OpenEuphoria

Final: code (using Win32lib) that doesnt seem to work proper.

• Posted by euman at bellsouth.net May 30, 2002
• 942 views

----- Original Message ----- 
From: "Derek Parnell" <Derek.Parnell at SYD.RABOBANK.COM>

> G'day,
> nice to hear from you again.

Thanks for responding so quickly.

> The reason you would be having trouble is that there are two DC's involved
> in the example code. 

I finally broke down and looked into this in the library.

> The one you get, and the one that drawEllipse() uses.
> They are NOT the same one. In Win32lib, each of the wrapped graphics
> routines, gets its own DC and releases it again before returning to the
> caller. The one exception is if all the draw routines are called inside a
> Paint event. In that case, all share the same DC until the paint event
> completes.

This would be a problem for graphic objects and slow the library down
not to mention bloat the library with repeat code.
If you were to use "OwnDC" then a Window DC would be allocated
for the life of the Window and no other DC would be required, unless
you were using a Double buffering method ofcourse.

> Hope that helps. I'm currently rewriting the DC handling inside the library.
> One of the things you will be able to do is get a DC and then use that DC
> with the wrapped graphics routines until you decide to release it. I mostly
> got that working except for Pixmap and Bitmaps, so I should probably finish
> it this weekend.

You answered my reply above and this is a good thing for the library.
for example, there are some API's that arent wrapped yet that would require
a DC handle and we dont really need to obtain a handle, use it then destroy
each time we use a particular object. "one will do just fine"

Thanks Big-D I attached some more of that demo program for everyone to look at
(below) I think its a neat demo and has lots of potential written all over it.

P.S Derek look at the pInitExtent, I can use this "InitExtent =
getClientRect(MainWin)"
to obtain my client coords but must poke them if I need to use pointers. 
Is there already a routine for this?

P.P.S if you need any help with pixmaps and Bitmaps I could probably help out in
that area now. Im still working on my Installers but I need a small break before
I
go insane.

> ----------
> Derek.

Euman

-- Similar but not a copy of Chapter 10 - Windows 2000 Graphics API Black Book
(Coriolis & Damon Chandler))
-- Highly recommended Book for the Serious Windows API Programmers.
-- Euman 2002

without warning

include Win32Lib.ew

constant 
xSetViewportExtEx = registerw32Function(gdi32, "SetViewportExtEx",
 {C_LONG,C_INT,C_INT,C_INT},C_INT)
,xSetWindowExtEx = registerw32Function(gdi32,
"SetWindowExtEx",{C_LONG,C_INT,C_INT,C_POINTER},C_INT)
,iEllipse = registerw32Procedure(gdi32,
"Ellipse",{C_LONG,C_INT,C_INT,C_INT,C_INT})
,iDrawText = registerw32Procedure(user32,
"DrawTextA",{C_LONG,C_POINTER,C_INT,C_POINTER,C_UINT})

object junk

constant
MainWin = create( Window, "Mapping Mode Scaling Demo", NULL, 25, 25, 300, 200,
 0 )

sequence InitExtent

atom MainWinDC, hFont, oldMapMode, pInitExtent, pText

constant  
  MM_ANISOTROPIC = 8

-- onOpen_MainWin
procedure onOpen_MainWin( integer self, integer event, sequence parms )
sequence Text
  InitExtent = getClientRect( MainWin )
  
  pInitExtent = allocate(16)
  poke4(pInitExtent   , InitExtent[1])
  poke4(pInitExtent+4 , InitExtent[2])
  poke4(pInitExtent+8 , InitExtent[3])
  poke4(pInitExtent+12, InitExtent[4])
  
  MainWinDC = getDC ( MainWin )
  hFont = EzCreateFont(MainWin, MainWinDC,"Times New Roman",120,0,0,1,0)
  junk=w32Func(xSelectObject,{MainWinDC,hFont})

  oldMapMode = w32Func(xSetMapMode,{MainWinDC,MM_ANISOTROPIC})
  
  Text = "Euman's Win32lib Demo's"
  pText = allocate_string(Text)

  if w32Func(xSetGraphicsMode,{MainWinDC, GM_ADVANCED}) then
  end if
end procedure
setHandler(MainWin, w32HOpen, routine_id("onOpen_MainWin"))


-- onResize_MainWin
procedure onResize_MainWin( integer self, integer event, object parms )
sequence CurExtent

  CurExtent = getClientRect( MainWin )
  setPenColor( MainWin, White )
  repaintRect( MainWin, CurExtent[1], CurExtent[2], CurExtent[3], CurExtent[4])
if
  w32Func(xSetWindowExtEx,{MainWinDC,InitExtent[3]-InitExtent[1],InitExtent[4]-InitExtent[2],0})
  then
if
    w32Func(xSetViewportExtEx,{MainWinDC,CurExtent[3]-CurExtent[1],CurExtent[4]-CurExtent[2],0})
    then
w32Proc(iEllipse,{MainWinDC, InitExtent[1], InitExtent[2], InitExtent[3],
      InitExtent[4]})
w32Proc(iDrawText,{MainWinDC, pText, -1, pInitExtent, or_all({DT_CENTER,
      DT_VCENTER, DT_SINGLELINE})})
    end if
  end if
end procedure
setHandler(MainWin, w32HResize, routine_id("onResize_MainWin"))

-- onPaint_MainWin
procedure onPaint_MainWin( integer self, integer event, sequence parms )
object junk
  junk = w32Func( xInvalidateRect, {MainWin, NULL, 1} )
end procedure
setHandler(MainWin, w32HPaint, routine_id("onPaint_MainWin"))

-- onFocus_MainWin
procedure onFocus_MainWin( integer self, integer event, sequence parms )
  onResize_MainWin( 0,0,0)
end procedure
setHandler(MainWin, w32HGotFocus, routine_id("onFocus_MainWin"))

-- onClose_MainWin
procedure onClose_MainWin( integer self, integer event, sequence parms )
  free(pText)
  free(pInitExtent)
  releaseDC ( MainWin )
end procedure
setHandler(MainWin, w32HClose, routine_id("onClose_MainWin"))

WinMain( MainWin, Normal )