GDI C/C++ - BITMAP into an existing HBITMAP

Question

How can I create a device context compatible bitmap and then associating the obtained handle to a BITMAP struct? If I write:

...
HBITMAP hbitmap = CreateCompatibleBitmap(hdc, width, height); // these three arguments are initialized somewhere else
hbitmap = CreateBitmapIndirect(bitmap); // argument already initialized and properly filled
...

A HBITMAP handle compatible with hdc is created, and then a new HBITMAP (filled with bitmap data) is initialized, though without keeping its compatibility. Is there a function which allows not to create a HBITMAP from a BITMAP, but rather fills an initialized HBITMAP with an already existing BITMAP source?

It's not clear what you're asking here. You can't change an existing HBITMAP, all you can do is to create a new one with the desired characteristics and copy the bits to it. You should also consider using device-independent bitmaps instead. — Neil
I don't want to change an existing HBITMAP, but I'm looking for a function such as 'HBITMAP CreateCompatibleBitmapFromBitmap(HDC hDC, BITMAP *bitmap)' — Stencil

Neil Neil · Accepted Answer · 2011-10-19T20:56:41

CopyImage function

Creates a new image (icon, cursor, or bitmap) and copies the attributes of the specified image to the new one. If necessary, the function stretches the bits to fit the desired size of the new image.

HANDLE WINAPI CopyImage(
  HANDLE hImage,
  UINT uType,
  int cxDesired,
  int cyDesired,
  UINT fuFlags
);

hImage A handle to the image to be copied.

uType The type of image to be copied. This parameter can be one of the following values.

IMAGE_BITMAP 0 Copies a bitmap.
IMAGE_ICON 1 Copies an icon.
IMAGE_CURSOR 2 Copies a cursor.

cxDesired The desired width, in pixels, of the image. If this is zero, then the returned image will have the same width as the original hImage.

cyDesired The desired height, in pixels, of the image. If this is zero, then the returned image will have the same height as the original hImage.

fuFlags

GDI C/C++ - BITMAP into an existing HBITMAP

2 Answers