Add a new Lissajous Curves Visualizer (#171)

Fixes: #166 


![image](https://github.com/user-attachments/assets/9775f4cc-a557-4e88-86be-9a78d01fb9c6)

![image](https://github.com/user-attachments/assets/027fddff-49fb-4d28-963a-20fbae2efefa)

![image](https://github.com/user-attachments/assets/ad967f74-e139-4d58-a38a-f38aeabd5ae7)

The curves are generated in random motion.

@dinxsh @Soumya-Kushwaha Kindly review the PR.

Lissajous-Curves-Visualizer.py

@@ -0,0 +1,124 @@
+import numpy as np
+import pyaudio
+from kivy.app import App
+from kivy.uix.boxlayout import BoxLayout
+from kivy.uix.button import Button
+from kivy.uix.widget import Widget
+from kivy.clock import Clock
+from kivy.graphics import Line, Color
+import random
+import subprocess
+
+# Constants
+CHUNK = 1024
+RATE = 44100
+
+class LissajousWidget(Widget):
+    def __init__(self, **kwargs):
+        super(LissajousWidget, self).__init__(**kwargs)
+        self.points = []
+        self.offset_x = self.width / 2
+        self.offset_y = self.height / 2
+
+    def update(self, data, a=5, b=4, delta=np.pi / 2):
+        self.canvas.clear()
+        with self.canvas:
+            Color(1, 0, 0)
+            t = np.linspace(0, 2 * np.pi, 1000)
+            amplitude = np.max(data) / 32768.0 * 2  # Increase size by scaling amplitude
+            x = np.sin(a * t + delta) * amplitude * self.width / 2 + self.width / 2 + self.offset_x
+            y = np.sin(b * t) * amplitude * self.height / 2 + self.height / 2 + self.offset_y
+            self.points = list(zip(x, y))
+            flattened_points = [coord for point in self.points for coord in point]
+            Line(points=flattened_points, width=1.5)
+
+            # Randomly move the curves over the screen
+            self.offset_x = random.uniform(-self.width / 2, self.width / 2)
+            self.offset_y = random.uniform(-self.height / 2, self.height / 2)
+
+class AudioVisualizerApp(App):
+    def build(self):
+        # Initialize PyAudio
+        self.pAud = pyaudio.PyAudio()
+        try:
+            self.pAud.get_device_info_by_index(0)
+        except pyaudio.PyAudioError as e:
+            print(f"Error initializing PyAudio: {e}")
+            self.pAud = None
+
+        # Main layout
+        self.layout = BoxLayout(orientation='vertical', padding=10, spacing=10)
+
+        # Lissajous widget
+        self.lissajous_widget = LissajousWidget()
+
+        # Buttons
+        self.listen_button = Button(text='Listen', size_hint=(None, None), size=(100, 50))
+        self.listen_button.bind(on_press=self.listen)
+
+        self.stop_button = Button(text='Stop', size_hint=(None, None), size=(100, 50), disabled=True)
+        self.stop_button.bind(on_press=self.stop)
+
+        self.exit_button = Button(text='Exit', size_hint=(None, None), size=(100, 50))
+        self.exit_button.bind(on_press=self.close_app)
+
+        self.button_layout = BoxLayout(size_hint=(1, None), height=50, spacing=10)
+        self.button_layout.add_widget(self.listen_button)
+        self.button_layout.add_widget(self.stop_button)
+        self.button_layout.add_widget(self.exit_button)
+
+        self.layout.add_widget(self.lissajous_widget)
+        self.layout.add_widget(self.button_layout)
+
+        Clock.schedule_interval(self.update_plot, 1.0 / 30.0)  # Update plot every 1/30th of a second
+
+        return self.layout
+
+    def update_plot(self, dt):
+        if hasattr(self, 'audioData') and self.audioData.size != 0:
+            self.lissajous_widget.update(self.audioData)
+
+    def listen(self, instance):
+        self.stop_button.disabled = False
+        self.listen_button.disabled = True
+        if self.pAud:
+            try:
+                self.stream = self.pAud.open(
+                    format=pyaudio.paInt16,
+                    channels=1,
+                    rate=RATE,
+                    input=True,
+                    frames_per_buffer=CHUNK,
+                    stream_callback=self.callback,
+                )
+                self.stream.start_stream()
+            except pyaudio.PyAudioError as e:
+                print(f"Error opening stream: {e}")
+                self.listen_button.disabled = False
+                self.stop_button.disabled = True
+
+    def stop(self, instance=None):
+        if hasattr(self, 'stream'):
+            self.stream.stop_stream()
+            self.stream.close()
+            del self.stream
+            self.stop_button.disabled = True
+            self.listen_button.disabled = False
+
+    def callback(self, in_data, frame_count, time_info, status):
+        self.audioData = np.frombuffer(in_data, dtype=np.int16)
+        return (in_data, pyaudio.paContinue)
+
+    def close_app(self, instance):
+        self.stop()
+        if self.pAud:
+            self.pAud.terminate()
+        App.get_running_app().stop()
+
+    def run_visualizer(self, visualizer):
+        self.stop()
+        subprocess.Popen(['python', visualizer])
+        self.close_app(None)
+
+if __name__ == '__main__':
+    AudioVisualizerApp().run()

mainLanding.py

@@ -47,7 +47,8 @@ def build(self):
             "Waveform",
             "Spectrogram",
             "Intensity vs Frequency and Time",
-            "Depth-Perspective Visualizer"
+            "Depth-Perspective Visualizer",
+            "Lissajous-Curves Visualizer"
         ]
         for visualizer in visualizers:
             button = Button(
@@ -144,7 +145,8 @@ def launch_visualizer(self, instance):
             "Waveform": "Waveform.py",
             "Spectrogram": "Spectrogram.py",
             "Intensity vs Frequency and Time": "Intensity-vs-Frequency-and-Time.py",
-            "Depth-Perspective Visualizer": "Depth-Perspective-Visualizer.py"  
+            "Depth-Perspective Visualizer": "Depth-Perspective-Visualizer.py",
+            "Lissajous-Curves Visualizer": "Lissajous-Curves-Visualizer.py"
         }
 
         script_name = instance.text