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An example from https://learn.microsoft.com/en-us/windows/win32/direct2d/gaussian-blur:
ComPtr<ID2D1Effect> gaussianBlurEffect;
m_d2dContext->CreateEffect(CLSID_D2D1GaussianBlur, &gaussianBlurEffect);
gaussianBlurEffect->SetInput(0, bitmap);
gaussianBlurEffect->SetValue(D2D1_GAUSSIANBLUR_PROP_STANDARD_DEVIATION, 3.0f);
m_d2dContext->BeginDraw();
m_d2dContext->DrawImage(gaussianBlurEffect.Get());
m_d2dContext->EndDraw();
In the example above, I have understand how effect works in Direct2D. However, the example above is only limited to applying the effect into a bitmap (ID2D1Bitmap?).
What I want to achieve with Direct2D effect is:
Use ID2D1Effect::SetInputEffect to combine multiple effects
A quick test with CLSID_D2D1Crop, CLSID_D2D1Scale and CLSID_D2D1GaussianBlur (bad quality GIF for Gaussian, but it is for the idea...) :
Can I have the code?
Also, is the "bad quality" your mentioned an option (e.g we can set the quality) or it is the nature of Direct2D?
Edit: Is that an ID2D1Bitmap that you applied effect to? If yes, sorry but, it is different from what I mean... :I "Applying effect to part of the client area"
No, the bad quality is just about the GaussianBlur in the GIF.
Draft test code : Test effects
Thank you for helping me. However,
In your code, It seems only works for an existing bitmap (images, user-defined bitmap, etc), not the client area itself.
As stated in other thread, I need a way for Direct2D to get the part of the client area as bitmap (or something else that act as Image), then applying effects to it (not limited to).
Or, applying the specific part of client area directly with Direct2d effect.
But the client area is empty by default.
You must draw a ID2D1Bitmap to display something, then you do operations on ID2D1Bitmap
You can get a copy with PrintWindow to a memory DC and convert it or a part to ID2D1Bitmap, but it will be slower
I used DirectWrite to display something in the client area, later, in my main project, I need to blur out the entire client area.
There are previous draw operations before applying the effect, so the client area is not empty.
You can use CreateCompatibleRenderTarget and ID2D1BitmapRenderTarget to apply effects,
like I did in CScrollingText.cpp to apply a Shadow effect to the text drawn with DirectWrite
I haven't tried your solution, but I have understand most of your explanations. Thank you so much for the help.
Is CreateCompatibleRenderTarget() slow (at least in your case)?
No, code can be slower when GDI is mixed with Direct2D (if it uses CPU instead of GPU in animations for example)
I have tried to apply blur to entire client area, but does not work, see my WM_PAINT code:
state.d2dDeviceContext->BeginDraw();
// Begin Draw
state.d2dDeviceContext->Clear(D2D1::ColorF(1, 1, 1, 1));
PCWSTR text = L"テスト";
D2D1_SIZE_F clientSize = state.d2dDeviceContext->GetSize();
state.d2dDeviceContext->DrawTextW(
text,
wcslen(text),
state.textFormat,
D2D1::RectF(10, 10, 100, 100),
state.defaultBrush
);
if (FAILED(state.d2dDeviceContext->CreateCompatibleRenderTarget(
&state.d2dBitmapRenderTarget
))) return false;
if (FAILED(state.d2dBitmapRenderTarget->GetBitmap(
&state.d2dBitmap
))) return false;
state.d2dEffect->SetInput(0, state.d2dBitmap);
state.d2dEffect->SetValue(D2D1_GAUSSIANBLUR_PROP_STANDARD_DEVIATION, 32.0f);
state.d2dDeviceContext->DrawImage(state.d2dEffect);
It does not work as expected, it should blur the text (entire client area).
Also, it seems annoying the program is working perfectly like nothing happens, without the blur effect being applied :I
Here is the full code
Hi, @thebluetropics
According to the Doc: Effects
You can use Direct2D to apply one or more high quality effects to an image or a set of images.
ID2D1Effect::SetInput method: Sets the given input image by index.
As far as I'm concerned, Direct2D Effects is limited to applying the effect to image.
It seems impossible for Direct2D effect to directly apply to the client area.
If it possible to crop a part of the client area as an ID2D1Bitmap, please let me know.