OpenEuphoria

1. Loading A Graphic Using CxImage From User Input

• Posted by Andy Jun 22, 2009
• 1391 views

Hey Guys,

Sorry for the long title, but I am in trouble. In my program Frost, I need to have it so a user can load a graphic file if his/her own and then have it displayed in the window inside of a group box. I am using the cxImage library so that the users can have more than just .bmp, anyways, here is my code.

 
procedure Add_Hero_WalkGfx(integer self, integer event, sequence parm) 
	fName = getOpenFileName(EDWin,file,GraphicType) 
	 
	if length(fName) = 0 then 
		return 
	end if 
	 
	handle = open(fName,"rb") 
	 
	if handle = -1 then 
		fn = message_box("File Load Error", 
						"File Error", 
						MB_TASKMODAL) 
	end if 
	 
	while 1 do 
		data = gets(handle) 
		 
	if atom(data) then 
		exit 
	end if 
	 
	data = data[1..length(data)-1] 
	 
	buffer = buffer & data 
	end while 
	 
	close(handle) 
	 
	HeroWalk_Gfx = CXI_LoadImage(file, CXI_FORMAT_UNKNOWN,0) 
	 
	CXI_Resize(HeroWalk_Gfx,120,100,CXI_GOOD_RESIZE) 
end procedure 
setHandler(Hero_WalkGfx_Add,w32HClick,routine_id("Add_Hero_WalkGfx")) 

I have declared some of the varialbes outside of the procedure, so don't worry about the variables not being declared.

3. Re: Loading A Graphic Using CxImage From User Input

• Posted by Andy Jun 22, 2009
• 1357 views

-- sequence CXI_GetDIB(atom image) 
--	Returns the sequence {bits, width, height, bpp}. 

Thanks for the help, but that still didn't work.

5. Re: Loading A Graphic Using CxImage From User Input

• Posted by Andy Jun 22, 2009
• 1368 views

I looked at it, added your code into my code, and my code still runs, however it is not displaying it on the screen. How do I use the function effectivley?

7. Re: Loading A Graphic Using CxImage From User Input

• Posted by Andy Jun 22, 2009
• 1337 views
• Last edited Jun 23, 2009

image = CXI_LoadImage( filename, filetype, 0 )
yourDIB = createDIBFromCxImage( image ) 

procedure Main_onPaint( integer pSelf, integer pEvent, sequence pParams )
 
    copyBlt( Main, 0, 0, yourDIB ) 
 
end procedure 
setHandler( Main, w32HPaint, routine_id("Main_onPaint") ) 

constant myBmp = create( Bitmap, "", Main, 10, 10, 100, 100, 0 )
setBitmap( myBmp, yourDIB ) 

Thanks, the code does work, but for some reason, when ever I try to load a "user" selected image, my program crashes on me. I am probably doing something wrong in my code.

9. Re: Loading A Graphic Using CxImage From User Input

• Posted by Andy Jun 22, 2009
• 1386 views
• Last edited Jun 23, 2009

	fName = getOpenFileName(EDWin,file,GraphicType) 
	 
	if length(fName) = 0 then 
		return 
	end if 
	 
	handle = open(fName,"rb") 
	 
	while 1 do 
		data = gets(handle) 
		 
	if atom(data) then 
		exit 
	end if 
	 
	buffer = buffer & data 
	end while 
	 
	close(handle) 
	 
	HeroWalk_Gfx = CXI_LoadImage(file,GraphicType,0) 
	 
	HeroWalk_Gfx = createDIBFromCXImage(HeroWalk_Gfx) 
	 
	copyBlt(EDWin,710,220,HeroWalk_Gfx) 
end procedure 
setHandler(Hero_WalkGfx_Add,w32HClick,routine_id("Add_Hero_WalkGfx")) 
setHandler(EDWin,w32HPaint,routine_id("Add_Hero_WalkGfx")) 

That is my code for the user selected image. However whenever I actually tried to click on the image to have it displayed on the window it crashes.

11. Re: Loading A Graphic Using CxImage From User Input

• Posted by ghaberek (admin) Jun 23, 2009
• 1393 views

Andy, you need to separate your onClick handler from your onPaint handler. The only thing you should be doing during a paint event, is painting. You should never interact with the user during a paint event, as doing so will halt the event and possibly cause a repainting, resulting in an infinite loop.

