[lazarus] Bitmap transparency?

Mattias Gaertner nc-gaertnma at netcologne.de
Mon Nov 10 14:55:51 EST 2003


On Mon, 10 Nov 2003 08:07:09 +0100
Micha Nelissen <M.Nelissen at student.tue.nl> wrote:


> I think I can fill the RawImageDesc fields except palette, and I don't 
> know what to do with RedPrec, RedShift, etc..

You need to find out the color format of the device/bitmap for this.

Example:
32 bits per pixel, 8 bit for red, 8 for green, 8 for blue, 8 bit for
nothing.
Let assume a pixel has the following double word: $RRGGBB00

Depth = 24
BitsPerPixel = 32
RedPrec = 8
RedShift = 24
GreenPrec = 8
GreenShift = 16
BluePrec = 8
BlueShift = 8



Mattias






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