initial scrappy integration

app/web/src/helpers/cadPackages/CSGToBuffers.js

@@ -0,0 +1,106 @@
+const setPoints = (points, p, i)=>{
+	points[i++] = p[0]
+	points[i++] = p[1]
+	points[i++] = p[2] || 0					
+}
+
+function CSG2Vertices(csg){
+    let idx = 0
+
+    let vLen = 0, iLen = 0
+    for (let poly of csg.polygons){
+    	let len = poly.vertices.length
+    	vLen += len *3
+    	iLen += 3 * (len-2)
+    }
+    const vertices = new Float32Array(vLen)
+    const indices  = vLen > 65535 ? new Uint32Array(iLen) : new Uint16Array(iLen)
+
+    let vertOffset = 0
+    let indOffset = 0
+    let posOffset = 0
+    let first = 0
+    for (let poly of csg.polygons){
+    	let arr = poly.vertices
+    	let len = arr.length
+    	first = posOffset
+    	vertices.set(arr[0], vertOffset)
+    	vertOffset +=3
+    	vertices.set(arr[1], vertOffset)
+    	vertOffset +=3
+    	posOffset  +=2
+    	for(let i=2; i<len; i++){
+	    	vertices.set(arr[i], vertOffset)
+	        
+	        indices[indOffset++] = first
+	        indices[indOffset++] = first + i -1
+	        indices[indOffset++] = first + i 
+	        
+        	vertOffset += 3
+        	posOffset  += 1
+    	}
+    }
+    return {vertices, indices, type:'mesh'}
+}
+
+
+function CSG2LineVertices(csg){
+	let vLen = csg.points.length * 3
+	if(csg.isClosed) vLen += 3
+
+	var vertices = new Float32Array(vLen)
+	
+	
+	csg.points.forEach((p,idx)=>setPoints(vertices, p, idx * 3 ))
+	
+	if(csg.isClosed){
+		setPoints(vertices, csg.points[0], vertices.length - 3 )
+	}
+	return {vertices, type:'line'}
+}			
+
+function CSG2LineSegmentsVertices(csg){
+	let vLen = csg.sides.length * 6
+
+	var vertices = new Float32Array(vLen)
+	csg.sides.forEach((side,idx)=>{
+		let i = idx * 6 
+		setPoints(vertices, side[0], i)
+		setPoints(vertices, side[1], i+3)
+	})
+	return {vertices, type:'lines'}
+
+}
+
+function CSGCached(func, data, cacheKey, transferable){
+	cacheKey = cacheKey || data
+
+	let geo = CSGToBuffers.cache.get(cacheKey)
+	if(geo) return geo
+
+	geo = func(data)
+
+	// fill transferable array for postMessage optimization
+	if(transferable){				
+		const {vertices, indices} = geo
+		transferable.push(vertices)
+		if(indices) transferable.push(indices)
+	}
+
+    CSGToBuffers.cache.set(cacheKey, geo)
+    return geo			
+}
+
+function CSGToBuffers(csg, transferable){
+	let obj
+
+	if(csg.polygons) obj = CSGCached(CSG2Vertices,csg,csg.polygons, transferable)
+	if(csg.sides && !csg.points) obj = CSGCached(CSG2LineSegmentsVertices,csg,csg.sides, transferable)
+	if(csg.points) obj = CSGCached(CSG2LineVertices,csg,csg.points, transferable)
+
+	return obj
+}
+CSGToBuffers.clearCache = ()=>{CSGToBuffers.cache = new WeakMap()}
+CSGToBuffers.clearCache()
+
+export  {CSGToBuffers}