I'm trying to create a bitmap that I can change the pixels of and then update the window with that bitmap. I've tried to research a way to just create a bitmap, but that was to no avail.
I need to know how to create a blank bitmap, then change its pixels using x and y coordinates and a color, and then how to draw it to the window. I don't need to save it to the computer and I don't want to convert an existing image into a bitmap.
I'm on windows and using Visual Studio with C++
Just to specify, I need to know the syntax for creating a blank bitmap with a certain width and height, and also what function I need to use to change the pixels' colors, and then how to draw a bitmap to the window. Thank you.
There is a free library ImgSource that you can use which has a huge amount of functionality for images.
http://www.smalleranimals.com/isource.htm
It is available in MSDN, but using a library like ImgSource may be to your advantage.
It provides simple methods for rendering your image onto a device context. And there is a good support forum.
Related
I've been trying to code an auto clicker for a simple game online (a php coded one), but I've had trouble analyzing the colors on-screen. (English isn't my first language, sorry!) I've already done a bit of C++ in university, but only for science-oriented simple console programs. (Edit: I'm working on windows!! forgot to mention)
I've already tried the getpixel function, but since my chrome window is zoomed out at 80% to get the full game in frame, it seems I'm having some DPI related issues, but looking into this made my head dizzy.
After watching a Codebullet video, I thought a better approach to this would be to take a screenshot of the problematic area, analyze it to see if the condition is filled, then delete the screenshot. The problem is, I have no idea how I could achieve this and Google didn't help much this time :\
My code is extremely messy so I can't show it right now, but it's basically just a:
-click there
-click there after 5 seconds
-click there if this pixel is this color
-repeat
Is there an easy answer to this? I'd be really thankful if there is. Have a nice day! :)
You don't need to save the screen shot if you don't want to:
Pass the target window handle to GetDC(), t will return the the device context of the window.
Pass the device context to CreateCompatibleDC() to create a compatible DC.
Use CreateCompatibleBitmap(), passing in the DC and the size of the window. This returns a handle to a bitmap
Use SelectObject() to select the bitmap
Use BitBlt() to do a bitblock transfer of the selected pixels from the regular DC into the compatible DC using the SRCCOPY raster operation code to do a normal copy.
Create a BITMAP object. Use GetObject() and pass the handle to the bitmap you created.
Create a BITMAPINFOHEADER and define the member vars. Create an array of unsigned chars big enough to fit all the pixels from your bitmap.
Use GetDIBits() passing in the handle to the compatible bitmap, the bitmap header and a pointer to the pixel array. This loads the pixels from the bitmap into the pixel array.
Now parse all that juicy pixel data, search for the colors you're looking for and test the results against your conditionals to decide what to do next.
Don't forget to delete objects and release memory & device contexts.
I believe this is the tutorial I followed where I learned this, courtesy of MSDN: https://learn.microsoft.com/en-us/windows/desktop/gdi/capturing-an-image
I just started using ATL::CImage in my MFC project, and this is very basic question about it.
I know ATL::CImage members support AlphaBlend() for controlling the transparency, and plgblt() for rotating. But they are all the independent functions for only "Displaying" on DC as I understand.
How Can I apply both transparency and rotation of the image and display/save it?
I know GDI+ supports everything what I want, but I wanna know how to realize them with CImage class members too.
Thank you.
This isn't possible in the same way. You can use a temporary DC for each operation.
Create a DC with a bitmap of the needed size.
Perform the operation of the CImage into the DC.
Get the Bitmap from the DC and form a new CImage or simply work on with the DC.
The better way is always to use GDI+ to perform such operations. CImage is only needed when you need to store the interim result, or need to reuse it.
I have been searching around about this problem for awhile. I am making a cross platform program and I have figured out how to load an animated cursor with the windows API and how to create a cursor during run time from raw bitmap data. However I can't find good documentation for this for X11, for my Unix/Linux build of my program. I know I need to use the XRender extension functions, XRenderCreateCursor and XRenderCreateAnimCursor from this documentation https://www.x.org/releases/X11R7.6/doc/libXrender/libXrender.txt but I do not know how to use these functions and the documentation does now show any examples.
Also the raw image data is in the ARGB format, and I want to support the Alpha channel if possible with these cursors.
Could someone show me how to use the X11 and XRender (or XCursor) Library to create a cursor, static and animated, and possibly how to do it so the cursor can be used with any X11 window.
