line.push({ r: pixel[0], g: pixel[1], b: pixel[2], a: pixel[3] });
}
img.bmp.push(line);
}
return img;
}, this).filter(Boolean);
if (!this.images.length) {
throw new Error('no image data or bad decompress');
}
}
// Rewritten version of:
// https://github.com/lbv/ka-cs-programs/blob/master/lib/gif-reader.js
GIF.prototype.decompress = function(input, codeSize) {
var bitDepth = codeSize + 1
, CC = 1 << codeSize
, EOI = CC + 1
, stack = []
, table = []
, ntable = 0
, oldCode = null
, buffer = 0
, nbuffer = 0
, p = 0
, buf = []
, bits
, read
, ans
, n
, code
, i
, K
, b
, maxElem;
for (;;) {
if (stack.length === 0) {
bits = bitDepth;
read = 0;
ans = 0;
while (read < bits) {
if (nbuffer === 0) {
if (p >= input.length) return buf;
buffer = input[p++];
nbuffer = 8;
}
n = Math.min(bits - read, nbuffer);
ans |= (buffer & ((1 << n) - 1)) << read;
read += n;
nbuffer -= n;
buffer >>= n;
}
code = ans;
if (code === EOI) {
break;
}
if (code === CC) {
table = [];
for (i = 0; i < CC; ++i) {
table[i] = [i, -1, i];
}
bitDepth = codeSize + 1;
maxElem = 1 << bitDepth;
ntable = CC + 2;
oldCode = null;
continue;
}
if (oldCode === null) {
oldCode = code;
buf.push(table[code][0]);
continue;
}
if (code < ntable) {
for (i = code; i >= 0; i = table[i][1]) {
stack.push(table[i][0]);
}
table[ntable++] = [
table[code][2],
oldCode,
table[oldCode][2]
];
} else {
K = table[oldCode][2];
table[ntable++] = [K, oldCode, K];
for (i = code; i >= 0; i = table[i][1]) {
stack.push(table[i][0]);
}
}
oldCode = code;
if (ntable === maxElem) {
maxElem = 1 << (++bitDepth);
if (bitDepth > 12) bitDepth = 12;
}
}
b = stack.pop();
if (b == null) break;
buf.push(b);
}
return buf;
};
/**
* Expose
*/
exports = PNG;
exports.png = PNG;
exports.gif = GIF;
module.exports = exports;
Zerion Mini Shell 1.0