From e96670bb05b80a6a8ab50e4860c02f3d266cf0dc Mon Sep 17 00:00:00 2001
From: Stewart Allen <stewart.allen@gmail.com>
Date: Sun, 13 Nov 2022 10:50:29 -0500
Subject: [PATCH] allow fdm driver override of extrusion calcs

---
 src/kiri-mode/fdm/driver.js | 19 +++++++++++++++++--
 src/kiri-mode/fdm/export.js | 14 +++++++++-----
 src/kiri/print.js           |  4 ----
 3 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/src/kiri-mode/fdm/driver.js b/src/kiri-mode/fdm/driver.js
index c9f68a96..7ab55ca9 100644
--- a/src/kiri-mode/fdm/driver.js
+++ b/src/kiri-mode/fdm/driver.js
@@ -4,9 +4,10 @@
 
 gapp.register("kiri-mode.fdm.driver", [], (root, exports) => {
 
-const { kiri } = root;
+const { base, kiri } = root;
 const { driver } = kiri;
-const FDM = driver.FDM = { getRangeParameters };
+const { util } = base;
+const FDM = driver.FDM = { getRangeParameters, extrudePerMM, extrudeMM };
 
 // shared by client and worker contexts
 function getRangeParameters(process, index) {
@@ -29,6 +30,20 @@ function getRangeParameters(process, index) {
     return params;
 }
 
+// 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
 kiri.load(api => {
 
diff --git a/src/kiri-mode/fdm/export.js b/src/kiri-mode/fdm/export.js
index bd224e0e..6fafc10e 100644
--- a/src/kiri-mode/fdm/export.js
+++ b/src/kiri-mode/fdm/export.js
@@ -128,7 +128,9 @@ FDM.export = function(print, online, ondone, ondebug) {
         // track purges for palette3 pings
         purgePos,
         purgeOn = 0,
-        purgeOff = 0;
+        purgeOff = 0,
+        extrudeMM = FDM.extrudeMM,
+        extrudePerMM = FDM.extrudePerMM;
 
     let tools_used = Object.keys(tools);
     for (let tool of tools_used) {
@@ -537,7 +539,7 @@ FDM.export = function(print, online, ondone, ondebug) {
             updateParams(path.layer, path.params);
         }
 
-        emitPerMM = print.extrudePerMM(
+        emitPerMM = extrudePerMM(
             lineWidth || extruder.extNozzle,
             extruder.extFilament,
             path.layer === 0 ?
@@ -665,7 +667,7 @@ FDM.export = function(print, online, ondone, ondebug) {
                 extruder = extruders[tool];
                 offset_x = extruder.extOffsetX;
                 offset_y = extruder.extOffsetY;
-                emitPerMM = print.extrudePerMM(
+                emitPerMM = extrudePerMM(
                     lineWidth || extruder.extNozzle,
                     extruder.extFilament,
                     path.layer === 0 ?
@@ -802,7 +804,8 @@ FDM.export = function(print, online, ondone, ondebug) {
                         }
                     }
                 } else {
-                    emitMM = emitPerMM * out.emit * dist;
+                    // emitMM = emitPerMM * out.emit * dist;
+                    emitMM = extrudeMM(dist, emitPerMM, out.emit);
                     moveTo({x:x, y:y, e:emitMM}, speedMMM);
                     emitted += emitMM;
                 }
@@ -847,7 +850,8 @@ FDM.export = function(print, online, ondone, ondebug) {
 
     function emitQrec(rec) {
         let {e, x, y, dist, emitPerMM, speedMMM} = rec;
-        emitMM = emitPerMM * e * dist;
+        // emitMM = emitPerMM * e * dist;
+        emitMM = extrudeMM(dist, emitPerMM, e);
         moveTo({x:x, y:y, e:emitMM}, speedMMM);
         emitted += emitMM;
     }
diff --git a/src/kiri/print.js b/src/kiri/print.js
index 0d1b19dc..393c31b7 100644
--- a/src/kiri/print.js
+++ b/src/kiri/print.js
@@ -128,10 +128,6 @@ class Print {
         return output.last().point;
     }
 
-    extrudePerMM(noz, fil, slice) {
-        return ((Math.PI * util.sqr(noz / 2)) / (Math.PI * util.sqr(fil / 2))) * (slice / noz);
-    }
-
     constReplace(str, consts, start, pad, short) {
         let cs = str.indexOf("{", start || 0),
             ce = str.indexOf("}", cs),