/*
    Copyright (c) 2005-2019 Intel Corporation

    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.




*/


#include "pch.h"
#include "DirectXPage.xaml.h"
#include "tbb/tbb.h"

using namespace tbbTachyon;

using namespace Platform;
using namespace Windows::Foundation;
using namespace Windows::Foundation::Collections;
using namespace Windows::UI::Input;
using namespace Windows::UI::Core;
using namespace Windows::UI::Xaml;
using namespace Windows::UI::Xaml::Controls;
using namespace Windows::UI::Xaml::Controls::Primitives;
using namespace Windows::UI::Xaml::Data;
using namespace Windows::UI::Xaml::Input;
using namespace Windows::UI::Xaml::Media;
using namespace Windows::UI::Xaml::Navigation;
using namespace Windows::Graphics::Display;

#include "src/tachyon_video.h"
extern int volatile global_number_of_threads;
extern volatile bool global_isCancelled;

#pragma intrinsic(_BitScanReverse)
static int log2( unsigned int x ) {
    DWORD i;
    _BitScanReverse(&i,(DWORD)x);
    return (int)i;
}

const unsigned interval_step_power = 1;
const unsigned num_interval_steps = 1 << (interval_step_power+1);

DirectXPage::DirectXPage() :
    m_renderNeeded(true)
{
    InitializeComponent();

    m_renderer = ref new tbbTachyonRenderer();

    m_renderer->Initialize(
        Window::Current->CoreWindow,
        this,
        DisplayProperties::LogicalDpi
        );

    m_eventToken = CompositionTarget::Rendering::add(ref new EventHandler<Object^>(this, &DirectXPage::OnRendering));

    int num_threads = 2*tbb::task_scheduler_init::default_num_threads();
    // The thread slider has geometric sequence with several intermidiate steps for each interval between 2^N and 2^(N+1).
    // The nearest (from below) the power of 2.
    int i_base = log2(num_threads);
    int base = 1 << i_base;
    // The step size for the current interval.
    int step = base / num_interval_steps;
    // The number of steps inside the interval.
    int i_step = (num_threads-base)/step;

    ThreadsSlider->Maximum = (i_base-interval_step_power)*num_interval_steps + i_step;
    global_number_of_threads = m_number_of_threads = tbb::task_scheduler_init::automatic;
}

DirectXPage::~DirectXPage()
{
}

void DirectXPage::OnRendering(Platform::Object^ sender, Platform::Object^ args)
{
    if (m_renderNeeded){
        m_renderer->Render();
        m_renderer->Present();
        m_renderNeeded = true;
    }
}

void tbbTachyon::DirectXPage::ThreadsApply_Click(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
    if (global_number_of_threads != m_number_of_threads){
        global_number_of_threads = m_number_of_threads;
        global_isCancelled = true;
        video->running = false;
        m_renderNeeded = true;
        ThreadsApply->Visibility=Windows::UI::Xaml::Visibility::Collapsed;
    }
}

void tbbTachyon::DirectXPage::Exit_Click(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
    m_renderNeeded = false;
    Application::Current->Exit();
}

void tbbTachyon::DirectXPage::ThreadsSliderValueChanged(Platform::Object^ sender, Windows::UI::Xaml::Controls::Primitives::RangeBaseValueChangedEventArgs^ e)
{
    int pos = (int) e->NewValue;

    // The nearest (from below) the power of 2.
    int base = pos<num_interval_steps ? 0 : 1 << (pos/num_interval_steps+interval_step_power);
    // The step size for the current interval.
    int step = max(1,base/num_interval_steps);
    m_number_of_threads = base + (pos%num_interval_steps)*step;

    if (m_number_of_threads == 0) m_number_of_threads = tbb::task_scheduler_init::automatic;

    NumberOfThreadsTextBlock->Text="Number Of Threads: " + (m_number_of_threads == tbb::task_scheduler_init::automatic? "Auto": m_number_of_threads.ToString());
    if (global_number_of_threads != m_number_of_threads){
        ThreadsApply->Visibility=Windows::UI::Xaml::Visibility::Visible;
    }else{
        ThreadsApply->Visibility=Windows::UI::Xaml::Visibility::Collapsed;
    }
}
