webxr-linux.patch

diff --git a/gfx/gl/SharedSurfaceGL.cpp b/gfx/gl/SharedSurfaceGL.cpp
--- a/gfx/gl/SharedSurfaceGL.cpp
+++ b/gfx/gl/SharedSurfaceGL.cpp
@@ -6,7 +6,9 @@
 #include "SharedSurfaceGL.h"
 
 #include "GLBlitHelper.h"
+#include "GLConsts.h"
 #include "GLContext.h"
+#include "GLContextEGL.h"
 #include "GLReadTexImageHelper.h"
 #include "mozilla/gfx/2D.h"
 #include "mozilla/layers/TextureForwarder.h"
@@ -16,6 +18,8 @@ namespace mozilla {
 namespace gl {
 
 /*static*/
+uint8_t* SharedSurface_Basic::pixelsBuffer = nullptr;
+
 UniquePtr<SharedSurface_Basic> SharedSurface_Basic::Create(
     const SharedSurfaceDesc& desc) {
   auto fb = MozFramebuffer::Create(desc.gl, desc.size, 0, false);
@@ -29,7 +33,25 @@ SharedSurface_Basic::SharedSurface_Basic
     : SharedSurface(desc, std::move(fb)) {}
 
 Maybe<layers::SurfaceDescriptor> SharedSurface_Basic::ToSurfaceDescriptor() {
-  return Nothing();
+  int width = mFb->mSize.width;
+  int height = mFb->mSize.height;
+  if (!pixelsBuffer) {
+    // Allocate the pixels buffer once.
+    pixelsBuffer = (uint8_t*)malloc(width * height * 4);
+  }
+
+  // Read the pixels from the frame buffer.
+  mDesc.gl->fBindFramebuffer(LOCAL_GL_FRAMEBUFFER, mFb->mFB);
+  mDesc.gl->fReadPixels(0, 0, width, height, LOCAL_GL_RGBA,
+                        LOCAL_GL_UNSIGNED_BYTE, pixelsBuffer);
+
+  // HACK: pass along the pointer to the pixelsBuffer in the 'fence' field.
+  return Some(layers::SurfaceDescriptorSharedGLTexture(
+      -1,
+      -1,
+      (uintptr_t)pixelsBuffer,
+      mFb->mSize,
+      true));
 }
 
 ////////////////////////////////////////////////////////////////////////
diff --git a/gfx/gl/SharedSurfaceGL.h b/gfx/gl/SharedSurfaceGL.h
--- a/gfx/gl/SharedSurfaceGL.h
+++ b/gfx/gl/SharedSurfaceGL.h
@@ -19,6 +19,10 @@ class SharedSurface_Basic final : public
   static UniquePtr<SharedSurface_Basic> Create(const SharedSurfaceDesc&);
 
  private:
+  // HACK: single static buffer for storing the pixel data.
+  // Image is uploaded and submitted to the compositor in OpenVRSession.
+  static uint8_t* pixelsBuffer;
+
   SharedSurface_Basic(const SharedSurfaceDesc& desc,
                       UniquePtr<MozFramebuffer>&& fb);
 
diff --git a/gfx/vr/VRManager.cpp b/gfx/vr/VRManager.cpp
--- a/gfx/vr/VRManager.cpp
+++ b/gfx/vr/VRManager.cpp
@@ -1378,7 +1378,8 @@ bool VRManager::SubmitFrame(const layers
   if (mState != VRManagerState::Active) {
     return false;
   }
-#if defined(XP_WIN) || defined(XP_MACOSX) || defined(MOZ_WIDGET_ANDROID)
+#if defined(XP_WIN) || defined(XP_MACOSX) || defined(MOZ_WIDGET_ANDROID) || \
+    defined(XP_LINUX)
   MOZ_ASSERT(mBrowserState.layerState[0].type ==
              VRLayerType::LayerType_Stereo_Immersive);
   VRLayer_Stereo_Immersive& layer =
@@ -1426,6 +1427,16 @@ bool VRManager::SubmitFrame(const layers
       layer.textureSize.width = desc.size().width;
       layer.textureSize.height = desc.size().height;
     } break;
+#  elif defined(XP_LINUX)
+    case SurfaceDescriptor::TSurfaceDescriptorSharedGLTexture: {
+      const SurfaceDescriptorSharedGLTexture& desc =
+          aTexture.get_SurfaceDescriptorSharedGLTexture();
+      layer.textureType = VRLayerTextureType::LayerTextureType_SharedGLTexture;
+      // HACK: Retrieve the pointer to the pixel data from the fence field.
+      layer.textureHandle = (void*)desc.fence();
+      layer.textureSize.width = desc.size().width;
+      layer.textureSize.height = desc.size().height;
+    } break;
 #  endif
     default: {
       MOZ_ASSERT(false);
@@ -1488,7 +1499,7 @@ void VRManager::SubmitFrameInternal(cons
     mCurrentSubmitTask = nullptr;
   }
 
