bv7_canvas

canvas

Dieses Skript sollte nicht direkt installiert werden. Es handelt sich hier um eine Bibliothek für andere Skripte, welche über folgenden Befehl in den Metadaten eines Skriptes eingebunden wird // @require https://update.greatest.deepsurf.us/scripts/39480/258533/bv7_canvas.js

Du musst eine Erweiterung wie Tampermonkey, Greasemonkey oder Violentmonkey installieren, um dieses Skript zu installieren.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

Sie müssten eine Skript Manager Erweiterung installieren damit sie dieses Skript installieren können

(Ich habe schon ein Skript Manager, Lass mich es installieren!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         bv7_canvas
// @namespace    bv7
// @version      0.3
// @description  canvas
// @author       bv7
// @require      https://greatest.deepsurf.us/scripts/39476-bv7-jpeg-encoder/code/bv7_jpeg_encoder.js
// @require      https://greatest.deepsurf.us/scripts/39479-bv7-jpeg2array/code/bv7_jpeg2array.js
// ==/UserScript==

class Canvas {
	constructor() {
		this.domCanvas = document.createElement('canvas');
		this.jpegEncoder = new JpegEncoder();
	}
	set width(v) {
		this.domCanvas.width = v;
		this.onresize();
	}
	set height(v) {
		this.domCanvas.height = v;
		this.onresize();
	}
	get width () {
		return this.domCanvas.width;
	}
	get height() {
		return this.domCanvas.height;
	}
	onresize() {
	}
	getContext(_id) {
		switch (_id) {
			case '2d':
				this.context = new class {
					constructor(canvas) {
						this.canvas     = canvas;
						this.domContext = this.canvas.domCanvas.getContext('2d');
						this.imageData  = this.domContext.getImageData(0, 0, this.canvas.domCanvas.width, this.canvas.domCanvas.height);
					}
					drawImage(image, sx, sy, sWidth, sHeight, dx, dy, dWidth, dHeight, then) {
						let myImage;
						let draw = () => {
							if (dWidth && sWidth && dHeight && sHeight) {
								let syStep  = sHeight / dHeight;
								let sxStep  = sWidth  / dWidth;
								let dyStep  = dHeight / sHeight;
								let dxStep  = dWidth  / sWidth ;
								let syStart = Math.max(0, sy, sy - dy / dyStep);
								let sxStart = Math.max(0, sx, sx - dx / dxStep);
								let syEnd   = Math.min(myImage.height, sy + sHeight, sy + (this.imageData.height - dy) / dyStep);
								let sxEnd   = Math.min(myImage.width , sx + sWidth , sx + (this.imageData.width  - dx) / dxStep);
								let dyStart = dy + (syStart - sy) * dyStep;
								let dxStart = dx + (sxStart - sx) * dxStep;
								let dyEnd   = dy + (syEnd   - sy) * dyStep;
								let dxEnd   = dx + (sxEnd   - sx) * dxStep;
								let sh1 = Math.max(1, syStep);
								let sw1 = Math.max(1, sxStep);
								let dh1 = Math.max(1, dyStep);
								let dw1 = Math.max(1, dxStep);
								let siPerLine, siStartLine, siStart;
								let diPerLine, diStartLine, diStart;
								let sy1, sy1Next, sy2Start, sy2End;
								let sx1, sx1Next, sx2Start, sx2End;
								let dy1, dy1Next, dy2Start, dy2End;
								let dx1, dx1Next, dx2Start, dx2End;
								let s2count;
								let r, g, b, a;
								siPerLine = myImage.imageData.width * 4;
								diPerLine =    this.imageData.width * 4;
								sy2Start  = Math.round(sy1 = syStart);
								dy2Start  = Math.round(dy1 = dyStart);
								while (sy1 < syEnd) {
									sy2End   = Math.round(sy1Next = sy1 + sh1);
									dy2End   = Math.round(dy1Next = dy1 + dh1);
									sx2Start = Math.round(sx1 = sxStart);
									dx2Start = Math.round(dx1 = dxStart);
									siStartLine = sy2Start * siPerLine;
									diStartLine = dy2Start * diPerLine;
									while (sx1 < sxEnd) {
										sx2End  = Math.round(sx1Next = sx1 + sw1);
										dx2End  = Math.round(dx1Next = dx1 + dw1);
										siStart = siStartLine + sx2Start * 4;
										diStart = diStartLine + dx2Start * 4;
										s2count = (sy2End - sy2Start) * (sx2End - sx2Start);
										r = g = b = a = 0;
										for (let sy2 = sy2Start; sy2 < sy2End; sy2++, siStart += siPerLine) for (let sx2 = sx2Start, si = siStart; sx2 < sx2End; sx2++) {
											r += myImage.imageData.data[si++];
											g += myImage.imageData.data[si++];
											b += myImage.imageData.data[si++];
											a += myImage.imageData.data[si++];
										}
										for (let dy2 = dy2Start; dy2 < dy2End; dy2++, diStart += diPerLine) for (let dx2 = dx2Start, di = diStart; dx2 < dx2End; dx2++) {
											this.imageData.data[di++] = (r - r % s2count) / s2count;
											this.imageData.data[di++] = (g - g % s2count) / s2count;
											this.imageData.data[di++] = (b - b % s2count) / s2count;
											this.imageData.data[di++] = (a - a % s2count) / s2count;
										}
										sx1      = sx1Next;
										dx1      = dx1Next;
										sx2Start = sx2End;
										dx2Start = dx2End;
									}
									sy1      = sy1Next;
									dy1      = dy1Next;
									sy2Start = sy2End;
									dy2Start = dy2End;
								}
								this.domContext.putImageData(this.imageData, 0, 0);
							}
							if (then) then();
						};
						if (Canvas.images.some((v) => (myImage = v).src == image.src)) 
							draw();
						else {
							myImage = new JpegImage();
							myImage.onload = () => {
								myImage.imageData = this.domContext.createImageData(myImage.width, myImage.height);
								myImage.copyToImageData(myImage.imageData);
								Canvas.images.push(myImage);
								draw();
							};
							myImage.src = image.src;
						}
					};
				} (this);
				break;
		}
		return this.context;
	}
	toDataUrl(type = 'image/png', encoderOptions = 0.92) {
		let r;
		switch (type) {
			case 'image/jpeg':
				r = this.jpegEncoder.encode(this.context.imageData, encoderOptions);
				break;
			default:
				r = '';
		}
		return r;
	}
}
Canvas.images = [];