c++ - SDL, How can I make the background picture render? -

i had render problem, fixed that. problem is, picture won't show up. know picture gets loaded because have error handler if isn't loaded. know code messy, need picture show up.

#include <sdl/sdl.h> #include <stdio.h> #include <iostream> #include <fstream> #include <string> using namespace std;  const int fps = 60;  sdl_window *window;   int main(int argc, char **argv) {     sdl_init(sdl_init_everything);     window = sdl_createwindow("", 300, 100, 1024, 800, sdl_window_opengl);      if (window == null)     {         cout << ("could not create window: %s/n", sdl_geterror());         return 1;     }     sdl_renderer *renderer = sdl_createrenderer(window, -1, 0);     int x = 0, y = 0;     sdl_surface  *screen;     sdl_surface *background = sdl_loadbmp("hockeyrink.bmp");     if(background == null)     {         sdl_showsimplemessagebox(0, "background init error",         sdl_geterror(), window);     }      if(renderer == null)     {         sdl_showsimplemessagebox(0, "renderer init error", sdl_geterror(), window);     }     sdl_texture *texture = sdl_createtexturefromsurface(renderer,background);     if(texture == null)     {         sdl_showsimplemessagebox(0, "texture init error", sdl_geterror(), window);     }      const int speed = 5;     sdl_rect camera;     camera.x = 0; //don't worry camera, need after background working.     camera.y = 0;     camera.w = 800;     camera.h = 600;     bool b[2] = {0,0};     uint32 start;      bool running = true;     while (running)     {         start = sdl_getticks();         sdl_event event;          while(sdl_pollevent(&event))         {             switch(event.type)             {             case sdl_quit:                 running = false;                 sdl_destroytexture(texture);                 sdl_freesurface(background);                 sdl_destroyrenderer(renderer);                 sdl_destroywindow(window);                 sdl_quit();                 break;             case sdl_keydown:                 switch(event.key.keysym.sym)                 {                 case sdlk_up:                     b[0]=1;                     break;                 case sdlk_left:                     b[1]=1;                     break;                 }                 break;             case sdl_keyup:                 switch(event.key.keysym.sym)                 {                 case sdlk_up:                     b[0]=0;                     break;                 case sdlk_left:                     b[1]=0;                     break;                 }                 break;             }         }          if(b[0])         {             x+=speed;             camera.y+=speed;             if (camera.y > 3000-800)             {                 camera.y=0;             }          }         else if(b[1])         {             x-=speed;             camera.y-=speed;              if (camera.y <= 0)             {                 camera.y = 2000-800;             }               sdl_rendercopy(renderer, texture, null, null);             sdl_renderpresent(renderer);         }         if(1000/fps>sdl_getticks()-start)         {             sdl_delay(1000/fps-(sdl_getticks() - start));         }     }      return 0; } 

you have initialized b[1] 0 , texture rendered when b[1] 1 in code.
should either put lines:

sdl_rendercopy(renderer, texture, null, null);  sdl_renderpresent(renderer); 

before loop,
or press left key of keyboard(i.e. sdlk_left)
render , present image on screen.

it works in system, should work in yours, too.