Refactor Vr activity into ChromeTabbedActivity.

chrome/browser/android/vr_shell/ui_elements.cc

+// Copyright 2016 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 "chrome/browser/android/vr_shell/ui_elements.h"
+
+#include <cmath>
+#include <vector>
+
+namespace vr_shell {
+
+namespace {
+
+float GetRayPlaneIntersection(gvr::Vec3f ray_origin,
+                              gvr::Vec3f ray_vector,
+                              gvr::Vec3f plane_origin,
+                              gvr::Vec3f plane_normal) {
+  float denom = vr_shell::VectorDot(ray_vector, plane_normal);
+  if (denom == 0) {
+    // TODO(mthiesse): Line could be contained in the plane, do we care?
+    return -std::numeric_limits<float>::infinity();
+  }
+  gvr::Vec3f rel;
+  rel.x = ray_origin.x - plane_origin.x;
+  rel.y = ray_origin.y - plane_origin.y;
+  rel.z = ray_origin.z - plane_origin.z;
+
+  return -vr_shell::VectorDot(plane_normal, rel) / denom;
+}
+
+}  // namespace
+
+ReversibleTransform::ReversibleTransform() { MakeIdentity(); }
+
+void ReversibleTransform::MakeIdentity() {
+  SetIdentityM(to_world);
+  SetIdentityM(from_world);
+  orientation.qx = orientation.qy = orientation.qz = 0.0f;
+  orientation.qw = 1.0f;
+}
+
+void ReversibleTransform::Rotate(gvr::Quatf quat) {
+  orientation = QuatMultiply(quat, orientation);
+
+  // TODO(klausw): use specialized rotation code? Constructing the matrix
+  // via axis-angle quaternion is inefficient.
+  gvr::Mat4f forward = QuatToMatrix(quat);
+  to_world = MatrixMul(forward, to_world);
+  gvr::Mat4f reverse = MatrixTranspose(forward);
+  from_world = MatrixMul(from_world, reverse);
+}
+
+void ReversibleTransform::Rotate(float ax, float ay, float az, float rad) {
+  // TODO(klausw): use specialized rotation code? Constructing the matrix
+  // via axis-angle quaternion is inefficient.
+  Rotate(QuatFromAxisAngle(ax, ay, az, rad));
+}
+
+void ReversibleTransform::Translate(float tx, float ty, float tz) {
+  TranslateM(to_world, to_world, tx, ty, tz);
+  TranslateMRight(from_world, from_world, -tx, -ty, -tz);
+}
+
+void ReversibleTransform::Scale(float sx, float sy, float sz) {
+  ScaleM(to_world, to_world, sx, sy, sz);
+  ScaleMRight(from_world, from_world, 1.0f / sx, 1.0f / sy, 1.0f / sz);
+}
+
+gvr::Vec3f WorldRectangle::GetCenter() const {
+  const gvr::Vec3f kOrigin = {0.0f, 0.0f, 0.0f};
+  return MatrixVectorMul(transform.to_world, kOrigin);
+}
+
+gvr::Vec3f WorldRectangle::GetNormal() const {
+  const gvr::Vec3f kNormalOrig = {0.0f, 0.0f, -1.0f};
+  return MatrixVectorRotate(transform.to_world, kNormalOrig);
+}
+
+float WorldRectangle::GetRayDistance(gvr::Vec3f ray_origin,
+                                     gvr::Vec3f ray_vector) const {
+  return GetRayPlaneIntersection(ray_origin, ray_vector, GetCenter(),
+                                 GetNormal());
+}
+
+ContentRectangle::ContentRectangle() = default;
+
+ContentRectangle::~ContentRectangle() = default;
+
+}  // namespace vr_shell
+