Add heart effect

src/effects/hearts/index.ts

@@ -0,0 +1,190 @@
+/*
+ Copyright 2021 The Matrix.org Foundation C.I.C.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+import ICanvasEffect from '../ICanvasEffect';
+import { arrayFastClone } from "../../utils/arrays";
+
+export type HeartOptions = {
+    /**
+     * The maximum number of hearts to render at a given time
+     */
+    maxCount: number;
+    /**
+     * The amount of gravity to apply to the hearts
+     */
+    gravity: number;
+    /**
+     * The maximum amount of drift (horizontal sway) to apply to the hearts. Each heart varies.
+     */
+    maxDrift: number;
+    /**
+     * The maximum amount of tilt to apply to the heart. Each heart varies.
+     */
+    maxRot: number;
+}
+
+type Heart = {
+    x: number;
+    y: number;
+    xCol: number;
+    scale: number;
+    maximumDrift: number;
+    maximumRot: number;
+    gravity: number;
+    color: string,
+}
+
+export const DefaultOptions: HeartOptions = {
+    maxCount: 120,
+    gravity: 3.2,
+    maxDrift: 5,
+    maxRot: 5,
+};
+
+const KEY_FRAME_INTERVAL = 15; // 15ms, roughly
+
+export default class Hearts implements ICanvasEffect {
+    private readonly options: HeartOptions;
+
+    constructor(options: { [key: string]: any }) {
+        this.options = { ...DefaultOptions, ...options };
+    }
+
+    private context: CanvasRenderingContext2D | null = null;
+    private particles: Array<Heart> = [];
+    private lastAnimationTime: number;
+
+    private colours = [
+        'rgba(194,210,224,1)',
+        'rgba(235,214,219,1)',
+        'rgba(255,211,45,1)',
+        'rgba(255,190,174,1)',
+        'rgba(255,173,226,1)',
+        'rgba(242,114,171,1)',
+        'rgba(228,55,116,1)',
+        'rgba(255,86,130,1)',
+        'rgba(244,36,57,1)',
+        'rgba(247,126,157,1)',
+        'rgba(243,142,140,1)',
+        'rgba(252,116,183,1)'];
+
+    public isRunning: boolean;
+
+    public start = async (canvas: HTMLCanvasElement, timeout = 3000) => {
+        if (!canvas) {
+            return;
+        }
+        this.context = canvas.getContext('2d');
+        this.particles = [];
+        const count = this.options.maxCount;
+        while (this.particles.length < count) {
+            this.particles.push(this.resetParticle({} as Heart, canvas.width, canvas.height));
+        }
+        this.isRunning = true;
+        requestAnimationFrame(this.renderLoop);
+        if (timeout) {
+            window.setTimeout(this.stop, timeout);
+        }
+    }
+
+    public stop = async () => {
+        this.isRunning = false;
+    }
+
+    private resetParticle = (particle: Heart, width: number, height: number): Heart => {
+        particle.color = this.colours[(Math.random() * this.colours.length) | 0];
+        particle.x = Math.random() * width;
+        particle.y = Math.random() * height + height;
+        particle.xCol = particle.x;
+        particle.scale = (Math.random() * 0.07) + 0.04;
+        particle.maximumDrift = (Math.random() * this.options.maxDrift) + 3.5;
+        particle.maximumRot = (Math.random() * this.options.maxRot) + 3.5;
+        particle.gravity = this.options.gravity + (Math.random() * 4.8);
+        return particle;
+    }
+
+    private renderLoop = (): void => {
+        if (!this.context || !this.context.canvas) {
+            return;
+        }
+        if (this.particles.length === 0) {
+            this.context.clearRect(0, 0, this.context.canvas.width, this.context.canvas.height);
+        } else {
+            const timeDelta = Date.now() - this.lastAnimationTime;
+            if (timeDelta >= KEY_FRAME_INTERVAL || !this.lastAnimationTime) {
+                // Clear the screen first
+                this.context.clearRect(0, 0, this.context.canvas.width, this.context.canvas.height);
+
+                this.lastAnimationTime = Date.now();
+                this.animateAndRenderHearts();
+            }
+            requestAnimationFrame(this.renderLoop);
+        }
+    };
+
+    private animateAndRenderHearts() {
+        if (!this.context || !this.context.canvas) {
+            return;
+        }
+        for (const particle of arrayFastClone(this.particles)) {
+            particle.y -= particle.gravity;
+
+            // We treat the drift as a sine function to have a more fluid-like movement instead
+            // of a pong-like movement off walls of the X column. This means that for
+            // $x=A\sin(\frac{2\pi}{P}y)$ we use the `maximumDrift` as the amplitude (A) and a
+            // large multiplier to create a very long waveform through P.
+            const peakDistance = 75 * particle.maximumDrift;
+            const PI2 = Math.PI * 2;
+            particle.x = 6 * particle.maximumDrift * Math.sin(0.7 * (PI2 / peakDistance) * particle.y);
+            particle.x += particle.xCol; // bring the particle to the right place
+
+            const posScale = 1 / particle.scale;
+            const x = particle.x * posScale;
+            const y = particle.y * posScale;
+
+            this.context.save();
+            this.context.scale(particle.scale, particle.scale);
+            this.context.beginPath();
+
+            // Rotate the heart about its centre.
+            // The tilt of the heart is modelled similarly to its horizontal drift,
+            // using a sine function.
+            this.context.translate(248 + x, 215 + y);
+            this.context.rotate((1 / 10) * particle.maximumRot * Math.sin((PI2 / peakDistance) * particle.y * 0.8));
+            this.context.translate(-248 - x, -215 - y);
+
+            // Use bezier curves to draw a heart using pre-calculated coordinates.
+            this.context.moveTo(140 + x, 20 + y);
+            this.context.bezierCurveTo(73 + x, 20 + y, 20 + x, 74 + y, 20 + x, 140 + y);
+            this.context.bezierCurveTo(20 + x, 275 + y, 156 + x, 310 + y, 248 + x, 443 + y);
+            this.context.bezierCurveTo(336 + x, 311 + y, 477 + x, 270 + y, 477 + x, 140 + y);
+            this.context.bezierCurveTo(477 + x, 74 + y, 423 + x, 20 + y, 357 + x, 20 + y);
+            this.context.bezierCurveTo(309 + x, 20 + y, 267 + x, 48 + y, 248 + x, 89 + y);
+            this.context.bezierCurveTo(229 + x, 48 + y, 188 + x, 20 + y, 140 + x, 20 + y);
+            this.context.closePath();
+
+            this.context.fillStyle = particle.color;
+            this.context.fill();
+
+            this.context.restore();
+
+            // Remove any dead hearts after a 100px wide margin.
+            if (particle.y < -100 ) {
+                const idx = this.particles.indexOf(particle);
+                this.particles.splice(idx, 1);
+            }
+        }
+    }
+}

