GUI Debug String with mutable arguments in C

#include <stdio.h> 
char vstr_bur[64];
void DB_Prt(char idx, char* char_ptr, ... ){
  va_list args;
  int i;
  static char tempstr[20][64]={""};
  static char index=0;
  char prt_idx=0;
  //const int left=800-6*64-20;
  const int left=800-6*64-20;

  va_start(args, char_ptr);
  vsprintf(vstr_bur, char_ptr, args);
  va_end(args);

  printf("%s",vstr_bur);
  if(idx != 0)
    index = idx;
  GUI_SetTextMode(GUI_TM_NORMAL);
  GUI_SetFont(&GUI_Font6x8);
  GUI_SetColor(GUI_WHITE);
  GUI_SetBkColor(GUI_TRANSPARENT);
  if(index >=20) index=0;
  strncpy(tempstr[index], vstr_bur, sizeof(tempstr[0])-1);
  #if 1
  GUI_DispStringAtCEOL(tempstr[index],left+10,10+index*10);
  #elif 0
  for(i=(index +1 )%20;i<20;i++,prt_idx++){
    if(i == index )
      GUI_DispStringAt("*",left,10+prt_idx*10);
    else
      GUI_DispStringAt(" ",left,10+prt_idx*10);
    GUI_DispStringAtCEOL(tempstr[prt_idx],left+10,10+prt_idx*10);
  }
  if(index!=19){
    for(i=0;i<=index;i++,prt_idx++){
      if(i == index )
        GUI_DispStringAt("*",left,10+prt_idx*10);
      else
        GUI_DispStringAt(" ",left,10+prt_idx*10);
      GUI_DispStringAtCEOL(tempstr[prt_idx],left+10,10+prt_idx*10);
    }
  }
  #else
  for(i=0;i<20;i++){
    if(i == index )
      GUI_DispStringAtCEOL("*",left,10+i*10);
    else
      GUI_DispStringAtCEOL(" ",left,10+i*10);
    GUI_DispStringAtCEOL(tempstr[i],left+10,10+i*10);
  }
  #endif
  index++;
  GUI_SetTextMode(GUI_TM_TRANS);	//透明文本
}
//#define printf(...)  DB_Prt(0,__VA_ARGS__)

#不定參數 C 語言

#GUI 除錯字串