move src/kiri/* to src/kiri/core and src/kiri-*/ to src/kiri/* and updated all imports

src/kiri/mode/fdm/client.js

@@ -0,0 +1,647 @@
+/** Copyright Stewart Allen <sa@grid.space> -- All Rights Reserved */
+
+import { $ } from '../../../moto/webui.js';
+import { api } from '../../core/api.js';
+import { conf } from '../../core/conf.js';
+import { util } from '../../../geo/base.js';
+import { client } from '../../core/client.js';
+import { addbox, delbox, getlastbox } from '../../core/boxes.js';
+import { Layers } from '../../core/layers.js';
+import { Stack } from '../../core/stack.js';
+import { Widget, newWidget } from '../../core/widget.js';
+import { space } from '../../../moto/space.js';
+
+const { Matrix4, Vector3, BufferAttribute, BufferGeometryUtils, Raycaster, Euler } = THREE;
+const { VIEWS } = api.const;
+
+const LANG = api.language.current;
+
+let lastBox, lastMode, lastView, lastPillar, fromPillar,
+    addingSupports = false,
+    isFdmMode = false,
+    nextID = Date.now(),
+    p1, p2, iw,
+    alert = [],
+    func = {};
+
+export function init() {
+    const { ui } = api;
+    const proc_keys = Object.keys(conf.defaults.fdm.p);
+    const rangeVars = {
+        // slice
+        // "sliceHeight": LANG.sl_lahi_s,
+        "sliceShells": LANG.sl_shel_s,
+        "sliceFillType": LANG.fi_type,
+        "sliceFillWidth": LANG.fi_wdth_s,
+        "sliceFillSparse": LANG.fi_pcnt_s,
+        "sliceFillRate": LANG.ou_feed_s,
+        "sliceFillGrow": LANG.fi_grow_s,
+        "sliceSolidRate": LANG.ou_fini_s,
+        "sliceSolidMinArea": LANG.ad_msol_s,
+        "sliceTopLayers": LANG.sl_ltop_s,
+        "sliceBottomLayers": LANG.sl_lbot_s,
+        "firstLayerRate": LANG.fl_rate_s,
+        "firstLayerPrintMult": LANG.fl_mult_s,
+        "firstLayerFanSpeed": LANG.ou_fans_s,
+        // prepare
+        "sliceShellOrder": LANG.sl_ordr_s,
+        "sliceFillOverlap": LANG.fi_over_s,
+        "outputFeedrate": LANG.ou_feed_s,
+        "outputFinishrate": LANG.ou_fini_s,
+        "outputShellMult": LANG.ou_shml_s,
+        "outputFillMult": LANG.ou_flml_s,
+        "outputSparseMult": LANG.ou_spml_s,
+        "outputRetractWipe": LANG.ad_wpln_s,
+        "outputAlternating": LANG.ad_altr_s,
+        "outputShortPoly": LANG.ad_spol_s,
+        "outputMinSpeed": LANG.ad_mins_s,
+        "outputCoastDist": LANG.ad_scst_s,
+        "outputLoops": LANG.ag_loop_s,
+        "sliceSupportDensity": LANG.sp_dens_s,
+        "sliceSupportOffset": LANG.sp_offs_s,
+        "sliceLayerStart": LANG.sl_strt_s,
+        "firstLayerBrim": LANG.fl_brim_s,
+        "firstLayerBrimIn": LANG.fl_brin_s,
+        "firstLayerBrimTrig": LANG.fl_brmn_s,
+        "firstLayerBrimGap": LANG.fl_brgp_s,
+        // export
+        "zHopDistance": LANG.ad_zhop_s,
+        "arcTolerance": LANG.ad_zhop_s,
+        "antiBacklash": LANG.ad_abkl_s,
+        "outputTemp": LANG.ou_nozl_s,
+        "outputBedTemp": LANG.ou_bedd_s,
+        "outputFanSpeed": LANG.ou_fans_s,
+        "outputRetractDist": LANG.ad_rdst_s,
+        "outputRetractSpeed": LANG.ad_rrat_s,
+        "outputRetractDwell": LANG.ad_rdwl_s,
+        "outputLayerRetract": LANG.ad_lret_s
+    };
+
+    for (let key of Object.keys(rangeVars)) {
+        if (ui[key]) {
+            ui[key].range = true;
+        }
+    }
+
+    function filterSynth() {
+        api.widgets.filter((widget) => {
+            if (widget.track.synth) {
+                space.world.remove(widget.mesh);
+                Widget.Groups.remove(widget);
+            }
+            return !widget.track.synth
+        });
+    }
+
+    function clearRanges() {
+        api.conf.get().process.ranges = [];
+        ui.fdmRanges.innerHTML = '';
+    }
+
+    // re-render ranges menu
+    function updateRanges(ranges = []) {
+        let html = [];
+        let bind = [];
+        let now = Date.now();
+        let sorted = ranges.sort((a,b) => b.lo - a.lo);
+        for (let range of sorted) {
+            let id = (now++).toString(36);
+            let rows = Object.entries(range.fields).map(a => `<div><label class="pad">${rangeVars[a[0]]}</label><span></span><label class="val">${a[1]}</label></div>`).join('');
+            let hover = `<div id="hov_${id}" class="range-detail">${rows}</div>`;
+            let info = `<button id="sel_${id}" class="j-center grow">${range.lo} - ${range.hi}</button><button id="del_${id}"><i class="fa fa-trash"></i></button>`;
+            html.appendAll([
+                `<div id="rng_${id}" class="range-info">${hover}${info}</div>`
+            ]);
+            bind.push({id, range});
+        }
+        ui.fdmRanges.innerHTML = html.join('');
+        for (let rec of bind) {
+            $(`sel_${rec.id}`).onclick = () => {
+              api.show.layer(rec.range.hi, rec.range.lo);
+            };
+            $(`del_${rec.id}`).onclick = () => {
+                let io = ranges.indexOf(rec.range);
+                ranges.splice(io,1);
+                updateRanges(ranges);
+            };
+          }
+    }
+
+    api.event.on("function.animate", (mode) => {
+        if (!(isFdmMode && lastView === VIEWS.PREVIEW)) {
+            return;
+        }
+        let slider = $('top-slider');
+        slider.style.display = 'flex';
+        slider.oninput = slider.onchange = (ev) => {
+            api.const.STACKS.setFraction(parseInt(ev.target.value)/1000);
+            api.space.update();
+        };
+        $('anim-slider').value = 500;
+        api.const.STACKS.setFraction(0.5);
+    });
+
+    api.event.on("mode.set", mode => {
+        isFdmMode = mode === 'FDM';
+        lastMode = mode;
+        // hide/show fdm mode elements
+        for (let el of [...document.getElementsByClassName('mode-fdm')]) {
+            api.uc.setClass(el, 'hide', !isFdmMode);
+        }
+        updateSupportVisiblity();
+    });
+
+    api.event.on("view.set", view => {
+        $('top-slider').style.display = 'none';
+        lastView = view;
+        updateSupportVisiblity();
+        filterSynth();
+        func.sdone();
+        // let ranges = api.conf.get().process.ranges;
+        if (isFdmMode) {
+            if (lastView === VIEWS.SLICE) {
+                for (let key of proc_keys) {
+                    if (ui[key] && !ui[key].range) {
+                        ui[key].disabled = true;
+                    }
+                }
+            } else {
+                for (let key of proc_keys) {
+                    if (ui[key]) ui[key].disabled = false;
+                }
+            }
+        }
+    });
+
+    api.event.on("range.updates", updateRanges);
+
+    api.event.on("settings.load", (settings) => {
+        if (settings.mode !== 'FDM') return;
+        restoreSupports(api.widgets.all());
+        updateRanges(settings.process.ranges);
+    });
+
+    api.event.on("settings.saved", (settings) => {
+        updateRanges(settings.process.ranges);
+    });
+
+    api.event.on("button.click", target => {
+        switch (target) {
+            case api.ui.ssaGen: return func.sgen();
+            case api.ui.ssmAdd: return func.sadd();
+            case api.ui.ssmDun: return func.sdone();
+            case api.ui.ssmClr: return func.sclear();
+        }
+    });
+
+    api.event.on("fdm.supports.detect", func.sgen = () => {
+        let alerts = [];
+        let { process, device } = api.conf.get();
+        if (!device.bedBelt) {
+            if (process.sliceSupportAngle < 10) {
+                alerts.push(api.show.alert("angles below 10 degrees may fail"));
+            }
+        }
+        alerts.push(api.show.alert("analyzing part(s)...", 1000));
+        support_generate(array => {
+            func.sclear();
+            api.hide.alert(undefined,alerts);
+            for (let rec of array) {
+                let { widget, supports } = rec;
+                let wa = api.widgets.annotate(widget.id);
+                let ws = wa.support || [];
+                for (let support of supports) {
+                    let { from, to, mid } = support;
+                    let dw = api.conf.get().process.sliceSupportSize / 2;
+                    let dh = from.z - to.z;
+                    let rec = {
+                        x: mid.x,
+                        y: mid.y,
+                        z: mid.z,
+                        dw,
+                        dh,
+                        id: Math.random() * 0xffffffffff
+                    };
+                    addWidgetSupport(widget, rec);
+                    ws.push(Object.clone(rec));
+                }
+                wa.support = ws;
+            }
+            api.event.emit("fdm.supports.detected");
+        });
+    });
+
+    api.event.on("fdm.supports.add", func.sadd = () => {
+        alert = api.show.alert("[esc] key cancels support editing");
+        api.feature.hover = addingSupports = true;
+    });
+
+    api.event.on("fdm.supports.done", func.sdone = () => {
+        delbox('intZ');
+        delbox('intW');
+        delbox('supp');
+        api.hide.alert(alert);
+        api.feature.hover = addingSupports = false;
+        fromPillar = undefined;
+    });
+
+    api.event.on("fdm.supports.clear", func.sclear = () => {
+        func.sdone();
+        if (clearAllWidgetSupports()) {
+            api.conf.save();
+        }
+    });
+
+    api.event.on("slice.begin", () => {
+        if (!isFdmMode) {
+            return;
+        }
+        func.sdone();
+        updateSupportVisiblity();
+        // synth support widget for each widget group
+        // iow, create support meshes based on support widget annotation
+        for (let group of Widget.Groups.list()) {
+            let merge = group.filter(w => w.sups).map(w => Object.values(w.sups)).flat();
+            if (!merge.length) {
+                continue;
+            }
+            let boxen = merge.map(m => {
+                let geo = m.box.geometry.clone();
+                if (geo.index) geo = geo.toNonIndexed();
+                return geo.translate(m.x, m.y, m.z);
+            });
+            for (let box of boxen) {
+                // eliminate / normalize uv to allow other widget merge
+                box.setAttribute('uv',new BufferAttribute(new Float32Array(0), 3));
+            }
+            let bbg = BufferGeometryUtils.mergeGeometries(boxen);
