#include <stdio.h>
#include <stdlib.h>

#include "SDL.h"

SDL_Surface *grass;
SDL_Surface *stone;

SDL_Surface *screen;

int tileW = 36;
int tileH = 18;
int mapX = 60;
int mapY = 10;
int movement= 2;

//ignore the way this is done, just set up to test a couple of tiles.
int mapArray[100][100];

void Slock(SDL_Surface *screen)
{
  if ( SDL_MUSTLOCK(screen) )
  {
    if ( SDL_LockSurface(screen) < 0 )
    {
      return;
    }
  }
}

void Sulock(SDL_Surface *screen)
{
  if ( SDL_MUSTLOCK(screen) )
  {
    SDL_UnlockSurface(screen);
  }
}

SDL_Surface * ImageLoad(char *file)
{
  SDL_Surface *temp1, *temp2;
  temp1 = SDL_LoadBMP(file);
  temp2 = SDL_DisplayFormat(temp1);
  SDL_FreeSurface(temp1);
  return temp2;
}

int InitImages()
{
  grass = ImageLoad("grass.bmp");
  stone = ImageLoad("stone.bmp");
  return 0;
}



void DrawIMG(SDL_Surface *img, int x, int y)
{
  SDL_Rect dest;
  dest.x = x;
  dest.y = y;
  SDL_BlitSurface(img, NULL, screen, &dest);
  SDL_UpdateRects(screen, 1, &dest);
}

void DrawIMG(SDL_Surface *img, int x, int y, int w, int h, int x2, int y2)
{
  SDL_Rect dest;
  dest.x = x;
  dest.y = y;
  SDL_Rect dest2;
  dest2.x = x2;
  dest2.y = y2;
  dest2.w = w;
  dest2.h = h;
  SDL_BlitSurface(img, &dest2, screen, &dest);
  SDL_Flip(screen);
}

void DrawMap(){

     Slock(screen);
     
     SDL_SetColorKey(stone, SDL_SRCCOLORKEY, SDL_MapRGB(stone->format, 255, 0, 255));
     SDL_SetColorKey(grass, SDL_SRCCOLORKEY, SDL_MapRGB(grass->format, 255, 0, 255));

     for(int j = 0; j < 100; j++){
          for(int i = 0; i < 100; i++){
               if(mapArray[j] == 0){
                    if(((tileW/2)*(j-i))+mapX < (640+tileW) && ((tileW/2)*(j-i))+mapX > (0-tileW)){
                         if(((tileH/2)*(j+i))+mapY < (480+tileH) && ((tileH/2)*(j+i))+mapY > (0-tileH)){
                              DrawIMG(stone, ((tileW/2)*(j-i))+mapX, ((tileH/2)*(j+i))+mapY);
                         }
                    }

               }
               else{
                    DrawIMG(grass, ((tileW/2)*(j-i))+mapX, ((tileH/2)*(j+i))+mapY);
               }
          }
     }

     Sulock(screen);
}

int main(int argc, char *argv[]){


     Uint8* keys;

//ignore the way this is done, just set up to test a couple of tiles.
     mapArray[1][1] = 1;
     mapArray[2][1] = 1;
     mapArray[4][1] = 1;
     mapArray[50][50] = 1;
     mapArray[40][35] = 1;
     mapArray[50][40] = 1;
     mapArray[40][35] = 1;

  if ( SDL_Init(SDL_INIT_AUDIO|SDL_INIT_VIDEO) < 0 )
  {
    printf("Unable to init SDL: %s\n", SDL_GetError());
    exit(1);
  }
  atexit(SDL_Quit);

  screen=SDL_SetVideoMode(640,480,32,SDL_SWSURFACE|SDL_HWPALETTE|SDL_DOUBLEBUF|SDL_ANYFORMAT);

  if ( screen == NULL )
  {
    printf("Unable to set 640x480 video: %s\n", SDL_GetError());
    exit(1);
  }

  InitImages();
  DrawMap();

  int done=0;

     while(done == 0){
          SDL_Event event;

          while ( SDL_PollEvent(&event) ){

               if ( event.type == SDL_QUIT )  {  done = 1;  }

               if ( event.type == SDL_KEYDOWN ){
                    if ( event.key.keysym.sym == SDLK_ESCAPE ) { done = 1; }
               }
          }
    keys = SDL_GetKeyState(NULL);

    if ( keys[SDLK_UP] ) { 
         mapY = mapY-movement; 
    }
    if ( keys[SDLK_DOWN] ) { 
         mapY = mapY+movement; 
    }

    if ( keys[SDLK_LEFT] ) { 
         mapX = mapX-movement; 
    }

    if ( keys[SDLK_RIGHT] ) { mapX = mapX+movement; 
    }

    DrawMap();


 }

  return 0;
}