DrVoodoo:

And I dunno bout the stretchblt thing, my video hardware absolutely loves scaling (it blends pixels flawlessly at virtually any size with little performance penalty) so my computer probably is an exception to the rule... with most computers it might be slower. (then again I haven't done a benchmark on mine for a while so I could have just been wrong the whole time here...) Anyway there isn't really any reason to argue about it :)

does anyone know of a well commented display bitmap example? i found a few examples but there is like no comments and i have no clue how exactly it works, but it looks like something i can do if i knew how it actually works other than just an uncommented code snippet.

One way to draw a bitmap is using the GDI. First you get a HDC with the GetDC function next you create a compatible HDC with CreateCompatibleDC. Now you load the bitmap with LoadBitmap. You select the bitmap with the SelectObject function into the HDC created with CreateCompatibleDC. And now you use BitBlt to draw form one HDC to the other. When this is done you must not forget to clean up. This is done with ReleaseDC for the HDC you got with GetDC. DeleteDC for the other one and DeleteObject for the bitmap.

You should load the bitmap with LoadImage

StretchBlt is both faster and more powerful then BitBlt.

More flexible, yes but faster, no - BitBlt is quicker. :)

I think this one by Sunlight seems fairly clear, although it's pitched specifically at msvc users. You may also be interested in working though some of GameTutorials winapi gdi bitmap examples, although again the source is pitched at msvc (.net) users.

Really? I've always found it to be faster but it probably depends on your comp. Besides, you typically end up using StretchDIBits or some even more flexible function in real life applications (at least games :lol:)

Up to now I have always used BitBlt.

Sorry, I can't seem to find anything more than anecdotal evidence (for example, this ) on the web but I know that StretchBlt calls BitBlt internally if the image and destination dimensions are the same. Might be an idea to test them by timing the functions and see which performs better.... :)

Please forgive me if I appear argumentative - i'm simply enjoying an interesting discussion. :D

allright today i am focusing on getting a bitmap drawn. heres what i have:

global variables:

right at the begining of winmain

WM_CREATE

WM_PAINT

and all im getting is a black square, which isnt the bitmap "hello.bmp" but its better than what i got when i tryed before which was nothing....

Change 'BLACKNESS' (which is why you're getting a black square) to 'SRCCOPY' in the BitBlt call and you should see your bitmap. :)

well when i tryed replacing "blackness" with "SRCCOPY" then i couldent see anything.... could the intergers in my bitblt function have anything to do with it?

**edit** i put

right under where i tryed to load the bitmap and the error poped up. so the reason i cant see an image must be cause the image isnt loading correctly... right?

I've always thought it was a little odd that the 'BLACKNESS' option even existed... Isn't that what the 'Rectangle' funciton is for?

I normaly do drawing not in a WM_PAINT message but in a WM_TIMER message. I load the resources right before the message loop and do clean up after the message loop before the the return statement. So my code normally looks something like this:

They indicate width&height, x&y in the window and x&y in the bitmap. If none of them is bigger than your actual surface (example if window width=200 and you draw at x=300 you wont see anything).

Yes, check if your bitmap exists in the same dir as the exe. I can't help much on loading files because I have, up to now, always done it with linked bitmaps.

well i dont think its the second parameter in loadbitmap because that file exists where my exe does...so it means it must be the first one.from msdn about the first parameter:

now maybey im using the wrong HINSTANCE..... im using it like

and my window structure deal has

so i sure thought that parameter would be hThisInstance....... anymore ideas on what im doing wrong just post please :D

oh btw, how do i use resource files to make my image then? MAKEINTRESOURCE kinda confuses me a bit... maybey that will help


***edit*** well looked around and the site Bodach said had a function on it

and i used that instead of loadbitmap and everything worked fine. now, why dident it before :huh:

Ahhhh! I thought you were using resources already. That changes things a bit. ;) :D

If you're going to load an image from file then use LoadImage, for example:

should load your image directly from file but note that if you're running your app from within the ide of msvc then the bitmap needs to be in the project directory (you could always use an absolute path to the bitmap file to be certain).

If you need to get the dimensions of the bitmap once it's loaded then GetObject is useful, eg:

If you would rather use resources instead of loading the bitmap directly from a file then let us know which compiler you are using because there are some differences in how to go about this depending on the compiler.

well yeah i did get it to load from the file, but someday i may actually get good at graphics (doubtfull) and might want to include them right in the exe. is that done with resources then? i have both vc++ and devc++ with mingw so information on loading from resources for both of them would be great, because yeah someday i might want to do that if i make a decent image :lol:

Yes. :)

For msvc there's a built in GUI resource editor. I think the options are Project menu, select add resource (it might be 'insert'). This should pop-open a dialog, select bitmap and import.... Just accept the default id for your bitmap (IDB_BITMAP1). You might have to add the resources to your project which you do from the project menu, select add to project (or add existing), select the *.rc and resource.h file and add them to your project. You should now have an extra 'resources' tab on the project view within the ide.

To use the resource(s) you have to include the resource.h header file in any code file that will be using it. Use the id with MAKEINTRESOURCE to get your bitmap, eg:

You are obviously unaware of the great GetBitmapDimensionEx

Yes, I was completely unaware of it - thankyou very much indeed for introducing us. ;) :D

But I wouldn't use it anyway because:

• The retrieved dimensions must have been set by the SetBitmapDimensionEx function. (from msdn description).
• It only retrieves the dimensions of a compatible bitmap.
• Even when I tested it raw (LoadBitmap/LoadImage on resource bitmap) it failed to provide any useful information - it zeroed the SIZE struct. The function seemed to work correctly because it returned a non-zero value indicating successful execution.

I may be using it wrong, though, so would appreciate an example of its proper usage if you have the time. :)

Thanks again for letting me know about it. :)

I've never used it before either actually (I've always used the approach you mentioned above), I had just heard about it a long time ago and was pointing out it's existence :)

If you want cntact to me to guide you