Thanks!
PS.
I am acually editing a open source libary for cross platfrom Gui that I am using for my program, and I am trying to add this feature into the libary but I am not used to programing with X11.
When it comes to X, nothing is simple.
First, review the specification of the X render extension.
The steps for creating an animated cursor are as follows.
First, you need to create a PICTURE for each frame of the animated cursor, using CreatePicture.
Use CreateCursor to create a CURSOR from each PICTURE. CreateCursor returns a CURSOR handle.
Then, you take the list of all CURSORs for all of the frames, and then use CreateAnimCursor to create a single CURSOR representing the animated cursor.
This all comes down to creating a PICTURE for each frame. A PICTURE is created using CreatePicture from a DRAWABLE and a PICTFORMAT. DRAWABLE would be the PIXMAP with the actual bitmask for the cursor's frame, and PICTFORMAT specifies which channels in the pixmap represent the red, color, and green channels, and must be one of the enumerated PICTFORMATs returned from QueryPictformat.
For more information, see the aforementioned X render extension specification.
It's been a long time since I've had to deal with Win32 menus. I need to add some PNG icons to a Win32 context popup menu. Naturally, I want to preserve PNG transparency and all the per-pixel-alpha in the process. Is this possible?
I was thinking on using SetMenuItemBitmaps. Is that the way to go?
I imported my PNGs as "PNG" resources but I can't seem to load them neither with LoadBitmap nor with LoadImage. I found some suggestions about using Gdi+ but obviously I won't be drawing the menu - the system will.
There seems to be a way to get a HBITMAP from a Gdi+ Bitmap but it looks as if all the alpha is getting lost in the process. AFAIK, a HBITMAP can happily host alpha information.
You need GDI+ to load a PNG. Then you need to create a 32-bit alpha bitmap of the correct size, create a Graphics on the bitmap, and use DrawImage to copy the PNG to the bitmap. That gives you a bitmap with an alpha channel.
Something like this:
Image* pimgSrc = Image::FromFile("MyIcon.png"L, FALSE);
Bitmap* pbmpImage = new Bitmap(
iWidth, iHeight,
PixelFormat32bppARGB
);
Graphics* pgraphics = Graphics::FromImage(bmpImage))
{
// This draws the PNG onto the bitmap, scaling it if necessary.
// You may want to set the scaling quality
graphics->DrawImage(
imageSrc,
Rectangle(0,0, bmpImage.Width, bmpImage.Height),
Rectangle(0,0, imgSrc.Width, imgSrc.Height),
GraphicsUnitPixel
);
}
// You can now get the HBITMAP from the Bitmap object and use it.
// Don't forget to delete the graphics, image and bitmap when done.
Perhaps you could use icon instead?
Here are my reasons for using icons instead of PNGs:
The Win32 API has good support icons, and it relatively much easier to draw icons, since GDI+ is not required.
Icons also support 8-bit transparency (just like PNGs).
Icons can be any size in pixels (just like PNGs).
Icons can easily be embedded in the executable as a resource.
Icons can be edited via Visual Studio.
To load an icon from a resource or a file use:
LoadImage()
To draw the icon, use:
DrawIcon() or DrawIconEx()
I would like a win32 program that takes the desktop and acts like it is shattering glass and in the end would put the pieces back together is there way reference on Doing this kind of effect with C++?
I wrote a program (unfortunately now lost) to do something like this a few years ago.
The desktop image can be retrieved by creating a DC for the screen, creating a compatible bitmap, then using BitBlt to copy the screen contents into the bitmap. Then use GetDIBits to get the pixels from this bitmap in a known format.
This link doesn't do exactly that, but it demonstrates the principle, albeit using MFC. I couldn't find a Win32-specific example:
http://www.flounder.com/screencapture.htm
For the shattering effect, best to use Direct3D or OpenGL. (Further details are up to you.) Create a texture using the bitmap data saved earlier.
By way of window for associating with OpenGL or D3D, create a borderless window that fills the entire screen and doesn't do painting or background erasing. This will prevent any flicker when switching from the desktop image to the copy of the desktop image being used to draw.
(If using D3D, you'll also find GetMonitorInfo useful in conjunction with IDirect3D9::GetAdapterMonitor and friends, as you'll need to create a separate device for each monitor and you'll therefore need to know which portion of the desktop corresponds to that device.)