I want to use brushes for a drawing effect, but I must be doing something wrong or missing some important part. I've created some custom brush patterns which need to be "merged" with a bitmap, so when I blit it to the screen, the pattern is not a seperate overlay but an actual part of the bitmap so if there is any other image underneath, it will be visible . I don't know if I'm making sense, so below is a visual example :P

I've tried some approaches using raster ops but the result always affects the whole window. This is being done in pure GDI. Here is how I set up and use my custom brush:

// at the top of the program

HBITMAP hBrush1 = NULL;
WORD bits1[8] = { 0x1f, 0xf, 0x4f, 0xf, 0xff, 0xff, 0xff, 0xff }; //heaviest

// init function

hBrush1= CreateBitmap( 4, 4, 1, 1, ( LPBYTE ) bits1 );

// draw function

HBRUSH hCustomBrush = CreatePatternBrush( hBrush1 );
HBRUSH hOldBrush = ( HBRUSH )SelectObject( hdcBuffer, hCustomBrush );

SetROP2(hdcBuffer, R2_MASKPEN^R2_MASKPENNOT); //test
ExtFloodFill(hdcBuffer,0,0,RGB( 255, 0, 255 ),FLOODFILLBORDER); //test

Not the solution, but you can't XOR the mix mode flags. The docs say one of the defined values.

@endurion

I have tried XORing the flags and get different results. Probably a case of undefined behaviour? None of the docs really talk about XORing two modes together. Anyway, I finally understand how this effect is done, and it's pretty simple. I switched out one graphic for another, ran the program and saw that it uses two versions of the same background; one without the heading, and one with the heading. My solution based on this is as follows:

1. Create bitmap objects for both backgrounds
2. Create the pattern
3. Create a temporary memory DC
4. Put the second bitmap (with heading) into this DC
5. Draw the pattern over this bitmap
6. Put the complete result into a new DC
7. Blit the first background to the screen DC with BitBlt
8. Blit the new background-with-pattern on top of the first one using TransparentBlt for the colour of the pattern to be transparent

That's it. I may not have explained this too well, but it's the most logical solution apart from actually loading in a bunch of sprites to simulate the effect, which would only serve to bloat the exe.