+            let sw = newWidget(null, group);
+            let fwp = group[0].track.pos;
+            sw.loadGeometry(bbg);
+            sw._move(fwp.x, fwp.y, fwp.z);
+            api.widgets.add(sw);
+            sw.track.synth = true;
+            sw.track.support = true;
+            space.world.add(sw.mesh);
+        }
+    });
+
+    api.event.on("slice.end", () => {
+        if (!isFdmMode) {
+            return;
+        }
+    });
+
+    api.event.on("key.esc", () => {
+        if (isFdmMode) {
+            func.sdone()
+        }
+    });
+
+    api.event.on("selection.scale", () => {
+        if (isFdmMode) {
+            clearRanges();
+            func.sclear();
+        }
+    });
+
+    api.event.on("widget.delete", widget => {
+        if (isFdmMode) {
+            clearRanges();
+        }
+    });
+
+    api.event.on("widget.duplicate", (widget, oldwidget) => {
+        if (!isFdmMode) {
+            return;
+        }
+        let ann = api.widgets.annotate(widget.id);
+        if (ann.support) {
+            for (let supp of Object.values(ann.support)) {
+                supp.id = Math.abs(Math.random() * 0xffffffffffff);
+            }
+            restoreSupports([widget]);
+        }
+    });
+
+    api.event.on("widget.mirror", widget => {
+        if (!isFdmMode) {
+            return;
+        }
+        let ann = api.widgets.annotate(widget.id);
+        let sups = ann.support || [];
+        sups.forEach(sup => {
+            let wsup = widget.sups[sup.id];
+            wsup.box.position.x = wsup.x = sup.x = -sup.x;
+        });
+    });
+
+    api.event.on("widget.rotate", rot => {
+        if (!isFdmMode) {
+            return;
+        }
+        let {widget, x, y, z} = rot;
+        if (x || y) {
+            clearWidgetSupports(widget);
+        } else {
+            let ann = api.widgets.annotate(widget.id);
+            let sups = ann.support || [];
+            sups.forEach(sup => {
+                let wsup = widget.sups[sup.id];
+                let vc = new Vector3(sup.x, sup.y, sup.z);
+                let m4 = new Matrix4();
+                m4 = m4.makeRotationFromEuler(new Euler(x || 0, y || 0, z || 0));
+                vc.applyMatrix4(m4);
+                wsup.box.position.x = wsup.x = sup.x = vc.x;
+                wsup.box.position.y = wsup.y = sup.y = vc.y;
+                wsup.box.position.z = wsup.z = sup.z = vc.z;
+            });
+        }
+    });
+
+    api.event.on("mouse.hover.up", func.hoverup = (on = {}) => {
+        let { event } = on;
+        if (!isFdmMode) {
+            return;
+        }
+        if (!addingSupports) {
+            return;
+        }
+        delbox('supp');
+        if (lastPillar) {
+            removeWidgetSupport(lastPillar.widget, lastPillar);
+            return;
+        }
+        lastBox = getlastbox();
+        if (!(iw && lastBox)) return;
+        let { point, dim } = lastBox;
+        p1.y = Math.max(0, p1.y);
+        p2.y = Math.max(0, p2.y);
+        let rz = dim.rz;
+        let dh = dim.z;
+        let dw = api.conf.get().process.sliceSupportSize / 2;
+        let ip = iw.track.pos;
+        let wa = api.widgets.annotate(iw.id);
+        let ws = (wa.support = wa.support || []);
+        let id = ++nextID;
+        let rec = {x: point.x - ip.x, y: -point.z - ip.y, z: point.y, rz, dw, dh, id};
+        if (fromPillar && event && event.shiftKey) {
+            let targets = api.widgets.meshes().append(space.internals().platform);
+            let from = fromPillar,
+                d = {
+                    x: rec.x - from.x,
+                    y: rec.y - from.y,
+                    z: rec.z - from.z
+                };
+            let dist = Math.sqrt(d.x*d.x + d.y*d.y + d.z*d.z);
+            let lerp = util.lerp(0,dist,dw).map(v => v/dist);
+            let angle = rec.rz = Math.atan2(d.y,d.x);
+            let fromrec = ws.filter(r => r.id === from.id)[0];
+            if (fromrec) {
+                from.rz = fromrec.rz = angle;
+                removeWidgetSupport(iw, fromPillar);
+                ws.push(Object.clone(fromrec));
+                addWidgetSupport(iw, fromrec);
+            }
+            lerp.pop();
+            let seed = Math.random();
+            for (let pct of lerp) {
+                let point = new Vector3(from.x + d.x * pct, from.z + d.z * pct, from.y + d.y * pct);
+                addSupportAtPoint(targets, point, ip, angle, seed++);
+            }
+        }
+        ws.push(Object.clone(rec));
+        fromPillar = addWidgetSupport(iw, rec);
+        api.conf.save();
+    });
+
+    function addSupportAtPoint(targets, point, ip, angle, id) {
+        let up = new Vector3(0,1,0)
+        let dn = new Vector3(0,-1,0)
+        let rp = new Vector3(point.x + ip.x, point.y, -point.z - ip.y);
+        let iup = new Raycaster(rp, up)
+            .intersectObjects(targets, false)
+            .filter(t => !t.object.pillar);
+        if (iup.length && iup.length % 2 === 0) {
+            let idn = new Raycaster(rp, dn)
+                .intersectObjects(targets, false)
+                .filter(t => !t.object.pillar);
+            if (idn.length && idn.length % 2 === 0) {
+                iw = iup[0].object.widget || iw;
+                let wa = api.widgets.annotate(iw.id);
+                let ws = (wa.support = wa.support || []);
+                let phi = iup[0].point;
+                let plo = idn[0].point;
+                let ply = Math.max(0, plo.y);
+                let mp = (phi.y + ply) / 2;
+                let dy = Math.abs(phi.y - ply);
+                let dw = api.conf.get().process.sliceSupportSize / 2;
+                let rec = { rz:angle, x:point.x, y:point.z, z:mp, dw, dh:dy, id };
+                ws.push(Object.clone(rec));
+                fromPillar = addWidgetSupport(iw, rec);
+            }
+        }
+    }
+
+    api.event.on("mouse.hover", data => {
+        if (!isFdmMode) {
+            return;
+        }
+        if (!addingSupports) {
+            return;
+        }
+        delbox('supp');
+        const { int, type, point, event } = data;
+        const pillar = int ? int.object.pillar : undefined;
+        if (lastPillar) {
+            lastPillar.box.material.color.r = 0;
+            lastPillar = null;
+        }
+        if (pillar) {
+            pillar.box.material.color.r = 0.5;
+            lastPillar = pillar;
+            if (event && (event.metaKey || event.ctrlKey)) {
+                return func.hoverup();
+            }
+            return;
+        }
+        if (int && type === 'widget') {
+            iw = int.object.widget || iw;
+        } else {
+            iw = null;
+        }
+        p1 = point;
+        let dir = new Vector3(0,1,0)
+        let ray = new Raycaster(point, dir);
+        let rz = int && int.face ? Math.atan2(int.face.normal.y, int.face.normal.x) : 0;
+        // when on object, project down on downward faces
+        if (int && int.face && int.face.normal.z < -0.1) {
+            dir.y = -1;
+        }
+        let targets = api.widgets.meshes().append(space.internals().platform);
+        let i2 = ray.intersectObjects(targets, false)
+            .filter(t => !t.object.pillar)  // eliminate other pillars
+            .filter(i => i.distance > 0.1); // false matches close to origin of ray
+        if (i2.length && i2.length % 2 === 0) {
+            p2 = i2[0].point;
+            iw = i2[0].object.widget || iw;
+            let p1y = Math.max(0, p1.y);
+            let p2y = Math.max(0, p2.y);
+            let hy = (p1y + p2y) / 2;
+            let dy = Math.abs(p1y - p2y);
+            let dw = api.conf.get().process.sliceSupportSize / 2;
+            addbox({x:p1.x, y:hy, z:p1.z}, 0x0000dd, 'supp', {
+                x:dw, y:dw, z:dy, rz
+            });
+        } else {
+            lastBox = null;
+        }
+        if (event && event.altKey) {
+            return func.hoverup();
+        }
+    });
+
+    api.event.on("export.debug", msg => {
+        if (msg.arcQ && msg.arcQ.length > 2) {
+            if (xpdebug) {
+                xpdebug.destroy();
+                xpdebug = undefined;
+            }
+            let poly = base.newPolygon().setOpen();
+            for (let rec of msg.arcQ) {
+                rec.z += 1;
+                poly.addObj(rec);
+            }
+
+            let layers = new Layers();
+            let layer = layers.setLayer("arcq", { line: 0xff00ff, face: 0xff00ff, opacity: 1 });
+            layer.addPoly(poly, {thin:true});
+
+            layer = layers.setLayer("arcc", { line: 0xff0000, face: 0xff0000, opacity: 1 });
+            for (let center of msg.arcQ.center) {
+                center.z += 0.5;
+                layer.addPoly(base.newPolygon().centerCircle(
+                    center, center.r, 20
+                ));
+            }
+
+            xpdebug = new Stack(space.world, false);
+            xpdebug.addLayers(layers);
+            xpdebug.setVisible(0,Infinity);
+            xpdebug.show();
+
+            space.refresh();
+
+            console.log(msg, poly);
+        }
+    });
+}
+
+let xpdebug;
+let supsave = {};
+let suptimer;
+
+function support_generate(ondone) {
+    client.clear();
+    client.sync();
+    const settings = api.conf.get();
+    const widgets = api.widgets.map();
+    client.send("fdm_support_generate", { settings }, (gen) => {
+        if (gen && gen.error) {
+            api.show.alert('support generation canceled');
+            return ondone([]);
+        }
+        for (let g of gen) {
+            g.widget = widgets[g.id];
+        }
+        ondone(gen);
+    });
+};
+
+function scheduleSupportSave(widget) {
+    clearTimeout(suptimer);
+    supsave[widget.id] = widget;
+    suptimer = setTimeout(() => {
+        for (let w of Object.values(supsave)) {
+            w.saveState();
+        }
+    }, 50);
+}
+
+export function restoreSupports(widgets) {
+    widgets.forEach(widget => {
+        const supports = api.widgets.annotate(widget.id).support || [];
+        supports.forEach(pos => {
+            addWidgetSupport(widget, pos);
+        });
+    });
+}
+
+function addWidgetSupport(widget, pos) {
+    const { x, y, z, rz, dw, dh, id } = pos;
+    const sups = widget.sups = (widget.sups || {});
