plectrum

commit 0ae6104e50f0b3cdc09be46ed3e3835fe3a43b10
parent 1c9f3fb10429fe33816ae51386512372d937bdff
Author: gstraube <gstraube@mailbox.org>
Date:   Sat, 10 Feb 2018 17:12:46 +0100

Add pitch adjuster (issue #14)

Diffstat:
A
app/src/main/java/com/github/cythara/PitchAdjuster.java
 | 
19
+++++++++++++++++++
A
app/src/main/res/layout/set_reference_pitch_dialog.xml
 | 
7
+++++++
A
app/src/test/java/com/github/cythara/PitchAdjusterTest.java
 | 
57
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++

3 files changed, 83 insertions(+), 0 deletions(-)
diff --git a/app/src/main/java/com/github/cythara/PitchAdjuster.java b/app/src/main/java/com/github/cythara/PitchAdjuster.java
@@ -0,0 +1,19 @@
+package com.github.cythara;
+
+class PitchAdjuster {
+
+    private static final float A440 = 440f;
+    private final float adjustmentFactor;
+
+    PitchAdjuster() {
+        adjustmentFactor = 1f;
+    }
+
+    PitchAdjuster(float referencePitch) {
+        adjustmentFactor = referencePitch / A440;
+    }
+
+    float adjustPitch(float pitch) {
+        return pitch / adjustmentFactor;
+    }
+}
diff --git a/app/src/main/res/layout/set_reference_pitch_dialog.xml b/app/src/main/res/layout/set_reference_pitch_dialog.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="vertical" android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+</LinearLayout>
+\ No newline at end of file
diff --git a/app/src/test/java/com/github/cythara/PitchAdjusterTest.java b/app/src/test/java/com/github/cythara/PitchAdjusterTest.java
@@ -0,0 +1,57 @@
+package com.github.cythara;
+
+import com.github.cythara.tuning.GuitarTuning;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import static com.github.cythara.NoteName.E;
+import static com.github.cythara.NoteName.G;
+import static com.github.cythara.tuning.GuitarTuning.Pitch;
+import static org.hamcrest.Matchers.is;
+
+public class PitchAdjusterTest {
+
+    @Test
+    public void pitch_is_unchanged_for_A440() {
+        PitchAdjuster pitchAdjuster = new PitchAdjuster();
+
+        for (Pitch pitch : GuitarTuning.Pitch.values()) {
+            Assert.assertThat(pitchAdjuster.adjustPitch(pitch.getFrequency()),
+                    is(pitch.getFrequency()));
+        }
+    }
+
+    @Test
+    public void pitch_is_adjusted() {
+        PitchAdjuster pitchAdjuster = new PitchAdjuster(442f);
+        Assert.assertThat(pitchAdjuster.adjustPitch(662.25f), is(659.2534f));
+
+        pitchAdjuster = new PitchAdjuster(434f);
+        Assert.assertThat(pitchAdjuster.adjustPitch(172.23f), is(174.61105f));
+    }
+
+    @Test
+    public void correct_note_is_retrieved_for_adjusted_pitch() {
+        PitchAdjuster pitchAdjuster = new PitchAdjuster(446f);
+        float adjustedPitch = pitchAdjuster.adjustPitch(198.67f);
+
+        Assert.assertThat(PitchComparator.retrieveNote(adjustedPitch).closest.getName(),
+                is(G));
+        Assert.assertThat(PitchComparator.retrieveNote(adjustedPitch).closest.getSign(),
+                is(""));
+        Assert.assertThat(PitchComparator.retrieveNote(adjustedPitch).closest.getOctave(),
+                is(3));
+
+        pitchAdjuster = new PitchAdjuster(432f);
+        adjustedPitch = pitchAdjuster.adjustPitch(80.91f);
+
+
+        Assert.assertThat(PitchComparator.retrieveNote(adjustedPitch).closest.getName(),
+                is(E));
+        Assert.assertThat(PitchComparator.retrieveNote(adjustedPitch).closest.getSign(),
+                is(""));
+        Assert.assertThat(PitchComparator.retrieveNote(adjustedPitch).closest.getOctave(),
+                is(2));
+    }
+}