Hi!
I hope everyone reading is doing well. I am working on developing a reinforcement learning agent that involves sending scan codes to a window, which I've been doing by sending virtual scan codes with CGEventCreateKeyboardEvent per the docs. There is no event source when I send the keyboard events.
However, when many keyboard events are happening (with the keys 'q', 'w', 'e', 'r', 'f', 'd', 's', space, arrow keys) in quick succession (<250ms), the enable dictation popup or the function button emojis popup appear for seemingly no reason. I have verified that I am using the correct scan codes for these keypresses, so I am wondering what else could cause this to happen. It is as if I am choosing to press f5 or fn. It does not happen when 'a' is the only button being pressed in quick succession.
One thing that I have not been able to easily find is the scan code inputs for dictation nor the function button. do these scan codes overlap somehow?
Thank you all for the help!
Hunter
Delve into the world of graphics and game development. Discuss creating stunning visuals, optimizing game mechanics, and share resources for game developers.
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Code is download from apple official metal4 sample
[https://developer.apple.com/documentation/metal/drawing-a-triangle-with-metal-4?language=objc]
enable metal gpu trace in macOS schema and trace a frame in Xcode.
Xcode may show segment fault on App from some 'GTTrace' function when click trace button.
When replay a .gputrace file, Xcode may crash , throw an internal error or a XPC error.
The example code using old metal-renderer can trace without any problem and everything works fine.
Test Environment:
Xcode Version 26.2 (17C52)
macOS 26.2 (25C56)
M1 Pro 16GB A2442
When trying to play with friends Krazy Krownz doesn’t allow me to click multiplayer even though my Apple Game Center connected and my friends Apple game center connected as well. I even tried sending an invite from Apple Game Center to friends and Krazy Krownz doesn’t even show up on the list of available multiplayer games.
I’ve signed out and back in the same issue remain.
I’ve try to contact the game developer, but the website doesn’t work.
Topic:
Graphics & Games
SubTopic:
GameKit
I am trying to create a simple portal like that in RealityKit, but using metal instead of RealityKit. Has anyone been able to create a window or portal like thing to show a skybox outside in mixed Reality?
Topic:
Graphics & Games
SubTopic:
Metal
I have an odd bug, if I use initWithFrame as the init routine for NSView subclass that uses layers I don't see this bug.
But if I embedded this view into a storyboard with a .nib file and use initWithCoder, I need to return true on
(BOOL) contentsAreFlipped
From the NSView subclass
If I don't the CALayer actually renders from 0,0 from the view upwards and off the window.
The frame sizes for the NSView and the CALayer are good.. when I see them in updateLayer.
Obviously I have a fix.. but I would like to understand why.
Topic:
Graphics & Games
SubTopic:
General
Leaderboards working fine in iOS 26.1 but seem to be broken in 26.2 and also in the 26.3 developer beta. Players cannot submit scores and neither can they view scores on Apple's default leaderboards. Custom leaderboards that rely on pulling information using GameKit APIs also fail.
Is there a workaround or patch for this?
Hello, I have some confusion regarding ResidencySet. Specifically, about the requestResidency() function: how often should we call it?
I have a captureOutput(_:didOutput:from:) method that is triggered at 60 or 120 fps. Inside this method, I am calling the following code every frame:
computeResidencySet.removeAllAllocations()
сomputeResidencySet.addAllocation(TextureA)
computeResidencySet.addAllocation(TextureB)
computeResidencySet.addAllocation(TextureC)
computeResidencySet.commit()
computeResidencySet.requestResidency() // Should we call it every frame?
Please keep in mind that TextureA, TextureB, and TextureC are unique for each call (new instances are provided on every frame)."
When previewing the recording of gameplay the buttons to exit or save are unclickable behind the top bar clock and Wi-Fi/5G status bar. Which means that you have to quit the game in order to continue.
Tested on multiple devices.
Does anyone have a solution to this? At the moment we have disabled it altogether for iOS 26 users.
I am integrating MetalFX FrameInterpolator into a custom Unity RenderGraph–based render pipeline (C++ native plugin + C# render passes), and I am hitting the following assertion at runtime:
/MetalFXDebugError.h:29: failed assertion `Color texture width mismatch from descriptor'
What makes this confusing is that all input/output textures have the correct width and height, and they exactly match the values specified in the MTLFXFrameInterpolatorDescriptor.
