Revert "feat: use CAMetalDisplayLink for metal renderer to fix refresh rate issues"

This reverts commit 628ce0f12e.

VoidLink/Database/TemporarySettings.m

@@ -52,15 +52,7 @@
     self.statsOverlay = [[NSUserDefaults standardUserDefaults] boolForKey:@"statsOverlay"];
     self.enableGraphs = [[NSUserDefaults standardUserDefaults] boolForKey:@"enableGraphs"];
     self.graphOpacity = [NSNumber numberWithInteger:[[NSUserDefaults standardUserDefaults] integerForKey:@"graphOpacity"]];
-    // Set rendering backend based on iOS version and user preference
+    self.renderingBackend = [NSNumber numberWithInteger:[[NSUserDefaults standardUserDefaults] integerForKey:@"renderingBackend"]];
-    NSInteger savedBackend = [[NSUserDefaults standardUserDefaults] integerForKey:@"renderingBackend"];
-    if (@available(iOS 17.0, *)) {
-        // iOS 17+ can use Performance mode (Metal renderer)
-        self.renderingBackend = [NSNumber numberWithInteger:savedBackend];
-    } else {
-        // iOS < 17 must use Balanced mode (AVSB renderer)
-        self.renderingBackend = [NSNumber numberWithInteger:RENDER_AVSB];
-    }
 
     NSInteger _screenSize = [[NSUserDefaults standardUserDefaults] integerForKey:@"streamResolution"];
     switch (_screenSize) {

VoidLink/ImGuiRenderer.h

@@ -28,7 +28,6 @@ typedef void (^MetricsHandler)(int plotId, CFTimeInterval value);
 @property (nonatomic) BOOL enableGraphs;
 @property (nonatomic) float graphOpacity;
 @property (nonatomic) BOOL imguiRunning;
-@property (nonatomic) int streamFps;
 @property (nonatomic) MetricsHandler _Nonnull metricsHandler;
 
 -(nonnull instancetype) initWithFrame:(CGRect)bounds

VoidLink/ImGuiRenderer.mm

@@ -42,9 +42,6 @@
 
     _plots = [ImGuiPlots sharedInstance].plots;
 
-    // Store stream FPS to synchronize MTKView
-    _streamFps = streamFps;
-
     return self;
 }
 
@@ -93,7 +90,7 @@
 
     self.mtkView.device = self.device;
     self.mtkView.delegate = self;
-    self.mtkView.preferredFramesPerSecond = _streamFps; // Synchronize with stream framerate
+    self.mtkView.preferredFramesPerSecond = 60; // ImGui overlay will always render at this rate
     self.mtkView.opaque = NO;
     self.mtkView.enableSetNeedsDisplay = NO;
 
@@ -176,7 +173,7 @@
 #if TARGET_OS_SIMULATOR
     [commandBuffer presentDrawable:view.currentDrawable];
 #else
-    [commandBuffer presentDrawable:view.currentDrawable afterMinimumDuration:1.0 / _streamFps];
+    [commandBuffer presentDrawable:view.currentDrawable afterMinimumDuration:1.0 / view.preferredFramesPerSecond];
 #endif
     [commandBuffer commit];
 #endif

VoidLink/Metal/MetalVideoRenderer.h

@@ -23,8 +23,7 @@
 @property (atomic) BOOL isStopping;
 
 - (nonnull instancetype)initWithMetalDevice:(nonnull id<MTLDevice>)device drawablePixelFormat:(MTLPixelFormat)drawablePixelFormat framerate:(float)framerate;
-- (void)renderFrame:(nonnull Frame *)frame withDrawable:(nonnull id<CAMetalDrawable>)drawable API_AVAILABLE(ios(17.0));
+- (void)renderFrame:(nonnull Frame *)frame toLayer:(nonnull CAMetalLayer *)layer;
-- (void)renderFrame:(nonnull Frame *)frame withDrawable:(nonnull id<CAMetalDrawable>)drawable targetPresentationTimestamp:(CFTimeInterval)targetPresentationTimestamp API_AVAILABLE(ios(17.0));
 - (void)waitToRenderTo:(nonnull CAMetalLayer *)layer;
 - (void)drawableResize:(CGSize)drawableSize;
 - (void)shutdown;

