1 files changed, 269 insertions, 0 deletions
diff --git a/dom/canvas/XRWebGLLayer.cpp b/dom/canvas/XRWebGLLayer.cpp
new file mode 100644
index 0000000000..95d7a2cd96
--- /dev/null
+++ b/dom/canvas/XRWebGLLayer.cpp
@@ -0,0 +1,269 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/XRWebGLLayer.h"
+#include "mozilla/dom/XRSession.h"
+#include "mozilla/dom/XRView.h"
+#include "mozilla/dom/XRViewport.h"
+#include "mozilla/dom/WebGLRenderingContextBinding.h"
+#include "WebGLFramebuffer.h"
+#include "mozilla/StaticPrefs_dom.h"
+#include "mozilla/StaticPrefs_webgl.h"
+#include "GLContext.h"
+#include "ScopedGLHelpers.h"
+#include "MozFramebuffer.h"
+#include "VRDisplayClient.h"
+#include "ClientWebGLContext.h"
+#include "nsContentUtils.h"
+#include "nsIScriptError.h"
+
+using namespace mozilla::gl;
+
+namespace mozilla::dom {
+
+static constexpr float XR_FRAMEBUFFER_MIN_SCALE = 0.2f;
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(XRWebGLLayer, mParent, mSession, mWebGL,
+                                      mFramebuffer, mLeftViewport,
+                                      mRightViewport)
+
+XRWebGLLayer::XRWebGLLayer(
+    nsISupports* aParent, XRSession& aSession, bool aIgnoreDepthValues,
+    double aFramebufferScaleFactor,
+    RefPtr<mozilla::ClientWebGLContext> aWebGLContext,
+    RefPtr<WebGLFramebufferJS> aFramebuffer,
+    const Maybe<const webgl::OpaqueFramebufferOptions>& aOptions)
+    : mParent(aParent),
+      mSession(&aSession),
+      mWebGL(std::move(aWebGLContext)),
+      mFramebufferScaleFactor(aFramebufferScaleFactor),
+      mCompositionDisabled(!aSession.IsImmersive()),
+      mIgnoreDepthValues(aIgnoreDepthValues),
+      mFramebuffer(std::move(aFramebuffer)),
+      mFramebufferOptions(aOptions) {}
+
+XRWebGLLayer::~XRWebGLLayer() { DeleteFramebuffer(); }
+
+void XRWebGLLayer::DeleteFramebuffer() {
+  if (mFramebuffer) {
+    mWebGL->DeleteFramebuffer(mFramebuffer.get(), true);
+    mFramebuffer = nullptr;
+  }
+}
+
+/* static */
+already_AddRefed<XRWebGLLayer> XRWebGLLayer::Constructor(
+    const GlobalObject& aGlobal, XRSession& aSession,
+    const WebGLRenderingContextOrWebGL2RenderingContext& aXRWebGLContext,
+    const XRWebGLLayerInit& aXRWebGLLayerInitDict, ErrorResult& aRv) {
+  // https://immersive-web.github.io/webxr/#dom-xrwebgllayer-xrwebgllayer
+
+  // Depth not supported in XR Compositor yet.
+  const bool ignoreDepthValues = true;
+
+  // If session’s ended value is true, throw an InvalidStateError and abort
+  // these steps.
+  if (aSession.IsEnded()) {
+    aRv.ThrowInvalidStateError(
+        "Can not create an XRWebGLLayer with an XRSession that has ended.");
+    return nullptr;
+  }
+  gfx::VRDisplayClient* display = aSession.GetDisplayClient();
+  const gfx::VRDisplayInfo& displayInfo = display->GetDisplayInfo();
+  const gfx::VRDisplayState& displayState = displayInfo.mDisplayState;
+
+  RefPtr<ClientWebGLContext> gl;
+  if (aXRWebGLContext.IsWebGLRenderingContext()) {
+    gl = &aXRWebGLContext.GetAsWebGLRenderingContext();
+  } else {
+    gl = &aXRWebGLContext.GetAsWebGL2RenderingContext();
+  }
+
+  // If context is lost, throw an InvalidStateError and abort these steps.
