From e690c6aecfbcb017f5b4cf08895ef30fe7dca371 Mon Sep 17 00:00:00 2001
From: Ahmet Inan <xdsopl@gmail.com>
Date: Fri, 12 Apr 2024 23:30:01 +0200
Subject: [PATCH] added simple scope for experimentation

---
 .../java/xdsopl/robot36/MainActivity.java     | 31 ++++++++++++++++++-
 app/src/main/res/layout/activity_main.xml     | 13 ++++++--
 app/src/main/res/values-night/colors.xml      |  6 ++++
 app/src/main/res/values/colors.xml            |  1 +
 app/src/main/res/values/strings.xml           |  1 +
 5 files changed, 49 insertions(+), 3 deletions(-)
 create mode 100644 app/src/main/res/values-night/colors.xml

diff --git a/app/src/main/java/xdsopl/robot36/MainActivity.java b/app/src/main/java/xdsopl/robot36/MainActivity.java
index 60c6169..ac6698d 100644
--- a/app/src/main/java/xdsopl/robot36/MainActivity.java
+++ b/app/src/main/java/xdsopl/robot36/MainActivity.java
@@ -7,11 +7,13 @@ Copyright 2024 Ahmet Inan <xdsopl@gmail.com>
 package xdsopl.robot36;
 
 import android.content.pm.PackageManager;
+import android.graphics.Bitmap;
 import android.media.AudioFormat;
 import android.media.AudioRecord;
 import android.media.MediaRecorder;
 import android.os.Bundle;
 import android.Manifest;
+import android.widget.ImageView;
 import android.widget.TextView;
 
 import androidx.activity.EdgeToEdge;
@@ -28,9 +30,15 @@ import java.util.List;
 
 public class MainActivity extends AppCompatActivity {
 
+	private final int scopeWidth = 256, scopeHeight = 256;
+	private Bitmap scopeBitmap;
+	private int[] scopePixels;
+	private ImageView scopeView;
 	private float[] recordBuffer;
 	private AudioRecord audioRecord;
 	private TextView status;
+	private int tint;
+	private int curLine;
 
 	private void setStatus(int id) {
 		status.setText(id);
@@ -44,9 +52,25 @@ public class MainActivity extends AppCompatActivity {
 		@Override
 		public void onPeriodicNotification(AudioRecord audioRecord) {
 			audioRecord.read(recordBuffer, 0, recordBuffer.length, AudioRecord.READ_BLOCKING);
+			processSamples();
 		}
 	};
 
+	private void processSamples() {
+		for (float v : recordBuffer) {
+			int x = Math.min((int) (scopeWidth * v * v), scopeWidth);
+			for (int i = 0; i < x; ++i)
+				scopePixels[scopeWidth * curLine + i] = tint;
+			for (int i = x; i < scopeWidth; ++i)
+				scopePixels[scopeWidth * curLine + i] = 0;
+			for (int i = 0; i < scopeWidth; ++i)
+				scopePixels[scopeWidth * (curLine + scopeHeight) + i] = scopePixels[scopeWidth * curLine + i];
+			curLine = (curLine + 1) % scopeHeight;
+		}
+		scopeBitmap.setPixels(scopePixels, scopeWidth * curLine, scopeWidth, 0, 0, scopeWidth, scopeHeight);
+		scopeView.invalidate();
+	}
+
 	private void initAudioRecord() {
 		int audioSource = MediaRecorder.AudioSource.UNPROCESSED;
 		int channelConfig = AudioFormat.CHANNEL_IN_MONO;
@@ -113,7 +137,12 @@ public class MainActivity extends AppCompatActivity {
 			v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
 			return insets;
 		});
-		status = (TextView) findViewById(R.id.status);
+		tint = getColor(R.color.tint);
+		status = findViewById(R.id.status);
+		scopeView = findViewById(R.id.scope);
+		scopeBitmap = Bitmap.createBitmap(scopeWidth, scopeHeight, Bitmap.Config.ARGB_8888);
+		scopeView.setImageBitmap(scopeBitmap);
+		scopePixels = new int[2 * scopeWidth * scopeHeight];
 		List<String> permissions = new ArrayList<>();
 		if (ContextCompat.checkSelfPermission(this, Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED) {
 			permissions.add(Manifest.permission.RECORD_AUDIO);
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index 8040d19..33621ff 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -8,6 +8,16 @@
 	android:layout_height="match_parent"
 	tools:context=".MainActivity">
 
+	<ImageView
+		android:id="@+id/scope"
+		android:layout_width="0dp"
+		android:layout_height="0dp"
+		android:contentDescription="@string/scope_description"
+		app:layout_constraintBottom_toBottomOf="parent"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toTopOf="parent" />
+
 	<TextView
 		android:id="@+id/status"
 		android:layout_width="wrap_content"
@@ -15,7 +25,6 @@
 		android:text="Hello World!"
 		app:layout_constraintBottom_toBottomOf="parent"
 		app:layout_constraintEnd_toEndOf="parent"
-		app:layout_constraintStart_toStartOf="parent"
-		app:layout_constraintTop_toTopOf="parent" />
+		app:layout_constraintStart_toStartOf="parent" />
 
 </androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/values-night/colors.xml b/app/src/main/res/values-night/colors.xml
new file mode 100644
index 0000000..9e8f90f
--- /dev/null
+++ b/app/src/main/res/values-night/colors.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+	<color name="black">#FF000000</color>
+	<color name="white">#FFFFFFFF</color>
+	<color name="tint">#FFFFFFFF</color>
+</resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/colors.xml b/app/src/main/res/values/colors.xml
index fa5fc6f..94a849e 100644
--- a/app/src/main/res/values/colors.xml
+++ b/app/src/main/res/values/colors.xml
@@ -2,4 +2,5 @@
 <resources>
 	<color name="black">#FF000000</color>
 	<color name="white">#FFFFFFFF</color>
+	<color name="tint">#FF000000</color>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 72f8c6f..ccceb42 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -5,4 +5,5 @@
 	<string name="audio_setup_failed">audio setup failed</string>
 	<string name="audio_permission_denied">audio permission denied</string>
 	<string name="audio_recording_error">audio recording error</string>
+	<string name="scope_description">visualization of audio signal</string>
 </resources>