mirror of
https://github.com/kkapsner/CanvasBlocker
synced 2024-12-22 21:00:23 +01:00
526 lines
16 KiB
JavaScript
526 lines
16 KiB
JavaScript
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
(function(){
|
|
"use strict";
|
|
|
|
var scope;
|
|
if ((typeof exports) !== "undefined"){
|
|
scope = exports;
|
|
}
|
|
else {
|
|
scope = require.register("./modifiedCanvasAPI", {});
|
|
}
|
|
|
|
const colorStatistics = require("./colorStatistics");
|
|
const logging = require("./logging");
|
|
const {copyCanvasToWebgl} = require("./webgl");
|
|
const {getWrapped, checkerWrapper} = require("./modifiedAPIFunctions");
|
|
|
|
var randomSupply = null;
|
|
|
|
function getContext(window, canvas){
|
|
return window.HTMLCanvasElement.prototype.getContext.call(canvas, "2d") ||
|
|
window.HTMLCanvasElement.prototype.getContext.call(canvas, "webgl") ||
|
|
window.HTMLCanvasElement.prototype.getContext.call(canvas, "experimental-webgl") ||
|
|
window.HTMLCanvasElement.prototype.getContext.call(canvas, "webgl2") ||
|
|
window.HTMLCanvasElement.prototype.getContext.call(canvas, "experimental-webgl2");
|
|
}
|
|
function getImageData(window, context){
|
|
var imageData;
|
|
var source;
|
|
if ((context.canvas.width || 0) * (context.canvas.height || 0) === 0){
|
|
imageData = new (getWrapped(window).ImageData)(0, 0);
|
|
source = new (getWrapped(window).ImageData)(0, 0);
|
|
}
|
|
else if (context instanceof window.CanvasRenderingContext2D){
|
|
imageData = window.CanvasRenderingContext2D.prototype.getImageData.call(
|
|
context,
|
|
0, 0,
|
|
context.canvas.width, context.canvas.height
|
|
);
|
|
source = imageData.data;
|
|
}
|
|
else {
|
|
imageData = new (getWrapped(window).ImageData)(context.canvas.width, context.canvas.height);
|
|
source = new Uint8Array(imageData.data.length);
|
|
(
|
|
context instanceof window.WebGLRenderingContext?
|
|
window.WebGLRenderingContext:
|
|
window.WebGL2RenderingContext
|
|
).prototype.readPixels.call(
|
|
context,
|
|
0, 0, context.canvas.width, context.canvas.height,
|
|
context.RGBA, context.UNSIGNED_BYTE,
|
|
source
|
|
);
|
|
}
|
|
return {
|
|
imageData,
|
|
source
|
|
};
|
|
}
|
|
|
|
var canvasCache = Object.create(null);
|
|
function getFakeCanvas(window, original, prefs){
|
|
try {
|
|
if (prefs("useCanvasCache")){
|
|
var originalDataURL = original.toDataURL();
|
|
var cached = canvasCache[originalDataURL];
|
|
if (cached){
|
|
return cached;
|
|
}
|
|
}
|
|
// original may not be a canvas -> we must not leak an error
|
|
var context = getContext(window, original);
|
|
var {imageData, source} = getImageData(window, context);
|
|
var desc = imageData.data;
|
|
var l = desc.length;
|
|
|
|
var ignoredColors = {};
|
|
var statistic;
|
|
if (prefs("ignoreFrequentColors")){
|
|
statistic = colorStatistics.compute(source);
|
|
ignoredColors = statistic.getMaxColors(prefs("ignoreFrequentColors"));
|
|
}
|
|
if (prefs("minColors")){
|
|
if (!colorStatistics.hasMoreColors(source, prefs("minColors"), statistic)){
|
|
return original;
|
|
}
|
|
}
|
|
|
|
var rng = randomSupply.getPixelRng(l, window, ignoredColors);
|
|
var fakeAlphaChannel = prefs("fakeAlphaChannel");
|
|
for (var i = 0; i < l; i += 4){
|
|
var [r, g, b, a] = rng(
|
|
source[i + 0],
|
|
source[i + 1],
|
|
source[i + 2],
|
|
source[i + 3],
|
|
i / 4
|
|
);
|
|