VoidLink/Metal/MetalVideoRenderer.m

@@ -459,30 +459,21 @@ CFStringRef __currentColorSpace;
     return YES;
 }
 
-
+- (void)renderFrame:(Frame *)frame toLayer:(CAMetalLayer *)layer {
-// Enhanced method that receives timing information from CAMetalDisplayLink
-- (void)renderFrame:(Frame *)frame withDrawable:(id<CAMetalDrawable>)drawable targetPresentationTimestamp:(CFTimeInterval)targetPresentationTimestamp API_AVAILABLE(ios(17.0)) {
     @autoreleasepool {
         if (self.isStopping) {
             Log(LOG_I, @"[MetalVideoRenderer] isStopping");
             return;
         }
 
-        // Calculate accurate frametime using CAMetalDisplayLink timing
-        if (self.lastPresented > 0.0f) {
-            CFTimeInterval frametime = targetPresentationTimestamp - self.lastPresented;
-            [[ImGuiPlots sharedInstance] observeFloat:PLOT_FRAMETIME value:(frametime * 1000.0)];
-        }
-        self.lastPresented = targetPresentationTimestamp;
-
         // Handle changes to the frame's colorspace from last time we rendered
         BOOL layerDidChange = NO;
-        if (![self updateColorSpaceForFrame:frame toLayer:(CAMetalLayer *)drawable.layer layerDidChange:&layerDidChange]) {
+        if (![self updateColorSpaceForFrame:frame toLayer:layer layerDidChange:&layerDidChange]) {
             return;
         }
 
         // Handle changes to the video size or drawable size
-        if (![self updateVideoRegionSizeForFrame:frame toLayer:(CAMetalLayer *)drawable.layer]) {
+        if (![self updateVideoRegionSizeForFrame:frame toLayer:layer]) {
             return;
         }
 
@@ -505,6 +496,13 @@ CFStringRef __currentColorSpace;
             }
         }
 
+        // Get the next drawable early to get its pixel format
+        id<CAMetalDrawable> drawable = [layer nextDrawable];
+        if (!drawable) {
+            Log(LOG_E, @"Failed to get nextDrawable");
+            return;
+        }
+        
         // Get the framebuffer pixel format for pipeline creation
         MTLPixelFormat framebufferPixelFormat = drawable.texture.pixelFormat;
 
@@ -598,7 +596,6 @@ CFStringRef __currentColorSpace;
             }
         }
 
-        // Use the provided drawable instead of getting nextDrawable from layer
         _renderPassDescriptor.colorAttachments[0].texture = drawable.texture;
 
         id<MTLCommandBuffer> commandBuffer = [_commandQueue commandBuffer];
@@ -612,7 +609,7 @@ CFStringRef __currentColorSpace;
         [renderEncoder setVertexBuffer:_VideoVertexBuffer offset:0 atIndex:0];
         [renderEncoder setFragmentBuffer:_CscParamsBuffer offset:0 atIndex:0];
 #if !TARGET_OS_TV
-        if (((CAMetalLayer *)drawable.layer).pixelFormat == MTLPixelFormatRGBA16Float) {
+        if (layer.pixelFormat == MTLPixelFormatRGBA16Float) {
             [self pollCurrentEDRHeadroom];
             [renderEncoder setFragmentBytes:&_currentEDRHeadroom length:sizeof(float) atIndex:1];
         }
@@ -620,6 +617,15 @@ CFStringRef __currentColorSpace;
         [renderEncoder drawPrimitives:MTLPrimitiveTypeTriangleStrip vertexStart:0 vertexCount:4];
         [renderEncoder endEncoding];
 
