<!-- NEW5 — TEST 5 · THE BEND AT THE HEART · part 365 -->
nd when array index)
//  - followed by an optional left bracket or dot (type of subscript)
//
// Note: These portions can be read in a non-overlapping fashion and
// allow straightforward parsing of the hierarchy that WebGL encodes
// in the uniform names.

function addUniform( container, uniformObject ) {

	container.seq.push( uniformObject );
	container.map[ uniformObject.id ] = uniformObject;

}

function parseUniform( activeInfo, addr, container ) {

	const path = activeInfo.name,
		pathLength = path.length;

	// reset RegExp object, because of the early exit of a previous run
	RePathPart.lastIndex = 0;

	while ( true ) {

		const match = RePathPart.exec( path ),
			matchEnd = RePathPart.lastIndex;

		let id = match[ 1 ];
		const idIsIndex = match[ 2 ] === ']',
			subscript = match[ 3 ];

		if ( idIsIndex ) id = id | 0; // convert to integer

		if ( subscript === undefined || subscript === '[' && matchEnd + 2 === pathLength ) {

			// bare name or "pure" bottom-level array "[0]" suffix

			addUniform( container, subscript === undefined ?
				new SingleUniform( id, activeInfo, addr ) :
				new PureArrayUniform( id, activeInfo, addr ) );

			break;

		} else {

			// step into inner node / create it in case it doesn't exist

			const map = container.map;
			let next = map[ id ];

			if ( next === undefined ) {

				next = new StructuredUniform( id );
				addUniform( container, next );

			}

			container = next;

		}

	}

}

// Root Container

class WebGLUniforms {

	constructor( gl, program ) {

		this.seq = [];
		this.map = {};

		const n = gl.getProgramParameter( program, gl.ACTIVE_UNIFORMS );

		for ( let i = 0; i < n; ++ i ) {

			const info = gl.getActiveUniform( program, i ),
				addr = gl.getUniformLocation( program, info.name );

			parseUniform( info, addr, this );

		}

		// Sort uniforms to prioritize shadow samplers first (for optimal texture unit allocation)

		const shadowSamplers = [];
		const otherUniforms = [];

		for ( const u of this.seq ) {

			if ( u.type === gl.SAMPLER_2D_SHADOW || u.type === gl.SAMPLER_CUBE_SHADOW || u.type === gl.SAMPLER_2D_ARRAY_SHADOW ) {

				shadowSamplers.push( u );

			} else {

				otherUniforms.push( u );

			}

		}

		if ( shadowSamplers.length > 0 ) {

			this.seq = shadowSamplers.concat( otherUniforms );

		}

	}

	setValue( gl, name, value, textures ) {

		const u = this.map[ name ];

		if ( u !== undefined ) u.setValue( gl, value, textures );

	}

	setOptional( gl, object, name ) {

		const v = object[ name ];

		if ( v !== undefined ) this.setValue( gl, name, v );

	}

	static upload( gl, seq, values, textures ) {

		for ( let i = 0, n = seq.length; i !== n; ++ i ) {

			const u = seq[ i ],
				v = values[ u.id ];

			if ( v.needsUpdate !== false ) {

				// note: always updating when .needsUpdate is undefined
				u.setValue( gl, v.value, textures );

			}

		}

	}

	static seqWithValue( seq, values ) {

		const r = [];

		for ( let i = 0, n = seq.length; i !== n; ++ i ) {

			const u = seq[ i ];
			if ( u.id in values ) r.push( u );

		}

		return r;

	}

}

function WebGLShader( gl, type, string ) {

	const shader = gl.createShader( type );

	gl.shaderSource( shader, string );
	gl.compileShader( shader );

	return shader;

}

// From https://www.khronos.org/registry/webgl/extensions/KHR_parallel_shader_compile/
const COMPLETION_STATUS_KHR = 0x91B1;

let programIdCount = 0;

function handleSource( string, errorLine ) {

	const lines = string.split( '\n' );
	const lines2 = [];

	const from = Math.max( errorLine - 6, 0 );
	const to = Math.min( errorLine + 6, lines.length );

	for ( let i = from; i < to; i ++ ) {

		const line = i + 1;
		lines2.push( `${line === errorLine ? '>' : ' '} ${line}: ${lines[ i ]}` );

	}

	return lines2.join( '\n' );

}

const _m0 = /*@__PURE__*/ new Matrix3();

function getEncodingComponents( colorSpace ) {

	ColorManagement._getMatrix( _m0, ColorManagement.workingColorSpace, colorSpace );

	const encodingMatrix = `mat3( ${ _m0.elements.map( ( v ) => v.toFixed( 4 ) ) } )`;

	switch ( ColorManagement.getTransfer( colorSpace ) ) {

		case LinearTransfer:
			return [ encodingMatrix, 'LinearTransferOETF' ];

		case SRGBTransfer:
			return [ encodingMatrix, 'sRGBTransferOETF' ];

		default:
			warn( 'WebGLProgram: Unsupported color space: ', colorSpace );
			return [ encodingMatrix, 'LinearTransferOETF' ];

	}

}

function getShaderErrors( gl, shader, type ) {

	const status = gl.getShaderParameter( shader, gl.COMPILE_STATUS );

	const shaderInfoLog = gl.getShaderInfoLog( shader ) || '';
	const errors = shaderInfoLog.trim();

	if ( status && errors === '' ) return '';

	const errorMatches = /ERROR: 0:(\d+)/.exec( errors );
	if ( errorMatches ) {

		// --enable-privileged-webgl-extension
		// log( '**' + type + '**', gl.getExtension( 'WEBGL_debug_shaders' ).getTranslatedShaderSource( shader ) );

		const errorLine = parseInt( errorMatches[ 1 ] );
		return type.toUpperCas