#define STRENGTH_SCALE  1.5e7
#define SPRING_SCALE    6.0e6
#define COST_SCALE      375.0
#define MASS_RADIUS     3.0
#define MASS_MASS       10.0
#define WIRE_PERCENT    0.99

#define RIVER_BANK_COLS 5
#define SKY_LINES       40

#define FIXED_X1        ((RIVER_BANK_COLS-1)*FONT_WIDTH)
#define FIXED_X2        ((RIVER_BANK_COLS-4)*FONT_WIDTH)
#define FIXED_X3        (TEXT_COLS*FONT_WIDTH>>1)
#define FIXED_Y1        ((SKY_LINES+1)*FONT_HEIGHT)
#define FIXED_Y2        ((SKY_LINES+5)*FONT_HEIGHT)
#define FIXED_Y3        ((TEXT_ROWS-8)*FONT_HEIGHT)

#define LOAD_WEIGHTS    8

U0 SpanBridge1Init(CMathODE *)
{
  I64 i;
  MyMass *tmpm;
  tmpm=PlaceMass(GR_WIDTH-FIXED_X1,FIXED_Y1);
  tmpm->flags|=MSF_FIXED;
  tmpm=PlaceMass(GR_WIDTH-FIXED_X2,FIXED_Y1);
  tmpm->flags|=MSF_FIXED;
  tmpm=PlaceMass(GR_WIDTH-FIXED_X1,FIXED_Y2);
  tmpm->flags|=MSF_FIXED;
  tmpm=PlaceMass(FIXED_X1,FIXED_Y1);
  tmpm->flags|=MSF_FIXED;
  tmpm=PlaceMass(FIXED_X2,FIXED_Y1);
  tmpm->flags|=MSF_FIXED;
  tmpm=PlaceMass(FIXED_X1,FIXED_Y2);
  tmpm->flags|=MSF_FIXED;
  tmpm=PlaceMass(FIXED_X3,FIXED_Y3);
  tmpm->flags|=MSF_FIXED;
  for (i=0; i<LOAD_WEIGHTS; i++)
  {
    tmpm=PlaceMass(FIXED_X1+(i+1)*(GR_WIDTH-2*FIXED_X1)/(LOAD_WEIGHTS+1),
                   FIXED_Y1);
    tmpm->load_t=(i+1.0)/LOAD_WEIGHTS;
    tmpm->color=RED;
  }
  DocClear;
  "$BG,LTCYAN$%h*c"
  ,SKY_LINES,'\n';
  for (i=0; i<10; i++)
  {
    "$BG,BROWN$%h*c",RIVER_BANK_COLS,CH_SPACE;
    "$BG,LTCYAN$%h*c"
    ,TEXT_COLS-2*RIVER_BANK_COLS,CH_SPACE;
    "$BG,BROWN$%h*c\n"
    ,RIVER_BANK_COLS,CH_SPACE;
  }
  for (i=0; i<5; i++)
  {
    "$BG,BROWN$%h*c",RIVER_BANK_COLS+i,CH_SPACE;
    "$BG,BLUE$%h*c"
    ,TEXT_COLS/2-RIVER_BANK_COLS-2*i,CH_SPACE;
    "$BG,BROWN$%h*c"
    ,2*i,CH_SPACE;
    "$BG,BLUE$%h*c"
    ,TEXT_COLS/2-RIVER_BANK_COLS-2*i,CH_SPACE;
    "$BG,BROWN$%h*c\n"
    ,RIVER_BANK_COLS+i,CH_SPACE;
  }
}

U0 AdjustLoads(CMathODE *ode)
{
  MyMass *tmpm=ode->next_mass;
  F64 d,tt=SpanTime/10.0;
  while (tmpm!=&ode->next_mass)
  {
    if (tmpm->load_t)
    {
      if (tt)
      {
        d=Abs(Sin(tmpm->load_t*pi+tt)); //0.0<=d<=1.0
        tmpm->mass=100.0*Sqr(Sqr(d+1.0));
        tmpm->radius=7.0*d+2.0;
      }
      else
      {
        tmpm->mass=MASS_MASS;
        tmpm->radius=MASS_RADIUS;
      }
    }
    tmpm=tmpm->next;
  }
}