+        __block MetalVideoRenderer *strongSelf = self;
+        [drawable addPresentedHandler:^(id<MTLDrawable> d) {
+            if (strongSelf.lastPresented > 0.0f) {
+                CFTimeInterval frametime = d.presentedTime - strongSelf.lastPresented;
+                [[ImGuiPlots sharedInstance] observeFloat:PLOT_FRAMETIME value:(frametime * 1000.0)];
+            }
+            strongSelf.lastPresented = d.presentedTime;
+        }];
+
         // signal semaphore, compute GPU time average, and clear textures
         __block dispatch_semaphore_t block_semaphore = _inFlightSemaphore;
         [commandBuffer addCompletedHandler:^(id<MTLCommandBuffer> cb) {
@@ -640,10 +646,15 @@ CFStringRef __currentColorSpace;
             CVMetalTextureCacheFlush(self->_textureCache, 0);
         }];
 
-        // CAMetalDisplayLink handles timing automatically, so we don't use afterMinimumDuration
+#if TARGET_OS_SIMULATOR
         [commandBuffer presentDrawable:drawable];
+#else
+        // present for a minimum duration for best frame pacing
+        [commandBuffer presentDrawable:drawable afterMinimumDuration:1.0f / _framerate];
+#endif
 
         [commandBuffer commit];
+        [commandBuffer waitUntilCompleted];
     }
 }
 

VoidLink/Metal/MetalView.h

@@ -16,14 +16,13 @@
 @protocol MetalViewDelegate <NSObject>
 
 - (void)drawableResize:(CGSize)size;
-- (void)renderWithDrawable:(nonnull id<CAMetalDrawable>)drawable toLayer:(nonnull CAMetalLayer *)layer API_AVAILABLE(ios(17.0));
+- (void)renderTo:(nonnull CAMetalLayer *)layer;
-- (void)renderWithDrawable:(nonnull id<CAMetalDrawable>)drawable toLayer:(nonnull CAMetalLayer *)layer targetPresentationTimestamp:(CFTimeInterval)targetPresentationTimestamp API_AVAILABLE(ios(17.0));
 - (void)waitToRenderTo:(nonnull CAMetalLayer *)layer;
 
 @end
 
 // The Metal game view base class.
-@interface MetalView : UIView <CALayerDelegate, CAMetalDisplayLinkDelegate>
+@interface MetalView : UIView <CALayerDelegate>
 
 @property (nonatomic, nonnull, readonly) CAMetalLayer *metalLayer;
 @property (nonatomic, nullable) id<MetalViewDelegate> delegate;

VoidLink/Metal/MetalView.m

@@ -11,13 +11,10 @@
 
 #import "MetalView.h"
 #import "MetalConfig.h"
-#import <QuartzCore/CAMetalDisplayLink.h>
 
 @implementation MetalView {
     // The secondary thread containing the render loop.
     NSThread *_renderThread;
-    // Metal display link for vsync synchronization (iOS 17+)
-    CAMetalDisplayLink *_metalDisplayLink API_AVAILABLE(ios(17.0));
 }
 
 #pragma mark - Initialization and Setup.
@@ -43,43 +40,15 @@
     self.layer.delegate = self;
 }
 
