From 19f034e8182d566d0defb8a895fe067769686f6e Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sun, 4 Jul 2021 20:35:56 +0900
Subject: [PATCH] internal/graphicsdriver/metal: Refactoring

---
 internal/graphicsdriver/metal/graphics.go | 54 ++++++++++++-----------
 1 file changed, 28 insertions(+), 26 deletions(-)

diff --git a/internal/graphicsdriver/metal/graphics.go b/internal/graphicsdriver/metal/graphics.go
index b1459e4e2..e3ab0c847 100644
--- a/internal/graphicsdriver/metal/graphics.go
+++ b/internal/graphicsdriver/metal/graphics.go
@@ -826,33 +826,35 @@ func (g *Graphics) HasHighPrecisionFloat() bool {
 }
 
 func (g *Graphics) MaxImageSize() int {
-	if g.maxImageSize == 0 {
+	if g.maxImageSize != 0 {
+		return g.maxImageSize
+	}
+
+	g.maxImageSize = 4096
+	// https://developer.apple.com/metal/Metal-Feature-Set-Tables.pdf
+	switch {
+	case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily5_v1):
+		g.maxImageSize = 16384
+	case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily4_v1):
+		g.maxImageSize = 16384
+	case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily3_v1):
+		g.maxImageSize = 16384
+	case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily2_v2):
+		g.maxImageSize = 8192
+	case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily2_v1):
 		g.maxImageSize = 4096
-		// https://developer.apple.com/metal/Metal-Feature-Set-Tables.pdf
-		switch {
-		case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily5_v1):
-			g.maxImageSize = 16384
-		case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily4_v1):
-			g.maxImageSize = 16384
-		case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily3_v1):
-			g.maxImageSize = 16384
-		case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily2_v2):
-			g.maxImageSize = 8192
-		case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily2_v1):
-			g.maxImageSize = 4096
-		case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily1_v2):
-			g.maxImageSize = 8192
-		case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily1_v1):
-			g.maxImageSize = 4096
-		case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_tvOS_GPUFamily2_v1):
-			g.maxImageSize = 16384
-		case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_tvOS_GPUFamily1_v1):
-			g.maxImageSize = 8192
-		case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_macOS_GPUFamily1_v1):
-			g.maxImageSize = 16384
-		default:
-			panic("metal: there is no supported feature set")
-		}
+	case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily1_v2):
+		g.maxImageSize = 8192
+	case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_iOS_GPUFamily1_v1):
+		g.maxImageSize = 4096
+	case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_tvOS_GPUFamily2_v1):
+		g.maxImageSize = 16384
+	case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_tvOS_GPUFamily1_v1):
+		g.maxImageSize = 8192
+	case g.view.getMTLDevice().SupportsFeatureSet(mtl.FeatureSet_macOS_GPUFamily1_v1):
+		g.maxImageSize = 16384
+	default:
+		panic("metal: there is no supported feature set")
 	}
 	return g.maxImageSize
 }