WebGLTextures: Make usage of WebGLMultisampleRenderTarget more robust

src/renderers/webgl/WebGLTextures.js

@@ -904,28 +904,37 @@ function WebGLTextures( _gl, extensions, state, properties, capabilities, utils,
 
 			if ( isMultisample ) {
 
-				renderTargetProperties.__webglMultisampledFramebuffer = _gl.createFramebuffer();
-				renderTargetProperties.__webglColorRenderbuffer = _gl.createRenderbuffer();
+				if ( capabilities.isWebGL2 ) {
 
-				_gl.bindRenderbuffer( _gl.RENDERBUFFER, renderTargetProperties.__webglColorRenderbuffer );
-				var glFormat = utils.convert( renderTarget.texture.format );
-				var glType = utils.convert( renderTarget.texture.type );
-				var glInternalFormat = getInternalFormat( glFormat, glType );
-				var samples = getRenderTargetSamples( renderTarget );
-				_gl.renderbufferStorageMultisample( _gl.RENDERBUFFER, samples, glInternalFormat, renderTarget.width, renderTarget.height );
+					renderTargetProperties.__webglMultisampledFramebuffer = _gl.createFramebuffer();
+					renderTargetProperties.__webglColorRenderbuffer = _gl.createRenderbuffer();
 
-				_gl.bindFramebuffer( _gl.FRAMEBUFFER, renderTargetProperties.__webglMultisampledFramebuffer );
-				_gl.framebufferRenderbuffer( _gl.FRAMEBUFFER, _gl.COLOR_ATTACHMENT0, _gl.RENDERBUFFER, renderTargetProperties.__webglColorRenderbuffer );
-				_gl.bindRenderbuffer( _gl.RENDERBUFFER, null );
+					_gl.bindRenderbuffer( _gl.RENDERBUFFER, renderTargetProperties.__webglColorRenderbuffer );
+					var glFormat = utils.convert( renderTarget.texture.format );
+					var glType = utils.convert( renderTarget.texture.type );
+					var glInternalFormat = getInternalFormat( glFormat, glType );
+					var samples = getRenderTargetSamples( renderTarget );
+					_gl.renderbufferStorageMultisample( _gl.RENDERBUFFER, samples, glInternalFormat, renderTarget.width, renderTarget.height );
 
-				if ( renderTarget.depthBuffer ) {
+					_gl.bindFramebuffer( _gl.FRAMEBUFFER, renderTargetProperties.__webglMultisampledFramebuffer );
+					_gl.framebufferRenderbuffer( _gl.FRAMEBUFFER, _gl.COLOR_ATTACHMENT0, _gl.RENDERBUFFER, renderTargetProperties.__webglColorRenderbuffer );
+					_gl.bindRenderbuffer( _gl.RENDERBUFFER, null );
 
-					renderTargetProperties.__webglDepthRenderbuffer = _gl.createRenderbuffer();
-					setupRenderBufferStorage( renderTargetProperties.__webglDepthRenderbuffer, renderTarget, true );
+					if ( renderTarget.depthBuffer ) {
 
-				}
+						renderTargetProperties.__webglDepthRenderbuffer = _gl.createRenderbuffer();
+						setupRenderBufferStorage( renderTargetProperties.__webglDepthRenderbuffer, renderTarget, true );
+
+					}
+
+					_gl.bindFramebuffer( _gl.FRAMEBUFFER, null );
+
+
+				} else {
 
-				_gl.bindFramebuffer( _gl.FRAMEBUFFER, null );
+					console.warn( 'THREE.WebGLRenderer: WebGLMultisampleRenderTarget can only be used with WebGL2.' );
+
+				}
 
 			}
 
@@ -1000,19 +1009,27 @@ function WebGLTextures( _gl, extensions, state, properties, capabilities, utils,
 
 		if ( renderTarget.isWebGLMultisampleRenderTarget ) {
 
-			var renderTargetProperties = properties.get( renderTarget );
+			if ( capabilities.isWebGL2 ) {
+
+				var renderTargetProperties = properties.get( renderTarget );
+
+				_gl.bindFramebuffer( _gl.READ_FRAMEBUFFER, renderTargetProperties.__webglMultisampledFramebuffer );
+				_gl.bindFramebuffer( _gl.DRAW_FRAMEBUFFER, renderTargetProperties.__webglFramebuffer );
 
-			_gl.bindFramebuffer( _gl.READ_FRAMEBUFFER, renderTargetProperties.__webglMultisampledFramebuffer );
-			_gl.bindFramebuffer( _gl.DRAW_FRAMEBUFFER, renderTargetProperties.__webglFramebuffer );
+				var width = renderTarget.width;
+				var height = renderTarget.height;
+				var mask = _gl.COLOR_BUFFER_BIT;
 
-			var width = renderTarget.width;
-			var height = renderTarget.height;
-			var mask = _gl.COLOR_BUFFER_BIT;
+				if ( renderTarget.depthBuffer ) mask |= _gl.DEPTH_BUFFER_BIT;
+				if ( renderTarget.stencilBuffer ) mask |= _gl.STENCIL_BUFFER_BIT;
 
-			if ( renderTarget.depthBuffer ) mask |= _gl.DEPTH_BUFFER_BIT;
-			if ( renderTarget.stencilBuffer ) mask |= _gl.STENCIL_BUFFER_BIT;
+				_gl.blitFramebuffer( 0, 0, width, height, 0, 0, width, height, mask, _gl.NEAREST );
 
-			_gl.blitFramebuffer( 0, 0, width, height, 0, 0, width, height, mask, _gl.NEAREST );
+			} else {
+
+				console.warn( 'THREE.WebGLRenderer: WebGLMultisampleRenderTarget can only be used with WebGL2.' );
+
+			}
 
 		}