Merge pull request #2774 from zhuxudong/fix/context-lost-immediately

fix: context lost immediately

packages/core/src/Engine.ts

@@ -131,7 +131,6 @@ export class Engine extends EventDispatcher {
   private _destroyed: boolean = false;
   private _frameInProcess: boolean = false;
   private _waitingDestroy: boolean = false;
-  private _isDeviceLost: boolean = false;
   private _waitingGC: boolean = false;
   private _postProcessPasses = new Array<PostProcessPass>();
   private _activePostProcessPasses = new Array<PostProcessPass>();
@@ -381,7 +380,7 @@ export class Engine extends EventDispatcher {
     }
 
     // Render scene and fire `onBeginRender` and `onEndRender`
-    if (!this._isDeviceLost) {
+    if (!this._hardwareRenderer.isContextLost()) {
       this._render(scenes);
     }
 
@@ -652,7 +651,6 @@ export class Engine extends EventDispatcher {
   }
 
   private _onDeviceLost(): void {
-    this._isDeviceLost = true;
     // Lose graphic resources
     this.resourceManager._lostGraphicResources();
     console.log("Device lost.");
@@ -677,7 +675,6 @@ export class Engine extends EventDispatcher {
       .then(() => {
         console.log("Graphic resource content restored.\n\n" + "Device restored.");
         this.dispatch("devicerestored", this);
-        this._isDeviceLost = false;
       })
       .catch((error) => {
         console.error(error);

packages/core/src/shader/ShaderProgram.ts

@@ -254,7 +254,6 @@ export class ShaderProgram {
     // Create program and link shader
     const program = gl.createProgram();
     if (!program) {
-      console.warn("Context lost while create program.");
       return null;
     }
 
@@ -285,7 +284,6 @@ export class ShaderProgram {
     const shader = gl.createShader(shaderType);
 
     if (!shader) {
-      console.warn("Context lost while create shader.");
       return null;
     }
 
@@ -469,7 +467,8 @@ export class ShaderProgram {
   private _getUniformInfos(): WebGLActiveInfo[] {
     const gl = this._gl;
     const program = this._glProgram;
-    const uniformCount = gl.getProgramParameter(program, gl.ACTIVE_UNIFORMS);
+    // uniformCount is `null` when context lost.
+    const uniformCount = gl.getProgramParameter(program, gl.ACTIVE_UNIFORMS) ?? 0;
 
     const uniformInfos = new Array<WebGLActiveInfo>(uniformCount);
     for (let i = 0; i < uniformCount; ++i) {
@@ -485,7 +484,8 @@ export class ShaderProgram {
     const program = this._glProgram;
     const attributeInfos = new Array<WebGLActiveInfo>();
 
-    const attributeCount = gl.getProgramParameter(program, gl.ACTIVE_ATTRIBUTES);
+    // attributeCount is `null` when context lost.
+    const attributeCount = gl.getProgramParameter(program, gl.ACTIVE_ATTRIBUTES) ?? 0;
     for (let i = 0; i < attributeCount; ++i) {
       const info = gl.getActiveAttrib(program, i);
       attributeInfos[i] = info;

packages/rhi-webgl/src/WebGLGraphicDevice.ts

@@ -542,6 +542,14 @@ export class WebGLGraphicDevice implements IHardwareRenderer {
     extension.restoreContext();
   }
 
+  /**
+   * @remarks
+   * WebGL context loss and restore can happen at any GPU execution point. refs to: https://www.khronos.org/webgl/wiki/HandlingContextLost
+   */
+  isContextLost() {
+    return this.gl.isContextLost();
+  }
+
   resetState(): void {
     this._readFrameBuffer = null;
     this._enableGlobalDepthBias = false;