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HyperFlexed

Fri Jun 18, 2010 6:05 pm


SDL_image and SDL_LoadPNG (compile error)

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I had libsdl-dev and libsdl-image-dev installed (through apt-get). I was getting odd errors on compile:

[code]johnny@picard:~/coding/SDLtest$ g++ main.cpp -o main -lSDL -lSDL_image
main.cpp: In function ?int main(int, char**)?:
main.cpp:15: error: ?SDL_LoadPNG? was not declared in this scope[/code]

Because of this, I tried installing libsdl and libsdl_image from source. They compiled fine. The packages are sitting happily under /usr/local/lib

[code]johnny@picard:~/coding/SDLtest$ ls /usr/local/lib -l
total 7700
lrwxrwxrwx 1 root root       20 2010-06-18 18:56 libSDL-1.2.so.0 -> libSDL-1.2.so.0.11.3
-rwxr-xr-x 1 root root  2353825 2010-06-18 18:56 libSDL-1.2.so.0.11.3
-rw-r--r-- 1 root root  4940280 2010-06-18 18:56 libSDL.a
lrwxrwxrwx 1 root root       25 2010-06-18 18:50 libSDL_image-1.2.so.0 -> libSDL_image-1.2.so.0.8.2
-rwxr-xr-x 1 root root   199342 2010-06-18 18:50 libSDL_image-1.2.so.0.8.2
-rw-r--r-- 1 root root   356982 2010-06-18 18:50 libSDL_image.a
-rwxr-xr-x 1 root root      985 2010-06-18 18:50 libSDL_image.la
lrwxrwxrwx 1 root root       25 2010-06-18 18:50 libSDL_image.so -> libSDL_image-1.2.so.0.8.2
-rwxr-xr-x 1 root root      986 2010-06-18 18:56 libSDL.la
-rw-r--r-- 1 root root     4674 2010-06-18 18:56 libSDLmain.a
lrwxrwxrwx 1 root root       20 2010-06-18 18:56 libSDL.so -> libSDL-1.2.so.0.11.3
drwxr-xr-x 2 root root     4096 2010-06-18 18:56 pkgconfig
drwxrwsr-x 4 root staff    4096 2010-05-13 02:10 python2.6[/code]

I can't see where I'm going wrong in the source code:

[code]#include "SDL/SDL.h"
#include "SDL/SDL_image.h"

int main(int argc, char *args[]){
	SDL_Surface *screen = NULL;
	SDL_Surface *hello = NULL;
	
	// Initialize SDL
	SDL_Init(SDL_INIT_EVERYTHING);
	
	// Set up screen
	screen = SDL_SetVideoMode(640, 480, 32, SDL_SWSURFACE);
	
	// Load Image
	hello = SDL_LoadPNG("test.png");
	
	// Display image
	SDL_BlitSurface(hello, NULL, screen, NULL);
	SDL_Flip(screen);
	
	SDL_Delay(2000);
	
	// Quit SDL
	SDL_Quit();
	
	return 0;
}[/code]

and as far as I can tell libpng and zlib are installed. It seems like the compiler can't find SDL_LoadPNG, but as I understand this should be included with SDL_image. If anyone can recommend further troubleshooting steps or offer some advice, I'd be glad to hear it. This has to be the most complicated hello world I've ever done :P


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CodeMonkey2000

Fri Jun 18, 2010 6:17 pm


RE:SDL_image and SDL_LoadPNG (compile error)

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That's telling you that SDL_LoadPNG is not part of the library. What you want is IMG_load, read the SDL_image documentation

http://jcatki.no-ip.org:8080/SDL_image/SDL_image_frame.html


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HyperFlexed

Fri Jun 18, 2010 6:22 pm


Re: SDL_image and SDL_LoadPNG (compile error)

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My hero! Thanks a tonne. I saw references on forums to some mysterious SDL_LoadPNG function, I guess I'll be sure to check the API next time. :)