add brim trigger threshold. disable first layer anchor (for now)

src/kiri/conf.js

@@ -310,6 +310,7 @@
                     firstLayerNozzleTemp: 0,
                     firstLayerBedTemp: 0,
                     firstLayerBrim: 0,
+                    firstLayerBrimTrig: 0,
                     outputRaft: false,
                     outputRaftSpacing: 0.2,
                     outputTemp: 200,

src/kiri/init.js

@@ -1629,6 +1629,7 @@
             firstLayerLineMult:  UC.newInput(LANG.fl_sfac_s, {title:LANG.fl_sfac_l, convert:UC.toFloat, bound:UC.bound(0.5,2), modes:FDM, show:isNotBelt}),
             firstLayerPrintMult: UC.newInput(LANG.fl_mult_s, {title:LANG.fl_mult_l, convert:UC.toFloat, modes:FDM}),
             firstLayerBrim:      UC.newInput(LANG.fl_brim_s, {title:LANG.fl_brim_l, convert:UC.toFloat, modes:FDM, show:isBelt}),
+            firstLayerBrimTrig:  UC.newInput(LANG.fl_brmn_s, {title:LANG.fl_brmn_l, convert:UC.toFloat, modes:FDM, show:isBelt}),
             fdmSep:              UC.newBlank({class:"pop-sep", modes:FDM, show:isNotBelt}),
             outputBrimCount:     UC.newInput(LANG.fl_skrt_s, {title:LANG.fl_skrt_l, convert:UC.toInt, modes:FDM, show:isNotBelt}),
             outputBrimOffset:    UC.newInput(LANG.fl_skro_s, {title:LANG.fl_skro_l, convert:UC.toFloat, modes:FDM, show:isNotBelt}),

src/mode/fdm/prepare.js

@@ -34,6 +34,7 @@
             firstLayerRate = process.firstLayerRate,
             firstLayerMult = process.firstLayerPrintMult,
             firstLayerBrim = process.firstLayerBrim,
+            firstLayerBrimTrig = process.firstLayerBrimTrig,
             maxLayers = 0,
             layer = 0,
             zoff = 0,
@@ -447,10 +448,10 @@
             }
             // correct y offset to desired layer offset
             let miny = process.firstLayerYOffset || 0;
+            let poff = minby - miny;
             for (let layer of output) {
                 for (let rec of layer) {
-                    let point = rec.point;
-                    point.y += minby - miny;
+                    rec.point.y += poff;
                 }
             }
             let thresh = firstLayerHeight * 1.05;
@@ -459,19 +460,28 @@
             for (let layer of output) {
                 let lastout, first = false;
                 let minz = Infinity, maxy = -Infinity, minx = Infinity, maxx = -Infinity;
-                for (let out of layer) {
-                    let point = out.point;
-                    let belty = out.belty = -point.y + point.z * bfactor;
-                    if (out.emit && belty <= thresh && lastout && lastout.belty <= thresh) {
-                        out.speed = firstLayerRate;
-                        out.emit *= firstLayerMult;
+                let mins = Infinity;
+                let miny = Infinity;
+                for (let rec of layer) {
+                    let point = rec.point;
+                    let belty = rec.belty = -point.y + point.z * bfactor;
+                    miny = Math.min(miny, belty);
+                    if (rec.emit && belty <= thresh && lastout && Math.abs(lastout.belty - belty) < 0.005) {
+                        rec.speed = firstLayerRate;
+                        rec.emit *= firstLayerMult;
                         minx = Math.min(minx, point.x, lastout.point.x);
                         maxx = Math.max(maxx, point.x, lastout.point.x);
                         maxy = Math.max(maxy, point.y);
                         minz = Math.min(minz, point.z);
-                        first = out;
+                        first = rec;
+                        // find length of shortest bed-facing segment
+                        mins = Math.min(mins, lastout.point.distTo2D(rec.point));
                     }
-                    lastout = out;
+                    lastout = rec;
+                }
+                // skip if brig trigger not met
+                if (firstLayerBrimTrig && mins > firstLayerBrimTrig) {
+                    continue;
                 }
                 // add brim, if specified
                 if (first && firstLayerBrim) {

src/mode/fdm/slice.js

@@ -509,7 +509,8 @@
             shellout += top.shells.length;
 
             // add anchor extrusion if missing on the first belt layer
-            if (opt.belt0 && top.shells.length === 0 && slice.up && slice.up.tops.length) {
+            // todo: fix. disabled because throws off layer min y calculations in some cases
+            if (false && opt.belt0 && top.shells.length === 0 && slice.up && slice.up.tops.length) {
                 for (let up of slice.up.tops) {
                     let bounds = up.poly.bounds,
                         midy = (bounds.miny + bounds.maxy) / 2;

web/kiri/lang/en.js

@@ -213,10 +213,6 @@ kiri.lang['en-us'] = {
     fl_mult_l:      "extrusion multiplier\n0.0 - 2.0",
     fl_sfac_s:      "width factor",
     fl_sfac_l:      "multiplier on nozzle size\nchanges line spacing",
-    fl_zoff_s:      "layer offset",
-    fl_zoff_l:      "height offset from belt\nof lowest extrusion\nin millimeters",
-    fl_brim_s:      "brim size",
-    fl_brim_l:      "add brim to part bottom\nsize is width in millimeters\n0 to disable",
     fl_skrt_s:      "skirt count",
     fl_skrt_l:      "number of first-layer offset\nbrims to generate",
     fl_skro_s:      "skirt offset",
@@ -230,6 +226,14 @@ kiri.lang['en-us'] = {
     fr_nabl_s:      "raft enable",
     fr_nabl_l:      "create a raft under the\nmodel for better adhesion\nuses skirt offset and\ndisables skirt output",
 
+    // FDM BELT ONLY
+    fl_zoff_s:      "layer offset",
+    fl_zoff_l:      "height offset from belt\nof lowest extrusion\nin millimeters",
+    fl_brim_s:      "brim size",
+    fl_brim_l:      "add brim to part bottom\nsize is width in millimeters\n0 to disable",
+    fl_brmn_s:      "brim trigger",
+    fl_brmn_l:      "add brims only when segment\nfacing belt is shorter than this\nvalue in millimeters\n0 = Infinity",
+
     // FDM SUPPORT
     sp_menu:        "support",
     sp_detect:      "detect",