From a4fe96954b0cacc8761b74ff51a4a5f5e03cd8df Mon Sep 17 00:00:00 2001
From: tildearrow <me@tildearrow.org>
Date: Sun, 14 Apr 2024 19:39:43 -0500
Subject: [PATCH] Metal backend, part 10

---
 src/gui/render/renderMetal.h  |  6 +++++-
 src/gui/render/renderMetal.mm | 20 ++++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/gui/render/renderMetal.h b/src/gui/render/renderMetal.h
index 6a1470c53..ed6219b3a 100644
--- a/src/gui/render/renderMetal.h
+++ b/src/gui/render/renderMetal.h
@@ -24,6 +24,7 @@ struct FurnaceGUIRenderMetalPrivate;
 class FurnaceGUIRenderMetal: public FurnaceGUIRender {
   SDL_Renderer* sdlRend;
   FurnaceGUIRenderMetalPrivate* priv;
+  bool swapIntervalSet;
   public:
     ImTextureID getTextureID(FurnaceGUITexture* which);
     bool lockTexture(FurnaceGUITexture* which, void** data, int* pitch);
@@ -35,6 +36,7 @@ class FurnaceGUIRenderMetal: public FurnaceGUIRender {
     void setBlendMode(FurnaceGUIBlendMode mode);
     void clear(ImVec4 color);
     bool newFrame();
+    bool canVSync();
     void createFontsTexture();
     void destroyFontsTexture();
     void renderGUI();
@@ -42,6 +44,7 @@ class FurnaceGUIRenderMetal: public FurnaceGUIRender {
     void present();
     bool getOutputSize(int& w, int& h);
     int getWindowFlags();
+    void setSwapInterval(int swapInterval);
     void preInit();
     bool init(SDL_Window* win, int swapInterval);
     void initGUI(SDL_Window* win);
@@ -49,5 +52,6 @@ class FurnaceGUIRenderMetal: public FurnaceGUIRender {
     bool quit();
     FurnaceGUIRenderMetal():
       sdlRend(NULL),
-      priv(NULL) {}
+      priv(NULL),
+      swapIntervalSet(false) {}
 };
diff --git a/src/gui/render/renderMetal.mm b/src/gui/render/renderMetal.mm
index 81fa74aa7..ccfb9f732 100644
--- a/src/gui/render/renderMetal.mm
+++ b/src/gui/render/renderMetal.mm
@@ -130,6 +130,10 @@ bool FurnaceGUIRenderMetal::newFrame() {
   return ImGui_ImplMetal_NewFrame(priv->renderPass);
 }
 
+bool FurnaceGUIRenderMetal::canVSync() {
+  return swapIntervalSet;
+}
+
 void FurnaceGUIRenderMetal::createFontsTexture() {
   logI("Metal: createFontsTexture()");
   ImGui_ImplMetal_CreateFontsTexture(priv->context.device);
@@ -167,6 +171,15 @@ int FurnaceGUIRenderMetal::getWindowFlags() {
   return 0;
 }
 
+void FurnaceGUIRenderMetal::setSwapInterval(int swapInterval) {
+  if (SDL_RenderSetVSync(sdlRend,(swapInterval>=0)?1:0)!=0) {
+    swapIntervalSet=false;
+    logW("tried to enable VSync but couldn't!");
+  } else {
+    swapIntervalSet=true;
+  }
+}
+
 void FurnaceGUIRenderMetal::preInit() {
   SDL_SetHint(SDL_HINT_RENDER_DRIVER,"metal");
   priv=new FurnaceGUIRenderMetalPrivate;
@@ -180,6 +193,13 @@ bool FurnaceGUIRenderMetal::init(SDL_Window* win, int swapInterval) {
 
   if (sdlRend==NULL) return false;
 
+  if (SDL_RenderSetVSync(sdlRend,(swapInterval>=0)?1:0)!=0) {
+    swapIntervalSet=false;
+    logW("tried to enable VSync but couldn't!");
+  } else {
+    swapIntervalSet=true;
+  }
+
   logI("retrieving context...");
 
   priv->context=(__bridge CAMetalLayer*)SDL_RenderGetMetalLayer(sdlRend);