desc[i + 0] = r;
|
|
desc[i + 1] = g;
|
|
desc[i + 2] = b;
|
|
desc[i + 3] = fakeAlphaChannel? a: source[i + 3];
|
|
}
|
|
var canvas = original.cloneNode(true);
|
|
context = window.HTMLCanvasElement.prototype.getContext.call(canvas, "2d");
|
|
context.putImageData(imageData, 0, 0);
|
|
if (prefs("useCanvasCache")){
|
|
canvasCache[originalDataURL] = canvas;
|
|
canvasCache[canvas.toDataURL()] = canvas;
|
|
}
|
|
return canvas;
|
|
}
|
|
catch (e){
|
|
logging.warning("Error while faking:", e);
|
|
return original;
|
|
}
|
|
}
|
|
function randomMixImageData(window, imageData1, imageData2){
|
|
var data1 = imageData1.data;
|
|
var data2 = imageData2.data;
|
|
var l = data1.length;
|
|
if (l === data2.length){
|
|
var rng = randomSupply.getPixelRng(l, window, {});
|
|
|
|
for (var i = 0; i < l; i += 4){
|
|
const signR = data1[i + 0] > data2[i + 0]? -1: 1;
|
|
const signG = data1[i + 1] > data2[i + 1]? -1: 1;
|
|
const signB = data1[i + 2] > data2[i + 2]? -1: 1;
|
|
const signA = data1[i + 3] > data2[i + 3]? -1: 1;
|
|
|
|
var [deltaR, deltaG, deltaB, deltaA] = rng(
|
|
signR * (data2[i + 0] - data1[i + 0]),
|
|
signG * (data2[i + 1] - data1[i + 1]),
|
|
signB * (data2[i + 2] - data1[i + 2]),
|
|
signA * (data2[i + 3] - data1[i + 3]),
|
|
i / 4
|
|
);
|
|
data2[i + 0] = data1[i + 0] + signR * deltaR;
|
|
data2[i + 1] = data1[i + 1] + signG * deltaG;
|
|
data2[i + 2] = data1[i + 2] + signB * deltaB;
|
|
data2[i + 3] = data1[i + 3] + signA * deltaA;
|
|
}
|
|
}
|
|
return imageData2;
|
|
}
|
|
|
|
function canvasSizeShouldBeFaked(canvas, prefs){
|
|
if (canvas){
|
|
var size = canvas.height * canvas.width;
|
|
var maxSize = prefs("maxFakeSize") || Number.POSITIVE_INFINITY;
|
|
var minSize = prefs("minFakeSize") || 0;
|
|
return size > minSize & size <= maxSize;
|
|
}
|
|
else {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
function getProtectedPartChecker(pref, url){
|
|
const protectedPart = pref("protectedCanvasPart", url);
|
|
if (protectedPart === "everything"){
|
|
return function(){
|
|
return true;
|
|
};
|
|
}
|
|
else if (protectedPart === "nothing"){
|
|
return function(){
|
|
return false;
|
|
};
|
|
}
|
|
else {
|
|
return function(parts){
|
|
if (Array.isArray(parts)){
|
|
return parts.some(function(part){
|
|
return part === protectedPart;
|
|
});
|
|
}
|
|
else {
|
|
return parts === protectedPart;
|
|
}
|
|
};
|
|
}
|
|
}
|
|
|
|
scope.setRandomSupply = function(supply){
|
|
randomSupply = supply;
|
|
};
|
|
var canvasContextType = new WeakMap();
|
|
// changed functions and their fakes
|
|
scope.changedFunctions = {
|
|
getContext: {
|
|
type: "context",
|
|
getStatus: function(obj, status, prefs){
|
|
if (status.internal){
|
|
return {
|
|
mode: "allow",
|
|
type: status.type,
|
|
active: false
|
|
};
|
|
}
|
|
else if (getProtectedPartChecker(prefs, status.url)("input")){
|
|
return {
|
|
mode: status.mode,
|
|
type: status.type,
|
|
active: true
|
|
};
|
|
}
|
|
else {
|
|
status = Object.create(status);
|
|
status.active = false;
|
|
return status;
|
|
}
|
|
},
|
|
object: "HTMLCanvasElement",
|
|
fakeGenerator: function(checker){
|
|
return function(context, contextAttributes){
|
|
return checkerWrapper(checker, this, arguments, function(args, check){
|
|
var {prefs, notify, window, original} = check;
|
|