Setup
Input resolution: 1024 x 512
Output resolution: 2048 x 1024
MTLFXTemporalScaler is created first and then passed into MTLFXFrameInterpolator
The TemporalScaler and FrameInterpolator descriptors use the same input/output sizes and formats
All Metal textures:
Have no parentTexture
Are 2D textures
Match the descriptor sizes exactly (verified via logging)
Texture bindings at encode time
frameInterpolator.colorTexture = mtlTexColor; // 1024 x 512
frameInterpolator.prevColorTexture = mtlTexPrevColor; // 1024 x 512
frameInterpolator.motionTexture = mtlTexMotion; // 1024 x 512
frameInterpolator.depthTexture = mtlTexDepth; // 1024 x 512
frameInterpolator.uiTexture = mtlTexUI; // 2048 x 1024
frameInterpolator.outputTexture = mtlTexOutput; // 2048 x 1024
All widths/heights are logged and match:
Color : 1024 x 512 (input)
PrevColor : 1024 x 512 (input)
Motion : 1024 x 512 (input)
Depth : 1024 x 512 (input)
UI : 2048 x 1024 (output)
Output : 2048 x 1024 (output)
The TemporalScaler works correctly on its own.
The assertion only occurs when using FrameInterpolator.
Important detail about colorTexture
Originally, colorTexture was copied from BuiltinRenderTextureType.CurrentActive.
After reading that this might violate MetalFX semantics, I changed the pipeline so that:
colorTexture now comes from a dedicated private RenderGraph texture
It is not the backbuffer
It is not a drawable
It is not used as a final output
It is created before UI rendering
Despite this, the assertion still occurs.
Question
Can uiTexture for MTLFXFrameInterpolator legally come from a texture copied from BuiltinRenderTextureType.CurrentActive?
More generally:
Are there additional hidden constraints on colorTexture / prevColorTexture (such as Metal usage, storageMode, aliasing, or hazard tracking) that could cause this assertion, even when sizes match?
Does FrameInterpolator require colorTexture and prevColorTexture to be created in a very specific way (e.g. non-aliased, ShaderRead usage, identical Metal resource properties)?
Any clarification on the exact semantic requirements for colorTexture, prevColorTexture, or uiTexture in MetalFX FrameInterpolator would be greatly appreciated.
We are developing a standalone AI avatar application for hospital reception kiosks using Mac mini (M2/M4). The app runs on SwiftUI + RealityKit, displays on a 75-inch monitor, and utilizes a USB-connected 4K camera and external sensors (LiDAR/mmWave).
We have several technical concerns regarding the transition from iPadOS to macOS. Could you please provide insights on the following?
ARKit/Vision Framework on macOS with External Camera On iPadOS, ARKit provides robust Face Tracking. On macOS with an external USB 4K camera:
Can we achieve real-time face tracking (expression/gaze/depth) with Vision framework or ARKit comparable to iPadOS performance?
Are there any specific limitations for accessing the Neural Engine via Vision framework for real-time 4K video analysis on macOS?
Accessing External Hardware (LiDAR/Sensors) in Sandbox We plan to connect external LiDAR and mmWave sensors (e.g., Akara) via USB/Bluetooth.
Is it feasible to communicate with these custom drivers/devices within the App Sandbox environment?
Would DriverKit be required, or can we use standard serial communication APIs?
On-Device LLM (MLX) & Thermals We intend to run a local LLM (e.g., Llama 3 using MLX framework) for offline conversation, alongside 3D rendering.
With the M2/M4 Mac mini fan design, is there a risk of thermal throttling during 10+ hours of continuous operation (simultaneous CoreML + 3D rendering)?
Is the Mac Studio recommended over the Mac mini for this thermal profile?
Long-running Speech API
Are there any known issues (memory leaks, API limits) when using Spherch framework and AVSpeechSynthesizer continuously for over 10 hours daily?
3D Display Output
Are there any macOS constraints for rendering a SwiftUI window in a specific 3D format (e.g., Side-by-Side) and outputting it via HDMI to a 3D digital signage display (fixed refresh rate/resolution)?
