Changeset 230630 in webkit

Timestamp:

Apr 13, 2018, 8:19:00 AM (8 years ago)

Author:

svillar@igalia.com

Message:

[WebVR][OpenVR] Implement requestPresent()/exitPresent() and getLayers()
​https://bugs.webkit.org/show_bug.cgi?id=184530

Reviewed by Žan Doberšek.

WebVR apps should invoke requestPresent() to start presenting contents of a VRLayerInit
(right now a HTML canvas with a WebGL context) on the VRDisplay. This request might fail for
a variety of reasons and can be eventually cancelled with exitPresent(). Once we are
presenting we could access the presenting layers (right now just one) with getLayers().

Note that we are not presenting anything to the HMD yet, that will be done later in a follow
up patch.

I took the chance to correct a mistak in the VRDisplayCapabilities object which has a method
that should be called maxLayers instead of maxLayer.

• Modules/webvr/VRDisplay.cpp:

(WebCore::VRDisplay::requestPresent):
(WebCore::VRDisplay::stopPresenting):
(WebCore::VRDisplay::exitPresent):
(WebCore::VRDisplay::getLayers const):
(WebCore::VRDisplay::isPresenting const): Deleted. Implemented in the header file.

• Modules/webvr/VRDisplay.h:

(WebCore::VRDisplay::isPresenting const):

• Modules/webvr/VRDisplayCapabilities.h:

(WebCore::VRDisplayCapabilities::maxLayers const): Renamed from maxLayer().
(WebCore::VRDisplayCapabilities::maxLayer const): Deleted.

• Modules/webvr/VRDisplayCapabilities.idl:

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• Modules/webvr/VRDisplay.cpp (modified) (3 diffs)
• Modules/webvr/VRDisplay.h (modified) (6 diffs)
• Modules/webvr/VRDisplayCapabilities.h (modified) (1 diff)
• Modules/webvr/VRDisplayCapabilities.idl (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2018-04-13  Sergio Villar Senin  <svillar@igalia.com>
+
+        [WebVR][OpenVR] Implement requestPresent()/exitPresent() and getLayers()
+        https://bugs.webkit.org/show_bug.cgi?id=184530
+
+        Reviewed by Žan Doberšek.
+
+        WebVR apps should invoke requestPresent() to start presenting contents of a VRLayerInit
+        (right now a HTML canvas with a WebGL context) on the VRDisplay. This request might fail for
+        a variety of reasons and can be eventually cancelled with exitPresent(). Once we are
+        presenting we could access the presenting layers (right now just one) with getLayers().
+
+        Note that we are not presenting anything to the HMD yet, that will be done later in a follow
+        up patch.
+
+        I took the chance to correct a mistak in the VRDisplayCapabilities object which has a method
+        that should be called maxLayers instead of maxLayer.
+
+        * Modules/webvr/VRDisplay.cpp:
+        (WebCore::VRDisplay::requestPresent):
+        (WebCore::VRDisplay::stopPresenting):
+        (WebCore::VRDisplay::exitPresent):
+        (WebCore::VRDisplay::getLayers const):
+        (WebCore::VRDisplay::isPresenting const): Deleted. Implemented in the header file.
+        * Modules/webvr/VRDisplay.h:
+        (WebCore::VRDisplay::isPresenting const):
+        * Modules/webvr/VRDisplayCapabilities.h:
+        (WebCore::VRDisplayCapabilities::maxLayers const): Renamed from maxLayer().
+        (WebCore::VRDisplayCapabilities::maxLayer const): Deleted.
+        * Modules/webvr/VRDisplayCapabilities.idl:
+
 2018-04-13  Miguel Gomez  <magomez@igalia.com>
 

trunk/Source/WebCore/Modules/webvr/VRDisplay.cpp

@@ -27 +27 @@
 #include "VRDisplay.h"
 
+#include "CanvasRenderingContext.h"
 #include "Chrome.h"
+#include "DOMException.h"
 #include "Page.h"
 #include "ScriptedAnimationController.h"
+#include "UserGestureIndicator.h"
 #include "VRDisplayCapabilities.h"
 #include "VREyeParameters.h"
@@ -67 +70 @@
 
     return m_display->getDisplayInfo().isConnected();
-}
-
-bool VRDisplay::isPresenting() const
-{
-    return false;
 }
 