+    // prevent duplicate restore from repeated settings load calls
+    if (!sups[id]) {
+        pos.box = addbox(
+            { x, y, z }, 0x0000dd, id,
+            { x:dw, y:dw, z:dh, rz }, { group: widget.mesh }
+        );
+        pos.box.pillar = Object.assign({widget}, pos);
+        sups[id] = pos;
+        widget.adds.push(pos.box);
+        scheduleSupportSave(widget);
+    }
+    return sups[id];
+}
+
+function removeWidgetSupport(widget, rec) {
+    const { box, id } = rec;
+    widget.adds.remove(box);
+    widget.mesh.remove(box);
+    delete widget.sups[id];
+    let sa = api.widgets.annotate(widget.id).support;
+    let ix = 0;
+    sa.forEach((rec,i) => {
+        if (rec.id === id) {
+            ix = i;
+        }
+    });
+    sa.splice(ix,1);
+    api.conf.save();
+    scheduleSupportSave(widget);
+    fromPillar = undefined;
+}
+
+function updateSupportVisiblity() {
+    const visible = (lastMode === 'FDM' && lastView === VIEWS.ARRANGE);
+    for (let w of api.widgets.all()) {
+        setSupportVisiblity(w, visible);
+    }
+}
+
+function setSupportVisiblity(widget, bool) {
+    Object.values(widget.sups || {}).forEach(support => {
+        support.box.visible = bool;
+    });
+}
+
+function clearAllWidgetSupports() {
+    let cleared = 0;
+    api.widgets.all().forEach(widget => {
+        cleared += clearWidgetSupports(widget);
+    });
+    return cleared;
+}
+
+function clearWidgetSupports(widget) {
+    let cleared = 0;
+    Object.values(widget.sups || {}).forEach(support => {
+        widget.adds.remove(support.box);
+        widget.mesh.remove(support.box);
+        cleared++;
+    });
+    widget.sups = {};
+    delete api.widgets.annotate(widget.id).support;
+    scheduleSupportSave(widget);
+    return cleared;
+}

src/kiri/mode/fdm/driver-be.js

@@ -0,0 +1,44 @@
+/** Copyright Stewart Allen <sa@grid.space> -- All Rights Reserved */
+
+import { util } from '../../../geo/base.js';
+import { fdm_slice } from './slice.js';
+import { fdm_prepare } from './prepare.js';
+import { fdm_export } from './export.js';
+
+// noz = nozzle diameter
+// fil = filament diameter
+// slice = slice height
+function extrudePerMM(noz, fil, slice) {
+    return ((Math.PI * util.sqr(noz / 2)) / (Math.PI * util.sqr(fil / 2))) * (slice / noz);
+};
+
+// dist = distance between extrusion points
+// perMM = amount extruded per MM (from extrudePerMM)
+// factor = scaling factor (usually 1.0)
+function extrudeMM(dist, perMM, factor) {
+    return dist * perMM * factor;
+}
+
+// defer loading until client and worker exist
+function init(worker) {
+
+    worker.dispatch.fdm_support_generate = function(data, send) {
+        const { settings } = data;
+        const widgets = Object.values(worker.cache);
+        const fresh = widgets.filter(widget => FDM.supports(settings, widget));
+        send.done(kiri.codec.encode(fresh.map(widget => { return {
+            id: widget.id,
+            supports: widget.supports,
+        } } )));
+    };
+
+}
+
+export const FDM = {
+    init,
+    extrudePerMM,
+    extrudeMM,
+    slice: fdm_slice,
+    prepare: fdm_prepare,
+    export: fdm_export
+};

src/kiri/mode/fdm/driver.js

@@ -0,0 +1,22 @@
+/** Copyright Stewart Allen <sa@grid.space> -- All Rights Reserved */
+
+// shared by client and worker contexts
+export function getRangeParameters(process, index) {
+    if (index === undefined || index === null || index < 0) {
+        return process;
+    }
+    let ranges = process.ranges;
+    if (!(ranges && ranges.length)) {
+        return process;
+    }
+    let params = Object.clone(process);
+    for (let range of ranges) {
+        if (index >= range.lo && index <= range.hi) {
+            for (let [key, value] of Object.entries(range.fields)) {
+                params[key] = value;
+                params._range = true;
+            }
+        }
+    }
+    return params;
+}

src/kiri/mode/fdm/export.js

@@ -0,0 +1,991 @@
+/** Copyright Stewart Allen <sa@grid.space> -- All Rights Reserved */
+
+import { base, util } from '../../../geo/base.js';
+import { getRangeParameters } from './driver.js';
+import { FDM } from './driver-be.js';
+import { version } from '../../../moto/license.js';
+
+const { config } = base;
+const debug = false;
+
+export function fdm_export(print, online, ondone, ondebug) {
+    const { widgets, settings, belty, tools, firstTool } = print;
+    const { bounds, controller, device, process, filter, mode } = settings;
+    const { extruders, fwRetract } = device;
+    const { bedWidth, bedDepth, bedRound, bedBelt, maxHeight } = device;
+    const { gcodeFan, gcodeLayer, gcodeTrack, gcodePause, gcodeFeature, gcodeChange } = device;
+
+    let model_labels = [];
+    for (let widget of widgets) {
+        model_labels.push(widget.track.grid_id);
+    }
+
+    let layers = print.output,
+        extras = device.extras || {},
+        isBambu = extras.bbl,
+        { extrudeAbs } = device,
+        { exportThumb } = controller,
+        { extrudeMM, extrudePerMM } = FDM,
+        extused = Object.keys(print.extruders).map(v => parseInt(v)),
+        timeFactor = (device.gcodeTime || 1) * 1.5,
+        decimals = config.gcode_decimals || 4,
+        zMoveMax = device.deviceZMax || 0,
+        isBelt = bedBelt,
+        bedType = isBelt ? "belt" : "fixed",
+        time = 0,
+        layer = 0,
+        layerno = 0,
+        pause = [],
+        output = [],
+        outputLength = 0, // absolute extruder position
+        lastProgress = 0,
+        progress = 0,
+        distance = 0,
+        emitted = 0,
+        retracted = 0,
+        axis = { X:' X', Y:' Y', Z:' Z', E:' E'},
+        pos = { x:0, y:0, z:0, f:0 },
+        lout = { x:0, y:0, z:0 },
+        last = null,
+        zpos = 0,
+        bmax = 0,
+        blastz = 0,
+        belt_add_y = (process.firstLayerYOffset || 0) - (belty || 0),
+        oloops = process.outputLoops || 0,
+        zhop = process.zHopDistance || 0, // range
+        lineWidth = process.sliceLineWidth || 0,
+        seekMMM = process.outputSeekrate * 60,
+        retDist = process.outputRetractDist || 0, // range
+        retSpeed = process.outputRetractSpeed * 60 || 1, // range
+        retDwell = process.outputRetractDwell || 0, // range
+        timeDwell = retDwell / 1000,
+        arcDist = isBelt ? 0 : (process.arcTolerance || 0),
+        arcMin = 1,
+        arcRes = 20,
+        arcDev = 0.5,
+        arcMax = 40,
+        originCenter = device.originCenter || bedRound,
+        offset = originCenter ? {
+            x: 0,
+            y: 0,
+            z: 0
+        } : {
+            x: bedWidth/2,
+            y: isBelt ? 0 : bedDepth/2,
+            z: 0
+        },
+        tool = firstTool || 0,
+        extruder = extruders[tool],
+        offset_x = extruder.extOffsetX,
+        offset_y = extruder.extOffsetY,
+        extrudeSet = false,
+        nozzleTemp = process.firstLayerNozzleTemp || process.outputTemp,
+        bedTemp = process.firstLayerBedTemp || process.outputBedTemp,
+        fanSpeedSave = undefined,
+        fanSpeedBase = 0,
+        fanSpeed = 0,
+        lastType = undefined,
+        lastNozzleTemp = nozzleTemp,
+        lastBedTemp = bedTemp,
+        lastFanSpeed = fanSpeed,
+        subst = {
+            minx: bounds.min.x + offset.x,
+            maxx: bounds.max.x + offset.x,
+            miny: bounds.min.y + offset.y,
+            maxy: bounds.max.y + offset.y,
+            travel_speed: seekMMM,
+            retract_speed: retSpeed,
+            retract_distance: retDist,
+            temp: nozzleTemp,
+            temp_bed: bedTemp,
+            bed_temp: bedTemp,
+            fan_speed_base: fanSpeedBase,
+            fan_speed: fanSpeed,
+            speed: fanSpeed, // legacy
+            top: offset.y ? bedDepth : bedDepth/2,
+            left: offset.x ? 0 : -bedWidth/2,
+            right: offset.x ? bedWidth : bedWidth/2,
+            bottom: offset.y ? 0 : -bedDepth/2,
+            z_max: maxHeight,
+            layers: layers.length,
+            progress: 0,
+            nozzle: tool,
+            tool: tool,
+            model_labels: model_labels.sort().join(',')
+        },
+        pidx, path, out, speedMMM, emitMM, emitPerMM, lastp, laste, dist,
+        lines = 0,
+        bytes = 0,
+        bcos = Math.cos(Math.PI / 4),
+        icos = 1 / bcos,
+        inloops = 0,
+        arcQ = [],
+        minz = { x: Infinity, y: Infinity, z: Infinity },
+        // lenghts of each filament (by nozzle) consumed
+        segments = [];
+
+    let tools_used = Object.keys(tools);
+    for (let tool of tools_used) {
+        subst[`tool_used_${tool}`] = true;
+    }
+    subst.tool_count = tools_used.length;
+
+    // encodes an array offset as a single "on" bit in an
+    // 8 byte array, then converts the array to base64 which
+    // is what Bambu's M624 uses to flag an object as currently
+    // being printed. the array is presented at the top of the
+    // gcode as a comment: "; model label id: {model_labels}"
+    function encodeBitOffset(index) {
+        let bytes = new Uint8Array(8);
+        let byteIndex = Math.floor(index / 8);
+        let bitPosition = index % 8;
+        bytes[byteIndex] |= (1 << bitPosition);
+        return btoa(String.fromCharCode(...bytes));
+    }
+
+    function setTempFanSpeed(tempSpeed) {
+        if (tempSpeed > 0) {
+            fanSpeedSave = fanSpeedSave >= 0 ? fanSpeedSave : fanSpeed;
+            fanSpeed = tempSpeed;
+            subst.fan_speed = fanSpeed;
+            subst.fan_speed_base = tempSpeed;
+        } else {
+            fanSpeed = fanSpeedSave >= 0 ? fanSpeedSave : fanSpeed
+            fanSpeedSave = undefined;
+            subst.fan_speed = fanSpeed;
+            subst.fan_speed_base = fanSpeedBase;
+        }
+    }
+
+    // smallish band-aid. refactor above to remove redundancy
+    function updateParams(layer, params) {
+        // params = getRangeParameters(process, layer);
+        zhop = params.zHopDistance || 0; // range
+        retDist = params.outputRetractDist || 0; // range
+        retSpeed = params.outputRetractSpeed * 60 || 1; // range
+        retDwell = params.outputRetractDwell || 0; // range
+        timeDwell = retDwell / 1000;
+        nozzleTemp = layer === 0 ?