The method should be:

1. React to a click event and prompt the user to select a file
2. Load the image and store it in a top-level variable
3. Trigger a repaint with repaintWindow()
4. Blit the image to the screen during the paint event

Mic, the CXI_LoadImage() routine works two ways: You can either feed it a filename or a buffer of a file in memory (in which case the third parameter should be the buffer size). The latter is useful for loading images from a database and such. But it seems Andy only needs to use the filename version, as his user is selecting a file via getOpenFileName().

-Greg

13. Re: Loading A Graphic Using CxImage From User Input

• Posted by ghaberek (admin) Jun 23, 2009
• 1338 views

-- CxImage wrapper for Euphoria 
-- /Mic, 2003 

LOL, nice... It's a wonder I never put that together.

-Greg

15. Re: Loading A Graphic Using CxImage From User Input

• Posted by mic_ Jun 23, 2009
• 1314 views

Do you know the exact place where it crashes? If you're not getting anything meaningful in ex.err, then at least try to find the function call that causes the crash (by commenting out calls until it no longer crashes).

17. Re: Loading A Graphic Using CxImage From User Input

• Posted by ghaberek (admin) Jun 23, 2009
• 1316 views

atom HeroWalk_Gfx
HeroWalk_Gfx = 0 
 
procedure Add_Hero_WalkGfx(integer self, integer event, sequence parm) 
	fName = getOpenFileName(EDWin,file,GraphicType) 
	 
	if length(fName) = 0 then 
		return 
	end if 
	 
	HeroWalk_Gfx = CXI_LoadImage(fName,GraphicType,0) 
	 
	HeroWalk_Gfx = createDIBFromCXImage(HeroWalk_Gfx) 
	 
	repaintWindow( Main ) 
 
end procedure 
setHandler(Hero_WalkGfx_Add,w32HClick,routine_id("Add_Hero_WalkGfx")) 
 
procedure EDWin_onPaint(integer self, integer event, sequence parm) 
 
	if HeroWalk_Gfx != 0 then 
		copyBlt(EDWin,710,220,HeroWalk_Gfx)  
	end if 
 
end procedure 
setHandler(EDWin,w32HPaint,routine_id("EDWin_onPaint")) 

-Greg

19. Re: Loading A Graphic Using CxImage From User Input

• Posted by ghaberek (admin) Jun 23, 2009
• 1323 views

Your GraphicType value needs to be one of these constants, from CxImage.ew:

-- Image types. Used with CXI_LoadImage and CXI_SaveImage.
global constant CXI_FORMAT_UNKNOWN = 0, 
        CXI_FORMAT_BMP = 1, 
        CXI_FORMAT_GIF = 2, 
        CXI_FORMAT_JPG = 3, 
        CXI_FORMAT_PNG = 4, 
        CXI_FORMAT_ICO = 5, 
        CXI_FORMAT_TGA = 6, 
        CXI_FORMAT_PCX = 7 

I suspect you're passing it a sequence of "Grap..." something. (At least that's what your error message seems to indicate.)

-Greg

21. Re: Loading A Graphic Using CxImage From User Input

• Posted by ghaberek (admin) Jun 23, 2009
• 1371 views

Rather than repainting the image on just part of your window, create a small child window the size of the image you want to display. That small window will receive its own paint events and will "clip" properly.

include Win32Lib.ew
without warning 
 
constant Main   = create( Window, "Test", 0, Default, Default, 640, 480, 0 ) 
constant PicWin = create( Window, "", Main, 10, 10, 64, 64, {WS_CHILD,WS_VISIBLE} ) 
 
procedure PicWin_onPaint( integer pSelf, integer pEvent, sequence pParams ) 
 
    copyBlt( PicWin, 0, 0, YourImage ) 
 
end procedure 
setHandler( PicWin, w32HPaint, routine_id("PicWin_onPaint") ) 
 
WinMain( Main, Normal )

Also, you may need to use transBlt() instead of copyBlt() if you need to preserve the transparent background of your image.

-Greg