Thank you for your assistance.
Topic:
Graphics & Games
SubTopic:
RealityKit
I'm developing a game that supports GameKit turn based matches. What I don't understand is this:
Is tapping on the Game Center notification push messages the only way for the GKTurnBasedEventListener to trigger? What if someone misses the push message (swiping it away by accident or something like that) but still wants to join? Is there some inbox somewhere where the pending messages can be seen or fetched?
Also it was mentioned in a very old WWDC video (from 2013, I think that's the latest with information about turn based matches) that the notification also includes a badge for the icon. However, I do not understand how to implement that. Is there any documentation for that?
I'm developing a turn based game. When I present the GKTurnBasedMatchmakerViewController players can opt in for automatch instead of selecting a specific friend as opponent.
How exactly does the matching work if a player doesn't specify anything explicitly?
Does Game Center send push notifications in a round robin fashion to all friends and the first one to accept is then matched as opponent? Is this documented somewhere?
Hi,
How to enable multitouch on ARView?
Touch functions (touchesBegan, touchesMoved, ...) seem to only handle one touch at a time. In order to handle multiple touches at a time with ARView, I have to either:
Use SwiftUI .simultaneousGesture on top of an ARView representable
Position a UIView on top of ARView to capture touches and do hit testing by passing a reference to ARView
Expected behavior:
ARView should capture all touches via touchesBegan/Moved/Ended/Cancelled.
Here is what I tried, on iOS 26.1 and macOS 26.1:
ARView Multitouch
The setup below is a minimal ARView presented by SwiftUI, with touch events handled inside ARView. Multitouch doesn't work with this setup.
Note that multitouch wouldn't work either if the ARView is presented with a UIViewController instead of SwiftUI.
import RealityKit
import SwiftUI
struct ARViewMultiTouchView: View {
var body: some View {
ZStack {
ARViewMultiTouchRepresentable()
.ignoresSafeArea()
}
}
}
#Preview {
ARViewMultiTouchView()
}
// MARK: Representable ARView
struct ARViewMultiTouchRepresentable: UIViewRepresentable {
func makeUIView(context: Context) -> ARView {
let arView = ARViewMultiTouch(frame: .zero)
let anchor = AnchorEntity()
arView.scene.addAnchor(anchor)
let boxWidth: Float = 0.4
let boxMaterial = SimpleMaterial(color: .red, isMetallic: false)
let box = ModelEntity(mesh: .generateBox(size: boxWidth), materials: [boxMaterial])
box.name = "Box"
box.components.set(CollisionComponent(shapes: [.generateBox(width: boxWidth, height: boxWidth, depth: boxWidth)]))
anchor.addChild(box)
return arView
}
func updateUIView(_ uiView: ARView, context: Context) { }
}
// MARK: ARView
class ARViewMultiTouch: ARView {
required init(frame: CGRect) {
super.init(frame: frame)
/// Enable multi-touch
isMultipleTouchEnabled = true
cameraMode = .nonAR
automaticallyConfigureSession = false
environment.background = .color(.gray)
/// Disable gesture recognizers to not conflict with touch events
/// But it doesn't fix the issue
gestureRecognizers?.forEach { $0.isEnabled = false }
}
required dynamic init?(coder decoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
/// # Problem
/// This should print for every new touch, up to 5 simultaneously on an iPhone (multi-touch)
/// But it only fires for one touch at a time (single-touch)
print("Touch began at: \(touch.location(in: self))")
}
}
}
Multitouch with an Overlay
This setup works, but it doesn't seem right. There must be a solution to make ARView handle multi touch directly, right?
