[librsvg] path_builder.rs: Declare a PathCommand enum

[Federico Mena Quintero <federico src gnome org>]

commit d7aff34d2fa7e5b6c059b049b9f50ed858949ebc
Author: Federico Mena Quintero <federico gnome org>
Date:   Thu Mar 2 12:15:52 2017 -0600

    path_builder.rs: Declare a PathCommand enum
    
    We will move PathBuilder from storing cairo::PathSegment directly, to
    storing its own PathCommand.  This will be an enum similar to Cairo's,
    but that can also store SVG's Arc command, and possibly SVG's quadratic
    Béziers, too.
    
    Currently, when adding markers to a path, we have unwanted markers in
    the middle of arcs, as they get exploded into Bézier curve segments.  By
    having our own Arc PathCommand, we can defer the arc-to-Béziers step
    until we finally feed the PathBuilder into Cairo.
    
    This should also make it possible to have tests for parsing Arc
    commands; currently there are none.

 rust/src/path_builder.rs |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/rust/src/path_builder.rs b/rust/src/path_builder.rs
index 55993bd..a7bda6f 100644
--- a/rust/src/path_builder.rs
+++ b/rust/src/path_builder.rs
@@ -4,6 +4,13 @@ use ::cairo_sys;
 use std::f64;
 use std::f64::consts::*;
 
+pub enum PathCommand {
+    MoveTo (f64, f64),
+    LineTo (f64, f64),
+    CurveTo ((f64, f64), (f64, f64), (f64, f64)), // (x2, y2), (x3, y3), (x4, y4) <- this is the destination 
point
+    ClosePath
+}
+
 #[repr(C)]
 pub struct RsvgPathBuilder {
     path_segments: Vec<cairo::PathSegment>,