BitBlt CreateCompatibleDC SelectObject CreateCompatib GetMapMode CreateCompatibleBitmap CreateDIBSection
Drawing Transparent Bitmaps
http://delphi.cjcsoft.net//viewthread.php?tid=45232
Title: Drawing Transparent Bitmaps
Question: How to draw a transparent bitmap
hdcTemp := CreateCompatibleDC(dc);
SelectObject(hdcTemp, hBmp); // Select the bitmap
GetObject(hBmp, sizeof(BITMAP), @bm);
ptSize.x := bm.bmWidth; // Get width of bitmap
ptSize.y := bm.bmHeight; // Get height of bitmap
DPtoLP(hdcTemp, ptSize, 1); // Convert from device
// to logical points
// Create some DCs to hold temporary data.
hdcBack := CreateCompatibleDC(dc);
hdcObject := CreateCompatibleDC(dc);
hdcMem := CreateCompatibleDC(dc);
hdcSave := CreateCompatibleDC(dc);
// Create a bitmap for each DC. DCs are required for a number of
// GDI functions.
// Monochrome DC
bmAndBack := CreateBitmap(ptSize.x, ptSize.y, 1, 1, nil);
// Monochrome DC
bmAndObject := CreateBitmap(ptSize.x, ptSize.y, 1, 1, nil);
bmAndMem := CreateCompatibleBitmap(dc, ptSize.x, ptSize.y);
bmSave := CreateCompatibleBitmap(dc, ptSize.x, ptSize.y);
// Each DC must select a bitmap object to store pixel data.
bmBackOld := SelectObject(hdcBack, bmAndBack);
bmObjectOld := SelectObject(hdcObject, bmAndObject);
bmMemOld := SelectObject(hdcMem, bmAndMem);
bmSaveOld := SelectObject(hdcSave, bmSave);
// Set proper mapping mode.
SetMapMode(hdcTemp, GetMapMode(dc));
https://programmerall.com/article/6686314819/
Add('SRCCOPY ');
Add('SRCPAINT ');
Add('SRCAND ');
Add('SRCINVERT ');
Add('SRCERASE ');
Add('NOTSRCCOPY ');
Add('NOTSRCERASE');
Add('MERGECOPY ');
Add('MERGEPAINT ');
Add('PATCOPY ');
Add('PATPAINT ');
Add('PATINVERT ');
Add('DSTINVERT ');
Add('BLACKNESS ');
Add('WHITENESS ');
delphi DIB embarcadero delphi graphics TBitmap Vcl.Graphics.GetDIB Device Independent Bitmaps
https://docs.microsoft.com/zh-tw/windows/win32/gdi/capturing-an-image
http://blog.livedoor.jp/junki560/archives/21910595.html
