tav-media/lib/src/wasm/wx-image-reader.js

Cross platform media editing framework

var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
    return new (P || (P = Promise))(function (resolve, reject) {
        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
        step((generator = generator.apply(thisArg, _arguments || [])).next());
    });
};
import { Http } from '../io/http';
import { tav } from '../tav';
export class WxImageReader {
    constructor(path, rect) {
        // Used on WeChat
        this.type = 1;
        this.contentTime = 0;
        this.renderRequest = false;
        this.released = false;
        this.width = rect.right - rect.left;
        this.height = rect.bottom - rect.top;
        this.path = path;
        const canvas = WxImageReader.sharedCanvas;
        this.canvas = canvas;
        WxImageReader.preload(path);
        this.imageEl = WxImageReader.images[path];
        this.width = this.imageEl.width || this.width;
        this.height = this.imageEl.height || this.height;
    }
    static preload(path) {
        return __awaiter(this, void 0, void 0, function* () {
            if (this.images[path]) {
                return this.images[path];
            }
            if (!this.sharedCanvas) {
                this.sharedCanvas = yield new Promise(((res) => {
                    wx.createSelectorQuery().select('#tavImageReaderCanvas')
                        .node((r) => {
                        const canvas = r.node;
                        canvas.width = 2048;
                        canvas.height = 2048;
                        res(canvas);
                    })
                        .exec();
                }));
            }
            const imageEl = this.sharedCanvas.createImage();
            imageEl.src = Http.getUrl(path);
            ;
            this.images[path] = imageEl;
            return new Promise((res, rej) => {
                imageEl.onload = _e => res(imageEl);
                imageEl.onerror = _e => rej(imageEl);
            });
        });
    }
    readSample() {
        let { width, height } = this;
        width = Math.min(width, this.canvas.width);
        height = Math.min(height, this.canvas.height);
        const context2D = this.canvas.getContext('2d');
        context2D.clearRect(0, 0, this.width, this.height);
        context2D.drawImage(this.imageEl, 0, 0, width, height);
        const imageData = context2D.getImageData(0, 0, width, height);
        const dataUint8Array = imageData.data;
        const module = tav;
        const numBytes = dataUint8Array.byteLength * dataUint8Array.BYTES_PER_ELEMENT;
        const dataPtr = module._malloc(numBytes);
        this.lastSampleData = dataPtr;
        const dataOnHeap = new Uint8ClampedArray(module.HEAPU8.buffer, dataPtr, numBytes);
        dataOnHeap.set(dataUint8Array);
        return {
            bytes: dataOnHeap.byteOffset,
            length: dataOnHeap.length,
            width,
            height,
        };
    }
    freeBuffer() {
        if (!this.lastSampleData) {
            return;
        }
        const module = tav;
        module._free(this.lastSampleData);
        this.lastSampleData = null;
    }
    release() {
        this.freeBuffer();
        this.released = true;
    }
}
WxImageReader.images = {};