function parseAsciiSTL(stl,fn) {
var src = "// OpenJSCAD.org: stl importer (ascii) '"+fn+"'\n\n";
var n = 0;
var converted = 0;
var o;
src += "function main() { return union(\n";
// -- Find all models
var objects = stl.split('endsolid');
src += "// objects: "+(objects.length-1)+"\n";
for (o = 1; o < objects.length; o++) {
// -- Translation: a non-greedy regex for facet {...} endloop pattern
var patt = /\bfacet[\s\S]*?endloop/mgi;
var vertices = [];
var triangles = [];
var normals = [];
var vertexIndex = 0;
var err = 0;
match = stl.match(patt);
if (match == null) continue;
for (var i = 0; i < match.length; i++) {
//if(converted%100==0) status('stl to jscad: converted '+converted+' out of '+match.length+ ' facets');
// -- 1 normal with 3 numbers, 3 different vertex objects each with 3 numbers:
//var vpatt = /\bfacet\s+normal\s+(-?\d+\.?\d*)\s+(-?\d+\.?\d*)\s+(-?\d+\.?\d*)\s*outer\s+loop\s+vertex\s+(-?\d+\.?\d*)\s+(-?\d+\.?\d*)\s+(-?\d+\.?\d*)\s*vertex\s+(-?\d+\.?\d*)\s+(-?\d+\.?\d*)\s+(-?\d+\.?\d*)\s*vertex\s+(-?\d+\.?\d*)\s+(-?\d+\.?\d*)\s+(-?\d+\.?\d*)/mgi;
// (-?\d+\.?\d*) -1.21223
// (-?\d+\.?\d*[Ee]?[-+]?\d*)
var vpatt = /\bfacet\s+normal\s+(\S+)\s+(\S+)\s+(\S+)\s+outer\s+loop\s+vertex\s+(\S+)\s+(\S+)\s+(\S+)\s+vertex\s+(\S+)\s+(\S+)\s+(\S+)\s+vertex\s+(\S+)\s+(\S+)\s+(\S+)\s*/mgi;
var v = vpatt.exec(match[i]);
if (v == null) continue;
if (v.length != 13) {
echo("Failed to parse " + match[i]);
break;
}
var skip = 0;
for(var k=0; k<v.length; k++) {
if(v[k]=='NaN') {
echo("bad normal or triangle vertice #"+converted+" "+k+": '"+v[k]+"', skipped");
skip++;
}
}
err += skip;
if(skip) {
continue;
}
if(0&&skip) {
var j = 1+3;
var v1 = []; v1.push(parseFloat(v[j++])); v1.push(parseFloat(v[j++])); v1.push(parseFloat(v[j++]));
var v2 = []; v2.push(parseFloat(v[j++])); v2.push(parseFloat(v[j++])); v2.push(parseFloat(v[j++]));
var v3 = []; v3.push(parseFloat(v[j++])); v3.push(parseFloat(v[j++])); v3.push(parseFloat(v[j++]));
echo("recalculate norm",v1,v2,v3);
var w1 = new CSG.Vector3D(v1);
var w2 = new CSG.Vector3D(v2);
var w3 = new CSG.Vector3D(v3);
var _u = w1.minus(w3);
var _v = w1.minus(w2);
var norm = _u.cross(_v).unit();
j = 1;
v[j++] = norm._x;
v[j++] = norm._y;
v[j++] = norm._z;
skip = false;
}
var j = 1;
var no = []; no.push(parseFloat(v[j++])); no.push(parseFloat(v[j++])); no.push(parseFloat(v[j++]));
var v1 = []; v1.push(parseFloat(v[j++])); v1.push(parseFloat(v[j++])); v1.push(parseFloat(v[j++]));
var v2 = []; v2.push(parseFloat(v[j++])); v2.push(parseFloat(v[j++])); v2.push(parseFloat(v[j++]));
var v3 = []; v3.push(parseFloat(v[j++])); v3.push(parseFloat(v[j++])); v3.push(parseFloat(v[j++]));
var triangle = []; triangle.push(vertexIndex++); triangle.push(vertexIndex++); triangle.push(vertexIndex++);
// -- Add 3 vertices for every triangle
// TODO: OPTIMIZE: Check if the vertex is already in the array, if it is just reuse the index
if(skip==0) { // checking cw vs ccw
// E1 = B - A
// E2 = C - A
// test = dot( Normal, cross( E1, E2 ) )
// test > 0: cw, test < 0: ccw
var w1 = new CSG.Vector3D(v1);
var w2 = new CSG.Vector3D(v2);
