add String functions for better printing/debugging (#40)

geom/geometry.go

@@ -1,6 +1,7 @@
 package geom
 
 import (
+	"fmt"
 	"math"
 )
 
@@ -55,6 +56,10 @@ type Vector2 struct {
 	X, Y float64
 }
 
+func (v *Vector2) String() string {
+	return fmt.Sprintf("{%0.3f,%0.3f}", v.X, v.Y)
+}
+
 func (v *Vector2) Add(v2 *Vector2) *Vector2 {
 	v.X += v2.X
 	v.Y += v2.Y
@@ -101,6 +106,10 @@ type Line struct {
 	X1, Y1, X2, Y2 float64
 }
 
+func (l *Line) String() string {
+	return fmt.Sprintf("{%0.3f,%0.3f->%0.3f,%0.3f}", l.X1, l.Y1, l.X2, l.Y2)
+}
+
 // Angle gets the angle of the line
 func (l *Line) Angle() float64 {
 	return math.Atan2(l.Y2-l.Y1, l.X2-l.X1)

geom3d/geometry.go

@@ -1,6 +1,7 @@
 package geom3d
 
 import (
+	"fmt"
 	"math"
 )
 
@@ -11,6 +12,10 @@ type Vector3 struct {
 	X, Y, Z float64
 }
 
+func (v *Vector3) String() string {
+	return fmt.Sprintf("{%0.3f,%0.3f,%0.3f}", v.X, v.Y, v.Z)
+}
+
 func (v *Vector3) Add(v3 *Vector3) *Vector3 {
 	v.X += v3.X
 	v.Y += v3.Y
@@ -38,6 +43,10 @@ type Line3d struct {
 	X1, Y1, Z1, X2, Y2, Z2 float64
 }
 
+func (l *Line3d) String() string {
+	return fmt.Sprintf("{%0.3f,%0.3f,%0.3f->%0.3f,%0.3f,%0.3f}", l.X1, l.Y1, l.Z1, l.X2, l.Y2, l.Z2)
+}
+
 // Heading gets the XY axis angle of the 3-dimensional line
 func (l *Line3d) Heading() float64 {
 	return math.Atan2(l.Y2-l.Y1, l.X2-l.X1)