When I bitblt onto my transparent window, a bmp smaller than the client area, it draws a fussy surrounding area instead of transparent like the set colorkey from:
SetLayeredWindowAttributes(hwnd, RGB(0,255,0), 120, LWA_COLORKEY | LWA_ALPHA); //colorkey & win alpha
The blit looks like this:
The candle-like test image makes its own area transparent like it should, but the surrounding client area gets grayed out according to the window-alpha value (120). Any ideas how to fix this? I've tried:
SetBkColor(hdc, crKey); and generating a background with
FillRect(background_hdc, &background_rect, hbrush); and blitting that first
Where neither work.
I have the feeling this should be alot easier than I'm making it out to be, and I still feel something like SetBkColor(hdc,crKey); should do the trick, but it doesnt. Maybe there is a similar command that does that I'm looking for?
Isnt it funny how you solve the problem just after you formulate it properly?
Obviously the hbrBackground in the WNDCLASSEX wc;
defines the background of the window. So by setting the brush background when registering the window like so:
wc.hbrBackground=CreateSolidBrush(RGB(240, 20, 120)); //COLORREF==crKey
it gets crKey cancelled out during the blit along with the bmps crKey color. Thanks.
Related
Background:
Sorry for my English . So I am in a slightly unique situation in the scenario. I am working on a project that involves using a DLL proxy to intercept DirectX9 calls and dnd control drawing of a game.They are things that are statically draw and I want to be able to draw them in another part of the screen.
The Question:
I am wanting to be able to save pixels in a rect on the screen and then draw exact rect somewhere else on the screen. So if I can grab the pixels at x100, y100, w30, h30 and copy that that to another location on the screen that would be great.
This is the code that I have so far which I assume is making a texture from a memory rect.
HRESULT myIDirect3DDevice9::EndScene(void)
{
GetInput();
// Draw anything you want before the scene is shown to the user
m_pIDirect3DDevice9->GetBackBuffer(iSwapChain, iBackBuffer, Type, ppBackBuffer);
LPDIRECT3DTEXTURE9 textureMap;
D3DXCreateTexture(m_pIDirect3DDevice9, 100, 100, D3DX_DEFAULT, D3DUSAGE_RENDERTARGET, D3DFMT_X8R8G8B8, D3DPOOL_DEFAULT, &textureMap);
m_pIDirect3DDevice9->SetTexture(0, textureMap);
// SP_DX9_draw_text_overlay();
return(m_pIDirect3DDevice9->EndScene());
}
Project is based off this:
Library_Wrappers
Other notes:
I want to avoid DLL injection to accomplish this.
My goal is to have a fullscreen overlaying invisible "canvas" on which I can draw using win32's various drawing functions.
The way I am currently attempting it is this:
WNDCLASSA myclass = { 0 };
myclass.lpfnWndProc = WindowProc3;
myclass.hInstance = GetModuleHandle(0);
myclass.lpszClassName = "MyCanvas";
myclass.hbrBackground = CreateSolidBrush(0xFEEDBEEF);
myclass.hCursor = LoadCursor(0, IDC_ARROW);
RegisterClassA(&myclass);
...
HWND wnd = CreateWindowExA(WS_EX_TOPMOST | WS_EX_LAYERED | WS_EX_TRANSPARENT, "MyCanvas", 0, WS_POPUP | WS_VISIBLE, 0, 0, screen_width, screen_height, 0, 0, GetModuleHandle(0), 0);
SetLayeredWindowAttributes(wnd, 0xFEEDBEEF, 0, LWA_COLORKEY);
Although this serves as a canvas, hours of googling later, I am still unable to draw on it semitransparently.
I have added a screenshot of what my program is currently displaying as I am writing this. What I would like to be able to do is, for example, make the black box in the top right corner (drawn with Rectangle) semitransparent so as to reveal the stackoverflow page content below it.
This is a question I found that I was hopeful about, but the resulting text is just a blended combination of the background color ((COLORREF)0xFEEDBEEF) and text color. Other things I have found have either just made the element fully invisible, done nothing at all, or required some library like MFC. I want to only use win32 functions if at all possible, as I would like to be able to achieve the highest FPS possible.
I do not care if this doesn't work on all Windows versions as long as it does on 7 up to 10.
If you only need transparency for a rectangular area where all pixels either have the same transparency (aka alpha) value or are completely transparent, you can use SetLayeredWindowAttributes() with a combination of alpha value and/or color key.
UpdateLayeredWindow() is the way to go if you need to be able to define transparency per-pixel.
For that you have to create memory DC and select a 32bpp bitmap into it. You may use the buffered paint API to ease the task. Raymond Chen has a blog post with a code sample about that.
