// Shared reproduction: continuously blow plain bagged sand straight above a stationary bot.
function pileBlowSetup() {
  pileCutWorld();
  for (let x=0;x<W;x++) { surfY[x]=480; dirtY[x]=490; }
  computeAmbient();
  for(let y=0;y<H;y++)for(let x=0;x<W;x++) {
    const i=y*W+x;mat[i]=y>=480?STONE:EMPTY;flags[i]=y>=480?F_NAT:0;temp[i]=AMB[y];
  }
  bot.x=384-bot.w/2;bot.y=330-bot.h/2;bot.vx=bot.vy=0;
  bag[SAND]=40000;bagTotal=40000;updateRoof();
}
function pileBlowStroke() { toolBlow(383.5,250,6,SAND); }
function pileBlowProfile() {
  let cliff=0,previous=0,grains=0,height=0;
  for(let x=0;x<W;x++) {
    let y=0;while(y<480&&mat[y*W+x]!==SAND)y++;
    const h=480-y;cliff=Math.max(cliff,Math.abs(h-previous));previous=h;height=Math.max(height,h);
    for(;y<480;y++)if(mat[y*W+x]===SAND)grains++;
  }
  return {cliff,height,grains,flying:flyers.length,bag:bagTotal,awake:awake.filter(v=>v).length};
}