Issue loading BMP image using SDL_image - c

Question

I am new to SDL_image and I am trying to use it in a C file to load a BMP image.
To that end, I have written the following code:
#include "SDL/SDL.h"
#include "SDL_image.h"
SDL_RWops *rwop;
rwop = SDL_RWFromFile("sample.bmp", "rb");
However, for some reason, although rwop after those lines are executed is not NULL anymore, IMG_isBMP(rwop) is 0.
Any idea what could be wrong?

Answer 1

Perhaps better example. This (might) yield more information and perhaps if BMP is supported:
https://www.libsdl.org/projects/SDL_image/docs/SDL_image_32.html
You could also try using IMG_LoadBMP_RW as per example here:
https://www.libsdl.org/projects/SDL_image/docs/SDL_image_16.html#SEC16
#include <stdio.h>
#include "SDL/SDL.h"
#include "SDL/SDL_image.h"
int main(int argc, char *argv[])
{
const char *fn = "sample.bmp";
SDL_Surface *surf;
if (argc > 1)
fn = argv[1];
if ((surf = SDL_LoadBMP(fn)) == NULL) {
printf("SDL_loadBMP failed: %s\n", SDL_GetError());
SDL_Quit();
return 1;
}
printf("%s is bmp\n", fn);
SDL_FreeSurface(surf);
SDL_Quit();
return 0;
}
Old answer:
Tested and validated:
#include <stdio.h>
#include "SDL/SDL.h"
#include "SDL/SDL_image.h"
int main(int argc, char *argv[])
{
const char *fn = "sample.bmp";
int v;
SDL_RWops *rwop;
if (argc > 1)
fn = argv[1];
if ((rwop = SDL_RWFromFile(fn, "rb")) == NULL) {
printf("SDL_RWFromFile failed: %s\n", SDL_GetError());
SDL_Quit();
return 1;
}
v = IMG_isBMP(rwop);
printf("%s is bmp = %d\n", fn, v);
SDL_FreeRW(rwop);
SDL_Quit();
return 0;
}
Compiled with:
gcc -Wall -Wextra -pedantic -o sdl sdl.c `sdl-config --libs` -lSDL_image
Yield for BMP images, e.g.:
$ ./sdltest lena.bmp
lena.bmp is bmp = 1