Original Post
Hi, how would I save a HDC to a bitmap? ..its to take screenshots thx
🔒 Locked
(c++ win32) How to save a DC to a bitmap?
Advertisement
CreateDIBSection()
StretchBlt()
Kuphryn
StretchBlt()
Kuphryn
Here, you can have my code. Though there may have to be some
changes done to it as it is like written way back for Win32s.
For Direct3D however, you might need to use the surface data,
because of hardware acceleration, GDI caps more than likely
won't work. There is also another way to do this by sending
the WM_PRINT message.
[Edited by - yadango on May 27, 2006 12:16:53 AM]
changes done to it as it is like written way back for Win32s.
For Direct3D however, you might need to use the surface data,
because of hardware acceleration, GDI caps more than likely
won't work. There is also another way to do this by sending
the WM_PRINT message.
void CaptureScreen(HWND window, const char* filename){ // get screen rectangle RECT windowRect; GetWindowRect(window, &windowRect); // bitmap dimensions int bitmap_dx = windowRect.right - windowRect.left; int bitmap_dy = windowRect.bottom - windowRect.top; // create file ofstream file(filename, ios::binary); if(!file) return; // save bitmap file headers BITMAPFILEHEADER fileHeader; BITMAPINFOHEADER infoHeader; fileHeader.bfType = 0x4d42; fileHeader.bfSize = 0; fileHeader.bfReserved1 = 0; fileHeader.bfReserved2 = 0; fileHeader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER); infoHeader.biSize = sizeof(infoHeader); infoHeader.biWidth = bitmap_dx; infoHeader.biHeight = bitmap_dy; infoHeader.biPlanes = 1; infoHeader.biBitCount = 24; infoHeader.biCompression = BI_RGB; infoHeader.biSizeImage = 0; infoHeader.biXPelsPerMeter = 0; infoHeader.biYPelsPerMeter = 0; infoHeader.biClrUsed = 0; infoHeader.biClrImportant = 0; file.write((char*)&fileHeader, sizeof(fileHeader)); file.write((char*)&infoHeader, sizeof(infoHeader)); // dibsection information BITMAPINFO info; info.bmiHeader = infoHeader; // ------------------ // THE IMPORTANT CODE // ------------------ // create a dibsection and blit the window contents to the bitmap HDC winDC = GetWindowDC(window); HDC memDC = CreateCompatibleDC(winDC); BYTE* memory = 0; HBITMAP bitmap = CreateDIBSection(winDC, &info, DIB_RGB_COLORS, (void**)&memory, 0, 0); SelectObject(memDC, bitmap); BitBlt(memDC, 0, 0, bitmap_dx, bitmap_dy, winDC, 0, 0, SRCCOPY); DeleteDC(memDC); ReleaseDC(window, winDC); // save dibsection data int bytes = (((24*bitmap_dx + 31) & (~31))/8)*bitmap_dy; file.write(memory, bytes); // HA HA, forgot paste in the DeleteObject lol, happy now ;)? DeleteObject(bitmap);}[Edited by - yadango on May 27, 2006 12:16:53 AM]
good eye. forgot to add DeleteObject ha ha ha.
if I use this instead:
HDC winDC = CreateDC("DISPLAY", 0,0,0);
do i just delete it: DeleteDC(winDC); ?
Also is there a way to capture the pixels from videos playing aswell. I know that they are playing on a different layer, but isn't there some higher level function of getting the pixels onscreen?
HDC winDC = CreateDC("DISPLAY", 0,0,0);
do i just delete it: DeleteDC(winDC); ?
Also is there a way to capture the pixels from videos playing aswell. I know that they are playing on a different layer, but isn't there some higher level function of getting the pixels onscreen?
Topic Locked
This topic has been locked by a moderator. New replies are not allowed.
Sign in to reply to this topic.
Advertisement