// Downhill screen whose outlet belt sits level with its last block (the jam the owner saw).
globalThis.jointScene = function(level = true) {
  const bx = Math.floor((SX - 100) / BS), by = Math.floor((SY + 12) / BS) - 8;
  for(let y=by*BS-64;y<by*BS+96;y++)for(let x=(bx-12)*BS;x<(bx+24)*BS;x++){const i=y*W+x;bgm[i]=0;setCell(i,y>=by*BS+88?STONE:EMPTY,20,0);}
  money=1e6;weather.next=1e15;
  for(let k=0;k<5;k++)placeBlock(BP_FILTER_DOWN,128,bx+k,by+k,true,{m:[GRAVEL],inv:0});
  for(let k=1;k<=5;k++)placeBlock(BP_BELT,1,bx-k,by,true);
  for(let k=5;k<10;k++)placeBlock(BP_BELT,1,bx+k,by+4+(level?0:1),true);
  for(let t=0;t<900;t++){for(let h=1;h<=6;h++){const i=(by*BS-h)*W+(bx-4)*BS+(t%3);if(mat[i]===EMPTY)setCell(i,COAL,20,0);}simTick();}
  CAM=[(bx+4)*BS,(by+3)*BS];updateRoof();
};