cocos-enhance-kit/engine/cocos2d/particle/CCPNGReader.js
2022-06-25 00:23:03 +08:00

336 lines
13 KiB
JavaScript

/****************************************************************************
Copyright (c) 2011 Devon Govett
Copyright (c) 2008-2010 Ricardo Quesada
Copyright (c) 2011-2012 cocos2d-x.org
Copyright (c) 2013-2016 Chukong Technologies Inc.
Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
http://www.cocos2d-x.org
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.
****************************************************************************/
const zlib = require('../compression/zlib.min');
const debug = require('../core/CCDebug');
/**
* A png file reader
* @name PNGReader
*/
var PNGReader = function(data){
var chunkSize, colors, delayDen, delayNum, frame, i, index, key, section, ccshort, text, _i, _j, _ref;
this.data = data;
this.pos = 8;
this.palette = [];
this.imgData = [];
this.transparency = {};
this.animation = null;
this.text = {};
frame = null;
while (true) {
chunkSize = this.readUInt32();
section = ((function() {
var _i, _results;
_results = [];
for (i = _i = 0; _i < 4; i = ++_i) {
_results.push(String.fromCharCode(this.data[this.pos++]));
}
return _results;
}).call(this)).join('');
switch (section) {
case 'IHDR':
this.width = this.readUInt32();
this.height = this.readUInt32();
this.bits = this.data[this.pos++];
this.colorType = this.data[this.pos++];
this.compressionMethod = this.data[this.pos++];
this.filterMethod = this.data[this.pos++];
this.interlaceMethod = this.data[this.pos++];
break;
case 'acTL':
this.animation = {
numFrames: this.readUInt32(),
numPlays: this.readUInt32() || Infinity,
frames: []
};
break;
case 'PLTE':
this.palette = this.read(chunkSize);
break;
case 'fcTL':
if (frame) {
this.animation.frames.push(frame);
}
this.pos += 4;
frame = {
width: this.readUInt32(),
height: this.readUInt32(),
xOffset: this.readUInt32(),
yOffset: this.readUInt32()
};
delayNum = this.readUInt16();
delayDen = this.readUInt16() || 100;
frame.delay = 1000 * delayNum / delayDen;
frame.disposeOp = this.data[this.pos++];
frame.blendOp = this.data[this.pos++];
frame.data = [];
break;
case 'IDAT':
case 'fdAT':
if (section === 'fdAT') {
this.pos += 4;
chunkSize -= 4;
}
data = (frame != null ? frame.data : void 0) || this.imgData;
for (i = _i = 0; 0 <= chunkSize ? _i < chunkSize : _i > chunkSize; i = 0 <= chunkSize ? ++_i : --_i) {
data.push(this.data[this.pos++]);
}
break;
case 'tRNS':
this.transparency = {};
switch (this.colorType) {
case 3:
this.transparency.indexed = this.read(chunkSize);
ccshort = 255 - this.transparency.indexed.length;
if (ccshort > 0) {
for (i = _j = 0; 0 <= ccshort ? _j < ccshort : _j > ccshort; i = 0 <= ccshort ? ++_j : --_j) {
this.transparency.indexed.push(255);
}
}
break;
case 0:
this.transparency.grayscale = this.read(chunkSize)[0];
break;
case 2:
this.transparency.rgb = this.read(chunkSize);
}
break;
case 'tEXt':
text = this.read(chunkSize);
index = text.indexOf(0);
key = String.fromCharCode.apply(String, text.slice(0, index));
this.text[key] = String.fromCharCode.apply(String, text.slice(index + 1));
break;
case 'IEND':
if (frame) {
this.animation.frames.push(frame);
}
this.colors = (function() {
switch (this.colorType) {
case 0:
case 3:
case 4:
return 1;
case 2:
case 6:
return 3;
}
}).call(this);
this.hasAlphaChannel = (_ref = this.colorType) === 4 || _ref === 6;
colors = this.colors + (this.hasAlphaChannel ? 1 : 0);
this.pixelBitlength = this.bits * colors;
this.colorSpace = (function() {
switch (this.colors) {
case 1:
return 'DeviceGray';
case 3:
return 'DeviceRGB';
}
}).call(this);
if(Uint8Array != Array)
this.imgData = new Uint8Array(this.imgData);
return;
default:
this.pos += chunkSize;
}
this.pos += 4;
if (this.pos > this.data.length) {
throw new Error(debug.getError(6017));
}
}
};
PNGReader.prototype = {
constructor: PNGReader,
read:function(bytes){
var i, _i, _results;
_results = [];
for (i = _i = 0; 0 <= bytes ? _i < bytes : _i > bytes; i = 0 <= bytes ? ++_i : --_i) {
_results.push(this.data[this.pos++]);
}
return _results;
},
readUInt32:function(){
var b1, b2, b3, b4;