canvasContextType.set(this, context);
|
|
return original.apply(this, window.Array.from(args));
|
|
});
|
|
};
|
|
}
|
|
},
|
|
toDataURL: {
|
|
type: "readout",
|
|
getStatus: function(obj, status, prefs){
|
|
const protectedPartChecker = getProtectedPartChecker(prefs, status.url);
|
|
status = Object.create(status);
|
|
status.active = protectedPartChecker("readout");
|
|
if (!status.active && protectedPartChecker("input")){
|
|
var contextType = canvasContextType.get(obj);
|
|
status.active = contextType !== "2d";
|
|
}
|
|
return status;
|
|
},
|
|
object: "HTMLCanvasElement",
|
|
fakeGenerator: function(checker){
|
|
return function toDataURL(){
|
|
return checkerWrapper(checker, this, arguments, function(args, check){
|
|
var {prefs, notify, window, original} = check;
|
|
if (canvasSizeShouldBeFaked(this, prefs)){
|
|
var fakeCanvas = getFakeCanvas(window, this, prefs);
|
|
if (fakeCanvas !== this){
|
|
notify("fakedReadout");
|
|
}
|
|
return original.apply(fakeCanvas, window.Array.from(args));
|
|
}
|
|
else {
|
|
return original.apply(this, window.Array.from(args));
|
|
}
|
|
});
|
|
};
|
|
}
|
|
},
|
|
toBlob: {
|
|
type: "readout",
|
|
getStatus: function(obj, status, prefs){
|
|
const protectedPartChecker = getProtectedPartChecker(prefs, status.url);
|
|
status = Object.create(status);
|
|
status.active = protectedPartChecker("readout");
|
|
if (!status.active && protectedPartChecker("input")){
|
|
var contextType = canvasContextType.get(obj);
|
|
status.active = contextType !== "2d";
|
|
}
|
|
return status;
|
|
},
|
|
object: "HTMLCanvasElement",
|
|
fakeGenerator: function(checker){
|
|
return function toBlob(callback){
|
|
return checkerWrapper(checker, this, arguments, function(args, check){
|
|
var {prefs, notify, window, original} = check;
|
|
if (canvasSizeShouldBeFaked(this, prefs)){
|
|
var fakeCanvas = getFakeCanvas(window, this, prefs);
|
|
if (fakeCanvas !== this){
|
|
notify("fakedReadout");
|
|
}
|
|
return original.apply(fakeCanvas, window.Array.from(args));
|
|
}
|
|
else {
|
|
return original.apply(this, window.Array.from(args));
|
|
}
|
|
});
|
|
};
|
|
},
|
|
exportOptions: {allowCallbacks: true}
|
|
},
|
|
mozGetAsFile: {
|
|
type: "readout",
|
|
getStatus: function(obj, status, prefs){
|
|
const protectedPartChecker = getProtectedPartChecker(prefs, status.url);
|
|
status = Object.create(status);
|
|
status.active = protectedPartChecker("readout");
|
|
if (!status.active && protectedPartChecker("input")){
|
|
var contextType = canvasContextType.get(obj);
|
|
status.active = contextType !== "2d";
|
|
}
|
|
return status;
|
|
},
|
|
object: "HTMLCanvasElement",
|
|
fakeGenerator: function(checker){
|
|
return function mozGetAsFile(callback){
|
|
return checkerWrapper(checker, this, arguments, function(args, check){
|
|
var {prefs, notify, window, original} = check;
|
|
if (canvasSizeShouldBeFaked(this, prefs)){
|
|
var fakeCanvas = getFakeCanvas(window, this, prefs);
|
|
if (fakeCanvas !== this){
|
|
notify("fakedReadout");
|
|
}
|
|
return original.apply(fakeCanvas, window.Array.from(args));
|
|
}
|
|
else {
|
|
return original.apply(this, window.Array.from(args));
|
|
}
|
|
});
|
|
};
|
|
}
|
|
},
|
|
getImageData: {
|
|
type: "readout",
|
|
getStatus: function(obj, status, prefs){
|
|
const protectedPartChecker = getProtectedPartChecker(prefs, status.url);
