From b774e63c8ab26beb8ab1601d54aeae48479aab48 Mon Sep 17 00:00:00 2001
From: Sameer Puri <sameer@users.noreply.github.com>
Date: Thu, 25 Apr 2019 17:17:37 -0500
Subject: [PATCH] Add initial position handling for close path

---
 README.md     |  1 +
 src/main.rs   |  2 +-
 src/turtle.rs | 32 +++++++++++++++++++++++++++-----
 3 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 4343099..59430a5 100644
--- a/README.md
+++ b/README.md
@@ -12,3 +12,4 @@ Convert any SVG 1.1 path to gcode for a pen plotter, laser engraver, etc.
 ## Known bugs & whether fixed
 - [ ] Smooth curves should not use the control point when the previous curve is not of the same type (quadratic -> smooth cubic, cubic -> smooth quadratic)
 - [x] Image coordinates mirrored in the y-axis because SVGs uses upper left corner as (0,0) while GCode uses lower left as (0,0)
+- [x] Close path command connects back to (0.0, 0.0) instead of the last move
diff --git a/src/main.rs b/src/main.rs
index bcb2caf..a4dfb6b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -164,7 +164,7 @@ fn svg2program(doc: &svgdom::Document, opts: ProgramOptions, mach: Machine) -> P
                                 }
                                 PathSegment::ClosePath { abs } => {
                                     // Ignore abs, should have identical effect: https://www.w3.org/TR/SVG/paths.html#PathDataClosePathCommand
-                                    p.extend(t.line(true, 0.0, 0.0, None, opts.feedrate))
+                                    p.extend(t.close(None, opts.feedrate))
                                 }
                                 PathSegment::LineTo { abs, x, y } => {
                                     p.extend(t.line(*abs, *x, *y, None, opts.feedrate));
diff --git a/src/turtle.rs b/src/turtle.rs
index ed3cbf6..e671329 100644
--- a/src/turtle.rs
+++ b/src/turtle.rs
@@ -6,6 +6,7 @@ use lyon_geom::{ArcFlags, CubicBezierSegment, QuadraticBezierSegment, SvgArc};
 
 pub struct Turtle {
     curpos: F64Point,
+    initpos: F64Point,
     curtran: Transform2D<f64>,
     scaling: Option<Transform2D<f64>>,
     transtack: Vec<Transform2D<f64>>,
@@ -17,6 +18,7 @@ impl Default for Turtle {
     fn default() -> Self {
         Self {
             curpos: point(0.0, 0.0),
+            initpos: point(0.0, 0.0),
             curtran: Transform2D::identity(),
             scaling: None,
             transtack: vec![],
@@ -46,7 +48,8 @@ impl Turtle {
         let mut to = point(x, y);
         to = self.curtran.transform_point(&to);
         self.curpos = to;
-        self.prev_ctrl = self.curpos;
+        self.initpos = to;
+        self.prev_ctrl = to;
 
         vec![
             self.mach.tool_off(),
@@ -61,6 +64,27 @@ impl Turtle {
         .collect()
     }
 
+    pub fn close<Z, F>(&mut self, z: Z, f: F) -> Program
+    where
+        Z: Into<Option<f64>>,
+        F: Into<Option<f64>>,
+    {
+        self.curpos = self.initpos;
+        vec![
+            self.mach.tool_on(),
+            self.mach.absolute(),
+            vec![GCode::LinearInterpolation {
+                x: self.initpos.x.into(),
+                y: self.initpos.y.into(),
+                z: z.into(),
+                f: f.into(),
+            }],
+        ]
+        .drain(..)
+        .flatten()
+        .collect()
+    }
+
     pub fn line<X, Y, Z, F>(&mut self, abs: bool, x: X, y: Y, z: Z, f: F) -> Program
     where
         X: Into<Option<f64>>,
@@ -334,9 +358,7 @@ impl Turtle {
             self.curtran = self.curtran.post_mul(&old_scaling.inverse().unwrap());
         }
         self.scaling = Some(scaling);
-        self.curtran = self
-                .curtran
-                .post_mul(&scaling);
+        self.curtran = self.curtran.post_mul(&scaling);
     }
 
     pub fn push_transform(&mut self, trans: Transform2D<f64>) {
@@ -346,7 +368,7 @@ impl Turtle {
                 .curtran
                 .post_mul(&scaling.inverse().unwrap())
                 .pre_mul(&trans)
-            .post_mul(&scaling);
+                .post_mul(&scaling);
         } else {
             self.curtran = self.curtran.post_mul(&trans);
         }