+            params.firstLayerNozzleTemp || params.outputTemp :
+            params.outputTemp || params.firstLayerNozzleTemp;
+        bedTemp = layer === 0 ?
+            params.firstLayerBedTemp || params.outputBedTemp :
+            params.outputBedTemp || params.firstLayerBedTemp;
+        fanSpeedBase = params.firstLayerFanSpeed || 0;
+        fanSpeed = layer >= (params.outputFanLayer ?? 1) ?
+            params.outputFanSpeed || 0 : fanSpeedBase;
+        Object.assign(subst, {
+            temp_bed: bedTemp,
+            bed_temp: bedTemp,
+            fan_speed: fanSpeed,
+            fan_speed_base: fanSpeedBase,
+            speed: fanSpeed, // legacy
+            retract_speed: retSpeed,
+            retract_distance: retDist,
+            temp: params.outputTemp, // range
+            temp_bed: params.outputBedTemp, // range
+            bed_temp: params.outputBedTemp, // range
+        });
+    }
+
+    let rloops = [];
+    if (oloops > 0) {
+        // if oloops set, loop entire part
+        rloops.push({
+            start: layers[0].slice.index,
+            end: Infinity,
+            iter: oloops - 1
+        });
+    } else if (oloops < 0) {
+        // if oloops negative, loop entire part to infinity
+        rloops.push({
+            start: layers[0].slice.index,
+            end: Infinity,
+            iter: 0
+        });
+    }
+    if (process.ranges) {
+        // collect loops from ranges and synth range array
+        for (let range of process.ranges) {
+            if (range.fields.outputLoops) {
+                rloops.push({
+                    start: range.lo,
+                    end: range.hi,
+                    iter: range.fields.outputLoops - 1
+                });
+            }
+        }
+    }
+    let loops = isBelt && rloops.length ? rloops : undefined;
+
+    function append(line) {
+        if (line) {
+            lines++;
+            bytes += line.length;
+            output.append(line);
+        }
+        // batch gcode output to free memory in worker
+        // consider alternate transfer schemes like indexeddb
+        // since this transfers the burden to the main thread
+        if (!line || output.length > 1000) {
+            online(output.join("\n"));
+            output = [];
+        }
+    };
+
+    function appendSubPad(line, pad) {
+        appendSub(line, true);
+    }
+
+    let subon = true;
+    let ifhit = false;
+
+    // eval() based var substitution (from print)
+    // with logic flow IF / ELIF / ELSE / END
+    // IF / IF is valid but will not nest
+    function appendSub(line, pad) {
+        if (line.indexOf(';; DEFINE ') === 0) {
+            // ignore var declarations
+        } else if (line.indexOf(';; IF ') === 0) {
+            line = line.substring(6).trim();
+            let evil = print.constReplace(line, subst, 0, 666);
+            subon = evil;
+            ifhit = subon;
+        } else if (line.indexOf(';; ELIF ') === 0) {
+            line = line.substring(6).trim();
+            let evil = print.constReplace(line, subst, 0, 666);
+            subon = !subon && evil;
+            ifhit = ifhit || subon;
+        } else if (line.indexOf(';; ELSE') === 0) {
+            subon = !ifhit && !subon;
+        } else if (line.indexOf(';; END') === 0) {
+            subon = true;
+            ifhit = false;
+        } else if (subon) {
+            append(print.constReplace(line, subst, 0, pad));
+        }
+    }
+
+    function appendAll(arr) {
+        if (!arr) return;
+        if (!Array.isArray(arr)) arr = [ arr ];
+        arr.forEach(function(line) { append(line) });
+    }
+
+    function appendAllSub(arr, pad) {
+        if (!arr || arr.length === 0) return;
+        if (!Array.isArray(arr)) arr = [ arr ];
+        arr.forEach(function(line) { appendSub(line, pad) });
+    }
+
+    function appendTok() {
+        let arg = [...arguments].map(v => {
+            return typeof(v) === 'object' ? JSON.stringify(v) : v;
+        });
+        append(arg.join(''));
+    }
+
+    function preamble() {
+        append(`; Generated by Kiri:Moto ${version}`);
+        append(`; ${new Date().toString()}`);
+        appendSub("; Bed left:{left} right:{right} top:{top} bottom:{bottom}");
+        append(`; Bed type: ${bedType}`);
+        append(`; Target: ${filter[mode]}`);
+        // inject thumbnail preview
+        if (exportThumb && worker.snap) {
+            let { width, height, url } = worker.snap;
+            let data = url.substring(url.indexOf(',') + 1);
+            append(`; thumbnail begin ${width} ${height} ${data.length}`);
+            for (let i=0; i<data.length; i += 78) {
+                append(`; ${data.substring(i, i + 78)}`);
+            }
+            append('; thumbnail end');
+        }
+        append("; --- process ---");
+        for (let pk in process) {
+            appendTok("; ", pk, " = ", process[pk]);
+        }
+        append("; --- startup ---");
+    }
+
+    // looking for ";; PREAMBLE <MODE>" comment
+    let pre = 0;
+    let gcpre = [];
+    for (let line of device.gcodePre) {
+        line = line.trim();
+        if (line.indexOf(";; PREAMBLE") === 0) {
+            if (line === ';; PREAMBLE OFF') pre = 1;
+            else if (line === ';; PREAMBLE END') pre = 2;
+            else gcpre.push(pre = 123);
+        } else if (line.indexOf(";; AXISMAP ") === 0) {
+            let axmap = JSON.parse(line.substring(11).trim());
+            for (let key in axmap) {
+                axis[key] = ` ${axmap[key]}`;
+            }
+        } else {
+            gcpre.push(line);
+        }
+    }
+
+    if (pre === 0) preamble();
+
+    let t0 = false;
+    let t1 = false;
+    for (let line of gcpre) {
+        if (line === pre) {
+            preamble();
+            continue;
+        }
+        if (line.indexOf('T0') === 0) t0 = true; else
+        if (line.indexOf('T1') === 0) t1 = true; else
+        if (line.indexOf('M82') === 0) {
+            extrudeAbs = true;
+            extrudeSet = true;
+        } else
+        if (line.indexOf('M83') === 0) {
+            extrudeAbs = false;
+            extrudeSet = true;
+        } else
+        if (line.indexOf('G90') === 0 && !extrudeSet) extrudeAbs = true; else
+        if (line.indexOf('G91') === 0 && !extrudeSet) extrudeAbs = false; else
+        if (line.indexOf('G92') === 0) {
+            line.split(";")[0].split(' ').forEach(function (tok) {
+                let val = parseFloat(tok.substring(1) || 0) || 0;
+                switch (tok[0]) {
+                    case 'X': pos.x = val; break;
+                    case 'Y': pos.y = val; break;
+                    case 'Z': pos.z = val; break;
+                    case 'E': outputLength = val; break;
+                }
+            });
+        }
+        if (line.indexOf('E') > 0) {
+            line.split(";")[0].split(' ').forEach(function (tok) {
+                // use max E position from gcode-preamble
+                if (tok[0] == 'E') {
+                    if (extrudeAbs) {
+                        outputLength = Math.max(outputLength, parseFloat(tok.substring(1)) || 0);
+                        emitted = outputLength;
+                    } else {
+                        emitted += parseFloat(tok.substring(1) || 0);
+                    }
+                }
+            });
+        }
+        appendSubPad(line);
+    }
+
+    if (pre === 2) preamble();
+
+    function dwell(ms) {
+        time += ms/1000;
+        // break up dwell times over 4s because of
+        // limitations in some firmwares
+        while (ms > 0) {
+            let wait = Math.min(4000, ms);
+            append(`G4 P${wait}`);
+            ms -= wait;
+            if (ms) {
+                append('G1');
+            }
+        }
+    }
+
+    function retract(zhop) {
+        if (retracted) {
+            // console.log({double_retract: zhop});
+            return;
+        }
+        retracted = retDist;
+        if (fwRetract) {
+            append('G10');
+        } else {
+            moveTo({e:-retracted}, retSpeed, `e-retract ${retDist}`);
+        }
+        if (zhop) moveTo({z:zpos + zhop}, seekMMM, "z-hop start");
+        time += (retDist / retSpeed) * 60 * 2; // retraction time
+    }
+
+    function unretract() {
+        if (!retracted) {
+            return;
+        }
+        drainQ();
+        // console.log({engage:zhop});
+        // when enabled, resume previous Z
+        if (zhop && pos.z != zpos) moveTo({z:zpos}, seekMMM, "z-hop end");
+        // re-engage retracted filament
+        if (fwRetract) {
+            append('G11');
+        } else {
+            moveTo({e:retracted}, retSpeed, `e-engage ${retracted}`);
+        }
+        retracted = 0;
+        // optional dwell after re-engaging filament to allow pressure to build
+        if (retDwell) dwell(retDwell);
+        time += (retDist / retSpeed) * 60 * 2; // retraction time
+    }
+
+    let taxis = new THREE.Vector3( 1, 0, 0 );
+    let tcent = new THREE.Vector2( 0, 0 );
+    let angle = -Math.PI / 4;
+    let savePos = pos;
+
+    function pushPos(newpos, rate, comment) {
+        savePos = Object.clone(pos);
+        moveTo({
+            x: newpos.x + offset.x,
+            y: newpos.y + offset.y,
+            z: newpos.z + offset.z
+        }, rate, comment);
+    }
+
+    function popPos(rate, comment) {
+        moveTo(savePos, rate, comment);
+    }
+
+    function moveTo(newpos, rate, comment) {
+        let o = [!rate && !newpos.e ? 'G0' : 'G1'];
+        let emit = { x: false, y: false, z: false };
+        if (typeof newpos.x === 'number' && newpos.x !== pos.x) {
+            pos.x = newpos.x;
+            emit.x = true;
+        }
+        if (typeof newpos.y === 'number' && newpos.y !== pos.y) {
+            pos.y = newpos.y;
+            emit.y = true;
+            if (isBelt) emit.z = true;
+        }
+        if (typeof newpos.z === 'number' && newpos.z !== pos.z) {
+            pos.z = newpos.z;
+            emit.z = true;
+            if (isBelt) emit.y = true;
+        }
+        let epos = isBelt ? { x: pos.x, y: pos.y, z: pos.z } : pos;
+        if (isBelt) {
+            let zheight = path ? path.height || 0 : 0;
+            epos.x = originCenter ? -pos.x : device.bedWidth - pos.x;
+            epos.z = blastz = pos.z * icos;
+            epos.y = -pos.y + epos.z * bcos + belt_add_y;
+            lout = epos;
+        }
+        if (emit.x) o.append(axis.X).append(epos.x.toFixed(decimals));
+        if (emit.y) o.append(axis.Y).append(epos.y.toFixed(decimals));
+        if (emit.z) o.append(axis.Z).append(epos.z.toFixed(decimals));
+        if (debug) {
+            if (emit.x) minz.x = Math.min(minz.x, epos.x);
+            if (emit.y) minz.y = Math.min(minz.y, epos.y);
+            if (emit.z) minz.z = Math.min(minz.z, epos.z);
+        }
+        if (typeof newpos.e === 'number') {
+            outputLength += newpos.e;
+            if (extrudeAbs) {
+                // for cumulative (absolute) extruder positions
+                o.append(axis.E).append(outputLength.toFixed(decimals));
+            } else {
+                o.append(axis.E).append(newpos.e.toFixed(decimals));
+            }
+        }
+        if (zMoveMax && emit.z) {
+            rate = Math.min(zMoveMax, rate) * 60;
+        }
+        if (rate && rate != pos.f) {
+            o.append(" F").append(Math.round(rate));
+            pos.f = rate
+        }
+        if (comment) {
+            o.append(` ; ${comment}`);
+        }
+        if (o.length === 1) {
+            // console.trace({no_move: o, out, newpos, pos, lastp, emit});
+            return;
+        }
+        let line = o.join('');
+        if (last == line) {
+            // console.log({dup:line});
+            return;
+        }
+        last = line;
+        subst.pos_x = epos.x.round(decimals);
+        subst.pos_y = epos.y.round(decimals);
+        subst.pos_z = epos.z.round(decimals);
+        append(line);
+    }
+
+    // calc total distance traveled by head as proxy for progress
+    let allout = [];
+    let totaldistance = 0;
+    layers.forEach(function(outs) {
+        allout.appendAll(outs);
+    });
+    allout.forEachPair(function (o1, o2) {
+        totaldistance += o1.point.distTo2D(o2.point);
+    }, 1);
+
+    // retract before first move
+    retract();
+
+    while (layer < layers.length) {
+        path = layers[layer];
+        layerno = path.slice.index;
+        // range overrides
+        if (path.layer >= 0) {
+            updateParams(path.layer, path.params);
+        }
+
+        emitPerMM = extrudePerMM(
+            lineWidth || extruder.extNozzle,
+            extruder.extFilament,
+            path.layer === 0 ?