-- (void)setFramerate:(float)framerate {
-    _framerate = framerate;
-    
-    if (@available(iOS 17.0, *)) {
-        if (_metalDisplayLink) {
-            _metalDisplayLink.preferredFrameRateRange = CAFrameRateRangeMake(framerate, framerate, framerate);
-        }
-    }
-}
-
 - (void)shutdown {
-    // First cancel the thread to stop the run loop
     if (_renderThread) {
         Log(LOG_I, @"[MetalView] sending renderThread a cancel message");
         [_renderThread cancel];
-        
-        // Invalidate metal display link to stop callbacks
-        if (@available(iOS 17.0, *)) {
-            if (_metalDisplayLink) {
-                Log(LOG_I, @"[MetalView] invalidating metal display link");
-                [_metalDisplayLink invalidate];
-                _metalDisplayLink = nil;
-            }
-        }
-        
-        // Now wait for thread to finish
         Log(LOG_I, @"[MetalView] waiting on renderThread to finish");
-        NSDate *timeout = [NSDate dateWithTimeIntervalSinceNow:2.0]; // 2 second timeout
+        while (!_renderThread.isFinished) {
-        while (!_renderThread.isFinished && [timeout timeIntervalSinceNow] > 0) {
+            usleep(100);
-            usleep(1000);
-        }
-        
-        if (_renderThread.isFinished) {
-            Log(LOG_I, @"[MetalView] renderThread has finished");
-        } else {
-            Log(LOG_E, @"[MetalView] renderThread failed to finish in time");
         }
+        Log(LOG_I, @"[MetalView] renderThread has finished");
         _renderThread = nil;
     }
 }
@@ -92,28 +61,6 @@
     [self movedToWindow];
 }
 
-// CAMetalDisplayLinkDelegate method (iOS 17+)
-- (void)metalDisplayLink:(CAMetalDisplayLink *)link needsUpdate:(CAMetalDisplayLinkUpdate *)update API_AVAILABLE(ios(17.0)) {
-    // Skip rendering if we're shutting down
-    if ([NSThread currentThread].isCancelled) {
-        return;
-    }
-    @autoreleasepool {
-        [self.delegate waitToRenderTo:self.metalLayer];
-        
-        // Get the drawable from the update object
-        id<CAMetalDrawable> drawable = update.drawable;
-        if (drawable) {
-            // Pass timing information to the renderer
-            if ([self.delegate respondsToSelector:@selector(renderWithDrawable:toLayer:targetPresentationTimestamp:)]) {
-                [self.delegate renderWithDrawable:drawable toLayer:self.metalLayer targetPresentationTimestamp:update.targetPresentationTimestamp];
-            } else {
-                [self.delegate renderWithDrawable:drawable toLayer:self.metalLayer];
-            }
-        }
-    }
-}
-
 - (void)movedToWindow {
     if (!self.window) {
         Log(LOG_I, @"[MetalView] movedToWindow(nil): shutting down...");
@@ -121,33 +68,12 @@
         return;
     }
 
-    // Create CAMetalDisplayLink for vsync-synchronized rendering (iOS 17+ only)
+    // Render on a new thread
-    if (@available(iOS 17.0, *)) {
-        _metalDisplayLink = [[CAMetalDisplayLink alloc] initWithMetalLayer:_metalLayer];
-        _metalDisplayLink.delegate = self;
-        _metalDisplayLink.preferredFrameRateRange = CAFrameRateRangeMake(_framerate, _framerate, _framerate);
-        Log(LOG_I, @"[MetalView] Using CAMetalDisplayLink for optimal Metal rendering");
-    }
-    
-    // Start the display link on a background thread
     _renderThread = [[NSThread alloc] initWithBlock:^{
-        // Add metal display link to this thread's run loop
+        while (![NSThread currentThread].isCancelled) {
-        if (@available(iOS 17.0, *)) {
-            [self->_metalDisplayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
-        }
-        
-        // Keep the run loop alive, checking for cancellation regularly
-        while (![NSThread currentThread].isCancelled && self->_metalDisplayLink) {
             @autoreleasepool {
-                // Run the run loop for a short time to allow checking cancellation
+                [self.delegate waitToRenderTo:self.metalLayer];
-                [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate dateWithTimeIntervalSinceNow:0.1]];
+                [self.delegate renderTo:self.metalLayer];
-            }
-        }
-        
-        // Remove from run loop if still valid
-        if (@available(iOS 17.0, *)) {
-            if (self->_metalDisplayLink) {
-                [self->_metalDisplayLink removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
             }
         }
         Log(LOG_I, @"[MetalView] renderThread is exiting");
@@ -155,7 +81,7 @@
     _renderThread.name = @"MetalVideoRenderer";
     _renderThread.qualityOfService = NSQualityOfServiceUserInteractive;
     [_renderThread start];
-    Log(LOG_I, @"[MetalView] started renderThread with CAMetalDisplayLink at %f fps", _framerate);
+    Log(LOG_I, @"[MetalView] started renderThread %@", _renderThread);
 
