scrolling_text.c

#include "scrolling_text.h"

static scrolling_text *first_text = NULL;
static scrolling_text *last_text = NULL;
static TTF_Font *scrolling_font[s_text_frames];

static void scrolling_text_exit(void)
{
  int counter;
  for(counter = 0; counter < s_text_frames; counter++)
    TTF_CloseFont(scrolling_font[counter]);
  
  free_all_scrolling_texts();
}
int init_scrolling_text()
{
  int counter = 0;
  while(counter < s_text_frames)
  {
    if(!(scrolling_font[counter] = TTF_OpenFont("gfx/LiberationSans-Regular.ttf", counter + 15)))
      return 0;
    
    counter++;
  }
  
  atexit(scrolling_text_exit);
  
  return 1;
}

scrolling_text *new_scrolling_text(const double x, const double y, const char *text,
                                   const Uint8 r, const Uint8 g, const Uint8 b)
{
  /* allocate memory and set new text to last text */
  if(!first_text)
  {
    first_text = (scrolling_text *)malloc(sizeof(scrolling_text));
    if(!first_text)
      return NULL;
    
    first_text->next = NULL;
    first_text->prev = NULL;
    last_text = first_text;
  }
  else
  {
    last_text->next = (scrolling_text *)malloc(sizeof(scrolling_text));
    if(!last_text->next)
      return NULL;
    
    last_text->next->prev = last_text;
    last_text->next->next = NULL;
    last_text = last_text->next;
  }
  
  /* set text properties */
  strncpy(last_text->text, text, TEXT_BUFFER);
  last_text->color.r = r;
  last_text->color.g = g;
  last_text->color.b = b;
  
  last_text->x = x;
  last_text->y = y;
  
  last_text->start_time = SDL_GetTicks();
  
  return last_text;
}
scrolling_text *new_scrolling_int(const double x, const double y, const int value,
                                  const Uint8 r, const Uint8 g, const Uint8 b)
{
  char tmp_string[TEXT_BUFFER] = {0};
  
  sprintf(tmp_string, "%i", value);
  
  return new_scrolling_text(x, y, tmp_string, r, g, b);
}
void free_scrolling_text(scrolling_text *scr_text)
{
  if(!scr_text)
    return;
  
  if(scr_text == first_text)
  {
    first_text = scr_text->next;
    
    if(scr_text->next)
      scr_text->next->prev = NULL;
    else
      last_text = NULL;
  }
  else if(scr_text == last_text)
  {
    scr_text->prev->next = NULL;
    last_text = scr_text->prev;
  }
  else
  {
    scr_text->next->prev = scr_text->prev;
    scr_text->prev->next = scr_text->next;
  }
  
  free(scr_text);
}

void blit_all_scrolling_texts(SDL_Surface *dst)
{
  SDL_Rect tmp_dst;
  
  SDL_Surface *cache_surface = NULL;
  
  scrolling_text *tmp_text = first_text;
  scrolling_text *cache_text = NULL;
  
  while(tmp_text)
  {
    /* remove timed out text */
    if(SDL_GetTicks() - tmp_text->start_time > s_text_duration)
    {
      cache_text = tmp_text;
      tmp_text = tmp_text->next;
      free_scrolling_text(cache_text);
      continue;
    }
    
    /* render damage text */
    cache_surface = TTF_RenderText_Blended(scrolling_font[(int)((SDL_GetTicks() - tmp_text->start_time)/(s_text_duration/s_text_frames + 1))],
                                          tmp_text->text, tmp_text->color);
    
    /* blit current damage_list element */
    tmp_dst.x = tmp_text->x - cache_surface->w/2;
    tmp_dst.y = tmp_text->y - cache_surface->h/2 - (int)((SDL_GetTicks() - tmp_text->start_time)/(s_text_duration/s_text_frames + 1)) * 1.5;
    SDL_BlitSurface(cache_surface, NULL, dst, &tmp_dst);
    
    SDL_FreeSurface(cache_surface);
    tmp_text = tmp_text->next;
  }
}
void extend_all_scrolling_texts_timestamp(const Uint32 time)
{
  scrolling_text *tmp_text = NULL;
  
  for(tmp_text = first_text; tmp_text; tmp_text = tmp_text->next)
    tmp_text->start_time += time;
}
void free_all_scrolling_texts(void)
{
  while(first_text)
    free_scrolling_text(first_text);
}