import SwiftUI
import RealityKit
struct MultiTouchOverlayView: View {
var body: some View {
ZStack {
MultiTouchOverlayRepresentable()
.ignoresSafeArea()
Text("Multi touch with overlay view")
.font(.system(size: 24, weight: .medium))
.foregroundStyle(.white)
.offset(CGSize(width: 0, height: -150))
}
}
}
#Preview {
MultiTouchOverlayView()
}
// MARK: Representable Container
struct MultiTouchOverlayRepresentable: UIViewRepresentable {
func makeUIView(context: Context) -> UIView {
/// The view that SwiftUI will present
let container = UIView()
/// ARView
let arView = ARView(frame: container.bounds)
arView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
arView.cameraMode = .nonAR
arView.automaticallyConfigureSession = false
arView.environment.background = .color(.gray)
let anchor = AnchorEntity()
arView.scene.addAnchor(anchor)
let boxWidth: Float = 0.4
let boxMaterial = SimpleMaterial(color: .red, isMetallic: false)
let box = ModelEntity(mesh: .generateBox(size: boxWidth), materials: [boxMaterial])
box.name = "Box"
box.components.set(CollisionComponent(shapes: [.generateBox(width: boxWidth, height: boxWidth, depth: boxWidth)]))
anchor.addChild(box)
/// The view that will capture touches
let touchOverlay = TouchOverlayView(frame: container.bounds)
touchOverlay.autoresizingMask = [.flexibleWidth, .flexibleHeight]
touchOverlay.backgroundColor = .clear
/// Pass an arView reference to the overlay for hit testing
touchOverlay.arView = arView
/// Add views to the container.
/// ARView goes in first, at the bottom.
container.addSubview(arView)
/// TouchOverlay goes in last, on top.
container.addSubview(touchOverlay)
return container
}
func updateUIView(_ uiView: UIView, context: Context) {
}
}
// MARK: Touch Overlay View
/// A UIView to handle multi-touch on top of ARView
class TouchOverlayView: UIView {
weak var arView: ARView?
override init(frame: CGRect) {
super.init(frame: frame)
isMultipleTouchEnabled = true
isUserInteractionEnabled = true
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
let totalTouches = event?.allTouches?.count ?? touches.count
print("--- Touches Began --- (New: \(touches.count), Total: \(totalTouches))")
for touch in touches {
let location = touch.location(in: self)
/// Hit testing.
/// ARView and Touch View must be of the same size
if let arView = arView {
let entity = arView.entity(at: location)
if let entity = entity {
print("Touched entity: \(entity.name)")
} else {
print("Touched: none")
}
}
}
}
override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) {
let totalTouches = event?.allTouches?.count ?? touches.count
print("--- Touches Cancelled --- (Cancelled: \(touches.count), Total: \(totalTouches))")
}
}
Hi fellow devs, I have a quick question is it possible to have virtual controllers on Mac. For instance can my app exclusively manage the controller and output it into the Game Controller framework? And create a virtual controller to allow for features such as controller emulation, haptic control, and others.
I’m trying to use EXR lightmaps to overlay baked lighting on top of a base texture in the RCP Shader Graph.
When I multiply an EXR image set to Image(float) with an 8-bit base texture, the output becomes Image(float). I can’t connect that to the BaseColor input on the UnlitSurface node, since it only accepts Color3f.
I expected to be able to use a Convert node between the Multiply node and the BaseColor input, but when I do that, the result becomes black and white instead of the expected outcome: the EXR multiplied with the base texture using a baseline value of 1, where values below 1 in the EXR would darken the base texture and values above 1 would brighten it.
Is there any documentation on how to properly overlay a 32-bit EXR lightmap in the RCP Shader Graph, or is the black-and-white output from the Convert node a bug?
Topic:
Graphics & Games
SubTopic:
RealityKit
Tags:
RealityKit
Reality Composer Pro
Shader Graph Editor
Hi all,
Wondering how I would go about creating a plugin/class to support a new (physical/hardware) device with the game controller framework?
Between GCVirtualController on iOS and the "KeyboardAndMouseSupport.bundle" I see inside GameController.framework on my Mac, it looks like the framework must be designed to support this but I can't find any documentation.
Thanks!
[CRITICAL] Metal API Memory Leak - Heap Memory Never Released to OS (CWE-400)
Security Classification
This issue constitutes a resource exhaustion vulnerability (CWE-400):
Aspect
Details
Type
Uncontrolled Resource Consumption
CWE
CWE-400
Vector
Local (any Metal application)
Impact
System instability, denial of service
User Control
None - no mitigation available
Recovery
Requires application restart
Summary
Metal heap allocations are never released back to macOS, even when the memory is entirely unused. This causes continuous, unbounded memory growth until system instability or crash. The issue affects any application using Metal API heap allocation.