+  if (gl->IsContextLost()) {
+    aRv.ThrowInvalidStateError(
+        "Could not create an XRWebGLLayer, as the WebGL context was lost.");
+    return nullptr;
+  }
+
+  RefPtr<mozilla::WebGLFramebufferJS> framebuffer;
+  Maybe<const webgl::OpaqueFramebufferOptions> framebufferOptions;
+  if (aSession.IsImmersive()) {
+    // If session is an immersive session and context’s XR compatible boolean
+    // is false, throw an InvalidStateError and abort these steps.
+    if (!gl->IsXRCompatible()) {
+      aRv.ThrowInvalidStateError(
+          "Can not create an XRWebGLLayer without first calling "
+          "makeXRCompatible "
+          "on the WebGLRenderingContext or WebGL2RenderingContext.");
+      return nullptr;
+    }
+
+    const auto document = gl->GetCanvas()->OwnerDoc();
+    if (aXRWebGLLayerInitDict.mAlpha) {
+      nsContentUtils::ReportToConsoleNonLocalized(
+          u"XRWebGLLayer doesn't support no alpha value. "
+          "Alpha will be enabled."_ns,
+          nsIScriptError::warningFlag, "DOM"_ns, document);
+    }
+    if (aXRWebGLLayerInitDict.mDepth != aXRWebGLLayerInitDict.mStencil) {
+      nsContentUtils::ReportToConsoleNonLocalized(
+          nsLiteralString(
+              u"XRWebGLLayer doesn't support separate "
+              "depth or stencil buffers. They will be enabled together."),
+          nsIScriptError::warningFlag, "DOM"_ns, document);
+    }
+
+    bool antialias = aXRWebGLLayerInitDict.mAntialias;
+    if (antialias && !StaticPrefs::webgl_msaa_force()) {
+      antialias = false;
+      nsContentUtils::ReportToConsoleNonLocalized(
+          u"XRWebGLLayer antialiasing is not supported."
+          "Antialiasing will be disabled."_ns,
+          nsIScriptError::warningFlag, "DOM"_ns, document);
+    }
+
+    webgl::OpaqueFramebufferOptions options;
+    options.antialias = antialias;
+    options.depthStencil =
+        aXRWebGLLayerInitDict.mDepth || aXRWebGLLayerInitDict.mStencil;
+
+    // Clamp the requested framebuffer size to ensure it's not too
+    // small to see or larger than the max native resolution.
+    const float maxScale =
+        std::max(displayState.nativeFramebufferScaleFactor, 1.0f);
+    const float scaleFactor =
+        std::max(XR_FRAMEBUFFER_MIN_SCALE,
+                 std::min((float)aXRWebGLLayerInitDict.mFramebufferScaleFactor,
+                          maxScale));
+
+    options.width =
+        (int32_t)ceilf(2.0f * displayState.eyeResolution.width * scaleFactor);
+    options.height =
+        (int32_t)ceilf(displayState.eyeResolution.height * scaleFactor);
+    framebuffer = gl->CreateOpaqueFramebuffer(options);
+
+    if (!framebuffer) {
+      aRv.ThrowOperationError(
+          "Could not create an XRWebGLLayer. XRFramebuffer creation failed.");
+      return nullptr;
+    }
+    framebufferOptions.emplace(options);
+  }
+
+  RefPtr<XRWebGLLayer> obj =
+      new XRWebGLLayer(aGlobal.GetAsSupports(), aSession, ignoreDepthValues,
+                       aXRWebGLLayerInitDict.mFramebufferScaleFactor, gl,
+                       framebuffer, framebufferOptions);
+  return obj.forget();
+}
+
+JSObject* XRWebGLLayer::WrapObject(JSContext* aCx,
+                                   JS::Handle<JSObject*> aGivenProto) {
+  return XRWebGLLayer_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+nsISupports* XRWebGLLayer::GetParentObject() const { return mParent; }
+
+bool XRWebGLLayer::Antialias() {
+  if (mFramebufferOptions) {
+    return mFramebufferOptions->antialias;
+  }
+  return mWebGL->ActualContextParameters().antialias;
+}
+
+bool XRWebGLLayer::Depth() {
+  if (mFramebufferOptions) {
+    return mFramebufferOptions->depthStencil;
+  }
+  return mWebGL->ActualContextParameters().depth;
+}
+
+bool XRWebGLLayer::Stencil() {
+  if (mFramebufferOptions) {
+    return mFramebufferOptions->depthStencil;
+  }
+  return mWebGL->ActualContextParameters().stencil;
+}
+
+bool XRWebGLLayer::Alpha() {
+  if (mFramebufferOptions) {
+    // Alpha is always true when using Opaque Framebuffers.