+                (process.firstSliceHeight || process.sliceHeight) : path.height);
+
+        zpos = path.z || zpos;
+        bmax = Math.max(bmax, pos.z * icos);
+        subst.z = subst.Z = zpos.round(3);
+        subst.e = subst.E = outputLength;
+        subst.layer = layer;
+        subst.height = path.height;
+
+        if (isBelt) {
+            pos.z = zpos;
+        }
+
+        if (gcodePause && pause.indexOf(layer) >= 0) {
+            appendAllSub(gcodePause)
+        }
+
+        let endloop = 0;
+        if (loops) {
+            for (let loop of loops) {
+                if (layerno === loop.start && !loop.started) {
+                    loop.started = true;
+                    append(`M808 L${loop.iter}`);
+                    if (extrudeAbs) {
+                        append(`G92 Z${lout.z.round(decimals)} E${outputLength.round(decimals)}`);
+                    } else {
+                        append(`G92 Z${lout.z.round(decimals)}`);
+                    }
+                    inloops++;
+                }
+                if (layerno === loop.end && !loop.ended) {
+                    loop.ended = true;
+                    endloop++;
+                    inloops--;
+                }
+            }
+        }
+
+        if (gcodeLayer && gcodeLayer.length) {
+            appendAllSub(gcodeLayer);
+        } else {
+            append(`;; --- layer ${layer} (${subst.height.toFixed(3)} @ ${subst.z.round(3)}) ---`);
+        }
+
+        // layer temp and fan overrides at layer changes
+        if (fanSpeed !== lastFanSpeed) {
+            appendAllSub(gcodeFan);
+            lastFanSpeed = fanSpeed;
+        }
+        if (bedTemp !== lastBedTemp) {
+            append(`M140 S${bedTemp} T0`);
+            lastBedTemp = bedTemp;
+        }
+        if (nozzleTemp !== lastNozzleTemp) {
+            if (t0) append(`M104 S${nozzleTemp} T0`);
+            if (t1) append(`M104 S${nozzleTemp} T1`);
+            if (!(t0 || t1)) append(`M104 S${nozzleTemp} T${tool}`);
+            lastNozzleTemp = nozzleTemp;
+        }
+
+        // move Z to layer height
+        if (layer > 0 || !isBelt) {
+            moveTo({z:zpos}, seekMMM);
+        }
+
+        let cwidget;
+        // iterate through layer outputs
+        for (pidx=0; pidx<path.length; pidx++) {
+            out = path[pidx];
+            speedMMM = (out.speed || process.outputFeedrate) * 60; // range
+
+            // hint to controller that we're working on a specific object
+            // so that gcode between start/stop comments can be cancelled
+            if (out.widget !== cwidget) {
+                if (cwidget) {
+                    append(`; end object id: ${cwidget.track.grid_id}`);
+                    isBambu && append('M625');
+                }
+                if (out.widget) {
+                    let off = model_labels.indexOf(out.widget.track.grid_id);
+                    let b64 = encodeBitOffset(off);
+                    append(`; start object id: ${out.widget.track.grid_id}`);
+                    isBambu && append(`M624 ${b64}`);
+                }
+                cwidget = out.widget;
+            }
+
+            // emit comment on output type chage
+            if (last && out.type !== last.type) {
+                lastType = subst.feature = out.type;
+                if (gcodeFeature && gcodeFeature.length) {
+                    appendAllSub(gcodeFeature);
+                } else {
+                    append(`; feature ${out.type}`);
+                }
+            }
+
+            // look for extruder change, run scripts, recalc emit factor
+            if (out.tool !== undefined && out.tool != tool) {
+                segments.push({emitted, tool});
+                subst.last_tool = tool;
+                tool = out.tool;
+                subst.nozzle = subst.tool = tool;
+                extruder = extruders[tool];
+                offset_x = extruder.extOffsetX;
+                offset_y = extruder.extOffsetY;
+                emitPerMM = extrudePerMM(
+                    lineWidth || extruder.extNozzle,
+                    extruder.extFilament,
+                    path.layer === 0 ?
+                        (process.firstSliceHeight || process.sliceHeight) : path.height);
+                appendAllSub(gcodeChange ?? [ "T{tool}" ]);
+            }
+
+            // if no point in output, it's a dwell command
+            if (!out.point) {
+                dwell(out.speed);
+                continue;
+            }
+
+            let x = out.point.x + offset_x,
+                y = out.point.y + offset_y,
+                z = out.point.z;
+
+            // adjust for inversions and origin offsets
+            if (process.outputInvertX) x = -x;
+            if (process.outputInvertY) y = -y;
+            if (offset) {
+                x += offset.x;
+                y += offset.y;
+            }
+
+            dist = lastp ? lastp.distTo2D(out.point) : 0;
+
+            // re-engage post-retraction before new extrusion
+            if (out.emit && retracted) {
+                unretract();
+            }
+
+            // in belt mode, fan can change per segment (for base)
+            if (isBelt) {
+                setTempFanSpeed(out.fan);
+                if (fanSpeed !== lastFanSpeed) {
+                    appendAllSub(gcodeFan);
+                    lastFanSpeed = fanSpeed;
+                }
+            }
+
+            if (lastp && out.emit) {
+                if (arcDist) {
+                    let rec = {e:out.emit, x, y, z, dist, emitPerMM, speedMMM};
+                    arcQ.push(rec);
+                    let deem = false; // do arcQ[0] and rec have differing emit values?
+                    let depm = false; // do arcQ[0] and rec have differing emit speeds?
+                    let desp = false; // do arcQ[0] and rec have differing move speeds?
+                    if (arcQ.length > 1) {
+                        let el = arcQ.length;
+                        deem = arcQ[0].e !== rec.e;
+                        depm = arcQ[0].emitPerMM !== rec.emitPerMM;
+                        desp = arcQ[0].speedMMM !== rec.speedMMM;
+                    }
+                    // ondebug({arcQ});
+                    if (arcQ.length > 2) {
+                        let el = arcQ.length;
+                        let e1 = arcQ[0]; // first in arcQ
+                        let e2 = arcQ[Math.floor(el/2)]; // mid in arcQ
+                        let e3 = arcQ[el-1]; // last in arcQ
+                        let e4 = arcQ[el-2]; // second last in arcQ
+                        let e5 = arcQ[el-3]; // third last in arcQ
+                        let cc = util.center2d(e1, e2, e3, 1); // find center
+                        let lr = util.center2d(e3, e4, e5, 1); // find local radius
+                        let dc = 0;
+
+                        let radFault = false;
+                        if (lr) {
+                            let angle = 2 * Math.asin(dist/(2*lr.r));
+                            radFault = Math.abs(angle) > Math.PI * 2 / arcRes; // enforce arcRes(olution)
+                            // if (arcQ.center) {
+                            //     arcQ.rSum = arcQ.center.reduce( function (t, v) { return t + v.r }, 0 );
+                            //     let avg = arcQ.rSum / arcQ.center.length;
+                            //     radFault = radFault || Math.abs(avg - lr.r) / avg > arcDev; // eliminate sharps and flats when local rad is out of arcDev(iation)
+                            // }
+                        } else {
+                            radFault = true;
+                        }
+
+                        if (cc) {
+                            if ([cc.x,cc.y,cc.z,cc.r].hasNaN()) {
+                                console.log({cc, e1, e2, e3});
+                            }
+                            if (arcQ.length === 3) {
+                                arcQ.center = [ cc ];
+                                arcQ.xSum = cc.x;
+                                arcQ.ySum = cc.y;
+                                arcQ.rSum = cc.r;
+                            } else {
+                                // check center point delta
+                                arcQ.xSum = arcQ.center.reduce( function (t, v) { return t + v.x }, 0 );
+                                arcQ.ySum = arcQ.center.reduce( function (t, v) { return t + v.y }, 0 );
+                                arcQ.rSum = arcQ.center.reduce( function (t, v) { return t + v.r }, 0 );
+                                let dx = cc.x - arcQ.xSum / arcQ.center.length;
+                                let dy = cc.y - arcQ.ySum / arcQ.center.length;
+                                dc = Math.sqrt(dx * dx + dy * dy);
+                            }
+
+                            // if new point is off the arc
+                            // if (deem || depm || desp || dc > arcDist || cc.r < arcMin || cc.r > arcMax || dist > cc.r) {
+                            if (deem || depm || desp || dc * arcQ.center.length / arcQ.rSum > arcDist || dist > cc.r || cc.r > arcMax || radFault || !arcValid()) {
+                                // let debug = [deem, depm, desp, dc * arcQ.center.length / arcQ.rSum > arcDist, dist > cc.r, cc.r > arcMax, radFault];
+                                if (arcQ.length === 4) {
+                                    // not enough points for an arc, drop first point and recalc center
+                                    emitQrec(arcQ.shift());
+                                    let tc = util.center2d(arcQ[0], arcQ[1], arcQ[2], 1);
+                                    // the new center is invalid as well. drop the first point
+                                    if (!tc) {
+                                        emitQrec(arcQ.shift());
+                                    } else {
+                                        arcQ.center = [ tc ];
+                                        let angle = 2 * Math.asin(arcQ[1].dist/(2*tc.r));
+                                        if (Math.abs(angle) > Math.PI * 2 / arcRes) { // enforce arcRes on initial angle
+                                            emitQrec(arcQ.shift());
+                                        }
+                                    }
+                                } else {
+                                    // enough to consider an arc, emit and start new arc
+                                    let defer = arcQ.pop();
+                                    drainQ();
+                                    // re-add point that was off the last arc
+                                    arcQ.push(defer);
+                                }
+                            } else {
+                                // new point is on the arc
+                                arcQ.center.push(cc);
+                            }
+                        } else {
+                            // drainQ on invalid center
+                            drainQ();
+                        }
+                    }
+                } else {
+                    // emitMM = emitPerMM * out.emit * dist;
+                    emitMM = extrudeMM(dist, emitPerMM, out.emit);
+                    moveTo({x:x, y:y, e:emitMM}, speedMMM);
+                    emitted += emitMM;
+                }
+            } else {
+                drainQ();
+                moveTo({x:x, y:y}, seekMMM);
+                // TODO disabling out of plane z moves until a better mechanism
+                // can be built that doesn't rely on computed zpos from layer heights...
