Change blur rate enabled by SetWindowCompositionAttribute - winapi

I am using an undocumented function SetWindowCompositionAttribute to enable blur behind transparent areas of my window.
However, I would like to control the degree of the blur effect. Is it possible? I can't find anything about that.

SetWindowCompositionAttribute() is just a wrapper for the documented DwmSetWindowAttribute() function. There is no DWM attribute, or other DWM API, to change the degree of blurriness.

Related

How are custom Windows Borders and styles done?

I have seen a program recently that has got what appears to be a custom Window border.
I don't know how this is accomplished. If anyone does know then please do tell me as this is interesting.
I am mostly interested in something similar shown in the picture
Window example of what I am trying to accomplish
You must handle the non-client messages like WM_NCPAINT. Depending on your design you might need to call DwmDefWindowProc as well.
Use SetWindowRgn if you want XP style rounded edges or SetLayeredWindowAttributes for full alpha support and custom shadows.

Common Controls on a Transparent Window?

While there are lots of variations of the question, there doesn't seem to be a specific answer to a simple case of wanting to use built-in common controls on a transparent window using Win32. I don't want the controls to be transparent, I just want the border around it to be transparent. I can't believe MS didn't update the .dll's to handle transparency when they added it, but I guess they forgot? Is there a specific method that works. A button can get close with WS_EX_TRANSPARENT, but flaky where it works most of the time but at times part of the border shows up. Edit controls, change depending on when get focus or not.
So the question is simply:
Is there a way to make common controls on transparent window so there is no white border around them?
If not, is there a good replacement library that does it via owner draw?
If some, which ones and what is the method?
Seems silly to reinvent the wheel just because of the area around the control.
TIA!!
If I am not mistaken, you can take the following steps to achieve this effect.
1.Create a GDI+ Bitmap object with the PixelFormat32bppPARGB pixel format.
2.Create a Graphics object to draw in this Bitmap object.
3.Do all your drawing into this object using GDI+.
4.Destroy the Graphics object created in step 2.
5.Call the GetHBITMAP method on the Bitmap object to get a Windows HBITMAP.
6.Destroy the Bitmap object.
7.Create a memory DC using CreateCompatibleDC and select the HBITMAP from step 5 into it.
8.Call UpdateLayeredWindow using the memory DC as a source.
9.Select previous bitmap and delete the memory DC.
10.Destroy the HBITMAP created in step 5.
This method should allow you to control the alpha channel of everything that is drawn: transparent for the background, opaque for the button.
A similar discussion: Transparent window containing opaque text and buttons

Custom NSControl of AppKit/Cocoa emulating style

I am developing a custom slider to support color selection functionality.
This is a screenshot of the current development so far:
The background coloring is very flexible and also offers to use the standard background coloring as implemented in NSSlider using system colors.
The implementation is realized by overriding a NSView rather than NSSlider, since I also want to support flexible sizes of the cells:
I am currently struggling with the shadowing of the knobs. The color sliders should be positioned right next to standard NSSliders. However, if I am not carefully replicated the shadow style of the standard NSSlider, it will look a bit awkward.
Is there any documentation on how the shadow styles (radius, offset, opacity, etc) in the standard controls are designed?
To put it simply: nope.
The control styles are always subject to change, and have never ever been documented. They are what they are and it's up to you to figure it out and mimic them if you need to.

About the translucent effect of three.js

I have a need. I need to make a window. The glass on the window is transparent. I have found some examples:
https://threejs.org/examples/#webgl_materials_shaders_fresnel
https://threejs.org/examples/#webgl_materials_cubemap_refraction
The background of these examples is static pictures.
My background is dynamic. How can I do it?
Maybe you can use THREE.Refractor like shown in this example. It allows you to create a refractive see-through surface. You might have to adjust the respective shader program in order to achieve your intended visual result (the default shader of THREE.Refractor does not perform any distortions).

Windows Vista/7 glass completely broken?

I'm trying to get the media player glass effect for an application, but I'm facing roadblocks all around. Is it me, or is it the API?
I started by calling:
MARGINS margins = { -1, -1, -1, -1 };
HRESULT result = ::DwmExtendFrameIntoClientArea(m_hWnd, &margins);
And erasing the background to black on:
OnEraseBkgnd
Everything was fine until I added an edit box. With EditBox, places where black text appears are replaced with glass. The problem is blown out of proportion with more advanced controls like ComboBoxEx and that like. Those start to look like mess.
The bright side with this approach is that the alpha blended images look alright. And are gradually blended into the glass.
The solution for edit boxes seems to be using WS_EX_LAYERED with LWA_COLORKEY and using some awful color for glass masking, and erasing the background to that color. Unfortunately this breaks other things. The alpha blending on icons looks super ugly with shadows blended to radioactive green, and the glass itself becomes click-throughable, even though I don't have a WS_EX_TRANSPARENT style on the window.
The third suggestion is sort of custom composition with GDI+, but that seems to be a bad approach, since GDI+ is a software fallback, and I can't find a way how to render EditBox or ComboBoxEx to an image that I could use for composition later.
Am I missing something?
The sources at SO also seem to face the same problems:
link1
link2
Kenny Kerr wrote an excellent article on displaying controls on glass, using edit controls as an example:
http://weblogs.asp.net/kennykerr/archive/2007/01/23/controls-and-the-desktop-window-manager.aspx
The simple answer is, you cannot do this.
All the standard controls render themselves with normal GDI calls. Normal GDI calls are alpha unaware and mostly set the alpha channel to zero.
The more complicated answer is, you can: There are some samples on the net where standard controls are mixed with aero glass. They fall into two basic categories:
WinForms (.NET) samples. WinForms don't actually use the native controls - the WinForms controls are all rewritten versions that, amongst other features, blit using alpha aware routines. This example is depressingly simple and makes me realize how much Microsoft hate native developers.
Subclassed samples: The only way to get the regular/native controls to paint on aero glass is to sublclass the controls, catch WM_PAINT messages to create a DIBBitmap, call WM_PRINT to render the controls content onto it. Use the DWM functions to repair the alpha channel data. Paint the resulting alpha'd bitap yourself using AlphaBlend.
This article on CodeProject contains a reference implementation that subclasses most of the standard controls rather well.
Try changing your text/foreground color on controls like the edit box to something "almost black" (like #010101). Then you should be able to skip the other rendering issues except alpha transparency for images/icons.
Edit: Drawing other stuff - might be some weird approaches to handle compatibility, but then again classic apps aren't glass themed by default ... don't know. Just try to avoid drawing stuff yourself, if possible.

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