b1 = this.data[this.pos++] << 24;
b2 = this.data[this.pos++] << 16;
b3 = this.data[this.pos++] << 8;
b4 = this.data[this.pos++];
return b1 | b2 | b3 | b4;
},
readUInt16:function(){
var b1, b2;
b1 = this.data[this.pos++] << 8;
b2 = this.data[this.pos++];
return b1 | b2;
},
decodePixels:function(data){
var ccbyte, c, col, i, left, length, p, pa, paeth, pb, pc, pixelBytes, pixels, pos, row, scanlineLength, upper, upperLeft, _i, _j, _k, _l, _m;
if (data == null) {
data = this.imgData;
}
if (data.length === 0) {
return new Uint8Array(0);
}
var inflate = new zlib.Inflate(data,{index:0, verify:false});
data = inflate.decompress();
pixelBytes = this.pixelBitlength / 8;
scanlineLength = pixelBytes * this.width;
pixels = new Uint8Array(scanlineLength * this.height);
length = data.length;
row = 0;
pos = 0;
c = 0;
while (pos < length) {
switch (data[pos++]) {
case 0:
for (i = _i = 0; _i < scanlineLength; i = _i += 1) {
pixels[c++] = data[pos++];
}
break;
case 1:
for (i = _j = 0; _j < scanlineLength; i = _j += 1) {
ccbyte = data[pos++];
left = i < pixelBytes ? 0 : pixels[c - pixelBytes];
pixels[c++] = (ccbyte + left) % 256;
}
break;
case 2:
for (i = _k = 0; _k < scanlineLength; i = _k += 1) {
ccbyte = data[pos++];
col = (i - (i % pixelBytes)) / pixelBytes;
upper = row && pixels[(row - 1) * scanlineLength + col * pixelBytes + (i % pixelBytes)];
pixels[c++] = (upper + ccbyte) % 256;
}
break;
case 3:
for (i = _l = 0; _l < scanlineLength; i = _l += 1) {
ccbyte = data[pos++];
col = (i - (i % pixelBytes)) / pixelBytes;
left = i < pixelBytes ? 0 : pixels[c - pixelBytes];
upper = row && pixels[(row - 1) * scanlineLength + col * pixelBytes + (i % pixelBytes)];
pixels[c++] = (ccbyte + Math.floor((left + upper) / 2)) % 256;
}
break;
case 4:
for (i = _m = 0; _m < scanlineLength; i = _m += 1) {
ccbyte = data[pos++];
col = (i - (i % pixelBytes)) / pixelBytes;
left = i < pixelBytes ? 0 : pixels[c - pixelBytes];
if (row === 0) {
upper = upperLeft = 0;
} else {
upper = pixels[(row - 1) * scanlineLength + col * pixelBytes + (i % pixelBytes)];
upperLeft = col && pixels[(row - 1) * scanlineLength + (col - 1) * pixelBytes + (i % pixelBytes)];
}
p = left + upper - upperLeft;
pa = Math.abs(p - left);
pb = Math.abs(p - upper);
pc = Math.abs(p - upperLeft);
if (pa <= pb && pa <= pc) {
paeth = left;
} else if (pb <= pc) {
paeth = upper;
} else {
paeth = upperLeft;
}
pixels[c++] = (ccbyte + paeth) % 256;
}
break;
default:
throw new Error(debug.getError(6018, data[pos - 1]));
}
row++;
}
return pixels;
},
copyToImageData:function(imageData,pixels){
var alpha, colors, data, i, input, j, k, length, palette, v, _ref;
colors = this.colors;
palette = null;
alpha = this.hasAlphaChannel;
if (this.palette.length) {
palette = (_ref = this._decodedPalette) != null ? _ref : this._decodedPalette = this.decodePalette();
colors = 4;
alpha = true;
}
data = imageData.data || imageData;
length = data.length;
input = palette || pixels;
i = j = 0;
if (colors === 1) {
while (i < length) {
k = palette ? pixels[i / 4] * 4 : j;
v = input[k++];
data[i++] = v;
data[i++] = v;
data[i++] = v;
data[i++] = alpha ? input[k++] : 255;
j = k;
}
} else {
while (i < length) {
k = palette ? pixels[i / 4] * 4 : j;
data[i++] = input[k++];
data[i++] = input[k++];
data[i++] = input[k++];
data[i++] = alpha ? input[k++] : 255;
j = k;
}
}
},
decodePalette:function(){
var c, i, palette, pos, ret, transparency, _i, _ref, _ref1;
palette = this.palette;
transparency = this.transparency.indexed || [];
ret = new Uint8Array((transparency.length || 0) + palette.length);
pos = 0;
c = 0;
for (i = _i = 0, _ref = palette.length; _i < _ref; i = _i += 3) {
ret[pos++] = palette[i];
ret[pos++] = palette[i + 1];
ret[pos++] = palette[i + 2];
ret[pos++] = (_ref1 = transparency[c++]) != null ? _ref1 : 255;
}
return ret;
},
render: function (canvas) {
var ctx, data;
canvas.width = this.width;
canvas.height = this.height;
ctx = canvas.getContext("2d");
data = ctx.createImageData(this.width, this.height);
this.copyToImageData(data, this.decodePixels());
return ctx.putImageData(data, 0, 0);
}
};
module.exports = PNGReader;