-#if defined(XP_WIN) || defined(XP_MACOSX)
+#if defined(XP_WIN) || defined(XP_MACOSX) || defined(XP_LINUX)
 
   /**
    * Trigger the next VSync immediately after we are successfully
diff --git a/gfx/vr/VRShMem.cpp b/gfx/vr/VRShMem.cpp
--- a/gfx/vr/VRShMem.cpp
+++ b/gfx/vr/VRShMem.cpp
@@ -247,12 +247,20 @@ void VRShMem::CreateShMemForAndroid() {
 
 void VRShMem::ClearShMem() {
   if (mExternalShmem != nullptr) {
+    // Note: If the generation is reset, the communication will fail.
+    // The other instance of VRShMem would still think to have read
+    // generation 1, meaning the first (important) update is ignored.
+    long generation = mExternalShmem->geckoGenerationA;
 #ifdef MOZILLA_INTERNAL_API
     // VRExternalShmem is asserted to be POD
     mExternalShmem->Clear();
 #else
     memset((void*)mExternalShmem, 0, sizeof(VRExternalShmem));
 #endif
+
+    // Continue counting generations where we left off.
+    mExternalShmem->geckoGenerationA = mExternalShmem->geckoGenerationB =
+        generation + 1;
   }
 }
 
diff --git a/gfx/vr/external_api/moz_external_vr.h b/gfx/vr/external_api/moz_external_vr.h
--- a/gfx/vr/external_api/moz_external_vr.h
+++ b/gfx/vr/external_api/moz_external_vr.h
@@ -451,7 +451,8 @@ enum class VRLayerTextureType : uint16_t
   LayerTextureType_None = 0,
   LayerTextureType_D3D10SurfaceDescriptor = 1,
   LayerTextureType_MacIOSurface = 2,
-  LayerTextureType_GeckoSurfaceTexture = 3
+  LayerTextureType_GeckoSurfaceTexture = 3,
+  LayerTextureType_SharedGLTexture = 4
 };
 
 struct VRLayer_2D_Content {
diff --git a/gfx/vr/service/OSVRSession.cpp b/gfx/vr/service/OSVRSession.cpp
--- a/gfx/vr/service/OSVRSession.cpp
+++ b/gfx/vr/service/OSVRSession.cpp
@@ -497,7 +497,7 @@ bool OSVRSession::SubmitFrame(
   return false;
   // TODO Implement
 }
-#elif defined(XP_MACOSX)
+#elif defined(XP_MACOSX) || defined(XP_LINUX)
 bool OSVRSession::SubmitFrame(
     const mozilla::gfx::VRLayer_Stereo_Immersive& aLayer,
     const VRLayerTextureHandle& aTexture) {
diff --git a/gfx/vr/service/OSVRSession.h b/gfx/vr/service/OSVRSession.h
--- a/gfx/vr/service/OSVRSession.h
+++ b/gfx/vr/service/OSVRSession.h
@@ -44,7 +44,7 @@ class OSVRSession : public VRSession {
 #if defined(XP_WIN)
   bool SubmitFrame(const mozilla::gfx::VRLayer_Stereo_Immersive& aLayer,
                    ID3D11Texture2D* aTexture) override;
-#elif defined(XP_MACOSX)
+#elif defined(XP_MACOSX) || defined(XP_LINUX)
   bool SubmitFrame(const mozilla::gfx::VRLayer_Stereo_Immersive& aLayer,
                    const VRLayerTextureHandle& aTexture) override;
 #endif
diff --git a/gfx/vr/service/OpenVRSession.cpp b/gfx/vr/service/OpenVRSession.cpp
--- a/gfx/vr/service/OpenVRSession.cpp
+++ b/gfx/vr/service/OpenVRSession.cpp
@@ -18,6 +18,8 @@
 #  include "mozilla/gfx/DeviceManagerDx.h"
 #elif defined(XP_MACOSX)
 #  include "mozilla/gfx/MacIOSurface.h"
+#elif defined(XP_LINUX)
+#  include "GLContextProvider.h"
 #endif
 
