OpenEuphoria

RE: Bitmap clearing

• Posted by Patrick.Barnes at transgrid.com.au Jan 30, 2003
• 526 views

Hey Jordah...
I found an error in your PatBLT procedure... I didn't notice until now, because
some of the pixmap wasn't clearing correctly, and I couldn't figure out why:

>-------------------------------------------
>procedure PatBlt(atom hdc,atom x,atom y,atom cx,atom cy,atom rop)
>-------------------------------------------
>   if not w32Func(zPatBlt,{hdc,x,y,cy,cy,rop}) then
>      warnErr("PatBlt Failed")      \-------perhaps that should be cx?  
>   end if
>end procedure

Very frustrating, I tore my program almost to pieces looking for the bug, and it
was your fault all along! :oP

Hopefully you don't have that same error sitting somewhere.

Thanks for the demo. VERY useful.

-Pat

-----Original Message-----
From: jordah at btopenworld.com [mailto:jordah at btopenworld.com]
Sent: Saturday, 25 January 2003 15:49
To: EUforum
Subject: Re: Bitmap clearing



Hi Patrick,

    I alittle bit under-estimated win32lib. It does alot of work for the
end-user. Its getDC has a very kewl construct. also, i have attached
BlankPixmap() which is a faster way to blank a pixmap.

Try this demo in  the win32lib directory because it requires mail.bmp

Hope this helps.
Jordah.

---------------------------------------------------------
--File   : Demo For Patrick
--Version:
--Date   :
--Author : Jordah Ferguson
---------------------------------------------------------

include win32lib.ew
-------------------------------------------

constant
  MainWindow = create(Window,"Demo for
Patrick",0,Default,Default,600,400,0),
  Pixmap1    = create(Pixmap,"",0,0,0,300,300,0),
  zPatBlt    =
registerw32Function(gdi32,"PatBlt",{C_LONG,C_LONG,C_INT,C_INT,C_INT,C_INT},C
_INT),
  -------------------------------------------
  Bitmap1    = loadBitmapFromFile(current_dir()&"\\mail.bmp")

-------------------------------------------
procedure PatBlt(atom hdc,atom x,atom y,atom cx,atom cy,atom rop)
-------------------------------------------
   if not w32Func(zPatBlt,{hdc,x,y,cy,cy,rop}) then
      warnErr("PatBlt Failed")
   end if
end procedure

-------------------------------------------
global procedure stretchBlt( atom dst, integer dstX, integer dstY,
      atom src, integer srcX, integer srcY,
      integer destWide, integer destHigh,
      integer srcWide, integer srcHigh,
      integer rop )
-------------------------------------------
    atom srcDC, dstDC
    srcDC = getDC( src )
    dstDC = getDC( dst )
    if not w32Func( xStretchBlt, {
      dstDC, dstX, dstY,
      destWide, destHigh,
      srcDC,
      srcX, srcY,
      srcWide, srcHigh,
      rop} ) then
      warnErr( "stretchBlt:StretchBlt failed." )
    end if
    releaseDC( dst )
    releaseDC( src )
end procedure

-------------------------------------------
procedure BlankPixmap(integer Pixmap,atom BkColor)
-------------------------------------------
   atom hdc,brush,oldbrush
   sequence rect
   rect = getRect(Pixmap)
   hdc = getDC(Pixmap) -- This already performs selectobject()
   brush = w32Func(xCreateSolidBrush,{BkColor})
   oldbrush = w32Func(xSelectObject,{hdc,brush})
   PatBlt(hdc,rect[1],rect[2],rect[3],rect[4],#00F00021)
   oldbrush = w32Func(xSelectObject,{hdc,oldbrush})
   oldbrush = w32Func(xDeleteObject,{brush})
   releaseDC(hdc)
end procedure


-------------------------------------------
procedure DrawToPixmap(integer Pix,atom hBmp,atom px,atom py,atom bitcx,atom
bitcy)
-------------------------------------------
   sequence rect
   rect = getRect(hBmp)
   stretchBlt(Pix,px,py,hBmp,0,0,bitcx,bitcy,rect[3],rect[4],SRCCOPY)
end procedure

-------------------------------------------
procedure DrawToScreen(integer dest,integer Pix,atom x,atom y,atom cx,atom
cy)
-------------------------------------------
   sequence rect
   rect = getRect(Pix)
   stretchBlt(dest,x,y,Pix,0,0,cx,cy,rect[3],rect[4],SRCCOPY)
end procedure

-------------------------------------------
procedure onPaint_Proc(integer id,integer event,sequence params)
-------------------------------------------
   sequence rect,rec,re
   re   = getClientRect(MainWindow)
   rect = getRect(Pixmap1)
   rec  = getRect(Bitmap1)
   BlankPixmap(Pixmap1,White)

DrawToPixmap(Pixmap1,Bitmap1,floor((rect[3]-rec[3])/2)-40,floor((rect[4]-rec
[4])/2)-40,rec[3]+40,rec[4]+40)
   DrawToScreen(MainWindow,Pixmap1,re[1],re[2],re[3],re[4])
end procedure
setHandler(MainWindow,w32HPaint,routine_id("onPaint_Proc"))

-------------------------------------------
procedure onResize_Proc(integer id,integer event,sequence params)
-------------------------------------------
   DrawToScreen(MainWindow,Pixmap1,0,0,params[2],params[3])
end procedure
setHandler(MainWindow,w32HResize,routine_id("onResize_Proc"))


-------------------------------------------
WinMain(MainWindow,Normal)



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