//
// MainPage.xaml.h
// Declaration of the MainPage class.
//

#pragma once#include "MainPage.g.h"namespace App2
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public ref class MainPage sealed
{
public:MainPage();void OnNavigatedTo(Windows::UI::Xaml::Navigation::NavigationEventArgs^ e) override;
private:void OnButtonClick(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e);void CreateDevice();Microsoft::WRL::ComPtr<IWICBitmapSource> LoadImageByWIC(const wchar_t* file);Microsoft::WRL::ComPtr<IWICBitmapSource> GetMask(IWICBitmapSource* src);void Draw(ISurfaceImageSourceNative* sisn, const wchar_t* mask);HRESULT PrepareDraw(ISurfaceImageSourceNative* sisn, const RECT& updateRect, IDXGISurface** surface, POINT* offset);Microsoft::WRL::ComPtr<IWICImagingFactory> m_factory;Microsoft::WRL::ComPtr<IDXGIDevice> m_dxgiDevice;Microsoft::WRL::ComPtr<ID2D1DeviceContext> m_d2dDeviceContext;Microsoft::WRL::ComPtr<IWICBitmapSource> m_img;
};
}

//
// MainPage.xaml.cpp
// Implementation of the MainPage class.
//

#include "pch.h"
#include "MainPage.xaml.h"using namespace App2;using namespace Platform;
using namespace Windows::Foundation;
using namespace Windows::Foundation::Collections;
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::Media::Imaging;
using namespace Windows::UI::Xaml::Navigation;using namespace Microsoft::WRL;
using namespace std;#define  HR(exp) hr = exp; assert(SUCCEEDED(hr))// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=402352&clcid=0x409

