added verdant caption preset

Author: k9p5

package.json

@@ -1,7 +1,7 @@
 {
   "name": "@diffusionstudio/core",
   "private": false,
-  "version": "1.0.0-beta.13",
+  "version": "1.0.0-beta.14",
   "type": "module",
   "description": "Build bleeding edge video processing applications",
   "files": [

src/tracks/caption/index.ts

@@ -14,3 +14,4 @@ export * from './preset.deserializer';
 export * from './preset.interface';
 export * from './preset.solar';
 export * from './preset.whisper';
+export * from './preset.verdant';

src/tracks/caption/preset.0.spec.ts

@@ -15,6 +15,7 @@ import { SpotlightCaptionPreset } from './preset.spotlight';
 import { CascadeCaptionPreset } from './preset.cascade';
 import { GuineaCaptionPreset } from './preset.guinea';
 import { CaptionPresetDeserializer } from './preset.deserializer';
+import { VerdantCaptionPreset } from './preset.verdant';
 
 import type { frame, hex } from '../../types';
 
@@ -123,6 +124,25 @@ describe('(0) The Caption Presets', () => {
 		}
 	});
 
+	it('should generate captions with a highlighted green word', async () => {
+		const strategy = new VerdantCaptionPreset({
+			color: '#333333',
+			generatorOptions: { count: [3] },
+		});
+
+		await strategy.applyTo(track);
+		expect(strategy.type).toBe('VERDANT');
+
+		expect(track.clips.length).toBe(18);
+		expect(track.clips.at(0)?.start.seconds).toBe(10);
+
+		for (const clip of track.clips as ComplexTextClip[]) {
+			expect(clip.text.length).toBeGreaterThan(0);
+			expect(clip.segments.length).toBe(1);
+			expect(clip.segments[0].start).not.toBeGreaterThan(clip.segments[0].stop ?? 0);
+		}
+	});
+
 	it('should generate captions with hidden words', async () => {
 		const strategy = new CascadeCaptionPreset({
 			generatorOptions: { count: [6] },

src/tracks/caption/preset.types.ts

@@ -16,6 +16,7 @@ export type CaptionPresetType =
 	| 'GUINEA'
 	| 'SOLAR'
 	| 'WHISPER'
+	| 'VERDANT'
 	| string;
 
 export type DefaultCaptionPresetConfig = {

src/tracks/caption/preset.verdant.ts

@@ -0,0 +1,104 @@
+/**
+ * Copyright (c) 2024 The Diffusion Studio Authors
+ *
+ * This Source Code Form is subject to the terms of the Mozilla 
+ * Public License, v. 2.0 that can be found in the LICENSE file.
+ */
+
+import { Timestamp } from '../../models';
+import { Serializer, serializable } from '../../services';
+import { ComplexTextClip, Font } from '../../clips';
+
+import type { SingleColorCaptionPresetConfig, CaptionPresetType, ScreenSize } from './preset.types';
+import type { CaptionPresetStrategy } from './preset.interface';
+import type { GeneratorOptions } from '../../models';
+import type { CaptionTrack } from './caption';
+import type { hex } from '../../types';
+
+export class VerdantCaptionPreset extends Serializer implements CaptionPresetStrategy {
+	private _initialized = false;
+
+	@serializable()
+	public generatorOptions: GeneratorOptions;
+
+	@serializable()
+	readonly type: CaptionPresetType = 'VERDANT';
+
+	@serializable()
+	public color: hex;
+
+	@serializable(ComplexTextClip)
+	public clip: ComplexTextClip | undefined;
+
+	public constructor(config: Partial<SingleColorCaptionPresetConfig> = {}) {
+		super();
+
+		this.generatorOptions = config.generatorOptions ?? { duration: [1] };
+		this.clip = config.clip;
+		this.color = config.color ?? '#69E34C';
+	}
+
+	public async init(composition?: ScreenSize) {
+		if (this._initialized || !composition) return;
+
+		if (!this.clip) {
+			this.clip = await new ComplexTextClip({
+				textAlign: 'center',
+				textBaseline: 'middle',
+				fontSize: 15,
+				fillStyle: '#FFFFFF',
+				shadow: {
+					color: '#000000',
+					blur: 4,
+					alpha: 0.7,
+					angle: Math.PI / 4,
+					distance: 2,
+				},
+				stroke: {
+					width: 3,
+					color: '#000000',
+				},
+				maxWidth: composition.width * 0.5,
+				leading: 1.1,
+				font: Font.fromFamily({ family: 'Montserrat', weight: '800' }),
+				textCase: 'upper',
+				styles: [{
+					fillStyle: this.color,
+					fontSize: 19,
+				}],
+				position: 'center',
+			});
+		}
+
+		await this.clip.font.load();
+		this._initialized = true;
+	}
+
+	public async applyTo(track: CaptionTrack): Promise<void> {
+		await this.init(track.composition);
+
+		if (!this.clip || !track.clip?.transcript) {
+			throw new Error('Preset needs to be initialized first');
+		}
+
+		const offset = track.clip?.offset ?? new Timestamp();
+
+		// add captions
+		for (const sequence of track.clip.transcript.iter(this.generatorOptions)) {
+			for (let i = 0; i < sequence.words.length; i++) {
+				const tokens = sequence.words.map((s) => s.text);
+				const clip = this.clip.copy().set({
+					text: tokens.join(' '),
+					stop: sequence.words[i].stop.add(offset),
+					start: sequence.words[i].start.add(offset),
+					segments: [{
+						index: 0,
+						start: tokens.slice(0, i).join(' ').length,
+						stop: tokens.slice(0, i + 1).join(' ').length,
+					}],
+				});
+				await track.appendClip(clip);
+			}
+		}
+	}
+}