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September 20, 2019 15:24
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function overrideDefaultMethods(r, g, b, a, scriptId) { | |
var scriptNode = document.getElementById(scriptId); | |
function overrideCanvasProto(root) { | |
function overrideCanvasInternal(name, old) { | |
root.prototype[name] = old; | |
Object.defineProperty(root.prototype, name, | |
{ | |
value: function () { | |
var width = this.width; | |
console.log(width); | |
var height = this.height; | |
console.log(height); | |
var context = this.getContext("2d"); | |
if (!context) { | |
var can = document.createElement('canvas'); | |
var imageData = can.getContext('2d').getImageData(0, 0, width, height); | |
} else { | |
var imageData = context.getImageData(0, 0, width, height); | |
} | |
console.log(imageData); | |
console.log(r, g, b, a); | |
for (var i = 0; i < height; i++) { | |
for (var j = 0; j < width; j++) { | |
var index = ((i * (width * 4)) + (j * 4)); | |
imageData.data[index + 0] = imageData.data[index + 0] + r; | |
imageData.data[index + 1] = imageData.data[index + 1] + g; | |
imageData.data[index + 2] = imageData.data[index + 2] + b; | |
imageData.data[index + 3] = imageData.data[index + 3] + a; | |
} | |
} | |
if (!context) { | |
can.getContext('2d').putImageData(imageData, 0, 0); | |
return old.apply(can, arguments); | |
} else { | |
context.putImageData(imageData, 0, 0); | |
return old.apply(this, arguments); | |
} | |
} | |
} | |
); | |
} | |
overrideCanvasInternal("toDataURL", root.prototype.toDataURL); | |
overrideCanvasInternal("toBlob", root.prototype.toBlob); | |
} | |
function overrideCanvaRendProto(root) { | |
const name = "getImageData"; | |
const getImageData = root.prototype.getImageData; | |
root.prototype[name] = getImageData; | |
Object.defineProperty(root.prototype, "getImageData", | |
{ | |
value: function () { | |
var imageData = getImageData.apply(this, arguments); | |
var height = imageData.height; | |
var width = imageData.width; | |
console.log(width); | |
console.log(height); | |
console.log(imageData); | |
for (var i = 0; i < height; i++) { | |
for (var j = 0; j < width; j++) { | |
var index = ((i * (width * 4)) + (j * 4)); | |
imageData.data[index + 0] = imageData.data[index + 0] + r; | |
imageData.data[index + 1] = imageData.data[index + 1] + g; | |
imageData.data[index + 2] = imageData.data[index + 2] + b; | |
imageData.data[index + 3] = imageData.data[index + 3] + a; | |
} | |
} | |
return imageData; | |
} | |
} | |
); | |
} | |
function inject(element) { | |
if (element.tagName.toUpperCase() === "IFRAME" && element.contentWindow) { | |
try { | |
var hasAccess = element.contentWindow.HTMLCanvasElement; | |
} catch (e) { | |
return; | |
} | |
overrideCanvasProto(element.contentWindow.HTMLCanvasElement); | |
overrideCanvaRendProto(element.contentWindow.CanvasRenderingContext2D); | |
overrideDocumentProto(element.contentWindow.Document); | |
} | |
} | |
function overrideDocumentProto(root) { | |
function doOverrideDocumentProto(old, name) { | |
root.prototype[name] = old; | |
Object.defineProperty(root.prototype, name, | |
{ | |
value: function () { | |
var element = old.apply(this, arguments); | |
if (element == null) { | |
return null; | |
} | |
if (Object.prototype.toString.call(element) === '[object HTMLCollection]' || | |
Object.prototype.toString.call(element) === '[object NodeList]') { | |
for (var i = 0; i < element.length; ++i) { | |
var el = element[i]; | |
inject(el); | |
} | |
} else { | |
inject(element); | |
} | |
return element; | |
} | |
} | |
); | |
} | |
doOverrideDocumentProto(root.prototype.createElement, "createElement"); | |
doOverrideDocumentProto(root.prototype.createElementNS, "createElementNS"); | |
doOverrideDocumentProto(root.prototype.getElementById, "getElementById"); | |
doOverrideDocumentProto(root.prototype.getElementsByName, "getElementsByName"); | |
doOverrideDocumentProto(root.prototype.getElementsByClassName, "getElementsByClassName"); | |
doOverrideDocumentProto(root.prototype.getElementsByTagName, "getElementsByTagName"); | |
doOverrideDocumentProto(root.prototype.getElementsByTagNameNS, "getElementsByTagNameNS"); | |
} | |
if (canvasNoise == 1) { | |
overrideCanvasProto(HTMLCanvasElement); | |
overrideCanvaRendProto(CanvasRenderingContext2D); | |
overrideDocumentProto(Document); | |
scriptNode.parentNode.removeChild(scriptNode); | |
} |
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