Method canBlockFreeze

src/main/java/net/minecraft/world/World.java:2698–2732

Checks to see if a given block is both water and cold enough to freeze. @param pos The block coordinates @param noWaterAdj If true, this method will only return true if there is a non-water block immediately adjacent to the specified block

(BlockPos pos, boolean noWaterAdj)

     * to the specified block
     */
    public boolean canBlockFreeze(BlockPos pos, boolean noWaterAdj)
    {
        BiomeGenBase biomegenbase = this.getBiomeGenForCoords(pos);
        float f = biomegenbase.getFloatTemperature(pos);

        if (f > 0.15F)
        {
            return false;
        }
        else
        {
            if (pos.getY() >= 0 && pos.getY() < 256 && this.getLightFor(EnumSkyBlock.BLOCK, pos) < 10)
            {
                IBlockState iblockstate = this.getBlockState(pos);
                Block block = iblockstate.getBlock();

                if ((block == Blocks.water || block == Blocks.flowing_water) && iblockstate.getValue(BlockLiquid.LEVEL) == 0)
                {
                    if (!noWaterAdj)
                    {
                        return true;
                    }

                    boolean flag = this.isWater(pos.west()) && this.isWater(pos.east()) && this.isWater(pos.north()) && this.isWater(pos.south());

                    if (!flag)
                    {
                        return true;
                    }
                }
            }

            return false;
        }
    }

    private boolean isWater(BlockPos pos)
    {