• ### Popular Now

• 14
• 12
• 9
• 10
• 9

This topic is 2081 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts

I am trying to make a Windows version of a game that uses SDL and SDL_image. The game's image files are PNG files. I am using SDL 1.2.15 and SDL_image 1.2.12. I compiled a release version of my game using Visual C++ 2008 Express on a 32-bit Vista virtual machine. The game builds with no errors. I create a Release version of the game and add the following files to the same directory as the executable file:

The PNG files
SDL.dll
SDL_image.dll
libpng15-15.dll
zlib1.dll

The dll files are the x86 versions from the SDL and SDL_image binary installations.

When I run the game from outside Visual C++, a window opens and the game crashes. Stepping through the code in the debugger, I discovered the following code returns a null pointer:

 SDL_RWops* textureFile; // filename is the argument I pass to the texture loading function. textureFile = SDL_RWFromFile(filename, "rb"); 

Adding a call to SDL's GetError functions to get more information about the error provides the error message "Couldn't open ImageFile.png", where ImageFile is one of the PNG files in the game. I figure the files aren't loading due to not having the PNG files or DLLs in the right location. But I thought putting them in the same location as the application was enough to get the image files to load. Are there additional libraries or files I need to place in the application folder to get the PNG files to load? I'm obviously missing something.

##### Share on other sites
Well, assuming you loaded the image as literally "ImageName.png" as opposed to something like "Data/Images/ImageName.png", then it should be in the same directory as the application. DLL files should also be in the same directory as well, it would come up with a DLL error if it couldn't find them. Anyway, as for your dilemma, I'm a bit puzzled as to why you would use SDL_RWFromFile() instead of IMG_Load().

I've had really bad luck in the past getting RW pointers to work properly. I suppose you could try SDL_RWFromFP and see if you still get a NULL pointer. That's about all I can think of for now, perhaps someone else has a better idea. Edited by Spirrwell

##### Share on other sites

Thanks for the help.

##### Share on other sites

Regarding the file names, I did notice that if I have a file named Tiles.png on Mac OS X, Windows Explorer shows the filename as Tiles. I added .png to the PNG files in Windows Explorer, but the file loading code fails both when the name is Tiles and Tiles.png.

##### Share on other sites
The file is still Tiles.png regardless, as that's the full file name. Try opening it as a FILE pointer with fopen to see if your error loading is to do with SDL loading functions or your file name. Have you tried any other images as well?

##### Share on other sites
The FILE pointer is NULL when I call fopen. I have tried to load five different images, and they all return NULL after calling IMG_Load. However, I have a text file in my game, and that file loads. It's just the PNG files that don't load. The text file is in the application directory, just like the PNG files.

##### Share on other sites
Well, that's a big clue for those smarter than me. It's clearly not an issue with SDL_image as it would load the file regardless with fopen. It's looking for the file with that file name and it isn't finding it because that file with that name is not there.

When you were talking about Windows Explorer not showing the file extension .png, it's because Windows automatically hides file extensions for known file types, sort of as a failsafe so somebody doesn't mess with it that doesn't know what they are doing. If the image has .blabla.xyz.etc, it may get cut off because of the .png extension. You could remove that by going to Computer->(You may need to press Alt key to bring up the menu)Tools->Folder Options->View-> uncheck "Hide extensions for known file types."->Apply

This way you will guarantee you will see the full name. If you still have the full file name, then someone smarter than me will have to help you. I'm not a debugger by any means, I just know what the code means. I mean you could just make something quick in paint like a white background and a few dots and save it (not neccesarily as a png) as test.png or test.jpg so you know for sure the name of the image.

That's all I can help with, I'm out of ideas from here.

##### Share on other sites

Thanks for the help Spirrwell. You got me thinking deeper about the problem. When I discover a solution to this problem, I'll post it here.