|
|
status = Object.create(status);
|
|
status.active = protectedPartChecker("readout");
|
|
return status;
|
|
},
|
|
object: "CanvasRenderingContext2D",
|
|
fakeGenerator: function(checker){
|
|
return function getImageData(sx, sy, sw, sh){
|
|
return checkerWrapper(checker, this, arguments, function(args, check){
|
|
var {prefs, notify, window, original} = check;
|
|
if (!this || canvasSizeShouldBeFaked(this.canvas, prefs)){
|
|
var fakeCanvas;
|
|
var context = this;
|
|
if (this && this.canvas) {
|
|
fakeCanvas = getFakeCanvas(window, this.canvas, prefs);
|
|
}
|
|
if (fakeCanvas && fakeCanvas !== this.canvas){
|
|
notify("fakedReadout");
|
|
context = window.HTMLCanvasElement.prototype.getContext.call(
|
|
fakeCanvas,
|
|
"2d"
|
|
);
|
|
}
|
|
return original.apply(context, window.Array.from(args));
|
|
}
|
|
else {
|
|
return original.apply(this, window.Array.from(args));
|
|
}
|
|
});
|
|
};
|
|
}
|
|
},
|
|
isPointInPath: {
|
|
type: "readout",
|
|
getStatus: function(obj, status, prefs){
|
|
const protectedPartChecker = getProtectedPartChecker(prefs, status.url);
|
|
status = Object.create(status);
|
|
status.active = protectedPartChecker("readout");
|
|
return status;
|
|
},
|
|
object: "CanvasRenderingContext2D",
|
|
fakeGenerator: function(checker){
|
|
return function isPointInPath(x, y){
|
|
return checkerWrapper(checker, this, arguments, function(args, check){
|
|
var {prefs, notify, window, original} = check;
|
|
var rng = randomSupply.getValueRng(1, window);
|
|
var originalValue = original.apply(this, window.Array.from(args));
|
|
if ((typeof originalValue) === "boolean"){
|
|
notify("fakedReadout");
|
|
var index = x + this.width * y;
|
|
return original.call(this, rng(x, index), rng(y, index), args[2]);
|
|
}
|
|
else {
|
|
return originalValue;
|
|
}
|
|
});
|
|
};
|
|
}
|
|
},
|
|
isPointInStroke: {
|
|
type: "readout",
|
|
getStatus: function(obj, status, prefs){
|
|
const protectedPartChecker = getProtectedPartChecker(prefs, status.url);
|
|
status = Object.create(status);
|
|
status.active = protectedPartChecker("readout");
|
|
return status;
|
|
},
|
|
object: "CanvasRenderingContext2D",
|
|
fakeGenerator: function(checker){
|
|
return function isPointInStroke(x, y){
|
|
return checkerWrapper(checker, this, arguments, function(args, check){
|
|
var {prefs, notify, window, original} = check;
|
|
var rng = randomSupply.getValueRng(1, window);
|
|
var originalValue = original.apply(this, window.Array.from(args));
|
|
if ((typeof originalValue) === "boolean"){
|
|
notify("fakedReadout");
|
|
if (x instanceof window.Path2D){
|
|
let path = x;
|
|
x = y;
|
|
y = args[2];
|
|
let index = x + this.width * y;
|
|
return original.call(this, path, rng(x, index), rng(y, index));
|
|
}
|
|
else {
|
|
let index = x + this.width * y;
|
|
return original.call(this, rng(x, index), rng(y, index));
|
|
}
|
|
}
|
|
else {
|
|
return originalValue;
|
|
}
|
|
});
|
|
};
|
|
}
|
|
},
|
|
fillText: {
|
|
type: "input",
|
|
getStatus: function(obj, status, prefs){
|
|
const protectedPartChecker = getProtectedPartChecker(prefs, status.url);
|
|
status = Object.create(status);
|
|
status.active = protectedPartChecker("input");
|
|
return status;
|
|
},
|
|
object: "CanvasRenderingContext2D",
|
|
fakeGenerator: function(checker){