src/effects/index.ts

@@ -20,6 +20,7 @@ import { Effect } from "./effect";
 import { FireworksOptions } from "./fireworks";
 import { SnowfallOptions } from "./snowfall";
 import { SpaceInvadersOptions } from "./spaceinvaders";
+import { HeartOptions } from "./hearts";
 
 /**
  * This configuration defines room effects that can be triggered by custom message types and emojis
@@ -73,6 +74,15 @@ export const CHAT_EFFECTS: Array<Effect<{ [key: string]: any }>> = [
             gravity: 0.01,
         },
     } as Effect<SpaceInvadersOptions>,
+    {
+        emojis: ["💝", "💖", "💞", "💕"],
+        msgType: "io.element.effect.hearts",
+        command: "hearts",
+        description: () => _td("Sends the given message with hearts"),
+        fallbackMessage: () => _t("sends hearts") + " 💝",
+        options: {
+            maxCount: 120,
+            gravity: 3.2,
+        },
+    } as Effect<HeartOptions>,
 ];
-
-

src/i18n/strings/en_EN.json

@@ -889,6 +889,8 @@
     "sends snowfall": "sends snowfall",
     "Sends the given message with a space themed effect": "Sends the given message with a space themed effect",
     "sends space invaders": "sends space invaders",
+    "Sends the given message with hearts": "Sends the given message with hearts",
+    "sends hearts": "sends hearts",
     "unknown person": "unknown person",
     "Consulting with %(transferTarget)s. <a>Transfer to %(transferee)s</a>": "Consulting with %(transferTarget)s. <a>Transfer to %(transferee)s</a>",
     "You held the call <a>Switch</a>": "You held the call <a>Switch</a>",