+                // when making z moves (like polishing) allow slowdown vs fast seek
+                // let moveSpeed = (lastp && lastp.z !== z) ? speedMMM : seekMMM;
+                // moveTo({x:x, y:y, z:z}, moveSpeed);
+            }
+
+            // retract filament if point retract flag set
+            if (out.retract) {
+                drainQ();
+                retract(zhop);
+            }
+
+            // update time and distance (should calc in moveTo() instead)
+            if (dist && speedMMM) {
+                time += (dist / speedMMM) * 60 * timeFactor;
+            }
+            // if (isNaN(time)) {
+            //     console.log({ layer, path, dist, speedMMM, timeFactor });
+            //     throw "NaN";
+            // }
+            distance += dist;
+            subst.progress = progress = Math.round((distance / totaldistance) * 100);
+
+            // emit tracked progress
+            if (gcodeTrack && progress != lastProgress) {
+                appendAllSub(gcodeTrack);
+                lastProgress = progress;
+            }
+
+            lastp = out.point;
+            laste = out.emit;
+        }
+        layer++;
+        if (cwidget) {
+            append(`; end object id: ${cwidget.track.grid_id}`);
+            isBambu && append('M625');
+            cwidget = undefined;
+        }
+
+        // end open loop when detected
+        while (endloop-- > 0) {
+            append(`M808`);
+        }
+        drainQ();
+    }
+
+    function emitQrec(rec) {
+        let {e, x, y, dist, emitPerMM, speedMMM} = rec;
+        // emitMM = emitPerMM * e * dist;
+        emitMM = extrudeMM(dist, emitPerMM, e);
+        moveTo({x:x, y:y, e:emitMM}, speedMMM);
+        emitted += emitMM;
+    }
+
+    function drainQ() {
+        if (!arcDist) {
+            return;
+        }
+        if (arcQ.length > 4) {
+            // ondebug({arcQ});
+            let vec1 = new THREE.Vector2(arcQ[1].x - arcQ[0].x, arcQ[1].y - arcQ[0].y);
+            let vec2 = new THREE.Vector2(arcQ.center[0].x - arcQ[0].x, arcQ.center[0].y - arcQ[0].y);
+            let gc = vec1.cross(vec2) < 0 ? 'G2' : 'G3';
+            let from = arcQ[0];
+            let to = arcQ.peek();
+            arcQ.xSum = arcQ.center.reduce( function (t, v) { return t + v.x }, 0 );
+            arcQ.ySum = arcQ.center.reduce( function (t, v) { return t + v.y }, 0 );
+            arcQ.rSum = arcQ.center.reduce( function (t, v) { return t + v.r }, 0 );
+            let cl = arcQ.center.length;
+            let cc;
+
+            let angle = util.thetaDiff(
+                Math.atan2((from.y - arcQ.ySum / cl), (from.x - arcQ.xSum / cl)),
+                Math.atan2((to.y - arcQ.ySum / cl), (to.x - arcQ.xSum / cl)),
+                gc === "G2"
+            );
+
+            if (Math.abs(angle) <= 3 * Math.PI / 4) {
+                cc = util.center2pr(from, to, arcQ.rSum / cl, gc === "G3");
+            }
+
+            if (!cc) {
+                cc = {x:arcQ.xSum/cl, y:arcQ.ySum/cl, z:arcQ[0].z, r:arcQ.rSum/cl};
+            }
+
+            // first arc point
+            emitQrec(from);
+            // console.log(arcQ.slice(), arcQ.center);
+            // console.log({first: from, last: arcQ.peek(), center: cc});
+            // rest of arc to final point
+            let dist = arcQ.slice(1).map(v => v.dist).reduce((a,v) => a+v);
+            let emit = from.e;//arcQ.slice(1).map(v => v.e).reduce((a,v) => a+v);
+            emit = (from.emitPerMM * emit * dist);
+            outputLength += emit;
+            emitted += emit;
+            if (extrudeAbs) {
+                emit = outputLength;
+            }
+            // XYR form
+            // let pre = `${gc} X${to.x.toFixed(decimals)} Y${to.y.toFixed(decimals)} R${cc.r.toFixed(decimals)} E${emit.toFixed(decimals)}`;
+            // XYIJ form
+            let pre = `${gc} X${to.x.toFixed(decimals)} Y${to.y.toFixed(decimals)} I${(cc.x - pos.x).toFixed(decimals)} J${(cc.y - pos.y).toFixed(decimals)} E${emit.toFixed(decimals)}`;
+            let add = pos.f !== from.speedMMM ? ` E${from.speedMMM}` : '';
+            append(`${pre}${add} ; merged=${cl-1} len=${dist.toFixed(decimals)} cp=${cc.x.round(2)},${cc.y.round(2)}`);
+            pos.x = to.x;
+            pos.y = to.y;
+            pos.z = to.z;
+        } else {
+            for (let rec of arcQ) {
+                emitQrec(rec);
+            }
+        }
+        arcQ.length = 0;
+        arcQ.center = undefined;
+    }
+
+    // comprehensive arc validator
+    function arcValid() {
+        if (arcQ.length < 3) {
+            return false;
+        }
+
+        let globalCenters = []; // see how a point first the curve within the context of the arc's end points.
+
+        for (let i = 0; i < arcQ.length - 2; i++) {
+            let cc = util.center2d(arcQ[0], arcQ[i+1], arcQ[arcQ.length - 1], 1);
+            if (!cc) {
+                return false;
+            }
+            globalCenters.push(cc);
+        }
+
+        let ac = { // average center
+            x:globalCenters.reduce( (t,v) =>  t + v.x , 0) / (globalCenters.length),
+            y:globalCenters.reduce( (t,v) =>  t + v.y , 0) / (globalCenters.length),
+            z:globalCenters.reduce( (t,v) =>  t + v.z , 0) / (globalCenters.length),
+            r:globalCenters.reduce( (t,v) =>  t + v.r , 0) / (globalCenters.length)
+        };
+
+        // make sure centers are within specified tolerance
+        for (let cc of globalCenters) {
+            let dc = Math.sqrt(Math.pow(cc.x - ac.x, 2) + Math.pow(cc.y - ac.y, 2));
+            if (dc / ac.r > arcDist) {
+                return false;
+            }
+        }
+
+        // make sure radii are within specified tolerance
+        for (let point of arcQ) {
+            let rad = Math.sqrt(Math.pow(point.x - ac.x, 2) + Math.pow(point.y - ac.y, 2));
+            if (Math.abs(rad - ac.r) > ac.r * arcDist) {
+                return false;
+            }
+        }
+
+        // enforce arcRes(olution)
+        for (let i = 1; i < arcQ.length; i++) {
+            let angle = 2 * Math.asin(arcQ[i].dist/(2*ac.r));
+            if (Math.abs(angle) > Math.PI * 2 / arcRes) {
+                return false;
+            }
+        }
+
+        // check points in the context of neighbors
+        for (let i = 0; i < arcQ.length - 2; i++) {
+            let cc = util.center2d(arcQ[i], arcQ[i+1], arcQ[i+2], 1);
+            if (!cc || Math.abs((cc.r - ac.r) / cc.r) > arcDev) {
+                return false;
+            }
+        }
+
+        return true;
+
+    }
+
+    if (inloops) {
+        append(`M808`);
+    }
+
+    segments.push({emitted, tool});
+    subst.material = util.round(emitted,2);
+    subst.time = util.round(time,2);
+    subst['print_time'] = subst.time;
+
+    append("; --- shutdown ---");
+    appendAllSub(device.gcodePost);
+    append(`; --- filament used: ${subst.material} mm ---`);
+    append(`; --- print time: ${time.toFixed(0)}s ---`);
+
+    // force emit of buffer
+    append();
+    // console.log({segments, emitted, outputLength});
+    print.distance = emitted;
+    print.lines = lines;
+    print.bytes = bytes + lines - 1;
+    print.time = time;
+    print.labels = model_labels;
+
+    if (debug) {
+        console.log('segments', segments);
+        console.log('minz', minz);
+    }
+};

src/kiri/mode/fdm/fill.js

@@ -0,0 +1,320 @@
+/** Copyright Stewart Allen <sa@grid.space> -- All Rights Reserved */
+
+import { newPolygon } from '../../../geo/polygon.js';
+import { slice as gyroid_slice } from '../../../geo/gyroid.js';
+
+export const fill_fixed = {
+    hex: fillHexFull,
+    grid: fillGrid,
+    triangle: fillTriangle
+};
+
+export const fill = {
+    hex: fillHexFull,
+    grid: fillGrid,
+    gyroid: fillGyroid,
+    triangle: fillTriangle,
+    linear: fillLinear,
+    cubic: fillCubic
+};
+
+const DEG2RAD = Math.PI / 180;
+
+function fillHexFull(target) {
+    fillHex(target, true);
+}
+
+/**
+ * emitter creates a hex infill pattern and sends to target
+ *
+ * @param {Object} target
+ * @param {boolean} full continuous walls
+ */
+function fillHex(target, full) {
+    // compute segment lengths (vert/horiz and 45)
+    let spacing = target.offset();
+    // let vhlen = (1 / target.density()) * (target.lineWidth() + spacing);
+    let vhlen = (1 / target.density()) * target.lineWidth() * 0.5;
+    let anxlen = (Math.cos(30 * DEG2RAD) * vhlen).round(7);
+    let anylen = (Math.sin(30 * DEG2RAD) * vhlen).round(7);
+    let bounds = target.bounds();
+    let even = true;
+    let evenZ = target.zIndex() % 2 === 0;
+    let maxy = bounds.max.y + (vhlen + anylen * 2);
+    let x, y;
+
+    if (full || evenZ) {
+        x = bounds.min.x;
+        for (;;) {
+            if (even && x > bounds.max.x) break;
+            if (!even && x > bounds.max.x + anxlen + spacing) break;
+            y = bounds.min.y;
+            target.newline();
+            while (y <= maxy) {
+                target.emit(x,y);
+                y += vhlen;
+                target.emit(x,y);
+                if (even) x += anxlen; else x -= anxlen;
+                y += anylen;
+                target.emit(x,y);
+                y += vhlen;
+                target.emit(x,y);
+                if (even) x -= anxlen; else x += anxlen;
