From 8427a73c36f0755be8d9407636b75db574c315aa Mon Sep 17 00:00:00 2001
From: assiduous <assiduous@diligentgraphics.com>
Date: Mon, 24 Feb 2020 11:01:43 -0800
Subject: Enabled VSync control in GL backend (on Windows and Linux)

---
 Graphics/GraphicsEngineOpenGL/include/GLContextAndroid.hpp |  2 +-
 Graphics/GraphicsEngineOpenGL/include/GLContextLinux.hpp   |  2 +-
 Graphics/GraphicsEngineOpenGL/include/GLContextWindows.hpp |  2 +-
 Graphics/GraphicsEngineOpenGL/src/GLContextAndroid.cpp     |  2 +-
 Graphics/GraphicsEngineOpenGL/src/GLContextLinux.cpp       |  9 ++++++++-
 Graphics/GraphicsEngineOpenGL/src/GLContextWindows.cpp     | 13 ++++++++++++-
 Graphics/GraphicsEngineOpenGL/src/SwapChainGLImpl.cpp      |  2 +-
 7 files changed, 25 insertions(+), 7 deletions(-)

(limited to 'Graphics/GraphicsEngineOpenGL')

diff --git a/Graphics/GraphicsEngineOpenGL/include/GLContextAndroid.hpp b/Graphics/GraphicsEngineOpenGL/include/GLContextAndroid.hpp
index e7d98d85..d50c7e51 100644
--- a/Graphics/GraphicsEngineOpenGL/include/GLContextAndroid.hpp
+++ b/Graphics/GraphicsEngineOpenGL/include/GLContextAndroid.hpp
@@ -39,7 +39,7 @@ public:
 
     bool Init(ANativeWindow* window);
 
-    void SwapBuffers();
+    void SwapBuffers(int SwapInterval);
 
     void UpdateScreenSize();
 
diff --git a/Graphics/GraphicsEngineOpenGL/include/GLContextLinux.hpp b/Graphics/GraphicsEngineOpenGL/include/GLContextLinux.hpp
index 5e616492..abff9239 100644
--- a/Graphics/GraphicsEngineOpenGL/include/GLContextLinux.hpp
+++ b/Graphics/GraphicsEngineOpenGL/include/GLContextLinux.hpp
@@ -33,7 +33,7 @@ public:
 
     GLContext(const struct EngineGLCreateInfo& InitAttribs, struct DeviceCaps& DeviceCaps, const struct SwapChainDesc* pSCDesc);
     ~GLContext();
-    void SwapBuffers();
+    void SwapBuffers(int SwapInterval);
 
     NativeGLContextType GetCurrentNativeGLContext();
 
diff --git a/Graphics/GraphicsEngineOpenGL/include/GLContextWindows.hpp b/Graphics/GraphicsEngineOpenGL/include/GLContextWindows.hpp
index 48c0a7ac..286e60e3 100644
--- a/Graphics/GraphicsEngineOpenGL/include/GLContextWindows.hpp
+++ b/Graphics/GraphicsEngineOpenGL/include/GLContextWindows.hpp
@@ -37,7 +37,7 @@ public:
 
     GLContext(const struct EngineGLCreateInfo& InitAttribs, struct DeviceCaps& DeviceCaps, const struct SwapChainDesc* pSCDesc);
     ~GLContext();
-    void SwapBuffers();
+    void SwapBuffers(int SwapInterval);
 
     NativeGLContextType GetCurrentNativeGLContext();
 
diff --git a/Graphics/GraphicsEngineOpenGL/src/GLContextAndroid.cpp b/Graphics/GraphicsEngineOpenGL/src/GLContextAndroid.cpp
index 705124eb..233cc487 100644
--- a/Graphics/GraphicsEngineOpenGL/src/GLContextAndroid.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/GLContextAndroid.cpp
@@ -248,7 +248,7 @@ GLContext::~GLContext()
     Terminate();
 }
 
-void GLContext::SwapBuffers()
+void GLContext::SwapBuffers(int /*SwapInterval*/)
 {
     if (surface_ == EGL_NO_SURFACE)
     {
diff --git a/Graphics/GraphicsEngineOpenGL/src/GLContextLinux.cpp b/Graphics/GraphicsEngineOpenGL/src/GLContextLinux.cpp
index a8e2e852..dac8af2d 100644
--- a/Graphics/GraphicsEngineOpenGL/src/GLContextLinux.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/GLContextLinux.cpp
@@ -155,10 +155,17 @@ GLContext::~GLContext()
 {
 }
 
-void GLContext::SwapBuffers()
+void GLContext::SwapBuffers(int SwapInterval)
 {
     if (m_WindowId != 0 && m_pDisplay != nullptr)
     {
+#if GLX_EXT_swap_control
+        if (glXSwapIntervalEXT != nullptr)
+        {
+            glXSwapIntervalEXT(SwapInterval);
+        }
+#endif
+
         auto wnd     = static_cast<Window>(m_WindowId);
         auto display = reinterpret_cast<Display*>(m_pDisplay);
         glXSwapBuffers(display, wnd);
diff --git a/Graphics/GraphicsEngineOpenGL/src/GLContextWindows.cpp b/Graphics/GraphicsEngineOpenGL/src/GLContextWindows.cpp
index 2aef9128..754902d0 100644
--- a/Graphics/GraphicsEngineOpenGL/src/GLContextWindows.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/GLContextWindows.cpp
@@ -307,12 +307,23 @@ GLContext::~GLContext()
     }
 }
 
-void GLContext::SwapBuffers()
+void GLContext::SwapBuffers(int SwapInterval)
 {
     if (m_WindowHandleToDeviceContext)
+    {
+#if WGL_EXT_swap_control
+        if (wglSwapIntervalEXT != nullptr)
+        {
+            wglSwapIntervalEXT(SwapInterval);
+        }
+#endif
+
         ::SwapBuffers(m_WindowHandleToDeviceContext);
+    }
     else
+    {
         LOG_ERROR("Swap buffer failed because window handle to device context is not initialized");
+    }
 }
 
 GLContext::NativeGLContextType GLContext::GetCurrentNativeGLContext()
diff --git a/Graphics/GraphicsEngineOpenGL/src/SwapChainGLImpl.cpp b/Graphics/GraphicsEngineOpenGL/src/SwapChainGLImpl.cpp
index 7c0dcfa8..a9af9b5d 100644
--- a/Graphics/GraphicsEngineOpenGL/src/SwapChainGLImpl.cpp
+++ b/Graphics/GraphicsEngineOpenGL/src/SwapChainGLImpl.cpp
@@ -88,7 +88,7 @@ void SwapChainGLImpl::Present(Uint32 SyncInterval)
 #if PLATFORM_WIN32 || PLATFORM_LINUX || PLATFORM_ANDROID
     auto* pDeviceGL = m_pRenderDevice.RawPtr<RenderDeviceGLImpl>();
     auto& GLContext = pDeviceGL->m_GLContext;
-    GLContext.SwapBuffers();
+    GLContext.SwapBuffers(static_cast<int>(SyncInterval));
 #elif PLATFORM_MACOS
     LOG_ERROR("Swap buffers operation must be performed by the app on MacOS");
 #else
-- 
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