stretchdibits

(This is related to the question on How would I load a PNG image using Win32/GDI (no GDI+ if possible)? .) Hi all, I was wondering, given that you have a PNG resource embedded in a binary file with the ID IDB_PNG1 , and an LPDRAWITEMSTRUCT to draw into (so that means you have the HDC and the rectangle for your target), how do you draw that image onto the screen using StretchDIBits ? I've worked with BitBlt and TransparentBlt before, but StretchDIBits seems to work differently, and LoadImage doesn't seem to work with PNG's. Thank you! (Note: The language I put is C++, but that's not too

I want to draw a dib on to a HDC, the same size. I am using : des and src are of the same size. ::StretchDIBits(hdc, des.left,des.top,des.right - des.left,des.bottom - des.top, src.left, GetHeight() - src.bottom, src.right - src.left,src.bottom - src.top, m_pImg->accessPixels(),m_pImg->getInfo(), DIB_RGB_COLORS, SRCCOPY); but I find it is slow, because the des size is the same, I just need to copy the dib onto a dc. Is there any method faster than StretchDIBits? just as StretchBlt (slow) vs Bitblt.(faster) StretchDIBits (slow ) vs ?(faster) The speed difference comes from doing any necessary

I timed a DDB drawing operation which uses multiple StretchBlt and StretchDIBits calls. And I found that, time to complete is increase/decrease proportionally to the destination window size. With 900x600 window it takes around 5ms, but with 1920x1080 it takes as large as 55ms (source image is 1280x640). It seems Stretch.. APIs don't use any hardware acceleration features. Source image (actually this is temporary drawing canvas) is created with CreateDIBSection because I need resulting (stretched and merged) bitmap's pixel data for every frame drawn . Let's assume, Windows GDI is hopeless. Then