title: How to blend two SDL2 textures to one texture?
body: <pre><code>SDL_RenderClear(g_ren);
  
  SDL_Texture *tex_bk = SDL_CreateTextureFromSurface(g_ren, bk);
  
  SDL_Texture *tex_des = SDL_CreateTextureFromSurface(g_ren, widget);
  SDL_RenderCopy(g_ren, tex_bk, NULL, NULL);
  SDL_SetTextureBlendMode(tex_des,blendMode);
  SDL_SetRenderDrawBlendMode(g_ren,blendMode);
  
  SDL_RenderCopy(g_ren, tex_des, NULL, NULL);
  
  SDL_RenderPresent(g_ren);
  SDL_DestroyTexture(tex_des);
  SDL_DestroyTexture(tex_bk);
  </code></pre>
  
  <p>I want use SDL_RenderCopy to copy the tex_bk and second time I use the SDL_RenderCopy blend the tex_des  .but the application always show the tex_des image.tex_bk image always disappear.</p>