This was discovered in Unreal Engine 5, but reproduces in a completely blank UE5 project with zero application code - confirming this is Metal framework behavior, not application-level.
Environment
OS: macOS Tahoe 26.2
Hardware: Apple Silicon M4 Max (also reproduced on M1, M2, M3)
API: Metal
Reproduction Steps
Run any Metal application that allocates and deallocates GPU buffers via Metal heaps
Open Activity Monitor and observe the application's memory usage
Let the application run idle (no user interaction required)
Observe memory growing continuously at ~1-2 MB per second
Memory never plateaus or stabilizes
Eventually system becomes unstable
For testing: Any Unreal Engine 5.4+ project on macOS will reproduce this. Even a blank project with no gameplay code exhibits the leak. (Tested on UE 5.7.1)
Observed Behavior
Memory Analysis
Using Unreal's memreport -full command, two reports taken 86 seconds apart:
Metric
Report 1 (183s)
Report 2 (269s)
Delta
Process Physical
4373.64 MB
4463.39 MB
+89.75 MB
Metal Heap Buffer
7168 MB
8192 MB
+1024 MB
Unused Heap
3453 MB
4477 MB
+1024 MB
Object Count
73,840
73,840
0 (no change)
Key Finding
Metal Heap grew by exactly 1 GB while "Unused Heap" also grew by 1 GB. This demonstrates:
Metal is allocating new heap blocks in ~1 GB increments
Previously allocated heap memory becomes "unused" but is never released
The unused memory accumulates indefinitely
No application-level objects are leaking (count remains constant)
Memory Growth Pattern
Continuous growth while idle (no user interaction)
Growth rate: approximately 1-2 MB per second
No plateau or stabilization occurs
Metal allocates new 1 GB heap blocks rather than reusing freed space
Eventually leads to system instability and crash
What is NOT Causing This
We verified the following are NOT the source:
Application objects - Object count remains constant
Application code - Blank project with no code reproduces the issue
Texture streaming - Disabling texture streaming had no effect
CPU garbage collection - Running GC has no effect (this is GPU memory)
Mitigations Attempted (None Worked)
setPurgeableState
Setting resources to purgeable state before release:
[buffer setPurgeableState:MTLPurgeableStateEmpty];
Result: Metal ignores this hint and does not reclaim heap memory.
Avoiding Heap Pooling
Forcing individual buffer allocations instead of heap-based pooling.
Result: Leak persists - Metal still manages underlying allocations.
Aggressive Buffer Compaction
Attempting to compact/defragment buffers within heaps every frame.
Result: Only moves data between existing heaps. Does NOT release heaps back to OS.
Reducing Pool Sizes
Minimizing all buffer pool sizes to force more frequent reuse.
Result: Slightly slows the leak rate but does not stop it.
Root Cause Analysis
How Metal Heap Allocation Appears to Work
Metal allocates GPU heap blocks in large chunks (~1 GB observed)
Application requests buffers from these heaps
When application releases buffers, memory becomes "unused" within the heap
Metal does NOT release heap blocks back to macOS, even when entirely unused
When fragmentation prevents reuse, Metal allocates new heap blocks
Result: Continuous memory growth with no upper bound
The Core Problem
There appears to be no Metal API to force heap memory release. The only way to reclaim this memory is to destroy the Metal device entirely, which requires restarting the application.
Expected Behavior
Metal should:
Release unused heaps - When a heap block is entirely unused, release it back to macOS
Respect purgeable hints - Honor setPurgeableState calls from applications
Compact allocations - Defragment heap allocations to reduce fragmentation
Provide control APIs - Allow applications to request heap compaction or release
Enforce limits - Have configurable maximum heap memory consumption
Security Implications
Local Denial of Service - Any Metal application can exhaust system memory, causing instability affecting all running applications
Memory Pressure Attack - Forces other applications to swap to disk, degrading system-wide performance
No Upper Bound - Memory consumption continues until system failure
Unmitigable - End users have no way to prevent or limit the leak
Affects All Metal Apps - Any application using Metal heaps is potentially affected
Impact
Applications become unstable after extended use
System-wide performance degrades as memory pressure increases
Users must periodically restart applications
Developers cannot work around this at the application level
Long-running applications (games, creative tools, servers) are particularly affected
Request
Investigate Metal heap memory management behavior
Implement heap release when blocks become entirely unused
Honor setPurgeableState hints from applications
Consider providing an API for applications to request heap compaction
Document any intended behavior or workarounds
Additional Notes
This issue has been observed across multiple Unreal Engine versions (5.4, 5.7) and multiple Apple Silicon generations (M1 through M4). The behavior is consistent and reproducible.
