Add configurable framesPerSecond preference for CADisplayLink

Allow users to configure the target frame rate via preferences instead of
hardcoding 30fps. Defaults to 30fps when not specified.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

screendump/FrameUpdater.h

@@ -14,7 +14,8 @@
                        nativeWidth:(size_t)nativeWidth
                       nativeHeight:(size_t)nativeHeight
                renderServerSurface:(IOSurfaceRef)renderServerSurface
-                  captureModeBlock:(CaptureMode(^)(void))captureModeBlock;
+                  captureModeBlock:(CaptureMode(^)(void))captureModeBlock
+          preferredFramesPerSecond:(int)preferredFramesPerSecond;
 - (void)startFrameLoop;
 - (void)stopFrameLoop;
 @end

screendump/FrameUpdater.m

@@ -22,6 +22,9 @@
 	IOSurfaceRef _renderServerSurface; // Separate surface for CARenderServer (avoids framebuffer locking)
 	CaptureMode(^_captureModeBlock)(void);
 
+	// Frame rate
+	int _preferredFramesPerSecond;
+
 	// Diagnostics
 	uint64_t _timerFires;
 	uint64_t _framesRendered;
@@ -40,7 +43,8 @@
                        nativeWidth:(size_t)nativeWidth
                       nativeHeight:(size_t)nativeHeight
                renderServerSurface:(IOSurfaceRef)renderServerSurface
-                  captureModeBlock:(CaptureMode(^)(void))captureModeBlock {
+                  captureModeBlock:(CaptureMode(^)(void))captureModeBlock
+          preferredFramesPerSecond:(int)preferredFramesPerSecond {
 	if ((self = [super init])) {
 		_q = [[NSOperationQueue alloc] init];
 		_q.maxConcurrentOperationCount = 1; // Serialize to prevent frame queue buildup
@@ -59,6 +63,7 @@
 
 		_renderServerSurface = renderServerSurface;
 		_captureModeBlock = [captureModeBlock copy];
+		_preferredFramesPerSecond = preferredFramesPerSecond;
 	}
 	return self;
 }
@@ -155,7 +160,7 @@
 
 	dispatch_async(dispatch_get_main_queue(), ^{
 		_displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(_updateFrame)];
-		_displayLink.preferredFramesPerSecond = 30;
+		_displayLink.preferredFramesPerSecond = _preferredFramesPerSecond;
 		[_displayLink addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSRunLoopCommonModes];
 	});
 }

screendump/ScreenDumpVNC.m

@@ -10,6 +10,7 @@
 @implementation ScreenDumpVNC {
 	int _prefsHeight;
 	int _prefsWidth;
+	int _prefsFramesPerSecond;
 	bool _enabled;
 	NSString *_password;
 	rfbScreenInfoPtr _rfbScreenInfo;
@@ -90,6 +91,9 @@
 	NSNumber *enabled = [defaults objectForKey:@"enabled"];
 	_enabled = enabled ? [enabled boolValue] : NO;
 	_password = [defaults objectForKey:@"password"];
+
+	NSNumber *framesPerSecond = [defaults objectForKey:@"framesPerSecond"];
+	_prefsFramesPerSecond = framesPerSecond ? [framesPerSecond intValue] : 30;
 }
 
 -(void)setupVNCAuthentication {
@@ -319,7 +323,8 @@
                                               captureModeBlock:^CaptureMode(void) {
         ScreenDumpVNC *strongSelf = weakSelf;
         return strongSelf ? strongSelf->_captureMode : CaptureModeCARenderServer;
-    }];
+    }
+                                      preferredFramesPerSecond:_prefsFramesPerSecond];
 }
 
 -(rfbBool)handleVNCAuthorization:(rfbClientPtr)client data:(const char *)data size:(int)size {

screendump/layout/Library/PreferenceLoader/Preferences/screendump/Preferences.plist

@@ -16,8 +16,6 @@
 		<dict>
 			<key>cell</key>
 			<string>PSGroupCell</string>
-			<key>label</key>
-			<string>General</string>
 		</dict>
 		<dict>
 			<key>PostNotification</key>
@@ -49,9 +47,7 @@
 			<key>cell</key>
 			<string>PSGroupCell</string>
 			<key>label</key>
-			<string>Custom Resolution</string>
-			<key>footerText</key>
-			<string>High Resolution Can Be Slow</string>
+			<string>Performance</string>
 		</dict>
 		<dict>
 			<key>PostNotification</key>
@@ -81,6 +77,22 @@
 			<key>isNumeric</key>
 			<true/>
 		</dict>
+		<dict>
+			<key>PostNotification</key>
+			<string>com.mousen.screendump/restart</string>
+			<key>cell</key>
+			<string>PSEditTextCell</string>
+			<key>defaults</key>
+			<string>com.mousen.screendump</string>
+			<key>key</key>
+			<string>framesPerSecond</string>
+			<key>label</key>
+			<string>Max FPS</string>
+			<key>default</key>
+			<integer>30</integer>
+			<key>isNumeric</key>
+			<true/>
+		</dict>
 	</array>
 </dict>
 </plist>