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Creating a basic game, and failing!

spy4hearts (11)
I cannot seem to make my spike move! can you point out what I am doing wrong?

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#include <cstdlib>
#include <ctime>

using namespace std;

#include "SDL.h"

#define SCREEN_WIDTH  640
#define SCREEN_HEIGHT 480
#define SPRITE_SIZE    32

#ifdef main
#undef main
#endif

int main ( int argc, char *argv[] )
{
    int spikeX;
    int spikeY;
    
    srand((unsigned)time(0)); 
   
int lowest=1, highest=640; 
int range=(highest-lowest)+1; 
int random_integer = lowest+int(range*rand()/(RAND_MAX + 1.0)); 

    

  SDL_Surface *screen, *ntemp, *temp, *sprite, *spike, *grass;
  SDL_Rect rcSprite, rcSpike, rcGrass;
  SDL_Event event;
  Uint8 *keystate;

  int colorkey, gameover;
  
    if (SDL_Init(SDL_INIT_VIDEO) != 0) {
    fprintf(stderr, "Unable to initialize SDL: %s\n", SDL_GetError());
    return false;
  }
  atexit(SDL_Quit);

  /* initialize SDL */
  SDL_Init(SDL_INIT_VIDEO);

  /* set the title bar */
  SDL_WM_SetCaption("SDL Move", "SDL Move");

  /* create window */
  screen = SDL_SetVideoMode(SCREEN_WIDTH, SCREEN_HEIGHT, 0, 0);

  /* load sprite */
  temp   = SDL_LoadBMP("sprite.bmp");
  sprite = SDL_DisplayFormat(temp);
  SDL_FreeSurface(temp);
  
    ntemp   = SDL_LoadBMP("spike.bmp");
  spike = SDL_DisplayFormat(ntemp);
  SDL_FreeSurface(ntemp);

  /* setup sprite colorkey and turn on RLE */
  colorkey = SDL_MapRGB(screen->format, 255, 0, 255);
  SDL_SetColorKey(sprite, SDL_SRCCOLORKEY | SDL_RLEACCEL, colorkey);

  /* load grass */
  temp  = SDL_LoadBMP("grass.bmp");
  grass = SDL_DisplayFormat(temp);
  SDL_FreeSurface(temp);

  /* set sprite position */
 
  rcSprite.x = 320;
  rcSprite.y = 220;
  
  rcSpike.x = random_integer;
  rcSpike.y = 0;
  
  gameover = 0;
// load spike

  

  
  /* message pump */
  while (!gameover)
  {
    /* look for an event */
    if (SDL_PollEvent(&event)) {
      /* an event was found */
      switch (event.type) {
        /* close button clicked */
        case SDL_QUIT:
          gameover = 1;
          break;

        /* handle the keyboard */
        case SDL_KEYDOWN:
          switch (event.key.keysym.sym) {
            case SDLK_ESCAPE:
            case SDLK_q:
              gameover = 1;
              break;
          }
          break;
      }
    }

    /* handle sprite movement */
    keystate = SDL_GetKeyState(NULL);
    if (keystate[SDLK_LEFT] ) {
      rcSprite.x -= 2;
    }
    if (keystate[SDLK_RIGHT] ) {
      rcSprite.x += 2;
    }
    if (keystate[SDLK_UP] ) {
      rcSprite.y -= 2;
    }
    if (keystate[SDLK_DOWN] ) {
      rcSprite.y += 2;
    }
    if (keystate[SDLK_a] ) {
      rcSprite.x -= 4;
    }
    if (keystate[SDLK_d] ) {
      rcSprite.x += 4;
    }
    if (keystate[SDLK_w] ) {
      rcSprite.y -= 4;
    }
    if (keystate[SDLK_s] ) {
      rcSprite.y += 4;
    }
    /* collide with edges of screen */
    
    
    if ( rcSprite.x < 0 ) {
      rcSprite.x = 0;
    }
    else if ( rcSprite.x > SCREEN_WIDTH-SPRITE_SIZE ) {
      rcSprite.x = SCREEN_WIDTH-SPRITE_SIZE;
    }
    if ( rcSprite.y < 0 ) {
      rcSprite.y = 0;
    }
    else if ( rcSprite.y > SCREEN_HEIGHT-SPRITE_SIZE ) {
      rcSprite.y = SCREEN_HEIGHT-SPRITE_SIZE;
    }

