three.js/examples/jsm/renderers/nodes/core/NodeBuilder.js

import NodeUniform from './NodeUniform.js';

const VERSION = '1';

class NodeBuilder {

	constructor( material, renderer ) {
		
		this.material = material;
		this.renderer = renderer;
		
		this.slots = { vertex: [], fragment: [] };
		this.defines = { vertex: {}, fragment: {} };
		this.uniforms = { vertex: [], fragment: [] };
		
		this.nodesData = new WeakMap();
		
		this.shaderStage = null;
		
	}
	
	addSlot( shader, slot ) {
		
		this.slots[ shader ].push( slot );
		
	}
	
	define( shader, name, value = '' ) {
		
		this.defines[ shader ][ name ] = value;
		
	}
	
	generateVec2( x, y ) {
		
		return `vec2( ${x}, ${y})`;
		
	}
	
	generateVec3( x, y, z ) {
		
		return `vec3( ${x}, ${y}, ${z} )`;
		
	}
	
	generateVec4( x, y, z, w ) {
		
		return `vec4( ${x}, ${y}, ${z}, ${w} )`;
		
	}
	
	generateFloat( value ) {
		
		return value + ( value % 1 ? '' : '.0' );
		
	}
	
	getUniformNSName( nodeUniform ) {
		
		return nodeUniform.name;
		
	}
	
	getTypeLength( type ) {

		if ( type === 'float' ) return 1;
		if ( type === 'vec2' ) return 2;
		if ( type === 'vec3' ) return 3;
		if ( type === 'vec4' ) return 4;

		return 0;

	}
	
	getDataFromNode( node, shaderStage = null ) {
		
		let nodeData = this.nodesData.get( node );
		
		if ( nodeData === undefined ) {
			
			nodeData = { vertex: {}, fragment: {} };
			
			this.nodesData.set( node, nodeData );
			
		}
		
		return shaderStage ? nodeData[ shaderStage ] : nodeData;
		
	}
	
	getUniformFromNode( node, shaderStage, type ) {
		
		const nodeData = this.getDataFromNode( node, shaderStage );
		
		let nodeUniform = nodeData.uniform;
		
		if ( nodeUniform === undefined ) {
			
			const uniforms = this.uniforms[shaderStage];
			const index = uniforms.length;
			
			nodeUniform = new NodeUniform( 'nodeU' + index, type, node );
			
			uniforms.push( nodeUniform );
			
			nodeData.uniform = nodeUniform;
			
		}
		
		return nodeUniform;
		
	}
	
	/*
	analyzeNode( node ) {
		
		
	}
	*/
	
	flowNode( node, output ) {
		
		let flowData = {};
		flowData.result = node.build( this, output );
		
		return flowData;
		
	}
	
	buildDefines( shader ) {
		
		const defines = this.defines[ shader ];
		
		let code = '';
		
		for ( let name in defines ) {
			
			code += `#define ${name} ${defines[name]}\n`;
			
		}
		
		return code;
		
	}
	
	build( shaderStage ) {
		
		this.shaderStage = shaderStage;
		
		const slots = this.slots[ shaderStage ];
		const uniforms = this.uniforms[ shaderStage ];
		
		if ( slots.length ) {
			
			this.define( shaderStage, 'NODE', VERSION );
			
			for( let i = 0; i < slots.length; i++) {
			
				let slot = slots[i];
				
				let flowData = this.flowNode( slot.node, slot.output );
				
				this.define( shaderStage, `NODE_${slot.name}`, flowData.result );
				
			}
			
			let uniformsCode = '';
			
			for( let i = 0; i < uniforms.length; i++) {
				
				let uniform = uniforms[i];
				
				uniformsCode += `${uniform.type} ${uniform.name}; `;
				
			}
			
			this.define( shaderStage, 'NODE_UNIFORMS', uniformsCode );
			
		}
		
		let defines = this.buildDefines( shaderStage );
		
		return {
			defines
		};
		
	}
	
	format( code, fromType, toType ) {

		const typeToType = `${fromType} -> ${toType}`;

		switch ( typeToType ) {

			case 'float -> vec3' : return `vec3( ${code} )`;
			
			case 'vec3 -> float' : return `${code}.x`;

		}

		return code;

	}
	
}

export default NodeBuilder;