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SDL_CreateSoftwareRenderer behaves strangely
grougrou


Joined: 06 Apr 2016
Posts: 1
Post Posted: Fri Apr 08, 2016 10:37 pm
Hello

I had a question, do we have to do something special when using a renderer created with
Code:
SDL_CreateSoftwareRenderer
because in my code when I use render created with
Code:
SDL_CreateRenderer
every thing is drawing great but when using
Code:
 SDL_CreateSoftwareRenderer
some draw command do not have any effet one the surface whyle other are working great here is what I did

I used
Code:
SDL_CreateSoftwareRenderer
to creat a renderer which renders to a surface and then I display that surface (or use it) which is in fact the window surface. (I need a surface for some reason...).

The rendering is then made in a loop :
Code:

        SDL_SetRenderDrawColor(gRenderer, 0XFF, 0XFF, 0X00, 0XFF);
      SDL_RenderClear(gRenderer);
      SDL_SetRenderDrawColor(gRenderer, 0X0F, 0X00, 0XF0, 0XFF);
      SDL_SetRenderDrawColor(gRenderer, 0X0F, 0X00, 0XF0, 0XFF);
      SDL_Rect rect;
      rect.x = 0;
      rect.y = 5;
      rect.w = 10;
      rect.h = 2;
      SDL_RenderFillRect(gRenderer, &rect);
      std::cout << "begin" << std::endl;

      for (auto& i : zIndexOrder) {
         //Rectangles[i]->get_x();
         Rectangles[i]->updat_move_fnct();
         if (Rectangles[i]->everyframe_fct != NULL)Rectangles[i]->everyframe_fct(Rectangles[i]);
         //Rectangles[i]->index_th = i;
      }
      for (auto u : Underwindows)u->Refresh();

      for (auto& i : zIndexOrder)Rectangles[i]->draw(this);
      
      
      SDL_SetRenderDrawColor(gRenderer, 0X0F, 0X00, 0XF0, 0XFF);
      rect.x = 0;
      rect.y = 5;
      rect.w = 5;
      rect.h = 5;
      SDL_RenderFillRect(gRenderer, &rect);

      std::cout << "true RENDERER " << gRenderer << std::endl;

        if (SOFTWARE_RENDERING) SDL_UpdateWindowSurface(gWindow);
      else SDL_RenderPresent(gRenderer);

The two rectangle drawn here with
Code:
SDL_RenderFillRect(gRenderer, &rect);
draw fine but, in
Code:
ectangles[i]->draw(this);
If I make the same call It doesn't work I mean I call

Code:
    SDL_SetRenderDrawColor(f->get_screen_render(), 0X0F, 0X00, 0XF0, 0XFF);
            SDL_Rect rect;
            rect.x = 6;
            rect.y = 5;
            rect.w = 10;
            rect.h = 55;
            SDL_RenderFillRect(f->get_screen_render(), &rect);

in
Code:
rectangles[i]->draw(this);
and the rectangle doesn't draw.

notice that the three rectangles are from different size to see the differences, the clear color is not the same as the draw color,
Code:
f->get_screen_render()
gives the same pointer to the renderer as the one in the two other call , and this part of the code is execute (I know this thanks to the console), and finally it executes between the two other draw. Note that those 3 rectangles ar only debug rectangle to show my problem but rectangle are drown on over parts.

I wonder why everything works with render created with
Code:
SDL_CreateRenderer
and not with
Code:
 SDL_CreateSoftwareRenderer


Thank you
capehill


Joined: 13 Feb 2016
Posts: 18
Post Posted: Sat Apr 09, 2016 1:25 pm
Code:

 if (SOFTWARE_RENDERING) SDL_UpdateWindowSurface(gWindow);
 else SDL_RenderPresent(gRenderer);


Without full source code, hard to understand what is going on but I guess the above code might be the problem. If you draw with a renderer, SW or not, you should call SDL_RenderPresent.