@@ -133 +131 @@
 }
 
-void VRDisplay::requestPresent(const Vector<VRLayerInit>&, Ref<DeferredPromise>&&)
-{
-}
-
-void VRDisplay::exitPresent(Ref<DeferredPromise>&&)
-{
-}
-
-const Vector<VRLayerInit>& VRDisplay::getLayers() const
-{
-    static auto mockLayers = makeNeverDestroyed(Vector<VRLayerInit> { });
-    return mockLayers;
+void VRDisplay::requestPresent(const Vector<VRLayerInit>& layers, Ref<DeferredPromise>&& promise)
+{
+    auto rejectRequestAndStopPresenting = [this, &promise] (ExceptionCode exceptionCode, ASCIILiteral message) {
+        promise->reject(Exception { exceptionCode, message });
+        if (m_presentingLayer)
+            stopPresenting();
+    };
+
+    if (!m_capabilities->canPresent()) {
+        rejectRequestAndStopPresenting(NotSupportedError, ASCIILiteral("VRDisplay cannot present"));
+        return;
+    }
+
+    if (!layers.size() || layers.size() > m_capabilities->maxLayers()) {
+        rejectRequestAndStopPresenting(InvalidStateError, ASCIILiteral(layers.size() ? "Too many layers" : "Not enough layers"));
+        return;
+    }
+
+    if (!m_presentingLayer && !UserGestureIndicator::processingUserGesture()) {
+        rejectRequestAndStopPresenting(InvalidAccessError, ASCIILiteral("Must request presentation from a user gesture handler."));
+        return;
+    }
+
+    RELEASE_ASSERT(layers.size() == 1);
+    auto layer = layers[0];
+
+    if (!layer.source) {
+        rejectRequestAndStopPresenting(InvalidStateError, ASCIILiteral("Layer does not contain any source"));
+        return;
+    }
+
+    auto* canvasContext = layer.source->getContext("webgl");
+    if (!canvasContext || !canvasContext->isWebGL()) {
+        rejectRequestAndStopPresenting(NotSupportedError, ASCIILiteral("WebVR requires VRLayerInit with WebGL context."));
+        return;
+    }
+
+    if ((layer.leftBounds.size() && layer.leftBounds.size() != 4)
+        || (layer.rightBounds.size() && layer.rightBounds.size() != 4)) {
+        rejectRequestAndStopPresenting(InvalidStateError, ASCIILiteral("Layer bounds must be either 0 or 4"));
+        return;
+    }
+
+    m_presentingLayer = layer;
+    promise->resolve();
+}
+
+void VRDisplay::stopPresenting()
+{
+    m_presentingLayer = std::nullopt;
+}
+
+void VRDisplay::exitPresent(Ref<DeferredPromise>&& promise)
+{
+    if (!m_presentingLayer) {
+        promise->reject(Exception { InvalidStateError, ASCIILiteral("VRDisplay is not presenting") });
+        return;
+    }
+
+    stopPresenting();
+}
+
+Vector<VRLayerInit> VRDisplay::getLayers() const
+{
+    Vector<VRLayerInit> layers;
+    if (m_presentingLayer)
+        layers.append(m_presentingLayer.value());
+    return layers;
 }
 

trunk/Source/WebCore/Modules/webvr/VRDisplay.h

@@ -30 +30 @@
 #include "JSDOMPromiseDeferred.h"
 #include "VREye.h"
+#include "VRLayerInit.h"
 #include <wtf/RefCounted.h>
 
 namespace WebCore {
 
+enum ExceptionCode;
 class RequestAnimationFrameCallback;
 class ScriptedAnimationController;
@@ -42 +44 @@
 class VRPose;
 class VRStageParameters;
-struct VRLayerInit;
 
 class VRDisplay : public RefCounted<VRDisplay>, public EventTargetWithInlineData, public ActiveDOMObject {
@@ -54 +55 @@
 
     bool isConnected() const;
-    bool isPresenting() const;
+    bool isPresenting() const { return !!m_presentingLayer; };
 
     const VRDisplayCapabilities& capabilities() const;
@@ -80 +81 @@
     void exitPresent(Ref<DeferredPromise>&&);
 
-    const Vector<VRLayerInit>& getLayers() const;
+    Vector<VRLayerInit> getLayers() const;
 
     void submitFrame();
@@ -99 +100 @@
     void stop() override;
 
+    void stopPresenting();
+
     WeakPtr<VRPlatformDisplay> m_display;
 
@@ -115 +118 @@
 
     RefPtr<ScriptedAnimationController> m_scriptedAnimationController;
+
+    std::optional<VRLayerInit> m_presentingLayer;
 };
 

trunk/Source/WebCore/Modules/webvr/VRDisplayCapabilities.h

@@ -44 +44 @@
     bool hasExternalDisplay() const { return m_flags & VRDisplayCapabilityFlagExternalDisplay; }
     bool canPresent() const { return m_flags & VRDisplayCapabilityFlagPresent; }
-    unsigned maxLayer() const { return canPresent() ? 1 : 0; }
+    unsigned maxLayers() const { return canPresent() ? 1 : 0; }
 
 private:

trunk/Source/WebCore/Modules/webvr/VRDisplayCapabilities.idl

@@ -32 +32 @@
     readonly attribute boolean hasExternalDisplay;
     readonly attribute boolean canPresent;
-    readonly attribute unsigned long maxLayer;
+    readonly attribute unsigned long maxLayers;
 };