TSL Transpiler: Support struct definitions and declarations

examples/jsm/transpiler/AST.js

@@ -125,7 +125,7 @@ export class Program extends ASTNode {
 
 export class VariableDeclaration extends ASTNode {
 
-	constructor( type, name, value = null, next = null, immutable = false ) {
+	constructor( type, name, value = null, next = null, immutable = false, isUserDefinedStructType = false ) {
 
 		super();
 
@@ -136,6 +136,8 @@ export class VariableDeclaration extends ASTNode {
 
 		this.immutable = immutable;
 
+		this.isUserDefinedStructType = isUserDefinedStructType;
+
 		this.isVariableDeclaration = true;
 
 		this.initialize();
@@ -629,3 +631,32 @@ export class SwitchCase extends ASTNode {
 	}
 
 }
+
+// helper class for StructDefinition
+export class StructMember {
+
+	constructor( type, name ) {
+
+		this.type = type;
+		this.name = name;
+		this.isStructMember = true;
+
+	}
+
+}
+
+export class StructDefinition extends ASTNode {
+
+	constructor( name, members = [] ) {
+
+		super();
+
+		this.name = name;
+		this.members = members;
+		this.isStructDefinition = true;
+
+		this.initialize();
+
+	}
+
+}

examples/jsm/transpiler/GLSLDecoder.js

@@ -1,6 +1,6 @@
-import { Program, FunctionDeclaration, Switch, For, AccessorElements, Ternary, Varying, DynamicElement, StaticElement, FunctionParameter, Unary, Conditional, VariableDeclaration, Operator, Number, String, FunctionCall, Return, Accessor, Uniform, Discard, SwitchCase, Continue, Break, While, Comment } from './AST.js';
+import { Program, FunctionDeclaration, Switch, For, AccessorElements, Ternary, Varying, DynamicElement, StaticElement, FunctionParameter, Unary, Conditional, VariableDeclaration, Operator, Number, String, FunctionCall, Return, Accessor, Uniform, Discard, SwitchCase, Continue, Break, While, Comment, StructMember, StructDefinition } from './AST.js';
 
-import { isType } from './TranspilerUtils.js';
+import { isBuiltinType } from './TranspilerUtils.js';
 
 const unaryOperators = [
 	'+', '-', '~', '!', '++', '--'
@@ -255,6 +255,7 @@ class GLSLDecoder {
 		this.index = 0;
 		this.tokenizer = null;
 		this.keywords = [];
+		this.userDefinedStructTypes = new Set();
 
 		this.addPolyfill( 'gl_FragCoord', 'vec3 gl_FragCoord = vec3( screenCoordinate.x, screenCoordinate.y.oneMinus(), screenCoordinate.z );' );
 
@@ -708,6 +709,7 @@ class GLSLDecoder {
 		if ( immutable ) index ++;
 
 		type = type || tokens[ index ++ ].str;
+		const isUserDefinedStructType = this.userDefinedStructTypes.has(type);
 		const name = tokens[ index ++ ].str;
 
 		const token = tokens[ index ];
@@ -738,7 +740,7 @@ class GLSLDecoder {
 
 		}
 
-		const variable = new VariableDeclaration( type, name, init, next, immutable );
+		const variable = new VariableDeclaration( type, name, init, next, immutable, isUserDefinedStructType );
 
 		return variable;
 
