From f4a1f90d9286123e1a0994aa7dc0ae4e4935e3e9 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sun, 17 May 2020 14:28:13 +0900
Subject: [PATCH] graphicsdriver/opengl/gl: Reduce reflect usage

---
 .../opengl/gl/conversions_notwindows.go       | 34 +++++++++----------
 .../opengl/gl/conversions_windows.go          | 34 +++++++++----------
 2 files changed, 32 insertions(+), 36 deletions(-)

diff --git a/internal/graphicsdriver/opengl/gl/conversions_notwindows.go b/internal/graphicsdriver/opengl/gl/conversions_notwindows.go
index 56703d56b..ba71aad63 100644
--- a/internal/graphicsdriver/opengl/gl/conversions_notwindows.go
+++ b/internal/graphicsdriver/opengl/gl/conversions_notwindows.go
@@ -28,25 +28,23 @@ func Ptr(data interface{}) unsafe.Pointer {
 		return unsafe.Pointer(nil)
 	}
 	var addr unsafe.Pointer
-	v := reflect.ValueOf(data)
-	switch v.Type().Kind() {
-	case reflect.Ptr:
-		e := v.Elem()
-		switch e.Kind() {
-		case
-			reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
-			reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
-			reflect.Float32, reflect.Float64:
-			addr = unsafe.Pointer(e.UnsafeAddr())
-		default:
-			panic(fmt.Errorf("unsupported pointer to type %s; must be a slice or pointer to a singular scalar value or the first element of an array or slice", e.Kind()))
-		}
-	case reflect.Uintptr:
-		addr = unsafe.Pointer(v.Pointer())
-	case reflect.Slice:
-		addr = unsafe.Pointer(v.Index(0).UnsafeAddr())
+	switch v := data.(type) {
+	case *uint8:
+		addr = unsafe.Pointer(v)
+	case *uint16:
+		addr = unsafe.Pointer(v)
+	case *float32:
+		addr = unsafe.Pointer(v)
+	case uintptr:
+		addr = unsafe.Pointer(v)
+	case []uint8:
+		addr = unsafe.Pointer(&v[0])
+	case []uint16:
+		addr = unsafe.Pointer(&v[0])
+	case []float32:
+		addr = unsafe.Pointer(&v[0])
 	default:
-		panic(fmt.Errorf("unsupported type %s; must be a slice or pointer to a singular scalar value or the first element of an array or slice", v.Type()))
+		panic(fmt.Errorf("unsupported type %T; must be a slice or pointer to a singular scalar value or the first element of an array or slice", v))
 	}
 	return addr
 }
diff --git a/internal/graphicsdriver/opengl/gl/conversions_windows.go b/internal/graphicsdriver/opengl/gl/conversions_windows.go
index 2f5a6ae1e..3d90940f5 100644
--- a/internal/graphicsdriver/opengl/gl/conversions_windows.go
+++ b/internal/graphicsdriver/opengl/gl/conversions_windows.go
@@ -23,25 +23,23 @@ func Ptr(data interface{}) unsafe.Pointer {
 		return unsafe.Pointer(nil)
 	}
 	var addr unsafe.Pointer
-	v := reflect.ValueOf(data)
-	switch v.Type().Kind() {
-	case reflect.Ptr:
-		e := v.Elem()
-		switch e.Kind() {
-		case
-			reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
-			reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
-			reflect.Float32, reflect.Float64:
-			addr = unsafe.Pointer(e.UnsafeAddr())
-		default:
-			panic(fmt.Errorf("unsupported pointer to type %s; must be a slice or pointer to a singular scalar value or the first element of an array or slice", e.Kind()))
-		}
-	case reflect.Uintptr:
-		addr = unsafe.Pointer(v.Pointer())
-	case reflect.Slice:
-		addr = unsafe.Pointer(v.Index(0).UnsafeAddr())
+	switch v := data.(type) {
+	case *uint8:
+		addr = unsafe.Pointer(v)
+	case *uint16:
+		addr = unsafe.Pointer(v)
+	case *float32:
+		addr = unsafe.Pointer(v)
+	case uintptr:
+		addr = unsafe.Pointer(v)
+	case []uint8:
+		addr = unsafe.Pointer(&v[0])
+	case []uint16:
+		addr = unsafe.Pointer(&v[0])
+	case []float32:
+		addr = unsafe.Pointer(&v[0])
 	default:
-		panic(fmt.Errorf("unsupported type %s; must be a slice or pointer to a singular scalar value or the first element of an array or slice", v.Type()))
+		panic(fmt.Errorf("unsupported type %T; must be a slice or pointer to a singular scalar value or the first element of an array or slice", v))
 	}
 	return addr
 }