    /* draw the grass */
    for (int x = 0; x < SCREEN_WIDTH / SPRITE_SIZE; x++) {
      for (int y = 0; y < SCREEN_HEIGHT / SPRITE_SIZE; y++) {
        rcGrass.x = x * SPRITE_SIZE;
        rcGrass.y = y * SPRITE_SIZE;
        SDL_BlitSurface(grass, NULL, screen, &rcGrass);
      }
    }
    /* draw the sprite */
    SDL_BlitSurface(sprite, NULL, screen, &rcSprite);
    SDL_BlitSurface(spike, NULL, screen, &rcSpike);
    /* update the screen */
    SDL_UpdateRect(screen, 0, 0, 0, 0);
  }
  system("PAUSE");
  /* clean up */
  SDL_FreeSurface(spike);
  SDL_FreeSurface(sprite);
  SDL_FreeSurface(grass);
  SDL_Quit();


}


eventually I want to make an actual game from this mess, but just trying to get the prelims done, and I have no real idea what I am doing

oh! using DevC++ and SDL!
Last edited on
Umz (205)
return from main i think
firedraco (6241)
Yeah, main returns an int so you MUST return a value.
spy4hearts (11)
ok kinda figured it out, 

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#include <cstdlib>
#include <ctime>

using namespace std;

#include "SDL.h"

#define SCREEN_WIDTH  640
#define SCREEN_HEIGHT 480
#define SPRITE_SIZE    32

#ifdef main
#undef main
#endif

int main ( int argc, char *argv[] )
{
    int spikeX;
    int spikeY;
    
    srand((unsigned)time(0)); 
   
int lowest=5, highest=200; 
int range=(highest-lowest)+1; 
int random_integer = lowest+int(range*rand()/(RAND_MAX + 1.0)); 

    

  SDL_Surface *screen, *ntemp, *temp, *sprite, *spike, *grass;
  SDL_Rect rcSprite, rcSpike, rcGrass;
  SDL_Event event;
  Uint8 *keystate;

  int colorkey, gameover;
  
    if (SDL_Init(SDL_INIT_VIDEO) != 0) {
    fprintf(stderr, "Unable to initialize SDL: %s\n", SDL_GetError());
    return false;
  }
  atexit(SDL_Quit);

  /* initialize SDL */
  SDL_Init(SDL_INIT_VIDEO);

  /* set the title bar */
  SDL_WM_SetCaption("SDL Move", "SDL Move");

  /* create window */
  screen = SDL_SetVideoMode(SCREEN_WIDTH, SCREEN_HEIGHT, 0, 0);

  /* load sprite */
  temp   = SDL_LoadBMP("sprite.bmp");
  sprite = SDL_DisplayFormat(temp);
  SDL_FreeSurface(temp);
  
    ntemp   = SDL_LoadBMP("spike.bmp");
  spike = SDL_DisplayFormat(ntemp);
  SDL_FreeSurface(ntemp);

  /* setup sprite colorkey and turn on RLE */
  colorkey = SDL_MapRGB(screen->format, 255, 0, 255);
  SDL_SetColorKey(sprite, SDL_SRCCOLORKEY | SDL_RLEACCEL, colorkey);

  /* load grass */
  temp  = SDL_LoadBMP("grass.bmp");
  grass = SDL_DisplayFormat(temp);
  SDL_FreeSurface(temp);