+    return true;
+  }
+  return mWebGL->ActualContextParameters().alpha;
+}
+
+bool XRWebGLLayer::IgnoreDepthValues() { return mIgnoreDepthValues; }
+
+WebGLFramebufferJS* XRWebGLLayer::GetFramebuffer() {
+  return mFramebuffer.get();
+}
+
+uint32_t XRWebGLLayer::FramebufferWidth() {
+  if (mFramebufferOptions) {
+    return mFramebufferOptions->width;
+  }
+  return mWebGL->GetWidth();
+}
+
+uint32_t XRWebGLLayer::FramebufferHeight() {
+  if (mFramebufferOptions) {
+    return mFramebufferOptions->height;
+  }
+  return mWebGL->GetHeight();
+}
+
+already_AddRefed<XRViewport> XRWebGLLayer::GetViewport(const XRView& aView) {
+  const int32_t width = (aView.Eye() == XREye::None) ? FramebufferWidth()
+                                                     : (FramebufferWidth() / 2);
+  gfx::IntRect rect(0, 0, width, FramebufferHeight());
+  if (aView.Eye() == XREye::Right) {
+    rect.x = width;
+  }
+  RefPtr<XRViewport>& viewport =
+      aView.Eye() == XREye::Right ? mRightViewport : mLeftViewport;
+  if (!viewport) {
+    viewport = new XRViewport(mParent, rect);
+  } else {
+    viewport->mRect = rect;
+  }
+  RefPtr<XRViewport> result = viewport;
+  return result.forget();
+}
+
+// https://www.w3.org/TR/webxr/#dom-xrwebgllayer-getnativeframebufferscalefactor
+/* static */ double XRWebGLLayer::GetNativeFramebufferScaleFactor(
+    const GlobalObject& aGlobal, const XRSession& aSession) {
+  if (aSession.IsEnded()) {
+    return 0.0f;
+  }
+  if (!aSession.IsImmersive()) {
+    return 1.0f;
+  }
+
+  const gfx::VRDisplayInfo& displayInfo =
+      aSession.GetDisplayClient()->GetDisplayInfo();
+  return displayInfo.mDisplayState.nativeFramebufferScaleFactor;
+}
+
+void XRWebGLLayer::StartAnimationFrame() {
+  if (mFramebuffer) {
+    mWebGL->SetFramebufferIsInOpaqueRAF(mFramebuffer.get(), true);
+  }
+}
+
+void XRWebGLLayer::EndAnimationFrame() {
+  if (mFramebuffer) {
+    mWebGL->SetFramebufferIsInOpaqueRAF(mFramebuffer.get(), false);
+  }
+}
+
+HTMLCanvasElement* XRWebGLLayer::GetCanvas() { return mWebGL->GetCanvas(); }
+
+void XRWebGLLayer::SessionEnded() { DeleteFramebuffer(); }
+
+}  // namespace mozilla::dom