shiny/driver/mtldriver: add darwin/arm64 (macOS) support

The Objective-C BOOL type is defined as a signed char on on Intel-based
Mac computers, but on Apple silicon, it is defined as as a native bool.¹

This makes it hard to write portable Cgo code across darwin/amd64 and
darwin/arm64 ports. So, stop relying on it, and use the bool type from
<stdbool.h> instead.

Update to a newer version of the mtl package with a similar change.

¹ https://developer.apple.com/documentation/apple_silicon/addressing_architectural_differences_in_your_macos_code#3616879

Fixes golang/go#43221.

Change-Id: I63334dc646a8f9b74cd6a969eadf133cdbc84fb7
Reviewed-on: https://go-review.googlesource.com/c/exp/+/279293
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Trust: Nigel Tao <nigeltao@golang.org>
Reviewed-by: Nigel Tao <nigeltao@golang.org>

Author: dmitshur

go.mod

@@ -3,7 +3,7 @@ module golang.org/x/exp
 go 1.12
 
 require (
-	dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9
+	dmitri.shuralyov.com/gpu/mtl v0.0.0-20201218220906-28db891af037
 	github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802
 	github.com/go-gl/glfw/v3.3/glfw v0.0.0-20200222043503-6f7a984d4dc4
 	golang.org/x/image v0.0.0-20190802002840-cff245a6509b

go.sum

@@ -1,5 +1,5 @@
-dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9 h1:VpgP7xuJadIUuKccphEpTJnWhS2jkQyMt6Y7pJCD7fY=
-dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
+dmitri.shuralyov.com/gpu/mtl v0.0.0-20201218220906-28db891af037 h1:+PdD6GLKejR9DizMAKT5DpSAkKswvZrurk1/eEt9+pw=
+dmitri.shuralyov.com/gpu/mtl v0.0.0-20201218220906-28db891af037/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802 h1:1BDTz0u9nC3//pOCMdNH+CiXJVYJh5UQNCOBG7jbELc=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/go-gl/glfw/v3.3/glfw v0.0.0-20200222043503-6f7a984d4dc4 h1:WtGNWLvXpe6ZudgnXrq0barxBImvnnJoMEhXAzcbM0I=

shiny/driver/mtldriver/internal/appkit/appkit.go

@@ -21,6 +21,7 @@ import (
 )
 
 /*
+#include <stdbool.h>
 #include "appkit.h"
 */
 import "C"
@@ -63,12 +64,5 @@ func (v View) SetLayer(l coreanim.Layer) {
 //
 // Reference: https://developer.apple.com/documentation/appkit/nsview/1483695-wantslayer.
 func (v View) SetWantsLayer(wantsLayer bool) {
-	C.View_SetWantsLayer(v.view, toCBool(wantsLayer))
-}
-
-func toCBool(b bool) C.BOOL {
-	if b {
-		return 1
-	}
-	return 0
+	C.View_SetWantsLayer(v.view, C.bool(wantsLayer))
 }

shiny/driver/mtldriver/internal/appkit/appkit.h

@@ -4,9 +4,7 @@
 
 // +build darwin
 
-typedef signed char BOOL;
-
 void * Window_ContentView(void * window);
 
 void View_SetLayer(void * view, void * layer);
-void View_SetWantsLayer(void * view, BOOL wantsLayer);
+void View_SetWantsLayer(void * view, bool wantsLayer);

shiny/driver/mtldriver/internal/appkit/appkit.m

@@ -15,6 +15,6 @@ void View_SetLayer(void * view, void * layer) {
 	((NSView *)view).layer = (CALayer *)layer;
 }
 
-void View_SetWantsLayer(void * view, BOOL wantsLayer) {
+void View_SetWantsLayer(void * view, bool wantsLayer) {
 	((NSView *)view).wantsLayer = wantsLayer;
 }

shiny/driver/mtldriver/internal/coreanim/coreanim.go

@@ -23,6 +23,7 @@ import (
 
 /*
 #cgo LDFLAGS: -framework QuartzCore -framework Foundation
+#include <stdbool.h>
 #include "coreanim.h"
 */
 import "C"
@@ -99,7 +100,7 @@ func (ml MetalLayer) SetMaximumDrawableCount(count int) {
 //
 // Reference: https://developer.apple.com/documentation/quartzcore/cametallayer/2887087-displaysyncenabled.
 func (ml MetalLayer) SetDisplaySyncEnabled(enabled bool) {
-	C.MetalLayer_SetDisplaySyncEnabled(ml.metalLayer, toCBool(enabled))
+	C.MetalLayer_SetDisplaySyncEnabled(ml.metalLayer, C.bool(enabled))
 }
 
 // SetDrawableSize sets the size, in pixels, of textures for rendering layer content.
@@ -137,10 +138,3 @@ func (md MetalDrawable) Drawable() unsafe.Pointer { return md.metalDrawable }
 func (md MetalDrawable) Texture() mtl.Texture {
 	return mtl.NewTexture(C.MetalDrawable_Texture(md.metalDrawable))
 }
-
-func toCBool(b bool) C.BOOL {
-	if b {
-		return 1
-	}
-	return 0
-}

shiny/driver/mtldriver/internal/coreanim/coreanim.h

@@ -4,7 +4,6 @@
 
 // +build darwin
 
-typedef signed char BOOL;
 typedef unsigned long uint_t;
 typedef unsigned short uint16_t;
 
@@ -14,7 +13,7 @@ uint16_t     MetalLayer_PixelFormat(void * metalLayer);
 void         MetalLayer_SetDevice(void * metalLayer, void * device);
 const char * MetalLayer_SetPixelFormat(void * metalLayer, uint16_t pixelFormat);
 const char * MetalLayer_SetMaximumDrawableCount(void * metalLayer, uint_t maximumDrawableCount);
-void         MetalLayer_SetDisplaySyncEnabled(void * metalLayer, BOOL displaySyncEnabled);
+void         MetalLayer_SetDisplaySyncEnabled(void * metalLayer, bool displaySyncEnabled);
 void         MetalLayer_SetDrawableSize(void * metalLayer, double width, double height);
 void *       MetalLayer_NextDrawable(void * metalLayer);
 

shiny/driver/mtldriver/internal/coreanim/coreanim.m

@@ -41,7 +41,7 @@ void MetalLayer_SetDevice(void * metalLayer, void * device) {
 	return NULL;
 }
 
-void MetalLayer_SetDisplaySyncEnabled(void * metalLayer, BOOL displaySyncEnabled) {
+void MetalLayer_SetDisplaySyncEnabled(void * metalLayer, bool displaySyncEnabled) {
 	((CAMetalLayer *)metalLayer).displaySyncEnabled = displaySyncEnabled;
 }