Files
bentopdf/src/js/workflow/nodes/posterize-node.ts

117 lines
3.9 KiB
TypeScript

import { ClassicPreset } from 'rete';
import { BaseWorkflowNode } from './base-node';
import { pdfSocket } from '../sockets';
import type { SocketData } from '../types';
import { requirePdfInput, processBatch } from '../types';
import { PDFDocument } from 'pdf-lib';
import * as pdfjsLib from 'pdfjs-dist';
export class PosterizeNode extends BaseWorkflowNode {
readonly category = 'Organize & Manage' as const;
readonly icon = 'ph-notepad';
readonly description = 'Split pages into tile grid for poster printing';
constructor() {
super('Posterize');
this.addInput('pdf', new ClassicPreset.Input(pdfSocket, 'PDF'));
this.addOutput(
'pdf',
new ClassicPreset.Output(pdfSocket, 'Posterized PDF')
);
this.addControl(
'rows',
new ClassicPreset.InputControl('number', { initial: 2 })
);
this.addControl(
'cols',
new ClassicPreset.InputControl('number', { initial: 2 })
);
}
async data(
inputs: Record<string, SocketData[]>
): Promise<Record<string, SocketData>> {
const pdfInputs = requirePdfInput(inputs, 'Posterize');
const rowsCtrl = this.controls['rows'] as
| ClassicPreset.InputControl<'number'>
| undefined;
const colsCtrl = this.controls['cols'] as
| ClassicPreset.InputControl<'number'>
| undefined;
const rows = Math.max(1, Math.min(8, rowsCtrl?.value ?? 2));
const cols = Math.max(1, Math.min(8, colsCtrl?.value ?? 2));
return {
pdf: await processBatch(pdfInputs, async (input) => {
const pdfjsDoc = await pdfjsLib.getDocument({ data: input.bytes })
.promise;
const newDoc = await PDFDocument.create();
for (let i = 1; i <= pdfjsDoc.numPages; i++) {
const page = await pdfjsDoc.getPage(i);
const viewport = page.getViewport({ scale: 2.0 });
const canvas = document.createElement('canvas');
canvas.width = viewport.width;
canvas.height = viewport.height;
const ctx = canvas.getContext('2d');
if (!ctx)
throw new Error(`Failed to get canvas context for page ${i}`);
await page.render({ canvasContext: ctx, viewport, canvas }).promise;
const tileW = viewport.width / cols;
const tileH = viewport.height / rows;
for (let r = 0; r < rows; r++) {
for (let c = 0; c < cols; c++) {
const tileCanvas = document.createElement('canvas');
tileCanvas.width = tileW;
tileCanvas.height = tileH;
const tileCtx = tileCanvas.getContext('2d');
if (!tileCtx)
throw new Error('Failed to get tile canvas context');
tileCtx.drawImage(
canvas,
c * tileW,
r * tileH,
tileW,
tileH,
0,
0,
tileW,
tileH
);
const pngBlob = await new Promise<Blob | null>((resolve) =>
tileCanvas.toBlob(resolve, 'image/png')
);
if (!pngBlob)
throw new Error(
`Failed to render tile (row ${r}, col ${c}) of page ${i}`
);
const pngBytes = new Uint8Array(await pngBlob.arrayBuffer());
const pngImage = await newDoc.embedPng(pngBytes);
const newPage = newDoc.addPage([tileW / 2, tileH / 2]);
newPage.drawImage(pngImage, {
x: 0,
y: 0,
width: tileW / 2,
height: tileH / 2,
});
}
}
}
const pdfBytes = new Uint8Array(await newDoc.save());
return {
type: 'pdf',
document: newDoc,
bytes: pdfBytes,
filename: input.filename.replace(/\.pdf$/i, '_posterized.pdf'),
};
}),
};
}
}