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support for transparent colour blocks without palettes

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This commit is contained in:
Luke Page 2015-08-02 23:09:08 +01:00
parent 51365543ae
commit b9293eaa2b
3 changed files with 62 additions and 28 deletions
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22
lib/bitmapper.js
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@ -17,8 +17,7 @@ function bitRetriever(data, depth) {
case 16:
var byte2 = data[i];
i++;
byte = Math.floor((((byte << 8) + byte2) * 255) / (Math.pow(2, 16) - 1) + 0.5);
leftOver.push(byte);
leftOver.push(((byte << 8) + byte2));
break;
case 4:
var byte2 = byte & 0x0f;
@ -70,8 +69,14 @@ exports.dataToBitMap = function(data, width, height, bpp, depth, interlace) {
if (depth !== 8) {
var bits = bitRetriever(data, depth);
}
var pxData = new Buffer(width * height * 4);
var maxBit = depth >= 8 ? 255 : (Math.pow(2, depth) - 1);
var pxData;
if (depth <= 8) {
pxData = new Buffer(width * height * 4);
} else {
// TODO: could be more effecient and use a buffer but change how we write to use 16 bit write methods with index * 2
pxData = new Array(width * height * 4);
}
var maxBit = Math.pow(2, depth) - 1;
var rawPos = 0;
var pixelData;
var images;
@ -90,15 +95,6 @@ exports.dataToBitMap = function(data, width, height, bpp, depth, interlace) {
images = [{width: width, height: height}];
}
for (var y = 0; y < height; y++) {
for (var x = 0; x < width; x++) {
pxData[(y * 4 * width) + (x * 4) + 0] = 255;
pxData[(y * 4 * width) + (x * 4) + 1] = 0;
pxData[(y * 4 * width) + (x * 4) + 2] = 0;
pxData[(y * 4 * width) + (x * 4) + 3] = 255;
}
}
for(var imageIndex = 0; imageIndex < images.length; imageIndex++) {
var imageWidth = images[imageIndex].width;
var imageHeight = images[imageIndex].height;

66
lib/parser.js
View file

@ -252,6 +252,13 @@ Parser.prototype._parseTRNS = function(data) {
// for colorType 0 (grayscale) and 2 (rgb)
// there might be one gray/color defined as transparent
if (this._colorType === 0) {
// grey, 2 bytes
this._transColor = [data.readUInt16BE(0)];
}
if (this._colorType === 2) {
this._transColor = [data.readUInt16BE(0), data.readUInt16BE(2), data.readUInt16BE(4)];
}
this._handleChunkEnd();
};
@ -300,7 +307,9 @@ Parser.prototype._parseIEND = function(data) {
this.finished();
};
Parser.prototype.reverseFiltered = function(data, depth, width, height) {
Parser.prototype.reverseFiltered = function(indata, depth, width, height) {
var outdata = indata; // only different for 16 bits
if (this._colorType == 3) { // paletted
//console.log("paletted");
@ -312,28 +321,57 @@ Parser.prototype.reverseFiltered = function(data, depth, width, height) {
for (var x = 0; x < width; x++) {
var pxPos = pxRowPos + (x << 2),
color = this._palette[data[pxPos]];
color = this._palette[indata[pxPos]];
for (var i = 0; i < 4; i++)
data[pxPos + i] = color[i];
indata[pxPos + i] = color[i];
}
}
} else if (depth < 8) {
//console.log("adjusting");
} else {
var pxLineLength = width << 2;
var maxOutSample = 255;
var maxInSample = Math.pow(2, depth) - 1;
for (var y = 0; y < height; y++) {
var pxRowPos = y * pxLineLength;
if (this._transColor) {
for (var y = 0; y < height; y++) {
var pxRowPos = y * pxLineLength;
for (var x = 0; x < width; x++) {
var pxPos = pxRowPos + (x << 2);
for (var i = 0; i < 4; i++)
data[pxPos + i] = Math.floor((data[pxPos + i] * maxOutSample) / maxInSample + 0.5);
for (var x = 0; x < width; x++) {
var pxPos = pxRowPos + (x << 2);
var makeTrans = false;
//console.log(pxPos);
if (this._transColor.length === 1) {
if (this._transColor[0] === indata[pxPos]) {
makeTrans = true;
}
} else if (this._transColor[0] === indata[pxPos] && this._transColor[1] === indata[pxPos + 1] && this._transColor[2] === indata[pxPos + 2]) {
makeTrans = true;
}
if (makeTrans) {
for (var i = 0; i < 4; i++) {
indata[pxPos + i] = 0;
}
}
}
}
}
if (depth !== 8) {
if (depth === 16) {
outdata = new Buffer(width * height * 4);
}
//console.log("adjusting");
var maxOutSample = 255;
var maxInSample = Math.pow(2, depth) - 1;
for (var y = 0; y < height; y++) {
var pxRowPos = y * pxLineLength;
for (var x = 0; x < width; x++) {
var pxPos = pxRowPos + (x << 2);
for (var i = 0; i < 4; i++)
outdata[pxPos + i] = Math.floor((indata[pxPos + i] * maxOutSample) / maxInSample + 0.5);
}
}
}
}
return data;
return outdata;
};

2
test/test.js
View file

@ -7,7 +7,7 @@ fs.readdir(__dirname + '/in/', function(err, files) {
files.forEach(function(file) {
if (!file.match(/.*\.png$/i))
if (!file.match(/\.png$/i))
return;
var expectedError = false;