+                y += anylen;
+            }
+            x += spacing;
+            if (even) x += (anxlen * 2);
+            even = !even;
+            target.newline();
+        }
+    } else {
+        y = bounds.min.y + vhlen;
+        for (;;) {
+            if (even && y > bounds.max.y) break;
+            if (!even && y > bounds.max.y + anylen) break;
+            x = bounds.min.x;
+            target.newline();
+            while (x < bounds.max.x) {
+                target.emit(x,y);
+                if (even) y += anylen; else y -= anylen;
+                x += anxlen;
+                target.emit(x,y);
+                x += spacing;
+                target.emit(x,y);
+                if (even) y -= anylen; else y += anylen;
+                x += anxlen;
+                target.emit(x,y);
+                x += spacing;
+            }
+            y += vhlen;
+            if (even) y += (anylen * 2);
+            even = !even;
+            target.newline();
+        }
+    }
+}
+
+function fillGyroid(target) {
+    let bounds = target.bounds();
+    let height = target.zHeight();
+    let span_x = bounds.max.x - bounds.min.x;
+    let span_y = bounds.max.y - bounds.min.y;
+    let density = target.density();
+    let tile = 1 + (1 - density) * 15;
+    let tile_x = span_x / tile;
+    let tile_y = span_y / tile;
+    let tile_z = 1 / tile;
+    let gen = gyroid_slice(target.zValue() * tile_z, (1 - density) * 500);
+
+    let polys = [];
+    if (gen.dir == 'lr') {
+        for (let ty=0; ty<=tile_y; ty++) {
+            for (let tx=0; tx<=tile_x; tx++) {
+                for (let poly of gen.polys) {
+                    target.newline();
+                    let points = poly.map(el => {
+                        return {
+                            x: el.x * tile + tx * tile + bounds.min.x,
+                            y: el.y * tile + ty * tile + bounds.min.y,
+                            z: 0
+                        }
+                    });
+                    polys.push(newPolygon().setOpen(true).addObj(points));
+                }
+            }
+            polys = connectOpenPolys(polys);
+        }
+    } else {
+        for (let tx=0; tx<=tile_x; tx++) {
+            for (let ty=0; ty<=tile_y; ty++) {
+                for (let poly of gen.polys) {
+                    target.newline();
+                    let points = poly.map(el => {
+                        return {
+                            x: el.x * tile + tx * tile + bounds.min.x,
+                            y: el.y * tile + ty * tile + bounds.min.y,
+                            z: 0
+                        }
+                    });
+                    polys.push(newPolygon().setOpen(true).addObj(points));
+                }
+            }
+            polys = connectOpenPolys(polys);
+        }
+    }
+    for (let poly of polys.filter(p => p.perimeter() > 2)) {
+        target.newline();
+        for (let point of poly.points) {
+            target.emit(point.x, point.y);
+        }
+    }
+}
+
+function connectOpenPolys(noff, dist = 0.1) {
+    if (noff.length <= 1) {
+        return noff;
+    }
+    let heal = 0;
+    // heal/rejoin open segments that have close endpoints
+    outer: for(;; heal++) {
+        let ntmp = noff, tlen = ntmp.length;
+        for (let i=0; i<tlen; i++) {
+            let s1 = ntmp[i];
+            if (!s1 || !s1.open) continue;
+            for (let j=i+1; j<tlen; j++) {
+                let s2 = ntmp[j];
+                if (!s2 || !s2.open) continue;
+                if (s1.last().distTo2D(s2.first()) <= dist) {
+                    s1.addPoints(s2.points);
+                    ntmp[j] = null;
+                    continue outer;
+                }
+                if (s1.first().distTo2D(s2.last()) <= dist) {
+                    s2.addPoints(s1.points);
+                    ntmp[i] = null;
+                    continue outer;
+                }
+                if (s1.first().distTo2D(s2.first()) <= dist) {
+                    s1.reverse();
+                    s1.addPoints(s2.points);
+                    ntmp[j] = null;
+                    continue outer;
+                }
+                if (s1.last().distTo2D(s2.last()) <= dist) {
+                    s2.reverse();
+                    s1.addPoints(s2.points);
+                    ntmp[j] = null;
+                    continue outer;
+                }
+            }
+        }
+        break;
+    }
+    if (heal > 0) {
+        // cull nulls
+        noff = noff.filter(o => o);
+    }
+    return noff;
+}
+
+function fillGrid(target) {
+    let bounds = target.bounds();
+    let height = target.zHeight();
+    let span_x = bounds.max.x - bounds.min.x;
+    let span_y = bounds.max.y - bounds.min.y;
+    let offset = target.offset() / 2;
+    let tile = (1 / target.density()) * target.lineWidth();
+    let tile_x = tile + offset;
+    let tile_xc = span_x / tile_x;
+    let tile_yc = span_y / tile;
+
+    for (let tx=0; tx<=tile_xc; tx++) {
+        target.newline();
+        for (let ty=0; ty<=tile_yc; ty++) {
+            let bx = tx * tile_x + bounds.min.x;
+            let by = ty * tile + bounds.min.y;
+            if ((tx + ty) % 2) {
+                target.emit(bx, by);
+                target.emit(bx + tile_x - offset, by + tile);
+            } else {
+                target.emit(bx + tile_x - offset, by);
+                target.emit(bx, by + tile);
+            }
+        }
+    }
+}
+
+function fillCubic(target) {
+    let bounds = target.bounds();
+    let span = Math.max(
+        bounds.max.x - bounds.min.x,
+        bounds.max.y - bounds.min.y
+    );
+    let steps = Math.floor((span / target.lineWidth()) * target.density());
+    let step = span / steps;
+    let ztype = Math.floor(target.zIndex() / target.repeat()) % 3;
+    if (ztype === 1) {
+        for (let tx=bounds.min.x; tx<=bounds.max.x; tx += step) {
+            target.newline();
+            target.emit(tx, bounds.min.y);
+            target.emit(tx, bounds.max.y);
+        }
+    } else if (ztype === 0) {
+        for (let ty=bounds.min.y; ty<=bounds.max.y; ty += step) {
+            target.newline();
+            target.emit(bounds.min.x, ty);
+            target.emit(bounds.max.x, ty);
+        }
+    } else {
+        step *- Math.sqrt(2);
+        for (let tx=bounds.min.x; tx<=bounds.max.x; tx += step) {
+            target.newline();
+            target.emit(tx, bounds.min.y);
+            target.emit(tx + 1000, bounds.max.y + 1000);
+        }
+        for (let ty=bounds.min.y; ty<=bounds.max.y; ty += step) {
+            target.newline();
+            target.emit(bounds.min.x, ty);
+            target.emit(bounds.min.x + 1000, ty + 1000);
+        }
+    }
+}
+
+function fillLinear(target) {
+    let bounds = target.bounds();
+    let span = Math.max(
+        bounds.max.x - bounds.min.x,
+        bounds.max.y - bounds.min.y
+    );
+    let steps = Math.floor((span / target.lineWidth()) * target.density());
+    let step = span / steps;
+    let ztype = Math.floor(target.zIndex() / target.repeat()) % 2;
+    if (ztype === 1) {
+        for (let tx=bounds.min.x; tx<=bounds.max.x; tx += step) {
+            target.newline();
+            target.emit(tx, bounds.min.y);
+            target.emit(tx, bounds.max.y);
+        }
+    } else if (ztype === 0) {
+        for (let ty=bounds.min.y; ty<=bounds.max.y; ty += step) {
+            target.newline();
+            target.emit(bounds.min.x, ty);
+            target.emit(bounds.max.x, ty);
+        }
+    }
+}
+
+function fillTriangle(target) {
+    let bounds = target.bounds();
+    let span_x = bounds.max.x - bounds.min.x;
+    let span_y = bounds.max.y - bounds.min.y;
+    let offset = target.offset();
+    let line_w = target.lineWidth() / 2;
+    let tile = (1 / target.density()) * (target.lineWidth() * 1.25);
+    let tile_x = tile + offset*2 + line_w;
+    let tile_xc = span_x / tile_x;
+    let tile_yc = span_y / tile;
+
+    for (let tx=0; tx<=tile_xc; tx++) {
+        target.newline();
+        for (let ty=0; ty<=tile_yc; ty++) {
+            let bx = tx * tile_x + bounds.min.x;
+            let by = ty * tile + bounds.min.y;
+            if ((tx + ty) % 2) {
+                target.emit(bx, by);
+                target.emit(bx + tile_x - offset - line_w, by + tile);
+            } else {
+                target.emit(bx + tile_x - offset - line_w, by);
+                target.emit(bx, by + tile);
+            }
+        }
+    }
+
+    for (let tx=0; tx<=tile_xc; tx++) {
+        let bx = tx * tile_x + bounds.min.x;
+        let xp = bx + tile_x - line_w/2 - offset/2;
+        target.newline();
+        target.emit(xp, bounds.min.y);
+        target.emit(xp, bounds.max.y);
+    }
+}

src/kiri/mode/fdm/post.js

@@ -0,0 +1,313 @@
+/** Copyright Stewart Allen <sa@grid.space> -- All Rights Reserved */
+
+import { base } from '../../../geo/base.js';
+import { polygons as POLY, fillArea } from '../../../geo/polygons.js';
+import { getRangeParameters } from './driver.js';
+import { slicer } from '../../../geo/slicer.js';
+
+slicer.slicePost.FDM = slicePost;
+
+/**
+ * may run in minion or worker context. do not create objects
+ * that will not quickly encode in threaded mode. add to existing
+ * data object. return is ignored.
