Possible to blit images with alpha mask onto transparent surface? - c++

Question

I am trying to do just that. I have an image of various tiles of an explosion in my game. I am trying to preprocess the explosion tiles and create the image and then blit it onto the screen.
Here is the tile sheet with the alpha mask:Explosion
Now, I want to blit these and have them maintain their alpha transparency onto a surface which I can then render.
Here is my code:
SDL_Surface* SpriteManager::buildExplosion(int id, SDL_Surface* image, int size)
{
// Create the surface that will hold the explosion image
SDL_Surface* explosion = SDL_CreateRGBSurface(SDL_HWSURFACE, size * 32 , size * 32, 32, 0, 0, 0, 255 );
// Our source and destination surfaces
SDL_Rect srcrect;
SDL_Rect dstrect;
int parentX = sprites[id].x;
int parentY = sprites[id].y;
int middle = size / 2;
// Create the first image
srcrect.x = sprites[id].imgBlockX * 32; // default for now
srcrect.y = sprites[id].imgBlockY * 32; // default for now
srcrect.w = 32;
srcrect.h = 32;
// Get the location it should be applied to
dstrect.x = middle * 32;
dstrect.y = middle * 32;
dstrect.w = 32;
dstrect.h = 32;
// Apply the texture
SDL_BlitSurface(image, &srcrect, explosion, &dstrect);
errorLog.writeError("Applying surface from x: %i y: %i to x: %i y:%i", srcrect.x, srcrect.y, dstrect.x, dstrect.y);
// Iterate through each explosion
for(int i = 0; i < sprites[id].children.size(); i++)
{
// Get the texture source
srcrect.x = 0; // default for now
srcrect.y = 0; // default for now
srcrect.w = 32;
srcrect.h = 32;
// Get the location it should be applied to
dstrect.x = sprites[id].children[i].x - parentX * 32;
dstrect.y = sprites[id].children[i].y - parentY * 32;
dstrect.w = 32;
dstrect.h = 32;
// Apply the texture
SDL_BlitSurface(image, &srcrect, explosion, &dstrect);
}
//return img;
return explosion;
}
I suspect it has to do with this line but I am really at a loss:
SDL_Surface* explosion = SDL_CreateRGBSurface(SDL_HWSURFACE, size * 32 , size * 32, 32, 0, 0, 0, 255 );
The SDL_Surface called image is the image I linked above just to make that clear. If anyone sees the error of my ways, many thanks!
My problem: The code above does either blits a completely invisible surface or a black surface with the images on them.
I guess I am curious if it possible to do what I described above and if I can modify this code to make that work.