Adding WebVR interface to Blink

Source/modules/vr/HMDVRDevice.cpp

Index: Source/modules/vr/HMDVRDevice.cpp
diff --git a/Source/modules/vr/HMDVRDevice.cpp b/Source/modules/vr/HMDVRDevice.cpp
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index 0000000000000000000000000000000000000000..1f065cecec91bc4b7aa6372f05fb5960782801bf
--- /dev/null
+++ b/Source/modules/vr/HMDVRDevice.cpp
@@ -0,0 +1,143 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "modules/vr/HMDVRDevice.h"
+
+#include "modules/vr/VRFieldOfView.h"
+#include "public/platform/Platform.h"
+#include "public/platform/WebSize.h"
+
+namespace blink {
+
+namespace {
+
+void setDomPoint(DOMPoint* point, const blink::WebVRVector3& vec)
+{
+    point->setX(vec.x);
+    point->setY(vec.y);
+    point->setZ(vec.z);
+    point->setW(0.0);
+}
+
+}
+
+HMDVRDevice::HMDVRDevice(VRHardwareUnit* hardwareUnit)
+    : VRDevice(hardwareUnit)
+{
+    m_recommendedFOVLeft = new VRFieldOfView();
+    m_recommendedFOVRight = new VRFieldOfView();
+    m_maximumFOVLeft = new VRFieldOfView();
+    m_maximumFOVRight = new VRFieldOfView();
+    m_eyeTranslationLeft = DOMPoint::create(0, 0, 0, 0);
+    m_eyeTranslationRight = DOMPoint::create(0, 0, 0, 0);
+}
+
+HMDVRDevice::VREye HMDVRDevice::StringToVREye(const String& whichEye)
+{
+    if (whichEye == "right") {
+        return VREyeRight;
+    }
+    return VREyeLeft;

[Ken Russell (switch to Gerrit), 2015/02/04 19:14:00]

This should explicitly check for "left" and return an error if the input string
doesn't match either.

+}
+
+void HMDVRDevice::updateFromWebVRDevice(const WebVRDevice& device)
+{
+    VRDevice::updateFromWebVRDevice(device);
+    const blink::WebVRHMDInfo &hmdInfo = device.hmdInfo;
+
+    m_recommendedFOVLeft->setFromWebVRFieldOfView(hmdInfo.recommendedFOVLeft);
+    m_recommendedFOVRight->setFromWebVRFieldOfView(hmdInfo.recommendedFOVRight);
+    m_maximumFOVLeft->setFromWebVRFieldOfView(hmdInfo.maximumFOVLeft);
+    m_maximumFOVRight->setFromWebVRFieldOfView(hmdInfo.maximumFOVRight);
+    setDomPoint(m_eyeTranslationLeft, hmdInfo.eyeTranslationLeft);
+    setDomPoint(m_eyeTranslationRight, hmdInfo.eyeTranslationRight);
+    hardwareUnit()->setFieldOfView(0, m_recommendedFOVLeft);
+    hardwareUnit()->setFieldOfView(1, m_recommendedFOVRight);
+}
+
+DOMPoint* HMDVRDevice::getEyeTranslation(const String& whichEye)
+{
+    switch (StringToVREye(whichEye)) {
+    case VREyeRight:
+        return m_eyeTranslationRight;
+    default:
+        return m_eyeTranslationLeft;

[Ken Russell (switch to Gerrit), 2015/02/04 19:13:59]

Throughout, all of the code returning the value for the left eye by default
should explicitly check for "left" and throw a JavaScript exception if the input
string is invalid. The spec should be updated to define this behavior for all
entry points.

+    }
+}
+
+VRFieldOfView* HMDVRDevice::getCurrentEyeFieldOfView(const String& whichEye)
+{
+    return hardwareUnit()->getCurrentEyeFieldOfView(StringToVREye(whichEye));
+}
+
+VRFieldOfView* HMDVRDevice::getRecommendedEyeFieldOfView(const String& whichEye)
+{
+    switch (StringToVREye(whichEye)) {
+    case VREyeRight:
+        return new VRFieldOfView(*m_recommendedFOVRight);
+    default:
+        return new VRFieldOfView(*m_recommendedFOVLeft);
+    }
+}
+
+VRFieldOfView* HMDVRDevice::getMaximumEyeFieldOfView(const String& whichEye)
+{
+    switch (StringToVREye(whichEye)) {
+    case VREyeRight:
+        return new VRFieldOfView(*m_maximumFOVRight);
+    default:
+        return new VRFieldOfView(*m_maximumFOVLeft);
+    }
+}
+
+void HMDVRDevice::setFieldOfView(VRFieldOfView* leftFov, VRFieldOfView* rightFov)
+{
+    // TODO: Clamp to maxFOV
+
+    if (leftFov) {
+        hardwareUnit()->setFieldOfView(0, leftFov);
+    } else {
+        hardwareUnit()->setFieldOfView(0, m_recommendedFOVLeft);
+    }
+
+    if (rightFov) {
+        hardwareUnit()->setFieldOfView(1, rightFov);
+    } else {
+        hardwareUnit()->setFieldOfView(1, m_recommendedFOVRight);
+    }
+}
+
+DOMRect* HMDVRDevice::getRecommendedEyeRenderRect(const String& whichEye)
+{
+    // TODO: This doesn't change unless you reset the FOV. Cache it.

[Ken Russell (switch to Gerrit), 2015/02/04 19:14:00]

Add owner for TODOs throughout.

+    blink::WebSize size;
+    blink::Platform::current()->getVRRenderTargetSize(index(),
+        hardwareUnit()->getFieldOfView(HMDVRDevice::VREyeLeft),
+        hardwareUnit()->getFieldOfView(HMDVRDevice::VREyeRight),
+        &size);
+
+    // TODO: We can actually fetch individual eye rects from the Oculus SDK.
+    // Plumb that through and expose it here.
+    switch (StringToVREye(whichEye)) {
+    case VREyeRight:
+        return DOMRect::create(size.width / 2.0f, 0, size.width / 2.0f, size.height);
+    default:
+        return DOMRect::create(0, 0, size.width / 2.0f, size.height);
+    }
+}
+
+void HMDVRDevice::trace(Visitor* visitor)
+{
+    VRDevice::trace(visitor);
+
+    visitor->trace(m_recommendedFOVLeft);
+    visitor->trace(m_recommendedFOVRight);
+    visitor->trace(m_maximumFOVLeft);
+    visitor->trace(m_maximumFOVRight);
+    visitor->trace(m_eyeTranslationLeft);
+    visitor->trace(m_eyeTranslationRight);
+}
+
+} // namespace blink