|
|
return function fillText(str, x, y){
|
|
return checkerWrapper(checker, this, arguments, function(args, check){
|
|
var {prefs, notify, window, original} = check;
|
|
if (!this || canvasSizeShouldBeFaked(this.canvas, prefs)){
|
|
notify("fakedInput");
|
|
var oldImageData;
|
|
try {
|
|
// "this" is not trustable - it may be not a context
|
|
oldImageData = getImageData(window, this).imageData;
|
|
}
|
|
catch (e){
|
|
// nothing to do here
|
|
}
|
|
// if "this" is not a correct context the next line will throw an error
|
|
var ret = original.apply(this, window.Array.from(args));
|
|
var newImageData = getImageData(window, this).imageData;
|
|
this.putImageData(randomMixImageData(window, oldImageData, newImageData), 0, 0);
|
|
return ret;
|
|
}
|
|
else {
|
|
return original.apply(this, window.Array.from(args));
|
|
}
|
|
});
|
|
};
|
|
}
|
|
},
|
|
strokeText: {
|
|
type: "input",
|
|
getStatus: function(obj, status, prefs){
|
|
const protectedPartChecker = getProtectedPartChecker(prefs, status.url);
|
|
status = Object.create(status);
|
|
status.active = protectedPartChecker("input");
|
|
return status;
|
|
},
|
|
object: "CanvasRenderingContext2D",
|
|
fakeGenerator: function(checker){
|
|
return function strokeText(str, x, y){
|
|
return checkerWrapper(checker, this, arguments, function(args, check){
|
|
var {prefs, notify, window, original} = check;
|
|
if (!this || canvasSizeShouldBeFaked(this.canvas, prefs)){
|
|
notify("fakedInput");
|
|
var oldImageData;
|
|
try {
|
|
// "this" is not trustable - it may be not a context
|
|
oldImageData = getImageData(window, this).imageData;
|
|
}
|
|
catch (e){
|
|
// nothing to do here
|
|
}
|
|
// if "this" is not a correct context the next line will throw an error
|
|
var ret = original.apply(this, window.Array.from(args));
|
|
var newImageData = getImageData(window, this).imageData;
|
|
this.putImageData(randomMixImageData(window, oldImageData, newImageData), 0, 0);
|
|
return ret;
|
|
}
|
|
else {
|
|
return original.apply(this, window.Array.from(args));
|
|
}
|
|
});
|
|
};
|
|
}
|
|
},
|
|
readPixels: {
|
|
type: "readout",
|
|
getStatus: function(obj, status, prefs){
|
|
const protectedPartChecker = getProtectedPartChecker(prefs, status.url);
|
|
status = Object.create(status);
|
|
status.active = protectedPartChecker(["readout", "input"]);
|
|
return status;
|
|
},
|
|
object: ["WebGLRenderingContext", "WebGL2RenderingContext"],
|
|
fakeGenerator: function(checker){
|
|
return function readPixels(x, y, width, height, format, type, pixels){ // eslint-disable-line max-params
|
|
return checkerWrapper(checker, this, arguments, function(args, check){
|
|
var {prefs, notify, window, original} = check;
|
|
if (!this || canvasSizeShouldBeFaked(this.canvas, prefs)){
|
|
notify("fakedReadout");
|
|
var fakeCanvas = getFakeCanvas(window, this.canvas, prefs);
|
|
var {context} = copyCanvasToWebgl(
|
|
window,
|
|
fakeCanvas,
|
|
this instanceof window.WebGLRenderingContext? "webgl": "webgl2"
|
|
);
|
|
return original.apply(context, window.Array.from(args));
|
|
}
|
|
else {
|
|
return original.apply(this, window.Array.from(args));
|
|
}
|
|
});
|
|
};
|
|
}
|
|
}
|
|
};
|
|
Object.keys(scope.changedFunctions).forEach(function(key){
|
|
scope.changedFunctions[key].api = "canvas";
|
|
});
|
|
}()); |