| // Copyright 2017 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/vr/pose_util.h" |
| |
| #include <cmath> |
| |
| #include "ui/gfx/transform.h" |
| |
| namespace vr { |
| |
| // Provides the direction the head is looking towards as a 3x1 unit vector. |
| gfx::Vector3dF GetForwardVector(const gfx::Transform& head_pose) { |
| // Same as multiplying the inverse of the rotation component of the matrix by |
| // (0, 0, -1, 0). |
| return gfx::Vector3dF(-head_pose.matrix().get(2, 0), |
| -head_pose.matrix().get(2, 1), |
| -head_pose.matrix().get(2, 2)); |
| } |
| |
| gfx::Vector3dF GetUpVector(const gfx::Transform& head_pose) { |
| return gfx::Vector3dF(head_pose.matrix().get(1, 0), |
| head_pose.matrix().get(1, 1), |
| head_pose.matrix().get(1, 2)); |
| } |
| |
| bool HeadMoveExceedsThreshold(const gfx::Transform& old_pose, |
| const gfx::Transform& new_pose, |
| float angular_threshold_degrees) { |
| gfx::Vector3dF old_forward_vector = GetForwardVector(old_pose); |
| gfx::Vector3dF new_forward_vector = GetForwardVector(new_pose); |
| float angle = |
| gfx::AngleBetweenVectorsInDegrees(new_forward_vector, old_forward_vector); |
| |
| if (std::abs(angle) > angular_threshold_degrees) |
| return true; |
| |
| gfx::Vector3dF old_up_vector = GetUpVector(old_pose); |
| gfx::Vector3dF new_up_vector = GetUpVector(new_pose); |
| angle = gfx::AngleBetweenVectorsInDegrees(new_up_vector, old_up_vector); |
| |
| return std::abs(angle) > angular_threshold_degrees; |
| } |
| |
| } // namespace vr |
