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| 1 | +/** |
| 2 | + * @license |
| 3 | + * Copyright 2022 Google LLC. All Rights Reserved. |
| 4 | + * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | + * you may not use this file except in compliance with the License. |
| 6 | + * You may obtain a copy of the License at |
| 7 | + * |
| 8 | + * https://www.apache.org/licenses/LICENSE-2.0 |
| 9 | + * |
| 10 | + * Unless required by applicable law or agreed to in writing, software |
| 11 | + * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | + * See the License for the specific language governing permissions and |
| 14 | + * limitations under the License. |
| 15 | + * ============================================================================= |
| 16 | + */ |
| 17 | + |
| 18 | +import {VIDEO_SIZE} from './shared/params'; |
| 19 | +import {drawResults, isMobile} from './shared/util'; |
| 20 | + |
| 21 | +export class Camera { |
| 22 | + constructor() { |
| 23 | + this.video = document.getElementById('video'); |
| 24 | + this.canvas = document.getElementById('output'); |
| 25 | + this.ctx = this.canvas.getContext('2d'); |
| 26 | + } |
| 27 | + |
| 28 | + /** |
| 29 | + * Initiate a Camera instance and wait for the camera stream to be ready. |
| 30 | + * @param cameraParam From app `STATE.camera`. |
| 31 | + */ |
| 32 | + static async setupCamera(cameraParam) { |
| 33 | + if (!navigator.mediaDevices || !navigator.mediaDevices.getUserMedia) { |
| 34 | + throw new Error( |
| 35 | + 'Browser API navigator.mediaDevices.getUserMedia not available'); |
| 36 | + } |
| 37 | + |
| 38 | + const {targetFPS, sizeOption} = cameraParam; |
| 39 | + const $size = VIDEO_SIZE[sizeOption]; |
| 40 | + const videoConfig = { |
| 41 | + 'audio': false, |
| 42 | + 'video': { |
| 43 | + facingMode: 'user', |
| 44 | + // Only setting the video to a specified size for large screen, on |
| 45 | + // mobile devices accept the default size. |
| 46 | + width: isMobile() ? VIDEO_SIZE['360 X 270'].width : $size.width, |
| 47 | + height: isMobile() ? VIDEO_SIZE['360 X 270'].height : $size.height, |
| 48 | + frameRate: { |
| 49 | + ideal: targetFPS, |
| 50 | + }, |
| 51 | + }, |
| 52 | + }; |
| 53 | + |
| 54 | + const stream = await navigator.mediaDevices.getUserMedia(videoConfig); |
| 55 | + |
| 56 | + const camera = new Camera(); |
| 57 | + camera.video.srcObject = stream; |
| 58 | + |
| 59 | + await new Promise((resolve) => { |
| 60 | + camera.video.onloadedmetadata = () => { |
| 61 | + resolve(video); |
| 62 | + }; |
| 63 | + }); |
| 64 | + |
| 65 | + camera.video.play(); |
| 66 | + |
| 67 | + const videoWidth = camera.video.videoWidth; |
| 68 | + const videoHeight = camera.video.videoHeight; |
| 69 | + // Must set below two lines, otherwise video element doesn't show. |
| 70 | + camera.video.width = videoWidth; |
| 71 | + camera.video.height = videoHeight; |
| 72 | + |
| 73 | + camera.canvas.width = videoWidth; |
| 74 | + camera.canvas.height = videoHeight; |
| 75 | + const canvasContainer = document.querySelector('.canvas-wrapper'); |
| 76 | + canvasContainer.style = `width: ${videoWidth}px; height: ${videoHeight}px`; |
| 77 | + |
| 78 | + // Because the image from camera is mirrored, need to flip horizontally. |
| 79 | + camera.ctx.translate(camera.video.videoWidth, 0); |
| 80 | + camera.ctx.scale(-1, 1); |
| 81 | + |
| 82 | + return camera; |
| 83 | + } |
| 84 | + |
| 85 | + drawCtx() { |
| 86 | + this.ctx.drawImage( |
| 87 | + this.video, 0, 0, this.video.videoWidth, this.video.videoHeight); |
| 88 | + } |
| 89 | + |
| 90 | + drawResults(faces, triangulateMesh, boundingBox) { |
| 91 | + drawResults(this.ctx, faces, triangulateMesh, boundingBox); |
| 92 | + } |
| 93 | +} |
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