GDI compatiable with direct2d not working when using pushlayer and poplayer

Asked Dec 14 '20 at 06:25

Active Dec 14 '20 at 07:50

Viewed 176 times

I am working on a project, and try to convert GDI rendering into direct2d rendering. Sometimes I need to use ID2D1GdiInteropRenderTarget interface to rendering some GDI content to direct2d's render target. Here is the problem: If I use GetDC() ReleaseDC() between PushLayer and PopLayer. The content rendered to the HDC is gone, not composited into rendertarget. But If I use GerDC() ReleaseDC between PushAxisAlignedClip and PopAxisAlignedClip, it works correctly. Why It doesn't work between PushLayer and PopLayer, I need to use pushlayer to clip a round rect regeion.

Code is like as follows:

ID2D1HwndRenderTarget* render_target = NULL;
ID2D1GdiInteropRenderTarget* gdi_render_target = NULL;
//create ID2D1HwndRenderTarget and query ID2D1GdiInteropRenderTarget...

render_target->BeginDraw();

D2D1_LAYER_PARAMETERS params = D2D1::LayerParameters(round_rect, round_rect_geometry);
render_target->PushLayer(params, render_layer_);

HDC hdc = NULL;
gdi_render_target->GetDC(D2D1_DC_INITIALIZE_MODE_COPY, &hdc);

// Draw Line with hdc. some code is Omit. 
::MoveToEx(hdc, rc.left, rc.top, &ptTemp);
::LineTo(hdc, rc.right, rc.bottom);

gdi_render_target->ReleaseDC(0);

render_target->PopLayer();
render_target->EndDraw();

edited Dec 14 '20 at 07:50

asked Dec 14 '20 at 06:25

zhufachang

My develop machine is win10 – zhufachang Dec 14 '20 at 06:29
Do you call ID2D1DeviceContext::Flush before ReleaseDC? – Simon Mourier Dec 14 '20 at 07:29
@SimonMourier No, I didn't use ID2D1DeviceContext interface. – zhufachang Dec 14 '20 at 07:31
Sorry, I meant ID2D1RenderTarget::Flush (ID2D1DeviceContext derives from ID2D1DeviceContext). You can also try to enable the debug layer see if you don't have an interesting message. https://walbourn.github.io/direct3d-sdk-debug-layer-tricks/ – Simon Mourier Dec 14 '20 at 07:59
@SimonMourier I didn't use the ID2D1RenderTarget::Flush either. – zhufachang Dec 14 '20 at 08:06
ok, but have you tried? – Simon Mourier Dec 14 '20 at 08:43

GDI compatiable with direct2d not working when using pushlayer and poplayer

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