OpenXRUtils: implemented GetOpenXRGraphicsBindingGL on Android

Author: TheMostDiligent

Graphics/GraphicsEngineOpenGL/include/GLContextAndroid.hpp

@@ -65,13 +65,18 @@ class GLContext
     int32_t GetScreenWidth() const { return screen_width_; }
     int32_t GetScreenHeight() const { return screen_height_; }
 
+    EGLDisplay GetDisplay() const { return display_; }
+    EGLSurface GetSurface() const { return surface_; }
+    EGLContext GetEGLCtx() const { return context_; }
+    EGLConfig  GetConfig() const { return config_; }
+
 private:
     //EGL configurations
     ANativeWindow* window_  = nullptr;
     EGLDisplay     display_ = EGL_NO_DISPLAY;
     EGLSurface     surface_ = EGL_NO_SURFACE;
     EGLContext     context_ = EGL_NO_CONTEXT;
-    EGLConfig      config_;
+    EGLConfig      config_  = nullptr;
 
 #if DILIGENT_USE_OPENXR
     std::unique_ptr<OpenXRAttribs> openxr_attribs_;

Graphics/GraphicsEngineOpenGL/include/RenderDeviceGLImpl.hpp

@@ -190,7 +190,7 @@ class RenderDeviceGLImpl : public RenderDeviceBase<EngineGLImplTraits>
                                                                                   RESOURCE_DIMENSION Dimension,
                                                                                   Uint32             SampleCount) const override final;
 
-#if PLATFORM_WIN32
+#if PLATFORM_WIN32 || PLATFORM_ANDROID
     virtual NativeGLContextAttribs DILIGENT_CALL_TYPE GetNativeGLContextAttribs() const override final;
 #endif
 

Graphics/GraphicsEngineOpenGL/interface/RenderDeviceGL.h

@@ -49,7 +49,7 @@ static DILIGENT_CONSTEXPR INTERFACE_ID IID_RenderDeviceGL =
 // clang-format off
 
 #if PLATFORM_WIN32
-/// Native GL context attributes
+/// Win32 native GL context attributes
 struct NativeGLContextAttribsWin32
 {
     /// Device context handle
@@ -60,6 +60,24 @@ struct NativeGLContextAttribsWin32
 };
 typedef struct NativeGLContextAttribsWin32 NativeGLContextAttribsWin32;
 typedef struct NativeGLContextAttribsWin32 NativeGLContextAttribs;
+#elif PLATFORM_ANDROID
+/// Android native GL context attributes
+struct NativeGLContextAttribsAndroid
+{
+    /// EGL display
+    void* Display DEFAULT_INITIALIZER(nullptr);
+
+    // EGL surface
+    void* Surface DEFAULT_INITIALIZER(nullptr);
+
+    /// EGL context
+    void* Context DEFAULT_INITIALIZER(nullptr);
+
+    /// EGL config
+    void* Config DEFAULT_INITIALIZER(nullptr);
+};
+typedef struct NativeGLContextAttribsAndroid NativeGLContextAttribsAndroid;
+typedef struct NativeGLContextAttribsAndroid NativeGLContextAttribs;
 #endif
 
 /// Exposes OpenGL-specific functionality of a render device.
@@ -128,7 +146,7 @@ DILIGENT_BEGIN_INTERFACE(IRenderDeviceGL, IRenderDevice)
                                             RESOURCE_STATE        InitialState,
                                             ITexture**            ppTexture) PURE;
 
-#if PLATFORM_WIN32
+#if PLATFORM_WIN32 || PLATFORM_ANDROID
     /// Returns platform-specific GL context attributes
     VIRTUAL NativeGLContextAttribs METHOD(GetNativeGLContextAttribs)(THIS) CONST PURE;
 #endif

