com_osvr_example_EyeTracker.cpp

// Copyright 2015 Sensics Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Internal Includes
#include <osvr/PluginKit/PluginKit.h>
#include <osvr/PluginKit/EyeTrackerInterfaceC.h>

// Generated JSON header file
#include "com_osvr_example_EyeTracker_json.h"

// Library/third-party includes

// Standard includes
#include <iostream>
#include <memory>
#include <ctime>
#include <cmath>
#include <chrono>
#include <thread>

// Anonymous namespace to avoid symbol collision
namespace {

OSVR_MessageType eyeTrackerMessage;

class EyeTrackerDevice {
  public:
    EyeTrackerDevice(OSVR_PluginRegContext ctx) : m_Blink(false) {
        OSVR_DeviceInitOptions opts = osvrDeviceCreateInitOptions(ctx);

        osvrDeviceEyeTrackerConfigure(opts, &m_eyetracker, 2);

        m_dev.initAsync(ctx, "EyeTracker", opts);

        m_dev.sendJsonDescriptor(com_osvr_example_EyeTracker_json);

        m_dev.registerUpdateCallback(this);

        std::srand(std::time(0));
    }

    OSVR_ReturnCode update() {

        std::this_thread::sleep_for(std::chrono::milliseconds(
            250)); // Simulate waiting a quarter second for data.

        OSVR_TimeValue times;

        osvrTimeValueGetNow(&times);
        int randVal = std::rand();

        // Left eye Data
        OSVR_Vec2 gaze2D;
        gaze2D.data[0] = std::abs(std::sin(randVal));
        gaze2D.data[1] = std::abs(std::cos(randVal));

        OSVR_Vec3 gaze3D;
        gaze3D.data[0] = std::abs(std::sin(randVal) / (std::cos(randVal)));
        gaze3D.data[1] = std::abs(std::cos(randVal) / (std::sin(randVal)));
        gaze3D.data[2] = std::abs(std::sin(randVal) * std::sin(randVal));

        OSVR_EyeTracker2DState location;
        location = gaze2D;

        OSVR_EyeTracker3DState dir;
        dir.direction = gaze3D;
        dir.basePoint = gaze3D;

        osvrDeviceEyeTrackerReportGaze(m_eyetracker, location, dir.direction,
                                       dir.basePoint, 0, &times);
        m_Blink = !m_Blink;
        osvrDeviceEyeTrackerReportBlink(m_eyetracker, m_Blink, 0, &times);

        return OSVR_RETURN_SUCCESS;
    }

  private:
    bool m_Blink;
    osvr::pluginkit::DeviceToken m_dev;
    OSVR_EyeTrackerDeviceInterface m_eyetracker;
};

class HardwareDetection {
  public:
    HardwareDetection() : m_found(false) {}
    OSVR_ReturnCode operator()(OSVR_PluginRegContext ctx) {

        if (m_found) {
            return OSVR_RETURN_SUCCESS;
        }

        std::cout << "PLUGIN: Got a hardware detection request" << std::endl;

        // we always detect an eye tracker in sample plugin
        m_found = true;

        std::cout << "PLUGIN: We have detected Eye Tracker device! "
                  << std::endl;
        osvr::pluginkit::registerObjectForDeletion(ctx,
                                                   new EyeTrackerDevice(ctx));

        return OSVR_RETURN_SUCCESS;
    }

  private:
    bool m_found;
};
} // namespace

OSVR_PLUGIN(com_osvr_example_EyeTracker) {

    osvr::pluginkit::PluginContext context(ctx);

    context.registerHardwareDetectCallback(new HardwareDetection());

    return OSVR_RETURN_SUCCESS;
}