var w3 = new CSG.Vector3D(v3);
var e1 = w2.minus(w1);
var e2 = w3.minus(w1);
var t = new CSG.Vector3D(no).dot(e1.cross(e2));
if(t>0) { // 1,2,3 -> 3,2,1
var tmp = v3;
v3 = v1;
v1 = tmp;
}
}
vertices.push(v1);
vertices.push(v2);
vertices.push(v3);
normals.push(no);
triangles.push(triangle);
converted++;
}
if(n++) src += ",";
if(err) src += "// WARNING: import errors: "+err+" (some triangles might be misaligned or missing)\n";
src += "// object #"+(o)+": triangles: "+match.length+"\n";
src += vt2jscad(vertices,triangles,normals);
}
src += "); }\n";
return src;
}
function parseBinarySTL(stl,fn) {
// -- This makes more sense if you read http://en.wikipedia.org/wiki/STL_(file_format)#Binary_STL
var vertices = [];
var triangles = [];
var normals = [];
var vertexIndex = 0;
var converted = 0;
var err = 0;
var br = new BinaryReader(stl);
br.seek(80); //Skip header
//for(var i=0; i<80; i++)
// br.readInt8();
var totalTriangles = br.readUInt32(); //Read # triangles
for (var tr = 0; tr < totalTriangles; tr++) {
//if(tr%100==0) status('stl importer: converted '+converted+' out of '+totalTriangles+' triangles');
/*
REAL32[3] . Normal vector
REAL32[3] . Vertex 1
REAL32[3] . Vertex 2
REAL32[3] . Vertex 3
UINT16 . Attribute byte count */
// -- Parse normal
var no = []; no.push(br.readFloat()); no.push(br.readFloat()); no.push(br.readFloat());
// -- Parse every 3 subsequent floats as a vertex
var v1 = []; v1.push(br.readFloat()); v1.push(br.readFloat()); v1.push(br.readFloat());
var v2 = []; v2.push(br.readFloat()); v2.push(br.readFloat()); v2.push(br.readFloat());
var v3 = []; v3.push(br.readFloat()); v3.push(br.readFloat()); v3.push(br.readFloat());
var skip = 0;
if(1) {
for(var i=0; i<3; i++) {
if(isNaN(v1[i])) skip++;
if(isNaN(v2[i])) skip++;
if(isNaN(v3[i])) skip++;
if(isNaN(no[i])) skip++;
}
if(skip>0) {
echo("bad triangle vertice coords/normal: ",skip);
}
}
err += skip;
// -- every 3 vertices create a triangle.
var triangle = []; triangle.push(vertexIndex++); triangle.push(vertexIndex++); triangle.push(vertexIndex++);
br.readUInt16();
// -- Add 3 vertices for every triangle
// -- TODO: OPTIMIZE: Check if the vertex is already in the array, if it is just reuse the index
if(skip==0) { // checking cw vs ccw, given all normal/vertice are valid
// E1 = B - A
// E2 = C - A
// test = dot( Normal, cross( E1, E2 ) )
// test > 0: cw, test < 0 : ccw
var w1 = new CSG.Vector3D(v1);
var w2 = new CSG.Vector3D(v2);
var w3 = new CSG.Vector3D(v3);
var e1 = w2.minus(w1);
var e2 = w3.minus(w1);
var t = new CSG.Vector3D(no).dot(e1.cross(e2));
if(t>0) { // 1,2,3 -> 3,2,1
var tmp = v3;
v3 = v1;
v1 = tmp;
}
}
vertices.push(v1);
vertices.push(v2);
vertices.push(v3);
triangles.push(triangle);
normals.push(no);
converted++;
}
var src = "// OpenJSCAD.org: stl importer (binary) '"+fn+"'\n\n";
if(err) src += "// WARNING: import errors: "+err+" (some triangles might be misaligned or missing)\n";
src += "// objects: 1\n// object #1: triangles: "+totalTriangles+"\n";
src += "function main() { return ";
src += vt2jscad(vertices,triangles,normals);
src += "; }";
return src;
}