  /* set sprite position */
 
  rcSprite.x = 320;
  rcSprite.y = 220;
  
  rcSpike.x = random_integer;
  rcSpike.y = 10;
  
  gameover = 0;
// load spike

  

  
  /* message pump */
  while (!gameover)
  {
    /* look for an event */
    if (SDL_PollEvent(&event)) {
      /* an event was found */
      switch (event.type) {
        /* close button clicked */
        case SDL_QUIT:
          gameover = 1;
          break;

        /* handle the keyboard */
        case SDL_KEYDOWN:
          switch (event.key.keysym.sym) {
            case SDLK_ESCAPE:
            case SDLK_q:
              gameover = 1;
              break;
          }
          break;
      }
    }

    /* handle sprite movement */
    keystate = SDL_GetKeyState(NULL);
    if (keystate[SDLK_LEFT] ) {
      rcSprite.x -= 2;
    }
    if (keystate[SDLK_RIGHT] ) {
      rcSprite.x += 2;
    }
    if (keystate[SDLK_UP] ) {
      rcSprite.y -= 2;
    }
    if (keystate[SDLK_DOWN] ) {
      rcSprite.y += 2;
    }
    if (keystate[SDLK_a] ) {
      rcSprite.x -= 4;
    }
    if (keystate[SDLK_d] ) {
      rcSprite.x += 4;
    }
    if (keystate[SDLK_w] ) {
      rcSprite.y -= 4;
    }
    if (keystate[SDLK_s] ) {
      rcSprite.y += 4;
    }
     rcSpike.y +=2;
    /* collide with edges of screen */
    
    
    if ( rcSprite.x < 0 ) {
      rcSprite.x = 0;
    }
    else if ( rcSprite.x > SCREEN_WIDTH-SPRITE_SIZE ) {
      rcSprite.x = SCREEN_WIDTH-SPRITE_SIZE;
    }
    if ( rcSprite.y < 0 ) {
      rcSprite.y = 0;
    }
    else if ( rcSprite.y > SCREEN_HEIGHT-SPRITE_SIZE ) {
      rcSprite.y = SCREEN_HEIGHT-SPRITE_SIZE;
    }
    if ( rcSpike.x < 0 ) {
      rcSpike.x = random_integer;
    }
    else if ( rcSpike.x > SCREEN_WIDTH-SPRITE_SIZE ) {
      rcSpike.x = SCREEN_WIDTH-SPRITE_SIZE;
    }
    if ( rcSpike.y < 0 ) {
      rcSpike.y = 0;
    }
    else if ( rcSpike.y > SCREEN_HEIGHT-SPRITE_SIZE ) {
      rcSpike.y = SCREEN_HEIGHT-SPRITE_SIZE;
    }
    if ( (rcSprite.x == rcSpike.x) && (rcSprite.y == rcSpike.y )){
       rcSpike.y = 10;
       rcSpike.x = random_integer;
       
       }
    

    /* draw the grass */
    for (int x = 0; x < SCREEN_WIDTH / SPRITE_SIZE; x++) {
      for (int y = 0; y < SCREEN_HEIGHT / SPRITE_SIZE; y++) {
        rcGrass.x = x * SPRITE_SIZE;
        rcGrass.y = y * SPRITE_SIZE;
        SDL_BlitSurface(grass, NULL, screen, &rcGrass);
      }
    }
    /* draw the sprite */
    SDL_BlitSurface(sprite, NULL, screen, &rcSprite);
    SDL_BlitSurface(spike, NULL, screen, &rcSpike);
    /* update the screen */
    SDL_UpdateRect(screen, 0, 0, 0, 0);
  }
  /* clean up */
  SDL_FreeSurface(spike);
  SDL_FreeSurface(sprite);
  SDL_FreeSurface(grass);
  SDL_Quit();


}


now I need to figure out how to test for when the two objects are within 15 pixels of each other! Thank you for your input!

ps. I don't think that I need to return anything because I don't want the program to quit unless I click the x on the window.
Last edited on
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