@@ -780,6 +782,48 @@ class GLSLDecoder {
 
 	}
 
+	parseStructDefinition() {
+
+		const tokens = this.readTokensUntil( ';' );
+
+		const structName = tokens[ 1 ].str;
+		this.userDefinedStructTypes.add(structName);
+
+		if (tokens[ 2 ].str !== '{' ) {
+
+			throw new Error( 'Expected \'{\' after struct name ' );
+
+		}
+
+		const structMembers = [];
+		for ( let i = 3; i < tokens.length - 2; i += 3 ) {
+
+			const typeToken = tokens[ i ];
+			const nameToken = tokens[ i + 1 ];
+
+			if (typeToken.type != 'literal' || nameToken.type != 'literal') {
+				throw new Error( 'Invalid struct declaration' );
+			}
+
+			if (tokens[ i + 2 ].str !== ';' ) {
+				throw new Error( 'Missing \';\' after struct member name' );
+			}
+
+			const member = new StructMember(typeToken.str, nameToken.str);
+			structMembers.push(member);
+
+		}
+
+		if (tokens[ tokens.length - 2 ].str !== '}' ) {
+
+			throw new Error( 'Missing closing \'}\' for struct ' + structName );
+
+		}
+
+		return new StructDefinition(structName, structMembers);
+
+	}
+
 	parseReturn() {
 
 		this.readToken(); // skip 'return'
@@ -827,7 +871,8 @@ class GLSLDecoder {
 
 		let initialization;
 
-		if ( initializationTokens[ 0 ] && isType( initializationTokens[ 0 ].str ) ) {
+		const firstToken = initializationTokens[ 0 ];
+		if ( firstToken && ( isBuiltinType( firstToken.str ) || this.userDefinedStructTypes.has( firstToken.str ) ) ) {
 
 			initialization = this.parseVariablesFromToken( initializationTokens );
 
@@ -1079,7 +1124,11 @@ class GLSLDecoder {
 
 					statement = this.parseVarying();
 
-				} else if ( isType( token.str ) ) {
+				} else if ( token.str === 'struct' ) {
+
+					statement = this.parseStructDefinition();
+
+				} else if ( isBuiltinType( token.str ) || this.userDefinedStructTypes.has( token.str ) ) {
 
 					if ( this.getToken( 2 ).str === '(' ) {
 

examples/jsm/transpiler/TSLEncoder.js

@@ -314,6 +314,10 @@ class TSLEncoder {
 
 			code = this.emitVarying( node );
 
+		} else if ( node.isStructDefinition ) {
+
+			code = this.emitStructDefinition( node );
+
 		} else if ( node.isTernary ) {
 
 			code = this.emitTernary( node );
@@ -669,9 +673,17 @@ ${ this.tab }} )`;
 
 		} else {
 
-			varStr += ` = property( '${ type }' )`;
+			if ( node.isUserDefinedStructType ) {
+
+				varStr += ` = ${type}()`;
+
+			} else {
+
+				varStr += ` = property( '${ type }' )`;
 
-			this.addImport( 'property' );
+				this.addImport( 'property' );
+
+			}
 
 		}
 
@@ -702,6 +714,31 @@ ${ this.tab }} )`;
 
 	}
 
+	emitStructDefinition( node ) {
+
+		const { name, members } = node;
+
+		this.addImport( 'struct' );
+
+		let structString = `const ${ name } = struct({\n\n`;
+
+		for ( let i = 0; i < members.length; i += 1 ) {
+
+			const member = members[i];
+
+			structString += `${this.tab}\t${member.name}: '${member.type}'`;
+
+			const delimiter = (i != members.length - 1) ? ',\n' : '\n';
+			structString += delimiter;
+
+		}
+
+		structString += `\n${this.tab}}, \'${name}\' )`;
+
+		return structString;
+
+	}
+
 	emitOverloadingFunction( nodes ) {
 
 		const { name } = nodes[ 0 ];

examples/jsm/transpiler/TranspilerUtils.js

@@ -10,9 +10,9 @@ export function isPrimitive( value ) {
 
 }
 
-export function isType( str ) {
+export function isBuiltinType( str ) {
 
-	return /void|bool|float|u?int|mat[234]|mat[234]x[234]|(u|i|b)?vec[234]/.test( str );
+	return /^(void|bool|float|u?int|mat[234]|mat[234]x[234]|(u|i|b)?vec[234])$/.test( str );
 
 }