The Unreal Engine team has implemented various CVars to attempt mitigation (rhi.Metal.HeapBufferBytesToCompact, rhi.Metal.ResourcePurgeInPool, etc.) but none successfully address the issue because the root cause is at the Metal framework level.
Tested: January 2026
Platform: macOS Tahoe 26.2, Apple Silicon (M1/M2/M3/M4)
hello apple through this message i want to draw you attention to some problems with gptk and rosetta some games like marvel spiderman 2 have broken animations and t pose issues and other like uncharted and the last of us have severe memory leak issues so its my request please fix it asap
Issue
When an Entity with a ViewAttachmentComponent is:
disabled using isEnabled = false
removed using removeFromParent()
and then enabled or added back again, the attached SwiftUI view is rendered correctly, but tap interactions stop working.
Specifically:
Button actions inside the attached view do not fire
TapGesture closures on child views do not respond
Expected Behavior
Tap interactions inside the attached view should continue to work after the Entity is re-enabled or re-added.
Actual Behavior
After being disabled or removed once, all tap interactions stop responding.
Comparison
When displaying the same SwiftUI view using RealityViewAttachments, this issue does not occur.
Removing and re-displaying the attachment still allows taps to work correctly.
Reproduction
Attached sample code reproduces the issue:
A RealityView with an Entity that has a ViewAttachmentComponent
The attached SwiftUI view contains a Toggle
The toggle updates isEnabled on the Entity
After toggling off and on, tap interactions stop responding
Environment
Xcode 26
visionOS 26
Question
Is this expected behavior of ViewAttachmentComponent, or a bug?
Is there a recommended way to temporarily hide or disable an Entity with ViewAttachmentComponent without breaking tap interactions?
import SwiftUI
import RealityKit
struct GestureTestView: View {
@State var sampleEnabled = true
@State var sampleEntity: Entity?
var body: some View {
RealityView { contents, attachments in
// After deleting and re-displaying it, taps no longer respond.
let sample = Entity(components: ViewAttachmentComponent(rootView: SampleView()))
// Executed successfully
//let sample = attachments.entity(for: "SampleView")!
contents.add(sample)
sample.position = [0, 1.2, -1]
sampleEntity = sample
let toggleButton = Entity(components: ViewAttachmentComponent(rootView: ToggleButtonView(isOn: $sampleEnabled)))
contents.add(toggleButton)
toggleButton.position = [0, 1, -1]
} update: { _, _ in
// run update closure
print(sampleEnabled)
// update sample entity enable
sampleEntity?.isEnabled = sampleEnabled
} attachments: {
Attachment(id: "SampleView") {
SampleView()
}
}
}
}
struct ToggleButtonView: View {
@Binding var isOn: Bool
var body: some View {
VStack {
Toggle(isOn: $isOn) {
Text("Toggle")
}
}
.padding()
.glassBackgroundEffect()
}
}
struct SampleView: View {
var body: some View {
VStack {
Button {
print("Hello, World!")
} label: {
Text("Hello, World!")
.padding()
}
}
.padding()
.glassBackgroundEffect()
}
}
#Preview(immersionStyle: .mixed) {
GestureTestView()
}
Hello
XQuartz is an open-source effort to develop a version of the X.Org X Window System (https://www.xquartz.org/), widely used to bring graphical support to applications running in remote servers (usually via SSH).
Since macOS Tahoe, XQuartz fails to refresh properly on window resize (more info here https://github.com/XQuartz/XQuartz/issues/438#issuecomment-3371409500), leading to severe usability issues.
The XQuartz developers are already aware of the issue, but I’m wondering if there’s anything we can do at the OS level to resolve it and restore the usual behavior from before macOS Tahoe.
Thanks,
KiM
Topic:
Graphics & Games
SubTopic:
General