MainPage::MainPage()
{InitializeComponent();
}void MainPage::OnNavigatedTo(Windows::UI::Xaml::Navigation::NavigationEventArgs^ e)
{for (UIElement^ uiElem : btns->Children){auto btn = safe_cast<Button^>(uiElem);btn->Click += ref new RoutedEventHandler(this, &MainPage::OnButtonClick);}CreateDevice();HRESULT hr;HR(CoCreateInstance(CLSID_WICImagingFactory, nullptr, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&m_factory)));m_img = LoadImageByWIC(L"Assets/img.png");
}void MainPage::CreateDevice()
{static D3D_FEATURE_LEVEL featureLevels[] ={D3D_FEATURE_LEVEL_11_1,D3D_FEATURE_LEVEL_11_0,D3D_FEATURE_LEVEL_10_1,D3D_FEATURE_LEVEL_10_0,D3D_FEATURE_LEVEL_9_3,D3D_FEATURE_LEVEL_9_2,D3D_FEATURE_LEVEL_9_1};HRESULT hr;ComPtr<ID3D11Device> d3dDevice;ComPtr<ID2D1Device> d2dDevice;HR(D3D11CreateDevice(nullptr,D3D_DRIVER_TYPE_HARDWARE,0,D3D11_CREATE_DEVICE_BGRA_SUPPORT,featureLevels,extent<decltype(featureLevels)>::value,D3D11_SDK_VERSION,&d3dDevice,nullptr,nullptr));HR(d3dDevice.As(&m_dxgiDevice));HR(D2D1CreateDevice(m_dxgiDevice.Get(), nullptr, &d2dDevice));HR(d2dDevice->CreateDeviceContext(D2D1_DEVICE_CONTEXT_OPTIONS_NONE, &m_d2dDeviceContext));
}ComPtr<IWICBitmapSource> MainPage::LoadImageByWIC(const wchar_t* file)
{    ComPtr<IWICBitmapDecoder> decoder;ComPtr<IWICBitmapFrameDecode> frame;ComPtr<IWICFormatConverter> converter;HRESULT hr;HR(m_factory->CreateDecoderFromFilename(file, nullptr, GENERIC_READ, WICDecodeMetadataCacheOnDemand, &decoder));HR(decoder->GetFrame(0, &frame));HR(m_factory->CreateFormatConverter(&converter));HR(converter->Initialize(frame.Get(),GUID_WICPixelFormat32bppPBGRA, // Pre-multipled BGRA
        WICBitmapDitherTypeNone,nullptr,0,WICBitmapPaletteTypeCustom));return converter;
}ComPtr<IWICBitmapSource> MainPage::GetMask(IWICBitmapSource* src)
{uint32_t width, height;src->GetSize(&width, &height);size_t len = width * 4 * height;unique_ptr<byte[]> pixels(new byte[len]);src->CopyPixels(nullptr, width * 4, len, pixels.get());for (size_t i = 0; i < width * height; i++){// BGRA. The average of RGB channels is used as Alpha channel.pixels[i * 4 + 3] = (pixels[i * 4] + pixels[i * 4 + 1] + pixels[i * 4 + 2]) / 3;}ComPtr<IWICBitmap> bmp;m_factory->CreateBitmapFromMemory(width, height, GUID_WICPixelFormat32bppPBGRA, width * 4, len, pixels.get(), &bmp);return bmp;
}void MainPage::OnButtonClick(Object^ sender, RoutedEventArgs^ e)
{HRESULT hr;auto btn = safe_cast<Button^>(sender);auto maskPath = btn->Tag->ToString();SurfaceImageSource^ sis = ref new SurfaceImageSource(400, 400);ComPtr<ISurfaceImageSourceNative> sisn;HR(reinterpret_cast<IInspectable*>(sis)->QueryInterface(IID_PPV_ARGS(&sisn)));HR(sisn->SetDevice(m_dxgiDevice.Get())); // set device as DXGI device.// Note thisauto brush = ref new ImageBrush();brush->ImageSource = sis;canvas->Fill = brush;Draw(sisn.Get(), maskPath->Data());
}void MainPage::Draw(ISurfaceImageSourceNative* sisn, const wchar_t* mask)
{HRESULT hr;ComPtr<IDXGISurface> surface;RECT rect = { 0, 0, 400, 400 };POINT renderTargetOffset; // view port offset in surface.HR(PrepareDraw(sisn, rect, &surface, &renderTargetOffset));ComPtr<IWICBitmapSource> maskSrc = GetMask(LoadImageByWIC(mask).Get());ComPtr<ID2D1Bitmap> maskBmp;ComPtr<ID2D1Bitmap> imgBmp;ComPtr<ID2D1BitmapBrush> imgBrush;ComPtr<ID2D1Bitmap1> tgrBmp; // Note ID2D1Bitmap1HR(m_d2dDeviceContext->CreateBitmapFromWicBitmap(maskSrc.Get(), &maskBmp));HR(m_d2dDeviceContext->CreateBitmapFromWicBitmap(m_img.Get(), &imgBmp));HR(m_d2dDeviceContext->CreateBitmapBrush(imgBmp.Get(), &imgBrush));HR(m_d2dDeviceContext->CreateBitmapFromDxgiSurface(surface.Get(), nullptr, &tgrBmp));m_d2dDeviceContext->SetTarget(tgrBmp.Get());m_d2dDeviceContext->BeginDraw();m_d2dDeviceContext->SetTransform(D2D1::Matrix3x2F::Translation(renderTargetOffset.x, renderTargetOffset.y));m_d2dDeviceContext->Clear({0, 0, 1, 1}); // Clear with blue color.
    m_d2dDeviceContext->SetAntialiasMode(D2D1_ANTIALIAS_MODE_ALIASED); // Must set antialias mode.m_d2dDeviceContext->FillOpacityMask(maskBmp.Get(), imgBrush.Get());HR(m_d2dDeviceContext->EndDraw());m_d2dDeviceContext->SetTarget(nullptr);HR(sisn->EndDraw());
}HRESULT MainPage::PrepareDraw(ISurfaceImageSourceNative* sisn, const RECT& updateRect, IDXGISurface** surface, POINT* offset)
{HRESULT hr;hr = sisn->BeginDraw(updateRect, surface, offset);if ((hr == DXGI_ERROR_DEVICE_REMOVED) || (hr == DXGI_ERROR_DEVICE_RESET)){CreateDevice();// Device changed, try again.return PrepareDraw(sisn, updateRect, surface, offset);}else{return hr;}
}