Pressure sensor

int update_PRSN(UPDATE_FUNC_ARGS) {
	int r, rx, ry, rt;
	for (rx=-2; rx<3; rx++)
		for (ry=-2; ry<3; ry++)
			if (x+rx>=0 && y+ry>0 && x+rx<XRES && y+ry<YRES && (rx || ry))
			{
				r = pmap[y+ry][x+rx];
				if (!r)
					continue;
				rt = parts[r>>8].type;
				if (parts_avg(i,r>>8,PT_INSL) != PT_INSL)
	{
	if (parts[i].temp>=256.0+273.15)
			parts[i].temp=256.0+273.15;
		if (parts[i].temp<= -256.0+273.15)
			parts[i].temp = -256.0+273.15;

		if (pv[y/CELL][x/CELL]+273.14 > parts[i].temp)
		{
			if ((ptypes[rt].properties&PROP_CONDUCTS) && parts[r>>8].life==0 && abs(rx)+abs(ry) < 4)
			{
				parts[r>>8].life = 4;
				parts[r>>8].ctype = rt;
				part_change_type(r>>8,x+rx,y+ry,PT_SPRK);
			}
		}
	}
			}
		return 0;
}