clockface: refactor

clockface/clockface.go

@@ -43,23 +43,19 @@ func SVGWriter(w io.Writer, t time.Time) {
 // SecondHand is the unit vector of the second hand of an analogue clock at the time `t` represented as a Point
 func secondHand(w io.Writer, t time.Time) {
 	p := secondHandPoint(t)
-	p = Point{p.X * secondHandLength, p.Y * secondHandLength} // scale
+	makeHand(w, secondHandLength, p)
-	p = Point{p.X, -p.Y}                                      // flip
-	p = Point{p.X + clockCentreX, p.Y + clockCentreY}         // translate
-	fmt.Fprintf(
-		w,
-		`<line x1="150" y1="150" x2="%f" y2="%f" style="fill:none;stroke:#f00;stroke-width:3px;"/>`,
-		p.X,
-		p.Y,
-	)
 }
 
 // MinuteHand is the unit vector of the minute hand of an analogue clock at the time `t` represented as a Point
 func minuteHand(w io.Writer, t time.Time) {
 	p := minuteHandPoint(t)
-	p = Point{p.X * minuteHandLength, p.Y * minuteHandLength} // scale
+	makeHand(w, minuteHandLength, p)
-	p = Point{p.X, -p.Y}                                      // flip
+}
-	p = Point{p.X + clockCentreX, p.Y + clockCentreY}         // translate
+
+func makeHand(w io.Writer, length float64, p Point) {
+	p = Point{p.X * length, p.Y * length}             // scale
+	p = Point{p.X, -p.Y}                              // flip
+	p = Point{p.X + clockCentreX, p.Y + clockCentreY} // translate
 	fmt.Fprintf(
 		w,
 		`<line x1="150" y1="150" x2="%f" y2="%f" style="fill:none;stroke:#f00;stroke-width:3px;"/>`,