imgLoadTextureTypedIo function image

Pointer<SdlTexture> imgLoadTextureTypedIo(Pointer<SdlRenderer> renderer, Pointer<SdlIoStream> src, bool closeio, String? type,)

Load an image from an SDL data source into a GPU texture.

An SDL_Texture represents an image in GPU memory, usable by SDL's 2D Render API. This can be significantly more efficient than using a CPU-bound SDL_Surface if you don't need to manipulate the image directly after loading it.

If the loaded image has transparency or a colorkey, a texture with an alpha channel will be created. Otherwise, SDL_image will attempt to create an SDL_Texture in the most format that most reasonably represents the image data (but in many cases, this will just end up being 32-bit RGB or 32-bit RGBA).

If closeio is true, src will be closed before returning, whether this function succeeds or not. SDL_image reads everything it needs from src during this call in any case.

Even though this function accepts a file type, SDL_image may still try other decoders that are capable of detecting file type from the contents of the image data, but may rely on the caller-provided type string for formats that it cannot autodetect. If type is NULL, SDL_image will rely solely on its ability to guess the format.

There is a separate function to read files from disk without having to deal with SDL_IOStream: IMG_LoadTexture("filename.jpg") will call this function and manage those details for you, determining the file type from the filename's extension.

There is also IMG_LoadTexture_IO(), which is equivalent to this function except that it will rely on SDL_image to determine what type of data it is loading, much like passing a NULL for type.

If you would rather decode an image to an SDL_Surface (a buffer of pixels in CPU memory), call IMG_LoadTyped_IO() instead.

When done with the returned texture, the app should dispose of it with a call to SDL_DestroyTexture().

\param renderer the SDL_Renderer to use to create the GPU texture. \param src an SDL_IOStream that data will be read from. \param closeio true to close/free the SDL_IOStream before returning, false to leave it open. \param type a filename extension that represent this data ("BMP", "GIF", "PNG", etc). \returns a new texture, or NULL on error.

\since This function is available since SDL_image 3.0.0.

\sa IMG_LoadTexture \sa IMG_LoadTexture_IO

extern SDL_DECLSPEC SDL_Texture * SDLCALL IMG_LoadTextureTyped_IO(SDL_Renderer *renderer, SDL_IOStream *src, bool closeio, const char *type)

Implementation

Pointer<SdlTexture> imgLoadTextureTypedIo(
  Pointer<SdlRenderer> renderer,
  Pointer<SdlIoStream> src,
  bool closeio,
  String? type,
) {
  final imgLoadTextureTypedIoLookupFunction = _libImage
      .lookupFunction<
        Pointer<SdlTexture> Function(
          Pointer<SdlRenderer> renderer,
          Pointer<SdlIoStream> src,
          Uint8 closeio,
          Pointer<Utf8> type,
        ),
        Pointer<SdlTexture> Function(
          Pointer<SdlRenderer> renderer,
          Pointer<SdlIoStream> src,
          int closeio,
          Pointer<Utf8> type,
        )
      >('IMG_LoadTextureTyped_IO');
  final typePointer = type != null ? type.toNativeUtf8() : nullptr;
  final result = imgLoadTextureTypedIoLookupFunction(
    renderer,
    src,
    closeio ? 1 : 0,
    typePointer,
  );
  calloc.free(typePointer);
  return result;
}