From d0823b1acb80994ba89503831b8c9bd77c7bc3a8 Mon Sep 17 00:00:00 2001
From: Riley Testut <riley@rileytestut.com>
Date: Mon, 11 Jan 2021 14:12:44 -0600
Subject: [PATCH] Raises MelonDSDeltaCore maximum Fast Forward speed to 3x

---
 Delta/Emulation/GameViewController.swift    | 15 ++++++---------
 Delta/Extensions/UIDevice+Processor.swift   |  8 ++++++++
 Delta/Systems/DeltaCoreProtocol+Delta.swift | 18 ++++++++++--------
 3 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/Delta/Emulation/GameViewController.swift b/Delta/Emulation/GameViewController.swift
index 5ee2560..c3b199b 100644
--- a/Delta/Emulation/GameViewController.swift
+++ b/Delta/Emulation/GameViewController.swift
@@ -409,20 +409,17 @@ extension GameViewController
                 self.pausingGameController = gameController
             }
             
+            if self.emulatorCore?.deltaCore.supportedRates.upperBound == 1
+            {
+                pauseViewController.fastForwardItem = nil
+            }
+            
             switch self.game?.type
             {
-            case .n64? where !UIDevice.current.hasA9ProcessorOrBetter:
-                // A8 processors and earlier aren't powerful enough to run N64 games faster than 1x speed.
-                pauseViewController.fastForwardItem = nil
-            
             case .ds? where self.emulatorCore?.deltaCore == DS.core:
                 // Cheats are not supported by DeSmuME core.
                 pauseViewController.cheatCodesItem = nil
-                
-            case .ds? where !UIDevice.current.hasA9ProcessorOrBetter:
-                // A8 processors and earlier aren't powerful enough to run DS games faster than 1x speed.
-                pauseViewController.fastForwardItem = nil
-                
+
             default: break
             }
             
diff --git a/Delta/Extensions/UIDevice+Processor.swift b/Delta/Extensions/UIDevice+Processor.swift
index 4ff4bce..c6f6933 100644
--- a/Delta/Extensions/UIDevice+Processor.swift
+++ b/Delta/Extensions/UIDevice+Processor.swift
@@ -8,15 +8,23 @@
 
 import UIKit
 import ARKit
+import Metal
 
 extension UIDevice
 {
+    private static var mtlDevice: MTLDevice? = MTLCreateSystemDefaultDevice()
+    
     var hasA9ProcessorOrBetter: Bool {
         // ARKit is only supported by devices with an A9 processor or better, according to the documentation.
         // https://developer.apple.com/documentation/arkit/arconfiguration/2923553-issupported
         return ARConfiguration.isSupported
     }
     
+    var hasA11ProcessorOrBetter: Bool {
+        guard let mtlDevice = UIDevice.mtlDevice else { return false }
+        return mtlDevice.supportsFeatureSet(.iOS_GPUFamily4_v1) // iOS GPU Family 4 = A11 GPU
+    }
+    
     var supportsJIT: Bool {
         guard #available(iOS 14.2, *) else { return false }
         
diff --git a/Delta/Systems/DeltaCoreProtocol+Delta.swift b/Delta/Systems/DeltaCoreProtocol+Delta.swift
index bad62a5..57c76eb 100644
--- a/Delta/Systems/DeltaCoreProtocol+Delta.swift
+++ b/Delta/Systems/DeltaCoreProtocol+Delta.swift
@@ -60,16 +60,18 @@ struct DeltaCoreMetadata
 extension DeltaCoreProtocol
 {
     var supportedRates: ClosedRange<Double> {
+        return 1...self.maximumFastForwardSpeed
+    }
+    
+    private var maximumFastForwardSpeed: Double {
         switch self
         {
-        case NES.core: return 1...4
-        case SNES.core: return 1...4
-        case GBC.core: return 1...4
-        case GBA.core: return 1...3
-        case N64.core: return 1...3
-        case DS.core: return 1...3
-        case MelonDS.core: return 1...2
-        default: return 1...2
+        case NES.core, SNES.core, GBC.core: return 4
+        case GBA.core: return 3
+        case N64.core where UIDevice.current.hasA9ProcessorOrBetter: return 3
+        case DS.core where UIDevice.current.supportsJIT: return 3
+        case DS.core where UIDevice.current.hasA11ProcessorOrBetter: return 2
+        default: return 1
         }
     }