fix stl export size (kiri). add stl export (mesh)

src/kiri/main.js

@@ -1740,10 +1740,10 @@
             }
             return obj.join('\n');
         }
-        let stl = new Uint8Array(80 + 4 + facets * 50);
+        let stl = new Uint8Array(80 + 4 + facets/3 * 50);
         let dat = new DataView(stl.buffer);
         let pos = 84;
-        dat.setInt32(80, facets, true);
+        dat.setInt32(80, facets/3, true);
         for (let out of outs) {
             let { position } = out.geo.attributes;
             let pvals = position.array;

src/mesh/api.js

@@ -225,14 +225,14 @@ let file = {
         if (recs.length === 0) {
             return api.log.emit(`no models to export`);
         }
-        function doit() {
+        function doit(ext = 'obj') {
             api.log.emit(`exporting ${recs.length} model(s)`);
             let file = api.modal.bound.filename.value || "export.obj";
-            if (file.toLowerCase().indexOf(".obj") < 0) {
+            if (file.toLowerCase().indexOf(`.${ext}`) < 0) {
-                file = file + ".obj";
+                file = `${file}.${ext}`;
             }
             worker.file_export({
-                recs, format: "obj"
+                recs, format: ext
             }).then(data => {
                 if (data.length) {
                     util.download(data, file);
@@ -247,7 +247,8 @@ let file = {
                     h.input({ id: "filename", value: "mesh_export" })
                 ]),
                 h.div([
-                    h.button({ _: "download", onclick: doit })
+                    h.button({ _: "download OBJ", onclick() { doit('obj') } }),
+                    h.button({ _: "download STL", onclick() { doit('stl') } })
                 ])
             ]) ]
         });

src/mesh/work.js

@@ -100,22 +100,56 @@ let object = {
 let file = {
     export(data, send) {
         let { format, recs } = data;
+        let vtot = 0;
+        for (let rec of recs) {
+            let { id, matrix, file } = rec;
+            let vs = rec.varr = Array.from(translate_encode(id, matrix)).map(v => v.round(5));
+            vtot += (vs.length / 3);
+        }
         switch (format) {
             case "obj":
                 let p = 1;
-                let obj = [`# Generated By Kiri:Moto (units = millimeters)`];
+                let obj = [`# Generated By Mesh:Tool @ https://grid.space/mesh (units = millimeters)`];
                 for (let rec of recs) {
-                    let { id, matrix, file } = rec;
+                    let { id, matrix, file, varr } = rec;
-                    let verts = Array.from(translate_encode(id, matrix)).map(v => v.round(5));
                     obj.push(`g ${file}`);
-                    for (let i=0; i<verts.length; p += 3) {
+                    for (let i=0; i<varr.length; p += 3) {
-                        obj.push(`v ${verts[i++]} ${verts[i++]} ${verts[i++]}`);
+                        obj.push(`v ${varr[i++]} ${varr[i++]} ${varr[i++]}`);
-                        obj.push(`v ${verts[i++]} ${verts[i++]} ${verts[i++]}`);
+                        obj.push(`v ${varr[i++]} ${varr[i++]} ${varr[i++]}`);
-                        obj.push(`v ${verts[i++]} ${verts[i++]} ${verts[i++]}`);
+                        obj.push(`v ${varr[i++]} ${varr[i++]} ${varr[i++]}`);
                         obj.push(`f ${p} ${p+1} ${p+2}`);
                     }
                 }
                 return obj.join('\n');
+            case "stl":
+                let stl = new Uint8Array(80 + 4 + vtot/3 * 50);
+                let dat = new DataView(stl.buffer);
+                let pos = 84;
+                // todo put Kiri:Moto info in header
+                dat.setInt32(80, vtot/3, true);
+                for (let rec of recs) {
+                    let { id, matrix, file, varr } = rec;
+                    for (let i=0, l=varr.length; i<l;) {
+                        let p0 = new THREE.Vector3(varr[i++], varr[i++], varr[i++]);
+                        let p1 = new THREE.Vector3(varr[i++], varr[i++], varr[i++]);
+                        let p2 = new THREE.Vector3(varr[i++], varr[i++], varr[i++]);
+                        let norm = THREE.computeFaceNormal(p0, p1, p2);
+                        dat.setFloat32(pos +  0, norm.x, true);
+                        dat.setFloat32(pos +  4, norm.y, true);
+                        dat.setFloat32(pos +  8, norm.z, true);
+                        dat.setFloat32(pos + 12, p0.x, true);
+                        dat.setFloat32(pos + 16, p0.y, true);
+                        dat.setFloat32(pos + 20, p0.z, true);
+                        dat.setFloat32(pos + 24, p1.x, true);
+                        dat.setFloat32(pos + 28, p1.y, true);
+                        dat.setFloat32(pos + 32, p1.z, true);
+                        dat.setFloat32(pos + 36, p2.x, true);
+                        dat.setFloat32(pos + 40, p2.y, true);
+                        dat.setFloat32(pos + 44, p2.z, true);
+                        pos += 50;
+                    }
+                }
+                return stl;
             default:
                 throw `invalid format "${format}"`;
         }

web/mesh/index.css

@@ -171,15 +171,20 @@ button:hover {
     color: #888;
 }
 
+.export {
+    flex-direction: column;
+    font-family: monospace;
+}
+
 .export, .export div {
     gap: 4px;
     align-items: center;
     justify-content: center;
 }
 
-.export input {
+.export input, .export button {
-    padding: 3px;
     font-family: monospace;
+    padding: 3px;
 }
 
 .export button {