getAlphaModFloat method
Get the additional alpha value multiplied into render copy operations.
\param texture the texture to query. \param alpha a pointer filled in with the current alpha value. \returns true on success or false on failure; call SDL_GetError() for more information.
\threadsafety This function should only be called on the main thread.
\since This function is available since SDL 3.2.0.
\sa SDL_GetTextureAlphaMod \sa SDL_GetTextureColorModFloat \sa SDL_SetTextureAlphaModFloat
extern SDL_DECLSPEC bool SDLCALL SDL_GetTextureAlphaModFloat(SDL_Texture *texture, float *alpha)
{@category render}
Implementation
double? getAlphaModFloat() {
  double? result;
  final alphaPointer = calloc<Float>();
  if (sdlGetTextureAlphaModFloat(this, alphaPointer)) {
    result = alphaPointer.value;
  }
  calloc.free(alphaPointer);
  return result;
}