<!-- NEW3 — TEST 3 · THE RIVER'S JOURNEY · part 399 -->
ce );
		const renderTargetProperties = properties.get( renderTarget );
		const textureProperties = properties.get( texture );

		textureProperties.__renderTarget = renderTarget;

		if ( ! renderTargetProperties.__hasExternalTextures ) {

			const width = Math.max( 1, renderTarget.width >> level );
			const height = Math.max( 1, renderTarget.height >> level );

			if ( textureTarget === _gl.TEXTURE_3D || textureTarget === _gl.TEXTURE_2D_ARRAY ) {

				state.texImage3D( textureTarget, level, glInternalFormat, width, height, renderTarget.depth, 0, glFormat, glType, null );

			} else {

				state.texImage2D( textureTarget, level, glInternalFormat, width, height, 0, glFormat, glType, null );

			}

		}

		state.bindFramebuffer( _gl.FRAMEBUFFER, framebuffer );

		if ( useMultisampledRTT( renderTarget ) ) {

			multisampledRTTExt.framebufferTexture2DMultisampleEXT( _gl.FRAMEBUFFER, attachment, textureTarget, textureProperties.__webglTexture, 0, getRenderTargetSamples( renderTarget ) );

		} else if ( textureTarget === _gl.TEXTURE_2D || ( textureTarget >= _gl.TEXTURE_CUBE_MAP_POSITIVE_X && textureTarget <= _gl.TEXTURE_CUBE_MAP_NEGATIVE_Z ) ) { // see #24753

			_gl.framebufferTexture2D( _gl.FRAMEBUFFER, attachment, textureTarget, textureProperties.__webglTexture, level );

		}

		state.bindFramebuffer( _gl.FRAMEBUFFER, null );

	}

	// Setup storage for internal depth/stencil buffers and bind to correct framebuffer
	function setupRenderBufferStorage( renderbuffer, renderTarget, useMultisample ) {

		_gl.bindRenderbuffer( _gl.RENDERBUFFER, renderbuffer );

		if ( renderTarget.depthBuffer ) {

			// retrieve the depth attachment types
			const depthTexture = renderTarget.depthTexture;
			const depthType = depthTexture && depthTexture.isDepthTexture ? depthTexture.type : null;
			const glInternalFormat = getInternalDepthFormat( renderTarget.stencilBuffer, depthType );
			const glAttachmentType = renderTarget.stencilBuffer ? _gl.DEPTH_STENCIL_ATTACHMENT : _gl.DEPTH_ATTACHMENT;

			// set up the attachment
			if ( useMultisampledRTT( renderTarget ) ) {

				multisampledRTTExt.renderbufferStorageMultisampleEXT( _gl.RENDERBUFFER, getRenderTargetSamples( renderTarget ), glInternalFormat, renderTarget.width, renderTarget.height );

			} else if ( useMultisample ) {

				_gl.renderbufferStorageMultisample( _gl.RENDERBUFFER, getRenderTargetSamples( renderTarget ), glInternalFormat, renderTarget.width, renderTarget.height );

			} else {

				_gl.renderbufferStorage( _gl.RENDERBUFFER, glInternalFormat, renderTarget.width, renderTarget.height );

			}

			_gl.framebufferRenderbuffer( _gl.FRAMEBUFFER, glAttachmentType, _gl.RENDERBUFFER, renderbuffer );

		} else {

			const textures = renderTarget.textures;

			for ( let i = 0; i < textures.length; i ++ ) {

				const texture = textures[ i ];

				const glFormat = utils.convert( texture.format, texture.colorSpace );
				const glType = utils.convert( texture.type );
				const glInternalFormat = getInternalFormat( texture.internalFormat, glFormat, glType, texture.normalized, texture.colorSpace );

				if ( useMultisampledRTT( renderTarget ) ) {

					multisampledRTTExt.renderbufferStorageMultisampleEXT( _gl.RENDERBUFFER, getRenderTargetSamples( renderTarget ), glInternalFormat, renderTarget.width, renderTarget.height );

				} else if ( useMultisample ) {

					_gl.renderbufferStorageMultisample( _gl.RENDERBUFFER, getRenderTargetSamples( renderTarget ), glInternalFormat, renderTarget.width, renderTarget.height );

				} else {

					_gl.renderbufferStorage( _gl.RENDERBUFFER, glInternalFormat, renderTarget.width, renderTarget.height );

				}

			}

		}

		_gl.bindRenderbuffer( _gl.RENDERBUFFER, null );

	}

	// Setup resources for a Depth Texture for a FBO (needs an extension)
	function setupDepthTexture( framebuffer, renderTarget, cubeFace ) {

		const isCube = ( renderTarget.isWebGLCubeRenderTarget === true );

		state.bindFramebuffer( _gl.FRAMEBUFFER, framebuffer );

		if ( ! ( renderTarget.depthTexture && renderTarget.depthTexture.isDepthTexture ) ) {

			throw new Error( 'THREE.WebGLTextures: renderTarget.depthTexture must be an instance of THREE.DepthTexture.' );

		}

		const textureProperties = properties.get( renderTarget.depthTexture );
		textureProperties.__renderTarget = renderTarget;

		// upload an empty depth texture with framebuffer size
		if ( ! textureProperties.__webglTexture ||
				renderTarget.depthTexture.image.width !== renderTarget.width ||
				renderTarget.depthTexture.image.height !== renderTarget.height ) {

			renderTarget.depthTexture.image.width = renderTarget.width;
			renderTarget.depthTexture.image.height = renderTarget.height;
			renderTarget.depthTexture.needsUpdate = true;

		}

		if ( isCube ) {

			// For cube depth textures, initialize and bind without uploading image data
			if ( textureProperties.__webglInit === undefined ) {

				textureProperties.__webglInit = true;
				renderTarg