You can draw into the memory DC, but you can't use most of GDI API for that, because GDI ignores the alpha channel (transparency). I suggest using GDI+ which allows you to specify the alpha values.
After you have completed drawing into the memory DC, you would call UpdateLayeredWindow() and pass that memory DC as the argument for the hdcSrc parameter to make the result visible on screen.
Illustration of possible effects:
SetLayeredWindowAttributes( hwnd, 0, 176, LWA_ALPHA );
SetLayeredWindowAttributes( hwnd, colorkey, 0, LWA_COLORKEY );
SetLayeredWindowAttributes( hwnd, colorkey, 176, LWA_ALPHA|LWA_COLORKEY );
UpdateLayeredWindow( ... )
Note the antialiased edge of the shape and the transparency gradient in the last example. Things like that are only possible with UpdateLayeredWindow().
I'm trying to draw on the screen (the whole screen, on top of every other window) using GDI+.
I've passed NULL to GetDC to get a HDC to the screen, and then used that to create a Graphics object, and used DrawRectangle to draw rectangles on the screen.
Everything works..except...the inside of the rectangle won't update.
Like if I draw it over a command prompt, and move the command prompt, the inside of the rectangle remains black.
I expect to see whats under the rectangle.
Here's the code that's doing the drawing..
Pen BluePen(Color(255, 0, 255, 0), 2);
Graphics graphics(screenDC);
graphics.DrawRectangle(&BluePen, myRect);
Pretty simple, so is there something I have to do to get the inside of the rectangle to update when the screen does? Or to get it truely transparent.
================= EDIT =================
Well I had given up on this, and assumed it wasn't possible, until...I realized the Inspect tool that comes with the Windows SDK does this perfectly.
I would like to recreate something similar to the highlight rectangle, and if I select a window (such as Firefox) and then bring Inspect into focus I can move it around freely with everything being updated perfectly.
There's not even any flickering.
So...does anyone know how Inspect manages to do this?
Also answers in GDI instead of GDI+ are fine...
In windows the screen (and the windows ...) surface(s) are ... volatile, like sandboxes. The "overlapping" of windows and the re-painting of uncovered surfaces is an illusion made by proper event management.
Everything is drawn remain there until something else is drawn over it.
"Uncovering" a surface makes the window representing that surface to receive a WM_PAINT message. It's up to that window procedure to react to that message by re-painting everything is supposed to be under it.
Now, unless you intercept somehow the WM_PAINT message that is sent to the desktop window, you have mostly no chance to know the desktop needs a repaint and hence your paint code will not be called and no repaint will happen. Or better it happens following just the desktop window updating code, that's not aware of your paint.
I created a Transparent Layered window with a color key that I use to make the window transparent.
So far it works all fine.
Writing text on it - using GDI+ - works, too...
The problem I encounter is, that the text has a thin border of the colorkey-color around the letters...
What I do in the WM_PAINT is:
1. Clear the drawing area Graphics::Clear(ColorKey);
2. Draw the text on it.
Screenshot of what i mean: http://imageshack.us/photo/my-images/709/cutp.jpg/
Anyone knows about how to avoid this?
Try calling Graphics::SetTextRenderingHint(TextRenderingHintSingleBitPerPixelGridFit).
It's a while since I've done this, but I'm trying to add a custom button graphic to a windows button, with some transparent areas. I've tried various schemes but can't seem to get the transparent areas to show. Here's my code:
hbmpUpDisabled = LoadImage(instance,MAKEINTRESOURCE(IDB_UPARROWDISABLED), IMAGE_BITMAP, 0, 0, LR_DEFAULTSIZE | LR_LOADTRANSPARENT | LR_LOADMAP3DCOLORS );
SendMessage(GetDlgItem(hWndDlg, IDC_MOVEUP),BM_SETIMAGE,(WPARAM)IMAGE_BITMAP,(LPARAM)hbmpUpDisabled);
Does anyone notice any problems here? It works if my bitmap is a 1-bit bitmap. I couldn't get a 32 bit bitmap to work, and I'm not sure how to setup a 24 bit or 8 bit bitmap to do it.... I tried a custom 255,0,255 color (which IIRC is a default transparent value), but so far no joy....
LR_LOADMAP3DCOLORS should map grey - in the source image - to to the current button face color. Buttons do not use AlphaBlt or TransparentBlt so there is no way to actually (short of custom painting) set a bitmap with transparent or alpha'd areas onto a button and expect it to work. You just have to pre-prepare the bitmap with the correct button color in its background areas.
That said - I suspect that some of these restrictions may be lifted for buttons implemented by common controls v6. Add commctl 6 as a dependend assembly to your exe and see if the behaviour changes.