 #if !defined(XP_WIN)
@@ -1284,6 +1286,14 @@ bool OpenVRSession::SubmitFrame(
   return SubmitFrame(aTexture, ::vr::ETextureType::TextureType_IOSurface,
                      aLayer.leftEyeRect, aLayer.rightEyeRect);
 }
+#elif defined(XP_LINUX)
+bool OpenVRSession::SubmitFrame(
+    const mozilla::gfx::VRLayer_Stereo_Immersive& aLayer,
+    const VRLayerTextureHandle& aTexture) {
+  mTextureSize = aLayer.textureSize;
+  return SubmitFrame(aTexture, ::vr::ETextureType::TextureType_OpenGL,
+                     aLayer.leftEyeRect, aLayer.rightEyeRect);
+}
 #endif
 
 bool OpenVRSession::SubmitFrame(const VRLayerTextureHandle& aTextureHandle,
@@ -1303,32 +1313,46 @@ bool OpenVRSession::SubmitFrame(const VR
 
   CFTypeRefPtr<IOSurfaceRef> ioSurface = surf->GetIOSurfaceRef();
   tex.handle = (void*)ioSurface.get();
-#else
-  tex.handle = aTextureHandle;
 #endif
+  tex.eColorSpace = ::vr::EColorSpace::ColorSpace_Gamma;
   tex.eType = aTextureType;
-  tex.eColorSpace = ::vr::EColorSpace::ColorSpace_Auto;
+
+  if (!mGLContext) {
+    // Create a new GLX context for creating textures for the compositor.
+    nsCString discardFailureId;
+    mGLContext = gl::GLContextProviderGLX::CreateHeadless({}, &discardFailureId);
+  }
+
+  if (mTempTexture == 0) {
+    // Create texture to upload pixel data to.
+    mGLContext->fGenTextures(1, &mTempTexture);
+  }
+  mGLContext->fBindTexture(LOCAL_GL_TEXTURE_2D, mTempTexture);
+  mGLContext->fTexImage2D(LOCAL_GL_TEXTURE_2D, 0, LOCAL_GL_RGBA8,
+                          mTextureSize.width, mTextureSize.height, 0,
+                          LOCAL_GL_RGBA, LOCAL_GL_UNSIGNED_BYTE, (void*)aTextureHandle);
+  tex.handle = (void*)mTempTexture;
 
   ::vr::VRTextureBounds_t bounds;
   bounds.uMin = aLeftEyeRect.x;
-  bounds.vMin = 1.0 - aLeftEyeRect.y;
+  bounds.vMin = 1.0 - (aLeftEyeRect.y + aLeftEyeRect.height);
   bounds.uMax = aLeftEyeRect.x + aLeftEyeRect.width;
-  bounds.vMax = 1.0 - (aLeftEyeRect.y + aLeftEyeRect.height);
+  bounds.vMax = 1.0 - aLeftEyeRect.y;
 
   ::vr::EVRCompositorError err;
   err = mVRCompositor->Submit(::vr::EVREye::Eye_Left, &tex, &bounds);
   if (err != ::vr::EVRCompositorError::VRCompositorError_None) {
-    printf_stderr("OpenVR Compositor Submit() failed.\n");
+    printf_stderr("OpenVR Compositor Submit() failed: err=%d.\n", err);
   }
 
   bounds.uMin = aRightEyeRect.x;
-  bounds.vMin = 1.0 - aRightEyeRect.y;
+  bounds.vMin = 1.0 - (aRightEyeRect.y + aRightEyeRect.height);
   bounds.uMax = aRightEyeRect.x + aRightEyeRect.width;
-  bounds.vMax = 1.0 - (aRightEyeRect.y + aRightEyeRect.height);
+  bounds.vMax = 1.0 - aRightEyeRect.y;
 
   err = mVRCompositor->Submit(::vr::EVREye::Eye_Right, &tex, &bounds);
   if (err != ::vr::EVRCompositorError::VRCompositorError_None) {
-    printf_stderr("OpenVR Compositor Submit() failed.\n");
+    printf_stderr("OpenVR Compositor Submit() failed: err=%d\n", err);
   }
 
   mVRCompositor->PostPresentHandoff();
diff --git a/gfx/vr/service/OpenVRSession.h b/gfx/vr/service/OpenVRSession.h
--- a/gfx/vr/service/OpenVRSession.h
+++ b/gfx/vr/service/OpenVRSession.h
@@ -16,6 +16,8 @@
 
