DRAWING
Center a PICT
In rare case, but sometimes pict's rect TL is not alway (0,0) , you know, so you'd better use CALL OFFSETRECT to make sure pict's rect TL set to (0,0). I just re-write your code. (NOT TESTED!)
This routine center the image (when window is larger than image, if not, the image will be cutted in window's size) and paint background in gray checker pattern. This designed for the window which has vertical and horizontal scroll bars, and if you want to sync them, add oX or oY to BUTTON value.
Osamu Shigematsu
LOCAL
"Lt-Gray"
` dc.w $9999,$9999,$9999
"Dk-Gray"
` dc.w $6666,$6666,$6666
LOCAL FN centerpict(pict&)
DIM pRect;0,pT,pL,pB,pR
DIM wRect;8
DIM fRect;8
DIM oldRgn&,wndRgn&,picRgn&
pRect;8 = @pict&..picFrame.top% ' get the rectangle of pict handle
CALL OFFSETRECT (pRect,-pL,-pT) ' make TL to zero
oX = (WINDOW(_width) -1 - pR) / 2 ' calc horz offset as oX
oY = (WINDOW(_height) -1 - pB) / 2 ' calc vert offset as oY
CALL OFFSETRECT (pRect,oX,oY) ' center the image
oldRgn& = FN NEWRGN
CALL GETCLIP(oldRgn&) ' save old clip region for restore
CALL SETRECT (wRect,0,0,WINDOW(_width) - 1,WINDOW(_height) - 1)
CALL CLIPRECT (wRect) ' set new clip to windows content
fRect;8 = @pRect
CALL INSETRECT (fRect,-1,-1) ' inset to draw frame
CALL FORECOLOR(_blackColor) ' reset colors and pen
CALL BACKCOLOR(_whiteColor)
CALL PENNORMAL
CALL FRAMERECT(fRect) ' Draw frame
'
CALL RGBFORECOLOR (#LINE "Lt-Gray")
CALL RGBBACKCOLOR (#LINE "Dk-Gray")
wndRgn& = FN NEWRGN
picRgn& = FN NEWRGN
CALL RECTRGN (wndRgn&,wRect%)
CALL RECTRGN (picRgn&,fRect%)
CALL DIFFRGN (wndRgn&,picRgn&,picRgn&) ' Calculate background region
CALL DISPOSERGN (wndRgn&)
CALL FILLRGN (picRgn&,#[REGISTER(A5)] + _gray + 4) ' fill it
CALL DISPOSERGN (picRgn&)
CALL FORECOLOR (_blackColor)
CALL BACKCOLOR (_whiteColor)
'
CALL DRAWPICTURE(pict&,pRect) 'Draw image to the pRect
CALL SETCLIP (oldRgn&)
CALL DISPOSERGN (oldRgn&)
CALL VALIDRECT(wRect) ' Now Updated the window!
END FN