bebop: add ValidatePitch helper function for Parrot Bebop to package

Signed-off-by: deadprogram <ron@hybridgroup.com>

platforms/parrot/bebop/pitch.go

@@ -0,0 +1,17 @@
+package bebop
+
+import "math"
+
+// ValidatePitch helps validate pitch values such as those created by
+// a joystick to values between 0-100 that are required as
+// params to Parrot Bebop PCMDs
+func ValidatePitch(data float64, offset float64) int {
+	value := math.Abs(data) / offset
+	if value >= 0.1 {
+		if value <= 1.0 {
+			return int((float64(int(value*100)) / 100) * 100)
+		}
+		return 100
+	}
+	return 0
+}

platforms/parrot/bebop/pitch_test.go

@@ -0,0 +1,19 @@
+package bebop
+
+import (
+	"testing"
+
+	"gobot.io/x/gobot/gobottest"
+)
+
+func TestBebopValidatePitchWhenEqualOffset(t *testing.T) {
+	gobottest.Assert(t, ValidatePitch(32767.0, 32767.0), 100)
+}
+
+func TestBebopValidatePitchWhenTiny(t *testing.T) {
+	gobottest.Assert(t, ValidatePitch(1.1, 32767.0), 0)
+}
+
+func TestBebopValidatePitchWhenCentered(t *testing.T) {
+	gobottest.Assert(t, ValidatePitch(16383.5, 32767.0), 50)
+}