Graphics/GraphicsEngineOpenGL/src/RenderDeviceGLImpl.cpp

@@ -1740,6 +1740,16 @@ NativeGLContextAttribs RenderDeviceGLImpl::GetNativeGLContextAttribs() const
     Attribs.hGLRC = m_GLContext.GetHandle();
     return Attribs;
 }
+#elif PLATFORM_ANDROID
+NativeGLContextAttribs RenderDeviceGLImpl::GetNativeGLContextAttribs() const
+{
+    NativeGLContextAttribs Attribs;
+    Attribs.Display = m_GLContext.GetDisplay();
+    Attribs.Surface = m_GLContext.GetSurface();
+    Attribs.Context = m_GLContext.GetEGLCtx();
+    Attribs.Config = m_GLContext.GetConfig();
+    return Attribs;
+}
 #endif
 
 } // namespace Diligent

Graphics/GraphicsTools/src/OpenXRUtilitiesGL.cpp

@@ -49,6 +49,13 @@ constexpr XrStructureType XR_TYPE_SWAPCHAIN_IMAGE_GL = XR_TYPE_SWAPCHAIN_IMAGE_O
 
 #elif GLES_SUPPORTED
 
+#    if PLATFORM_ANDROID
+#        include <jni.h>
+#        include <EGL/egl.h>
+
+#        define XR_USE_PLATFORM_ANDROID
+#    endif
+
 typedef unsigned int EGLenum;
 
 #    define XR_USE_GRAPHICS_API_OPENGL_ES
@@ -77,11 +84,26 @@ void GetOpenXRGraphicsBindingGL(IRenderDevice*  pDevice,
     VERIFY_EXPR(pDeviceGL != nullptr);
     NativeGLContextAttribsWin32 GLCtxAttribs = pDeviceGL->GetNativeGLContextAttribs();
 
-    XrGraphicsBindingOpenGLWin32KHR& Binding = *reinterpret_cast<XrGraphicsBindingOpenGLWin32KHR*>(pDataBlob->GetDataPtr());
-    Binding.type                             = XR_TYPE_GRAPHICS_BINDING_D3D11_KHR;
-    Binding.next                             = nullptr;
-    Binding.hDC                              = static_cast<HDC>(GLCtxAttribs.hDC);
-    Binding.hGLRC                            = static_cast<HGLRC>(GLCtxAttribs.hGLRC);
+    XrGraphicsBindingOpenGLWin32KHR& Binding{*pDataBlob->GetDataPtr<XrGraphicsBindingOpenGLWin32KHR>()};
+    Binding.type  = XR_TYPE_GRAPHICS_BINDING_D3D11_KHR;
+    Binding.next  = nullptr;
+    Binding.hDC   = static_cast<HDC>(GLCtxAttribs.hDC);
+    Binding.hGLRC = static_cast<HGLRC>(GLCtxAttribs.hGLRC);
+
+    *ppGraphicsBinding = pDataBlob.Detach();
+#elif GLES_SUPPORTED && PLATFORM_ANDROID
+    RefCntAutoPtr<DataBlobImpl> pDataBlob{DataBlobImpl::Create(sizeof(XrGraphicsBindingOpenGLESAndroidKHR))};
+
+    RefCntAutoPtr<IRenderDeviceGL> pDeviceGL{pDevice, IID_RenderDeviceGL};
+    VERIFY_EXPR(pDeviceGL != nullptr);
+    NativeGLContextAttribsAndroid GLCtxAttribs = pDeviceGL->GetNativeGLContextAttribs();
+
+    XrGraphicsBindingOpenGLESAndroidKHR& Binding{*pDataBlob->GetDataPtr<XrGraphicsBindingOpenGLESAndroidKHR>()};
+    Binding.type    = XR_TYPE_GRAPHICS_BINDING_OPENGL_ES_ANDROID_KHR;
+    Binding.next    = nullptr;
+    Binding.display = GLCtxAttribs.Display;
+    Binding.config  = GLCtxAttribs.Config;
+    Binding.context = GLCtxAttribs.Context;
 
     *ppGraphicsBinding = pDataBlob.Detach();
 #else