// Begins drawing, allowing updates to content in the specified area.
void Scenario1ImageSource::BeginDraw(Windows::Foundation::Rect updateRect)
{
POINT offset;
ComPtr<IDXGISurface> surface;
// Express target area as a native RECT type.
RECT updateRectNative;
updateRectNative.left = static_cast<LONG>(updateRect.Left);
updateRectNative.top = static_cast<LONG>(updateRect.Top);
updateRectNative.right = static_cast<LONG>(updateRect.Right);
updateRectNative.bottom = static_cast<LONG>(updateRect.Bottom);
// Query for ISurfaceImageSourceNative interface.
Microsoft::WRL::ComPtr<ISurfaceImageSourceNative> sisNative;
DX::ThrowIfFailed(
reinterpret_cast<IUnknown*>(this)->QueryInterface(IID_PPV_ARGS(&sisNative))
);
// Begin drawing - returns a target surface and an offset to use as the top left origin when drawing.
HRESULT beginDrawHR = sisNative->BeginDraw(updateRectNative, &surface, &offset);
if (SUCCEEDED(beginDrawHR))
{
// Create render target.
ComPtr<ID2D1Bitmap1> bitmap;
DX::ThrowIfFailed(
m_d2dContext->CreateBitmapFromDxgiSurface(
surface.Get(),
nullptr,
&bitmap
)
);
// Set context's render target.
m_d2dContext->SetTarget(bitmap.Get());
// Begin drawing using D2D context.
m_d2dContext->BeginDraw();
// Apply a clip and transform to constrain updates to the target update area.
// This is required to ensure coordinates within the target surface remain
// consistent by taking into account the offset returned by BeginDraw, and
// can also improve performance by optimizing the area that is drawn by D2D.
// Apps should always account for the offset output parameter returned by
// BeginDraw, since it may not match the passed updateRect input parameter's location.
m_d2dContext->PushAxisAlignedClip(
D2D1::RectF(
static_cast<float>(offset.x),
static_cast<float>(offset.y),
static_cast<float>(offset.x + updateRect.Width),
static_cast<float>(offset.y + updateRect.Height)
),
D2D1_ANTIALIAS_MODE_ALIASED
);
m_d2dContext->SetTransform(
D2D1::Matrix3x2F::Translation(
static_cast<float>(offset.x),
static_cast<float>(offset.y)
)
);
}
else if (beginDrawHR == DXGI_ERROR_DEVICE_REMOVED || beginDrawHR == DXGI_ERROR_DEVICE_RESET)
{
// If the device has been removed or reset, attempt to recreate it and continue drawing.
CreateDeviceResources();
BeginDraw(updateRect);
}
else
{
// Notify the caller by throwing an exception if any other error was encountered.
DX::ThrowIfFailed(beginDrawHR);
}
}
void TextInlineFormat_Shadow::ApplyInlineFormat(ID2D1RenderTarget* target, IDWriteTextLayout* layout,
ID2D1SolidColorBrush* solidBrush, const UINT32& strLen, const D2D1_POINT_2F& drawPosition)
{
if (!target || !layout) return;
// In order to make a shadow effect using the built-in D2D effect, we first need to make
// certain parts of the string transparent. We then draw only the parts of the string we
// we want a shadow for onto a memory bitmap. From this bitmap we can create the shadow
// effect and draw it.
D2D1_COLOR_F color = D2D1::ColorF(0.0f, 0.0f, 0.0f, 0.0f);
Microsoft::WRL::ComPtr<ID2D1SolidColorBrush> transparent;
HRESULT hr = target->CreateSolidColorBrush(color, transparent.GetAddressOf());
if (FAILED(hr)) return;
// Only change characters outside of the range(s) transparent
for (UINT32 i = 0; i < strLen; ++i)
{
bool found = false;
for (const auto& range : GetRanges())
{
if (range.length <= 0) continue;
if (i >= range.startPosition && i < (range.startPosition + range.length))
{
found = true;
break;
}
}
if (!found)
{
DWRITE_TEXT_RANGE temp = { i, 1 };
layout->SetDrawingEffect(transparent.Get(), temp);
}
}
Microsoft::WRL::ComPtr<ID2D1Bitmap> bitmap;
Microsoft::WRL::ComPtr<ID2D1BitmapRenderTarget> bTarget;
hr = target->CreateCompatibleRenderTarget(bTarget.GetAddressOf());
if (FAILED(hr)) return;
// Draw onto memory bitmap target
bTarget->BeginDraw();
bTarget->DrawTextLayout(drawPosition, layout, solidBrush);
bTarget->EndDraw();
hr = bTarget->GetBitmap(bitmap.GetAddressOf());
if (FAILED(hr)) return;
// Shadow effects can only be drawn with a D2D device context
Microsoft::WRL::ComPtr<ID2D1DeviceContext> dc;
hr = target->QueryInterface(__uuidof(ID2D1DeviceContext), reinterpret_cast<void**>(dc.GetAddressOf()));
if (FAILED(hr)) return;
// Create shadow effect
Microsoft::WRL::ComPtr<ID2D1Effect> shadow;
hr = dc->CreateEffect(CLSID_D2D1Shadow, &shadow);
if (FAILED(hr)) return;
// Load shadow options to effect
shadow->SetInput(0, bitmap.Get());
shadow->SetValue(D2D1_SHADOW_PROP_BLUR_STANDARD_DEVIATION, m_Blur);
shadow->SetValue(D2D1_SHADOW_PROP_COLOR, ToVector4F(m_Color));
shadow->SetValue(D2D1_SHADOW_PROP_OPTIMIZATION, D2D1_SHADOW_OPTIMIZATION_SPEED);
// Draw effect
dc->DrawImage(shadow.Get(), m_Offset);
}