Thanks Logan. I used the rowBytes in place of the width and it works !! Aryeh
----- Original Message ----- From: "Logan Shaw" <[EMAIL PROTECTED]> To: "Palm Developer Forum" <[EMAIL PROTECTED]> Sent: Thursday, December 16, 2004 8:12 AM Subject: Re: Bitmap > [EMAIL PROTECTED] wrote: > > 1. I know we can request the current screen and get them saved to a > > bitmap ,this is for full screen but can I request for only part of the > > screen by specifying the co-ordinates? > > If you just want to save if, use WinSaveBits(). It takes a > RectangleType pointer as an argument. > > > Is it possible to with any direct > > API s that are available or how this can be done? > > > > 2.I want to compare a saved bitmap with another bitmap, any fast and > > straight way to do this??? > > Haven't done it, but you should be able to do this: > > Create both bitmaps yourself with BmpRsrcCreate(). Make them both > the same format. 16-bit should be good, but you may also want to > key off the screen format if they are both coming from the screen. > > Then use WinCreateBitmapWindow() to turn them both into a window. > Copy from wherever (such as the draw window) to the bitmaps using > WinCopyRectangle(). > > Now, to compare them, you can access the internals of the bitmap > since you have use BmpRsrcCreate() to create them and know that > they are not in some weird system format. So, use BmpGetBits() > to get a pointer to the pixel data and BmpGetDimensions() to > find out the bytes per row, then use your knowledge of the pixel > format (since you specified it when creating the bitmap) to > compare the relevant bytes on each row. You could just MemCmp() > the whole entire pixel data, but there is no guarantee that there > aren't unused bytes (or at least bits) between rows that might > be filled with random garbage. (In other words, rowbytes doesn't > necessarily equal 2 * bitmapwidth for all 16-bit bitmaps, and > it certainly doesn't equal bitmapwidth / 2 for all 4-bit bitmaps, > especially if bitmapwidth is an odd number!) > > - Logan > > -- > For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/ -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
