GS:MTL: Move texture size calculation to dedicated function

Author: TellowKrinkle

pcsx2/GS/Renderers/Metal/GSDeviceMTL.mm

@@ -35,14 +35,7 @@
 	{
 		GSAdapterInfo ai;
 		ai.name = [[dev name] UTF8String];
-		
-		ai.max_texture_size = 8192;
-		if ([dev supportsFeatureSet:MTLFeatureSet_macOS_GPUFamily1_v1])
-			ai.max_texture_size = 16384;
-		if (@available(macOS 10.15, iOS 13.0, *))
-			if ([dev supportsFamily:MTLGPUFamilyApple3])
-				ai.max_texture_size = 16384;
-
+		ai.max_texture_size = GSMTLDevice::GetMaxTextureSize(dev);
 		ai.max_upscale_multiplier = GSGetMaxUpscaleMultiplier(ai.max_texture_size);
 		list.push_back(std::move(ai));
 	}

pcsx2/GS/Renderers/Metal/GSMTLDeviceInfo.h

@@ -42,6 +42,8 @@ struct GSMTLDevice
 	GSMTLDevice() = default;
 	explicit GSMTLDevice(MRCOwned<id<MTLDevice>> dev);
 
+	static u32 GetMaxTextureSize(id<MTLDevice> dev);
+
 	bool IsOk() const { return dev && shaders; }
 	void Reset()
 	{

pcsx2/GS/Renderers/Metal/GSMTLDeviceInfo.mm

@@ -191,16 +191,23 @@ static DetectionResult detectIntelGPU(id<MTLDevice> dev, id<MTLLibrary> lib)
 	else
 		features.slow_color_compression = [[dev name] containsString:@"AMD"] || [[dev name] isEqualToString:@"Intel HD Graphics 4000"];
 
-	features.max_texsize = 8192;
-	if ([dev supportsFeatureSet:MTLFeatureSet_macOS_GPUFamily1_v1])
-		features.max_texsize = 16384;
-	if (@available(macOS 10.15, iOS 13.0, *))
-		if ([dev supportsFamily:MTLGPUFamilyApple3])
-			features.max_texsize = 16384;
+	features.max_texsize = GetMaxTextureSize(dev);
 
 	this->dev = std::move(dev);
 }
 
+u32 GSMTLDevice::GetMaxTextureSize(id<MTLDevice> dev)
+{
+	if (@available(macOS 10.15, iOS 13.0, *))
+	{
+		if ([dev supportsFamily:MTLGPUFamilyApple3])
+			return 16384;
+	}
+	if ([dev supportsFeatureSet:MTLFeatureSet_macOS_GPUFamily1_v1])
+		return 16384;
+	return 8192;
+}
+
 const char* to_string(GSMTLDevice::MetalVersion ver)
 {
 	switch (ver)