<!-- AVATAR-FORGE · part 142 -->
xture upload is required
				// even if the image contents are identical

				forceUpload = true;

			}

			webglTextures[ textureCacheKey ].usedTimes ++;

			// every time the texture cache key changes, it's necessary to check if an instance of
			// WebGLTexture can be deleted in order to avoid a memory leak.

			const webglTexture = webglTextures[ textureProperties.__cacheKey ];

			if ( webglTexture !== undefined ) {

				webglTextures[ textureProperties.__cacheKey ].usedTimes --;

				if ( webglTexture.usedTimes === 0 ) {

					deleteTexture( texture );

				}

			}

			// store references to cache key and WebGLTexture object

			textureProperties.__cacheKey = textureCacheKey;
			textureProperties.__webglTexture = webglTextures[ textureCacheKey ].texture;

		}

		return forceUpload;

	}

	function uploadTexture( textureProperties, texture, slot ) {

		let textureType = _gl.TEXTURE_2D;

		if ( texture.isDataArrayTexture || texture.isCompressedArrayTexture ) textureType = _gl.TEXTURE_2D_ARRAY;
		if ( texture.isData3DTexture ) textureType = _gl.TEXTURE_3D;

		const forceUpload = initTexture( textureProperties, texture );
		const source = texture.source;

		state.bindTexture( textureType, textureProperties.__webglTexture, _gl.TEXTURE0 + slot );

		const sourceProperties = properties.get( source );

		if ( source.version !== sourceProperties.__version || forceUpload === true ) {

			state.activeTexture( _gl.TEXTURE0 + slot );

			const workingPrimaries = ColorManagement.getPrimaries( ColorManagement.workingColorSpace );
			const texturePrimaries = texture.colorSpace === NoColorSpace ? null : ColorManagement.getPrimaries( texture.colorSpace );
			const unpackConversion = texture.colorSpace === NoColorSpace || workingPrimaries === texturePrimaries ? _gl.NONE : _gl.BROWSER_DEFAULT_WEBGL;

			_gl.pixelStorei( _gl.UNPACK_FLIP_Y_WEBGL, texture.flipY );
			_gl.pixelStorei( _gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, texture.premultiplyAlpha );
			_gl.pixelStorei( _gl.UNPACK_ALIGNMENT, texture.unpackAlignment );
			_gl.pixelStorei( _gl.UNPACK_COLORSPACE_CONVERSION_WEBGL, unpackConversion );

			let image = resizeImage( texture.image, false, capabilities.maxTextureSize );
			image = verifyColorSpace( texture, image );

			const glFormat = utils.convert( texture.format, texture.colorSpace );

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

			setTextureParameters( textureType, texture );

			let mipmap;
			const mipmaps = texture.mipmaps;

			const useTexStorage = ( texture.isVideoTexture !== true );
			const allocateMemory = ( sourceProperties.__version === undefined ) || ( forceUpload === true );
			const dataReady = source.dataReady;
			const levels = getMipLevels( texture, image );

			if ( texture.isDepthTexture ) {

				glInternalFormat = getInternalDepthFormat( texture.format === DepthStencilFormat, texture.type );

				//

				if ( allocateMemory ) {

					if ( useTexStorage ) {

						state.texStorage2D( _gl.TEXTURE_2D, 1, glInternalFormat, image.width, image.height );

					} else {

						state.texImage2D( _gl.TEXTURE_2D, 0, glInternalFormat, image.width, image.height, 0, glFormat, glType, null );

					}

				}

			} else if ( texture.isDataTexture ) {

				// use manually created mipmaps if available
				// if there are no manual mipmaps
				// set 0 level mipmap and then use GL to generate other mipmap levels

				if ( mipmaps.length > 0 ) {

					if ( useTexStorage && allocateMemory ) {

						state.texStorage2D( _gl.TEXTURE_2D, levels, glInternalFormat, mipmaps[ 0 ].width, mipmaps[ 0 ].height );

					}

					for ( let i = 0, il = mipmaps.length; i < il; i ++ ) {

						mipmap = mipmaps[ i ];

						if ( useTexStorage ) {

							if ( dataReady ) {

								state.texSubImage2D( _gl.TEXTURE_2D, i, 0, 0, mipmap.width, mipmap.height, glFormat, glType, mipmap.data );

							}

						} else {

							state.texImage2D( _gl.TEXTURE_2D, i, glInternalFormat, mipmap.width, mipmap.height, 0, glFormat, glType, mipmap.data );

						}

					}

					texture.generateMipmaps = false;

				} else {

					if ( useTexStorage ) {

						if ( allocateMemory ) {

							state.texStorage2D( _gl.TEXTURE_2D, levels, glInternalFormat, image.width, image.height );

						}

						if ( dataReady ) {

							state.texSubImage2D( _gl.TEXTURE_2D, 0, 0, 0, image.width, image.height, glFormat, glType, image.data );

						}

					} else {

						state.texImage2D( _gl.TEXTURE_2D, 0, glInternalFormat, image.width, image.height, 0, glFormat, glType, image.data );

					}

				}

			} else if ( texture.isCompressedTexture ) {

				if ( texture.isCompressedArrayTexture ) {

					if ( useTexStorage && allocateMemory ) {

						state.texStorage3D( _gl.TEXTURE_2D_ARRAY, levels, glInternalFormat, mipmaps[ 0 ].width, mipmaps[ 0 ].height, image.depth );

					}

					for ( let i = 0,