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#include "qwindowsdirect2dcontext.h"
#include "qwindowsdirect2dwindow.h"
#include "qwindowsdirect2ddevicecontext.h"
#include "qwindowsdirect2dhelpers.h"

#include <d3d11.h>
#include <d2d1_1.h>
using Microsoft::WRL::ComPtr;

QT_BEGIN_NAMESPACE

QWindowsDirect2DWindow::QWindowsDirect2DWindow(QWindow *window, const QWindowsWindowData &data)
    : QWindowsWindow(window, data)
    , m_needsFullFlush(true)
{
    if (window->type() == Qt::Desktop)
        return; // No further handling for Qt::Desktop

    DXGI_SWAP_CHAIN_DESC1 desc = {};

    desc.Format = DXGI_FORMAT_B8G8R8A8_UNORM;
    desc.SampleDesc.Count = 1;
    desc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
    desc.BufferCount = 1;
    desc.SwapEffect = DXGI_SWAP_EFFECT_SEQUENTIAL;

    HRESULT hr = QWindowsDirect2DContext::instance()->dxgiFactory()->CreateSwapChainForHwnd(
                QWindowsDirect2DContext::instance()->d3dDevice(), // [in]   IUnknown *pDevice
                handle(),                                         // [in]   HWND hWnd
                &desc,                                            // [in]   const DXGI_SWAP_CHAIN_DESC1 *pDesc
                NULL,                                             // [in]   const DXGI_SWAP_CHAIN_FULLSCREEN_DESC *pFullscreenDesc
                NULL,                                             // [in]   IDXGIOutput *pRestrictToOutput
                m_swapChain.ReleaseAndGetAddressOf());            // [out]  IDXGISwapChain1 **ppSwapChain

    if (FAILED(hr))
        qWarning("%s: Could not create swap chain: %#x", __FUNCTION__, hr);

    hr = QWindowsDirect2DContext::instance()->d2dDevice()->CreateDeviceContext(
                D2D1_DEVICE_CONTEXT_OPTIONS_NONE,
                m_deviceContext.GetAddressOf());
    if (FAILED(hr))
        qWarning("%s: Couldn't create Direct2D Device context: %#x", __FUNCTION__, hr);
}

QWindowsDirect2DWindow::~QWindowsDirect2DWindow()
{
}

void QWindowsDirect2DWindow::flush(QWindowsDirect2DBitmap *bitmap, const QRegion &region, const QPoint &offset)
{
    DXGI_SWAP_CHAIN_DESC1 desc;
    HRESULT hr = m_swapChain->GetDesc1(&desc);
    QRect geom = geometry();

    if (FAILED(hr) || (desc.Width != geom.width()) || (desc.Height != geom.height())) {
        resizeSwapChain(geom.size());
        m_swapChain->GetDesc1(&desc);
    }

    setupBitmap();
    if (!m_bitmap)
        return;

    m_bitmap->deviceContext()->begin();

    ID2D1DeviceContext *dc = m_bitmap->deviceContext()->get();
    if (!m_needsFullFlush) {
        QRegion clipped = region;
        clipped &= QRect(0, 0, desc.Width, desc.Height);

        foreach (const QRect &rect, clipped.rects()) {
            QRectF rectF(rect);
            dc->DrawBitmap(bitmap->bitmap(),
                           to_d2d_rect_f(rectF),
                           1.0,
                           D2D1_INTERPOLATION_MODE_LINEAR,
                           to_d2d_rect_f(rectF.translated(offset.x(), offset.y())));
        }
    } else {
        QRectF rectF(0, 0, desc.Width, desc.Height);
        dc->DrawBitmap(bitmap->bitmap(),
                       to_d2d_rect_f(rectF),
                       1.0,
                       D2D1_INTERPOLATION_MODE_LINEAR,
                       to_d2d_rect_f(rectF.translated(offset.x(), offset.y())));
        m_needsFullFlush = false;
    }

    m_bitmap->deviceContext()->end();
    m_swapChain->Present(0, 0);
}

void QWindowsDirect2DWindow::resizeSwapChain(const QSize &size)
{
    if (!m_swapChain)
        return;

    m_bitmap.reset();
    m_deviceContext->SetTarget(Q_NULLPTR);

    HRESULT hr = m_swapChain->ResizeBuffers(0,
                                            size.width(), size.height(),
                                            DXGI_FORMAT_UNKNOWN,
                                            0);
    if (FAILED(hr))
        qWarning("%s: Could not resize swap chain: %#x", __FUNCTION__, hr);

    m_needsFullFlush = true;
}

void QWindowsDirect2DWindow::setupBitmap()
{
    if (m_bitmap)
        return;

    if (!m_deviceContext)
        return;

    if (!m_swapChain)
        return;

    ComPtr<IDXGISurface1> backBufferSurface;
    HRESULT hr = m_swapChain->GetBuffer(0, IID_PPV_ARGS(&backBufferSurface));
    if (FAILED(hr)) {
        qWarning("%s: Could not query backbuffer for DXGI Surface: %#x", __FUNCTION__, hr);
        return;
    }

    ComPtr<ID2D1Bitmap1> backBufferBitmap;
    hr = m_deviceContext->CreateBitmapFromDxgiSurface(backBufferSurface.Get(), NULL, backBufferBitmap.GetAddressOf());
    if (FAILED(hr)) {
        qWarning("%s: Could not create Direct2D Bitmap from DXGI Surface: %#x", __FUNCTION__, hr);
        return;
    }

    m_bitmap.reset(new QWindowsDirect2DBitmap(backBufferBitmap.Get(), m_deviceContext.Get()));
}

QT_END_NAMESPACE