From ab3cda4f5136c9c1af2005df2fd6d793d4ee6f05 Mon Sep 17 00:00:00 2001
From: Vladimir Mandic <mandic00@live.com>
Date: Sun, 3 Oct 2021 08:12:26 -0400
Subject: [PATCH] fix backend order initialization

---
 demo/nodejs/node.js |  1 +
 src/tfjs/backend.ts | 16 ++++++++++++----
 src/tfjs/humangl.ts | 14 +++++++-------
 3 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/demo/nodejs/node.js b/demo/nodejs/node.js
index 5979e524..78969f7c 100644
--- a/demo/nodejs/node.js
+++ b/demo/nodejs/node.js
@@ -135,6 +135,7 @@ async function detect(input) {
   } else {
     log.data('  Gesture: N/A');
   }
+
   if (result && result.object && result.object.length > 0) {
     for (let i = 0; i < result.object.length; i++) {
       const object = result.object[i];
diff --git a/src/tfjs/backend.ts b/src/tfjs/backend.ts
index 4dbb395a..3b5de6d5 100644
--- a/src/tfjs/backend.ts
+++ b/src/tfjs/backend.ts
@@ -45,7 +45,7 @@ export async function check(instance, force = false) {
 
       if (!available.includes(instance.config.backend)) {
         log(`error: backend ${instance.config.backend} not found in registry`);
-        instance.config.backend = env.env.node ? 'tensorflow' : 'humangl';
+        instance.config.backend = env.env.node ? 'tensorflow' : 'webgl';
         if (instance.config.debug) log(`override: setting backend ${instance.config.backend}`);
       }
 
@@ -83,9 +83,17 @@ export async function check(instance, force = false) {
         log('changing webgl: WEBGL_DELETE_TEXTURE_THRESHOLD:', true);
         tf.ENV.set('WEBGL_DELETE_TEXTURE_THRESHOLD', 0);
       }
-      // @ts-ignore getGPGPUContext only exists on WebGL backend
-      const gl = await tf.backend().getGPGPUContext().gl;
-      if (instance.config.debug) log(`gl version:${gl.getParameter(gl.VERSION)} renderer:${gl.getParameter(gl.RENDERER)}`);
+      if (tf.backend().getGPGPUContext) {
+        const gl = await tf.backend().getGPGPUContext().gl;
+        if (instance.config.debug) log(`gl version:${gl.getParameter(gl.VERSION)} renderer:${gl.getParameter(gl.RENDERER)}`);
+      }
+    }
+
+    // handle webgpu
+    if (tf.getBackend() === 'humangl') {
+      tf.ENV.set('WEBGPU_USE_GLSL', true);
+      tf.ENV.set('WEBGL_PACK_DEPTHWISECONV', false);
+      tf.ENV.set('WEBGL_USE_SHAPES_UNIFORMS', true);
     }
 
     // wait for ready
diff --git a/src/tfjs/humangl.ts b/src/tfjs/humangl.ts
index f3500f49..f6fdec71 100644
--- a/src/tfjs/humangl.ts
+++ b/src/tfjs/humangl.ts
@@ -93,13 +93,6 @@ export async function register(instance): Promise<void> {
       log('error: cannot set WebGL context:', err);
       return;
     }
-    const current = tf.backend().getGPGPUContext ? tf.backend().getGPGPUContext().gl : null;
-    if (current) {
-      log(`humangl webgl version:${current.getParameter(current.VERSION)} renderer:${current.getParameter(current.RENDERER)}`);
-    } else {
-      log('error: no current gl context:', current, config.gl);
-      return;
-    }
     try {
       const ctx = new tf.GPGPUContext(config.gl);
       tf.registerBackend(config.name, () => new tf.MathBackendWebGL(ctx), config.priority);
@@ -117,6 +110,13 @@ export async function register(instance): Promise<void> {
       log('error: cannot update WebGL backend registration:', err);
       return;
     }
+    const current = tf.backend().getGPGPUContext ? tf.backend().getGPGPUContext().gl : null;
+    if (current) {
+      log(`humangl webgl version:${current.getParameter(current.VERSION)} renderer:${current.getParameter(current.RENDERER)}`);
+    } else {
+      log('error: no current gl context:', current, config.gl);
+      return;
+    }
     try {
       tf.ENV.set('WEBGL_VERSION', 2);
     } catch (err) {