added preloader

mnist_loader.js

@@ -1,27 +1,68 @@
-export async function loadMNIST(device, sampleCount = 1000) {
-    async function loadFile(path) {
-        const res = await fetch(path);
-        return new Uint8Array(await res.arrayBuffer());
-    }
+export async function loadMNIST( device, sampleCount = 1000, preloader ) {
 
-    const imgRaw = await loadFile("./models/train-images-idx3-ubyte");
-    const lblRaw = await loadFile("./models/train-labels-idx1-ubyte");
+	async function loadFile( path, progress ) {
 
-    const header = 16;
-    const fullCount = lblRaw.length - 8;
-    const count = Math.min(sampleCount, fullCount);
+		const res    = await fetch( path );
+		const buffer = await res.arrayBuffer();
 
-    const images = new Float32Array(count * 28 * 28);
-    const labels = new Uint32Array(count);
+		if ( preloader ) {
 
-    for (let i = 0; i < count; i++) {
-        labels[i] = lblRaw[8 + i];
-        const src = header + i * 784;
-        const dst = i * 784;
-        for (let j = 0; j < 784; j++) {
-            images[dst + j] = imgRaw[src + j] / 255;
-        }
-    }
+			preloader.setProgress( progress );
+
+		}
+
+		return new Uint8Array( buffer );
+
+	}
+
+	if ( preloader ) preloader.setText( "Loading MNIST images…" );
+	const imgRaw = await loadFile(
+		"./models/train-images-idx3-ubyte",
+		40
+	);
+
+	if ( preloader ) preloader.setText( "Loading MNIST labels…" );
+	const lblRaw = await loadFile(
+		"./models/train-labels-idx1-ubyte",
+		60
+	);
+
+	const header    = 16;
+	const fullCount = lblRaw.length - 8;
+	const count     = Math.min( sampleCount, fullCount );
+
+	const images = new Float32Array( count * 28 * 28 );
+	const labels = new Uint32Array( count );
+
+	for ( let i = 0; i < count; i++ ) {
+
+		labels[ i ] = lblRaw[ 8 + i ];
+
+		const src = header + i * 784;
+		const dst = i * 784;
+
+		for ( let j = 0; j < 784; j++ ) {
+
+			images[ dst + j ] = imgRaw[ src + j ] / 255;
+
+		}
+
+		if ( preloader && ( i % 64 === 0 ) ) {
+
+			preloader.setProgress(
+				60 + ( i / count ) * 40
+			);
+
+		}
+
+	}
+
+	if ( preloader ) {
+
+		preloader.setProgress( 100 );
+
+	}
+
+	return { images, labels, count };
 
-    return { images, labels, count };
 }