MobilePlatform: Implement initial support for a fps counter overlay

Still won't work on SDL (as it needs that UI overhaul) and Libretro
already has its own fps counter. As of right now, the overlay can
flash intermittently in some jars if the framerate is unlocked
(Asphalt 4 - K800i), but solid otherwise.

src/org/recompile/freej2me/AWTGUI.java

@@ -25,6 +25,8 @@
 
 import javax.microedition.media.Manager;
 
+import org.recompile.mobile.Mobile;
+
 public final class AWTGUI 
 {
 	/* This is used to indicate to FreeJ2ME that it has to call "settingsChanged()" to apply changes made here */
@@ -149,6 +151,7 @@ public final class AWTGUI
 	final CheckboxMenuItem enableRotation = new CheckboxMenuItem("Rotate Screen", false);
 	final CheckboxMenuItem useCustomMidi = new CheckboxMenuItem("Use custom midi soundfont", false);
 	final CheckboxMenuItem halveCanvasRes = new CheckboxMenuItem("Halve Canvas Resolution", false);
+	final CheckboxMenuItem showFPS = new CheckboxMenuItem("Show FPS Counter", false);
 
 	final CheckboxMenuItem stdLayout = new CheckboxMenuItem("Standard", true);
 	final CheckboxMenuItem nokiaLayout = new CheckboxMenuItem("Nokia", false);
@@ -401,6 +404,15 @@ public void itemStateChanged(ItemEvent e)
 			}
 		});
 
+		showFPS.addItemListener(new ItemListener() 
+		{
+			public void itemStateChanged(ItemEvent e) 
+			{
+				if(showFPS.getState()){ Mobile.getPlatform().setShowFPS(true); }
+				else{ Mobile.getPlatform().setShowFPS(false); }
+			}
+		});
+
 		stdLayout.addItemListener(new ItemListener() 
 		{
 			public void itemStateChanged(ItemEvent e) 
@@ -593,6 +605,7 @@ private void buildMenuBar()
 		optionMenu.add(useCustomMidi);
 		optionMenu.add(resChangeMenuItem);
 		optionMenu.add(halveCanvasRes);
+		optionMenu.add(showFPS);
 		optionMenu.add(phoneType);
 		optionMenu.add(fpsCap);
 		optionMenu.add(mapInputs);

src/org/recompile/mobile/MobilePlatform.java

@@ -22,12 +22,14 @@
 import java.util.concurrent.locks.LockSupport;
 import java.io.InputStream;
 
+import java.awt.Color;
 import java.awt.event.KeyEvent;
 
 import javax.microedition.lcdui.Canvas;
 import javax.microedition.lcdui.Display;
 import javax.microedition.lcdui.Displayable;
 import javax.microedition.lcdui.Font;
+import javax.microedition.lcdui.Graphics;
 import javax.microedition.lcdui.game.GameCanvas;
 import javax.microedition.lcdui.Image;
 import javax.microedition.m3g.Graphics3D;
@@ -47,11 +49,17 @@ public class MobilePlatform
 	public int lcdHeight;
 
 	// Frame Limit Variables
-	private long lastRenderTime = 0;
+	private long lastRenderTime = System.nanoTime();
 	private long requiredFrametime = 0;
 	private long elapsedTime = 0;
 	private long sleepTime = 0;
 
+	// Whether the user has toggled the ShowFPS option
+	private boolean showFPS = false;
+	private int frameCount = 0;
+	private long lastFpsTime = System.nanoTime();
+    private int fps = 0;
+
 	public MIDletLoader loader;
 	private EventQueue eventQueue;
 	private Displayable d;
@@ -224,7 +232,8 @@ public void flushGraphics(Image img, int x, int y, int width, int height)
 	{
 		limitFps();
 		gc.flushGraphics(img, x, y, width, height);
-
+
+		if(showFPS) { showFPS();}
 		painter.run();
 
 		//System.gc();
@@ -235,6 +244,7 @@ public void repaint(Image img, int x, int y, int width, int height)
 		limitFps();
 		gc.flushGraphics(img, x, y, width, height);
 
+		if(showFPS) { showFPS();}
 		painter.run();
 
 		//System.gc();
@@ -351,4 +361,28 @@ private void limitFps()
 
 		lastRenderTime = System.nanoTime();
 	}
+
+	// For now, the logic here works by updating the framerate counter every second
+	private void showFPS() 
+	{
+		frameCount++;
+
+        if (System.nanoTime() - lastFpsTime >= 1_000_000_000) 
+		{ // If 1 second or more has passed in nanoseconds
+            fps = frameCount; // Set fps to frames counted in the last second to then show it in the overlay.
+            frameCount = 0; // begin counting again from this point onwards until the next second passes
+			lastFpsTime = System.nanoTime(); // Reset last FPS time
+        }
+
+		// Set the overlay background
+        gc.getGraphics2D().setColor(new Color(0, 0, 105, 150)); // Semi-transparent dark blue
+        gc.fillRect(2, 2, 80, 20); // Background rectangle
+
+        // Draw the FPS text
+        gc.getGraphics2D().setColor(new Color(255, 175, 0, 255)); // Text color is orange
+        gc.setFont(Font.getDefaultFont());
+        gc.drawString("FPS: " + fps, 5, 4, Graphics.TOP|Graphics.LEFT); // Draw text at position (5, 5, from the top-left corner)
+	}
+
+	public void setShowFPS(boolean show) { showFPS = show; }
 }