Method isInsideOfMaterial

src/main/java/net/minecraft/entity/Entity.java:1215–1233

Checks if the current block the entity is within of the specified material type

(Material materialIn)

     * Checks if the current block the entity is within of the specified material type
     */
    public boolean isInsideOfMaterial(Material materialIn)
    {
        double d0 = this.posY + (double)this.getEyeHeight();
        BlockPos blockpos = new BlockPos(this.posX, d0, this.posZ);
        IBlockState iblockstate = this.worldObj.getBlockState(blockpos);
        Block block = iblockstate.getBlock();

        if (block.getMaterial() == materialIn)
        {
            float f = BlockLiquid.getLiquidHeightPercent(iblockstate.getBlock().getMetaFromState(iblockstate)) - 0.11111111F;
            float f1 = (float)(blockpos.getY() + 1) - f;
            boolean flag = d0 < (double)f1;
            return !flag && this instanceof EntityPlayer ? false : flag;
        }
        else
        {
            return false;
        }
    }

    public boolean isInLava()
    {