     // Perform any actions that need to know the size and scale of the drawable. When UIKit calls
     // didMoveToWindow after the view initialization, this is the first opportunity to notify

VoidLink/Metal/MetalViewController.m

@@ -82,25 +82,13 @@
     [_frameQueue waitForEnqueue];
 }
 
-
+/// Draw frame (used by manual loop)
-// New method for CAMetalDisplayLink that provides the drawable
+- (void)renderTo:(nonnull CAMetalLayer *)layer {
-- (void)renderWithDrawable:(nonnull id<CAMetalDrawable>)drawable toLayer:(nonnull CAMetalLayer *)layer API_AVAILABLE(ios(17.0)) {
     if (!_renderer.isStopping) {
         CFTimeInterval timeout = (1.0f / _framerate) - _renderer.averageGPUTime;
         Frame *frame = [_frameQueue dequeueWithTimeout:timeout];
         if (frame) {
-            [_renderer renderFrame:frame withDrawable:drawable];
+            [_renderer renderFrame:frame toLayer:layer];
-        }
-    }
-}
-
-// Enhanced method that receives timing information from CAMetalDisplayLink
-- (void)renderWithDrawable:(nonnull id<CAMetalDrawable>)drawable toLayer:(nonnull CAMetalLayer *)layer targetPresentationTimestamp:(CFTimeInterval)targetPresentationTimestamp API_AVAILABLE(ios(17.0)) {
-    if (!_renderer.isStopping) {
-        CFTimeInterval timeout = (1.0f / _framerate) - _renderer.averageGPUTime;
-        Frame *frame = [_frameQueue dequeueWithTimeout:timeout];
-        if (frame) {
-            [_renderer renderFrame:frame withDrawable:drawable targetPresentationTimestamp:targetPresentationTimestamp];
         }
     }
 }
@@ -114,14 +102,8 @@
 
     Log(LOG_I, @"[MetalViewController] viewDidDisappear");
 
-    // Shutdown the renderer first
     [_renderer shutdown];
     _renderer = nil;
-    
-    // Then shutdown the view's display link
-    if (_metalView) {
-        [_metalView shutdown];
-    }
 }
 
 #if TARGET_OS_IOS

VoidLink/ViewControllers/SettingsViewController.m

@@ -536,11 +536,7 @@ BOOL isCustomResolution(int resolutionSelected) {
     [self addSetting:self.pipStack ofId:@"pipStack" withInfoTag:YES withDynamicLabel:NO to:videoSection];
     [self addSetting:self.pipStack ofId:@"pipStack" withInfoTag:YES withDynamicLabel:NO to:videoSection];
     [self addSetting:self.frameQueueSizeStack ofId:@"frameQueueSizeStack" withInfoTag:NO withDynamicLabel:NO to:videoSection];
-    
+    [self addSetting:self.renderingBackendStack ofId:@"renderingBackendStack" withInfoTag:YES withDynamicLabel:NO to:videoSection];
-    // Only show Metal renderer option on iOS 17+ where CAMetalDisplayLink is available
-    if (@available(iOS 17.0, *)) {
-        [self addSetting:self.renderingBackendStack ofId:@"renderingBackendStack" withInfoTag:YES withDynamicLabel:NO to:videoSection];
-    }
 
     [videoSection addToParentStack:_parentStack];
     [videoSection setExpanded:YES];