 #if defined(XP_WIN)
 #  include <d3d11_1.h>
+#elif defined(XP_LINUX)
+#  include "GLContext.h"
 #endif
 class nsITimer;
 
@@ -58,6 +60,9 @@ class OpenVRSession : public VRSession {
 #elif defined(XP_MACOSX)
   bool SubmitFrame(const mozilla::gfx::VRLayer_Stereo_Immersive& aLayer,
                    const VRLayerTextureHandle& aTexture) override;
+#elif defined(XP_LINUX)
+  bool SubmitFrame(const mozilla::gfx::VRLayer_Stereo_Immersive& aLayer,
+                   const VRLayerTextureHandle& aTexture) override;
 #endif
 
  private:
@@ -73,6 +78,12 @@ class OpenVRSession : public VRSession {
   bool mIsWindowsMR;
   TimeStamp mLastHapticUpdate;
 
+#if defined(XP_LINUX)
+  RefPtr<gl::GLContext> mGLContext;
+  GLuint mTempTexture = 0;
+  IntSize_POD mTextureSize;
+#endif
+
   static void HapticTimerCallback(nsITimer* aTimer, void* aClosure);
   bool InitState(mozilla::gfx::VRSystemState& aSystemState);
   void UpdateStageParameters(mozilla::gfx::VRDisplayState& aState);
diff --git a/gfx/vr/service/PuppetSession.cpp b/gfx/vr/service/PuppetSession.cpp
--- a/gfx/vr/service/PuppetSession.cpp
+++ b/gfx/vr/service/PuppetSession.cpp
@@ -89,7 +89,7 @@ bool PuppetSession::SubmitFrame(
     ID3D11Texture2D* aTexture) {
   return VRPuppetCommandBuffer::Get().SubmitFrame();
 }
-#elif defined(XP_MACOSX)
+#elif defined(XP_MACOSX) || defined(XP_LINUX)
 bool PuppetSession::SubmitFrame(
     const mozilla::gfx::VRLayer_Stereo_Immersive& aLayer,
     const VRLayerTextureHandle& aTexture) {
diff --git a/gfx/vr/service/PuppetSession.h b/gfx/vr/service/PuppetSession.h
--- a/gfx/vr/service/PuppetSession.h
+++ b/gfx/vr/service/PuppetSession.h
@@ -41,7 +41,7 @@ class PuppetSession : public VRSession {
 #if defined(XP_WIN)
   bool SubmitFrame(const mozilla::gfx::VRLayer_Stereo_Immersive& aLayer,
                    ID3D11Texture2D* aTexture) override;
-#elif defined(XP_MACOSX)
+#elif defined(XP_MACOSX) || defined(XP_LINUX)
   bool SubmitFrame(const mozilla::gfx::VRLayer_Stereo_Immersive& aLayer,
                    const VRLayerTextureHandle& aTexture) override;
 #endif
diff --git a/gfx/vr/service/VRSession.cpp b/gfx/vr/service/VRSession.cpp
--- a/gfx/vr/service/VRSession.cpp
+++ b/gfx/vr/service/VRSession.cpp
@@ -148,6 +148,13 @@ bool VRSession::SubmitFrame(
     return SubmitFrame(aLayer, aLayer.textureHandle);
   }
 
+#elif defined(XP_LINUX)
+
+  if (aLayer.textureType ==
+      VRLayerTextureType::LayerTextureType_SharedGLTexture) {
+    return SubmitFrame(aLayer, aLayer.textureHandle);
+  }
+
 #endif
 
   return false;
diff --git a/gfx/vr/service/VRSession.h b/gfx/vr/service/VRSession.h
--- a/gfx/vr/service/VRSession.h
+++ b/gfx/vr/service/VRSession.h
@@ -80,7 +80,7 @@ class VRSession {
   ID3D11DeviceContext1* mContext;
   ID3DDeviceContextState* mDeviceContextState;
 
-#elif defined(XP_MACOSX)
+#elif defined(XP_MACOSX) || defined(XP_LINUX)
   virtual bool SubmitFrame(const mozilla::gfx::VRLayer_Stereo_Immersive& aLayer,
                            const VRLayerTextureHandle& aTexture) = 0;
 #endif