WebGLRenderer: Add 'failIfMajorPerformanceCaveat' preference

docs/api/en/renderers/WebGLRenderer.html

@@ -55,7 +55,10 @@
 
 		[page:String powerPreference] - Provides a hint to the user agent indicating what configuration
 		of GPU is suitable for this WebGL context. Can be *"high-performance"*, *"low-power"* or *"default"*. Default is *"default"*.
-		See the [link:https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.2 WebGL spec] for more information.<br />
+		See [link:https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.12 WebGL spec] for details.<br />
+
+		[page:Boolean failIfMajorPerformanceCaveat] - whether the renderer creation will fail upon low perfomance is detected. Default is *false*.
+		See [link:https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.12 WebGL spec] for details.<br />
 
 		[page:Boolean depth] - whether the drawing buffer has a
 		[link:https://en.wikipedia.org/wiki/Z-buffering depth buffer] of at least 16 bits.

src/renderers/WebGL2Renderer.js

@@ -23,7 +23,8 @@ function WebGL2Renderer( parameters ) {
 		_antialias = parameters.antialias !== undefined ? parameters.antialias : false,
 		_premultipliedAlpha = parameters.premultipliedAlpha !== undefined ? parameters.premultipliedAlpha : true,
 		_preserveDrawingBuffer = parameters.preserveDrawingBuffer !== undefined ? parameters.preserveDrawingBuffer : false,
-		_powerPreference = parameters.powerPreference !== undefined ? parameters.powerPreference : 'default';
+		_powerPreference = parameters.powerPreference !== undefined ? parameters.powerPreference : 'default',
+		_failIfMajorPerformanceCaveat = parameters.failIfMajorPerformanceCaveat !== undefined ? parameters.failIfMajorPerformanceCaveat : false;
 
 	// initialize
 
@@ -38,7 +39,8 @@ function WebGL2Renderer( parameters ) {
 			antialias: _antialias,
 			premultipliedAlpha: _premultipliedAlpha,
 			preserveDrawingBuffer: _preserveDrawingBuffer,
-			powerPreference: _powerPreference
+			powerPreference: _powerPreference,
+			failIfMajorPerformanceCaveat: _failIfMajorPerformanceCaveat
 		};
 
 		// event listeners must be registered before WebGL context is created, see #12753

src/renderers/WebGLRenderer.js

@@ -67,7 +67,8 @@ function WebGLRenderer( parameters ) {
 		_antialias = parameters.antialias !== undefined ? parameters.antialias : false,
 		_premultipliedAlpha = parameters.premultipliedAlpha !== undefined ? parameters.premultipliedAlpha : true,
 		_preserveDrawingBuffer = parameters.preserveDrawingBuffer !== undefined ? parameters.preserveDrawingBuffer : false,
-		_powerPreference = parameters.powerPreference !== undefined ? parameters.powerPreference : 'default';
+		_powerPreference = parameters.powerPreference !== undefined ? parameters.powerPreference : 'default',
+		_failIfMajorPerformanceCaveat = parameters.failIfMajorPerformanceCaveat !== undefined ? parameters.failIfMajorPerformanceCaveat : false;
 
 	var currentRenderList = null;
 	var currentRenderState = null;
@@ -189,7 +190,8 @@ function WebGLRenderer( parameters ) {
 			antialias: _antialias,
 			premultipliedAlpha: _premultipliedAlpha,
 			preserveDrawingBuffer: _preserveDrawingBuffer,
-			powerPreference: _powerPreference
+			powerPreference: _powerPreference,
+			failIfMajorPerformanceCaveat: _failIfMajorPerformanceCaveat
 		};
 
 		// event listeners must be registered before WebGL context is created, see #12753