+ */
+export function slicePost(data, options) {
+    const { z, lines, groups } = data;
+    const { useAssembly, post_args, zIndexes } = options;
+    const { process, isSynth, vaseMode } = post_args;
+    const { shellOffset, fillOffset, clipOffset } = post_args;
+    data.tops = POLY.nest(groups);
+    if (isSynth) {
+        const process = post_args.process;
+        if (process.sliceSupportGrow > 0) {
+            // expand synth supports here so they can be clipped later
+            data.tops  = POLY.expand(data.tops, process.sliceSupportGrow, data.z, []);
+        }
+        // do not shell synth widgets because
+        // they will be clipped against peers later
+        // which requires shelling post-clip
+        // but we still need to generate tops
+        delete data.groups;
+        return;
+    }
+    const index = zIndexes.indexOf(z);
+    const range = getRangeParameters(process, index);
+    // calculate fractional shells
+    let shellFrac = (range.sliceShells - (range.sliceShells | 0));
+    let sliceShells = range.sliceShells | 0;
+    if (shellFrac) {
+        let v1 = shellFrac > 0.5 ? 1 - shellFrac : shellFrac;
+        let v2 = 1 - v1;
+        let parts = Math.round(v2/v1) + 1;
+        let rem = index % parts;
+        let trg = shellFrac > 0.5 ? 1 : parts - 1;
+        sliceShells += rem >= trg ? 1 : 0;
+    }
+    const isFirst = index === 0;
+    const height = process.sliceHeight;
+    const spaceMult = isFirst ? process.firstLayerLineMult || 1 : 1;
+    const count = isSynth ? 1 : sliceShells;
+    const offset =  shellOffset * spaceMult;
+    const fillOff = fillOffset * spaceMult;
+    const thinType = isSynth ? undefined : process.sliceDetectThin;
+    const nutops = [];
+    // co-locate shell processing with top generation in slicer
+    for (let top of data.tops) {
+        nutops.push(doTopShells(z, top, count, offset/2, offset, fillOff, {
+            thinType,
+            vaseMode,
+            useAssembly
+        }));
+    }
+    data.clip = clipOffset ? POLY.offset(nutops.map(t => t.simple), clipOffset) : undefined;
+    data.tops = nutops;
+    delete data.groups;
+};
+
+function offset_default(params) {
+    let { z, top, count, top_poly, offset1, offsetN, wasm, last, gaps } = params;
+    // standard wall offsetting strategy
+    POLY.offset(
+        top_poly,
+        [-offset1, -offsetN],
+        {
+            z,
+            wasm,
+            count,
+            outs: top.shells,
+            flat: true,
+            call: (polys, onCount) => {
+                last = polys;
+                // mark each poly with depth (offset #) starting at 0
+                for (let p of polys) {
+                    p.depth = count - onCount;
+                    if (p.fill_off) p.fill_off.forEach(function(pi) {
+                        // use negative offset for inners
+                        pi.depth = -(count - onCount);
+                    });
+                    // mark inner depth to match parent
+                    if (p.inner) {
+                        for (let pi of p.inner) {
+                            pi.depth = p.depth;
+                        }
+                    }
+                }
+            }
+        }
+    );
+    return { last, gaps };
+}
+
+function thin_type_1(params) {
+    let { z, top, count, top_poly, offsetN, last, gaps } = params;
+    top.thin_fill = [];
+    top.fill_sparse = [];
+
+    let layers = POLY.inset(top_poly, offsetN, count, z, true);
+    last = layers.last().mid;
+    top.shells = layers.map(r => r.mid).flat();
+    top.gaps = layers.map(r => r.gap).flat();
+
+    let off = offsetN;
+    let min = off * 0.75;
+    let max = off * 4;
+
+    for (let poly of layers.map(r => r.gap).flat()) {
+        let centers = poly.centers(off/2, z, min, max, {lines:false});
+        top.fill_sparse.appendAll(centers);
+    }
+
+    return { last, gaps };
+}
+
+function thin_type_2(params) {
+    let { z, top, count, top_poly, offset1, offsetN, last, gaps, wasm } = params;
+
+    top.gaps = gaps;
+    top.thin_fill = [];
+    let oso = {z, count, gaps: [], outs: [], minArea: 0.05, wasm};
+    POLY.offset(top_poly, [-offset1, -offsetN], oso);
+
+    oso.outs.forEach((polys, i) => {
+        polys.forEach(p => {
+            p.depth = i;
+            if (p.fill_off) {
+                p.fill_off.forEach(pi => pi.depth = i);
+            }
+            if (p.inner) {
+                for (let pi of p.inner) {
+                    pi.depth = p.depth;
+                }
+            }
+            top.shells.push(p);
+        });
+        last = polys;
+    });
+
+    // slice.solids.trimmed = slice.solids.trimmed || [];
+    oso.gaps.forEach((polys, i) => {
+        let off = (i == 0 ? offset1 : offsetN);
+        polys = POLY.offset(polys, -off * 0.8, {z, minArea: 0, wasm});
+        top.thin_fill.appendAll(cullIntersections(
+            fillArea(polys, 45, off/2, [], 0.01, off*2),
+            fillArea(polys, 135, off/2, [], 0.01, off*2),
+        ));
+        gaps.push(...polys);
+    });
+
+    return { last, gaps };
+}
+
+function thin_type_3(params) {
+    let { z, top, count, offsetN, last, gaps } = params;
+    top.thin_fill = [];
+    top.fill_sparse = [];
+
+    let { noodle, remain } = top.poly.noodle(offsetN);
+    top.shells = noodle;
+    top.gaps = remain;
+    // top.fill_off = noodle;
+
+    // if (remain.length) {
+    //     top.gaps = [];
+    //     for (let poly of remain) {
+    //         let { noodle } = poly.noodle(offsetN);
+    //         console.log({ next_noodle: noodle });
+    //         top.gaps.push(...noodle);
+    //     }
+    // }
+
+    return { last, gaps };
+}
+
+/**
+ * may run in minion or worker context. performs shell offsetting
+ * including thin wall detection when enabled
+ */
+export function doTopShells(z, top, count, offset1, offsetN, fillOffset, opt = {}) {
+    // pretend we're a top object in minions
+    if (!top.poly) {
+        top = { poly: top };
+    }
+
+    // add simple (low rez poly) where less accuracy is OK
+    top.simple = top.poly.simple();
+
+    let wasm = opt.useAssembly;
+    let top_poly = [ top.poly ];
+
+    if (opt.vaseMode) {
+        // remove top poly inners in vase mode
+        top.poly = top.poly.clone(false);
+    }
+
+    top.shells = [];        // strategies output shells here
+    top.fill_off = [];      // offset from innermost shell for infill
+    top.fill_lines = [];    // fill lines inside fill_off
+
+    let last = [],
+        gaps = [];
+
+    if (count) {
+        // permit offset of 0 for laser and drag knife
+        if (offset1 === 0 && count === 1) {
+            last = top_poly.clone(true);
+            top.shells = last;
+        } else {
+            // heal top open polygons if the ends are close (benchy tilt test)
+            top_poly.forEach(p => { if (p.open) {
+                let dist = p.first().distTo2D(p.last());
+                if (dist < 1) p.open = false;
+            } });
+            let ret = { last, gaps };
+            switch (opt.thinType) {
+                case "type 1":
+                    ret = thin_type_1({ z, top, count, top_poly, offsetN, fillOffset });
+                    break;
+                case "type 2":
+                    ret = thin_type_2({ z, top, count, top_poly, offset1, offsetN, fillOffset, gaps, wasm });
+                    break;
+                case "type 3":
+                    ret = thin_type_3({ z, top, count, top_poly, offsetN });
+                    fillOffset = 0;
+                    break;
+                default:
+                    ret = offset_default({ z, top, count, top_poly, offset1, offsetN, wasm });
+                    break;
+            }
+            last = ret.last || last;
+            gaps = ret.gaps || gaps;
+        }
+    } else {
+        // no shells, just infill, is permitted
+        last = [top.poly];
+    }
+
+    // generate fill offset poly set from last offset to top.fill_off
+    if (fillOffset && last.length > 0) {
+        // if gaps present, remove that area from fill inset
+        if (gaps.length) {
+            let nulast = [];
+            POLY.subtract(last, gaps, nulast, null, z);
+            last = nulast;
+        }
+        last.forEach(function(inner) {
+            POLY.offset([inner], -fillOffset, {outs: top.fill_off, flat: true, z});
+        });
+    }
+
+    // for diffing
+    top.last = last;
+    // top.last_simple = last.map(p => p.clean(true, undefined, config.clipper / 10));
+
+    return top;
+}
+
+/**
+ * given an array of arrays of points (lines), eliminate intersections
+ * between groups, then return a unified array of shortest non-intersects.
+ */
+function cullIntersections() {
+    function toLines(pts) {
+        let lns = [];
+        for (let i=0, il=pts.length; i<il; i += 2) {
+            lns.push({a: pts[i], b: pts[i+1], l: pts[i].distTo2D(pts[i+1])});
+        }
+        return lns;
+    }
+    let aOa = [...arguments].filter(t => t);
+    if (aOa.length < 1) return;
+    let aa = toLines(aOa.shift());
+    while (aOa.length) {
+        let bb = toLines(aOa.shift());
+        loop: for (let i=0, il=aa.length; i<il; i++) {
+            let al = aa[i];
+            if (al.del) {
+                continue;
+            }
+            for (let j=0, jl=bb.length; j<jl; j++) {
+                let bl = bb[j];
+                if (bl.del) {
+                    continue;
+                }
+                if (base.util.intersect(al.a, al.b, bl.a, bl.b, base.key.SEGINT)) {
+                    if (al.l < bl.l) {
+                        bl.del = true;
+                    } else {
+                        al.del = true;
+                    }
+                    continue;
+                }
+            }
+        }
+        aa = aa.filter(l => !l.del).concat(bb.filter(l => !l.del));
+    }
+    let good = [];
+    for (let i=0, il=aa.length; i<il; i++) {
+        let al = aa[i];
+        good.push(al.a);
+        good.push(al.b);
+    }
+    return good.length > 2 ? good : [];
+}