loading an image causes EXCEPTION_ACCESS_VIOLATION

BlitzMax Forums/Brucey's Modules/loading an image causes EXCEPTION_ACCESS_VIOLATION

Peter

(Posted 2010) [#1]

I'm trying to load GIF images with wxMax but so far I didn't found a working solution.

Does anyone has a clue what's wrong with my code?

Import wx.wxApp
Import wx.wxFrame
Import wx.wxMenu
Import wx.wxMenuBar
Import wx.wxImage

Type tMainWindow Extends wxFrame
	Const pnID_LOADGIF:Int = 6000
	
	Method OnInit()
	'variables
		Local menuBar:wxMenuBar
		Local fileMenu:wxMenu
	'code
		'create menu bar
		fileMenu = wxMenu.CreateMenu()
		fileMenu.Append(pnID_LOADGIF, "&Load GIF")
		fileMenu.Append(wxID_EXIT, "&Quit")

		menuBar = wxMenuBar.CreateMenuBar()
		menuBar.Append(fileMenu, "&File")
		SetMenuBar(menuBar)
		
		Connect(pnID_LOADGIF, wxEVT_COMMAND_MENU_SELECTED, LoadGIF)
		Connect(wxID_EXIT, wxEVT_COMMAND_MENU_SELECTED, OnQuit)
	End Method 'OnInit
	
	Function LoadGIF(event:wxEvent)
	'variables
		Local img:wxImage
	'code
		If Not img.CreateFromFile("prep.gif", wxBITMAP_TYPE_GIF) Then
			DebugLog("Image not loaded")
		Else
			DebugLog("Image loaded")
		End If
	End Function 'LoadGIF

	Function OnQuit(event:wxEvent)
	'code
		wxWindow(event.parent).Close()
	End Function 'OnQuit
End Type

Type tGIF_Test Extends wxApp
	Field MainWindow:tMainWindow
	
	Method OnInit:Int()
		MainWindow = tMainWindow(New tMainWindow.Create(,, "GIF Test",,, 800, 600))
		SetTopWindow(MainWindow)
		MainWindow.CenterOnScreen()
		MainWindow.Show()
		Return(True)
	End Method 'OnInit

End Type 'tGIF_test

wxImage.AddHandler(New wxGIFHandler)
New tGIF_Test.Run()

rs22	(Posted 2010) [#2]

I had this problem, too. I ended up using FreeImage to load the images:

Local freeimage:TFreeImage = LoadFreeImage("blah.gif")
Local bitmap:wxBitmap = New wxBitmap.CreateFromPixmap(ConvertPixmap(freeimage.GetPixmap(), PF_RGBA8888))
Local image:wxImage = bitmap.ConvertToImage()

Peter

(Posted 2010) [#3]

Tried as you suggested, but there seem to be a problem with the FreeImage library.

I could build the mod without troubles but compiling my little test program ended in a massive amount of errors. Most of them read like the following:

C:/BlitzMax/mod/bah.mod/freeimage.mod/freeimage.debug.win32.x86.a(Plugin.cpp.debug.win32.x86.o):Plugin.cpp:(.text+0x4a8): 
  undefined reference to `_Unwind_Resume'

I tried it with the download version 1.05 and also with the latest svn release.

Maybe this is a compatibility problem with the latest BMax release.

I would appreciate if someone (Brucey?) has a clue for me how to solve this.

-- Peter

Peter

(Posted 2010) [#4]

BTW, I also tried to build the associated samples for the FreeImage library.

Compiling the samples also failed with the same error as compiling my own stuff.

Brucey, will you have a look into this issue?

- Peter

Brucey

(Posted 2011) [#5]

There's a bug in your code :

	'variables
		Local img:wxImage
	'code
		If Not img.CreateFromFile("prep.gif", wxBITMAP_TYPE_GIF) Then

This is invalid. CreateFromFile() is a Function, and therefore needs to be called using :

		If Not wxImage.CreateFromFile("prep.gif", wxBITMAP_TYPE_GIF) Then

Otherwise the program crashes on this line.
Interestingly, even in debug mode, it is a hard crash (1.41 OSX).