Double buffering and Force Clear

Attempting to clean up flicker - otherwise working

src/clock.py

@@ -67,7 +67,7 @@ class Clock:
         current_time = datetime.now(self.timezone)
         return current_time.strftime(self.clock_config.get('format', '%H:%M:%S'))
 
-    def display_time(self) -> None:
+    def display_time(self, force_clear: bool = False) -> None:
         """Display the current time."""
         current_time = self.get_current_time()
         
@@ -82,8 +82,7 @@ class Clock:
             y = (self.display_manager.matrix.height - 24) // 2
             
             logger.debug("Drawing time at position (%d, %d)", x, y)
-            self.display_manager.clear()
-            self.display_manager.draw_text(current_time, x, y)
+            self.display_manager.draw_text(current_time, x, y, force_clear=force_clear)
 
 if __name__ == "__main__":
     clock = Clock()

src/display_controller.py

@@ -28,6 +28,9 @@ class DisplayController:
                 current_time = time.time()
                 rotation_interval = self.config['display'].get('rotation_interval', 15)
 
+                # Track if we're switching modes
+                switching_modes = False
+
                 # Switch display if interval has passed
                 if current_time - self.last_switch > rotation_interval:
                     logger.info("Switching display from %s to %s", 
@@ -35,14 +38,15 @@ class DisplayController:
                               'weather' if self.current_display == 'clock' else 'clock')
                     self.current_display = 'weather' if self.current_display == 'clock' else 'clock'
                     self.last_switch = current_time
+                    switching_modes = True
 
                 # Display current screen
                 if self.current_display == 'clock':
                     logger.debug("Updating clock display")
-                    self.clock.display_time()
+                    self.clock.display_time(force_clear=switching_modes)
                 else:
                     logger.debug("Updating weather display")
-                    self.weather.display_weather()
+                    self.weather.display_weather(force_clear=switching_modes)
 
                 # Sleep for 0.5 seconds since we only need to check for second changes
                 time.sleep(0.5)

src/display_manager.py

@@ -59,6 +59,9 @@ class DisplayManager:
         logger.info("RGB matrix initialized successfully")
         logger.info(f"Matrix dimensions: {self.matrix.width}x{self.matrix.height}")
         
+        # Create double buffer
+        self.offscreen_canvas = self.matrix.CreateFrameCanvas()
+        
         # Create image with full chain width
         self.image = Image.new('RGB', (self.matrix.width, self.matrix.height))
         self.draw = ImageDraw.Draw(self.image)
@@ -88,25 +91,32 @@ class DisplayManager:
         # Draw some text
         self.draw.text((10, 10), "TEST", font=self.font, fill=(0, 0, 255))
         
-        # Update the display
-        self.matrix.SetImage(self.image)
+        # Update the display using double buffering
+        self.update_display()
         
         # Wait a moment
         time.sleep(2)
 
-    def _draw_text(self, text, x, y, font, color=(255, 255, 255)):
-        """Draw text on the canvas."""
-        self.draw.text((x, y), text, font=font, fill=color)
-        self.matrix.SetImage(self.image)
+    def update_display(self):
+        """Update the display using double buffering."""
+        # Copy the current image to the offscreen canvas
+        self.offscreen_canvas.SetImage(self.image)
+        # Swap the canvases
+        self.offscreen_canvas = self.matrix.SwapOnVSync(self.offscreen_canvas)
 
     def clear(self):
         """Clear the display."""
         self.draw.rectangle((0, 0, self.matrix.width, self.matrix.height), fill=(0, 0, 0))
-        self.matrix.SetImage(self.image)
+        self.update_display()
 
-    def draw_text(self, text: str, x: int = None, y: int = None, color: tuple = (255, 255, 255)):
+    def draw_text(self, text: str, x: int = None, y: int = None, color: tuple = (255, 255, 255), force_clear: bool = False):
         """Draw text on the display with automatic centering."""
-        self.clear()
+        if force_clear:
+            self.clear()
+        else:
+            # Just create a new blank image without updating display
+            self.image = Image.new('RGB', (self.matrix.width, self.matrix.height))
+            self.draw = ImageDraw.Draw(self.image)
         
         # Split text into lines if it contains newlines
         lines = text.split('\n')
@@ -138,7 +148,7 @@ class DisplayManager:
         current_y = y
         for i, line in enumerate(lines):
             if x is None:
-                # Center this line horizontally across full width (128 pixels)
+                # Center this line horizontally
                 line_x = (self.matrix.width - line_widths[i]) // 2
             else:
                 line_x = x
@@ -155,8 +165,8 @@ class DisplayManager:
             # Calculate next line position
             current_y += line_heights[i] + padding
         
-        # Update the display with the new image
-        self.matrix.SetImage(self.image)
+        # Update the display using double buffering
+        self.update_display()
 
     def cleanup(self):
         """Clean up resources."""

src/weather_manager.py

@@ -39,7 +39,7 @@ class WeatherManager:
             self._fetch_weather()
         return self.weather_data
 
-    def display_weather(self) -> None:
+    def display_weather(self, force_clear: bool = False) -> None:
         """Display weather information on the LED matrix."""
         weather_data = self.get_weather()
         if not weather_data:
@@ -52,4 +52,4 @@ class WeatherManager:
         display_text = f"{temp}°F\n{condition}"
         
         # Draw both lines at once using the multi-line support in draw_text
-        self.display_manager.draw_text(display_text) 
+        self.display_manager.draw_text(display_text, force_clear=force_clear)