Method relightBlock

src/main/java/net/minecraft/world/chunk/Chunk.java:400–506

Initiates the recalculation of both the block-light and sky-light for a given block inside a chunk.

(int x, int y, int z)

     * Initiates the recalculation of both the block-light and sky-light for a given block inside a chunk.
     */
    private void relightBlock(int x, int y, int z)
    {
        int i = this.heightMap[z << 4 | x] & 255;
        int j = i;

        if (y > i)
        {
            j = y;
        }

        while (j > 0 && this.getBlockLightOpacity(x, j - 1, z) == 0)
        {
            --j;
        }

        if (j != i)
        {
            this.worldObj.markBlocksDirtyVertical(x + this.xPosition * 16, z + this.zPosition * 16, j, i);
            this.heightMap[z << 4 | x] = j;
            int k = this.xPosition * 16 + x;
            int l = this.zPosition * 16 + z;

            if (!this.worldObj.provider.getHasNoSky())
            {
                if (j < i)
                {
                    for (int j1 = j; j1 < i; ++j1)
                    {
                        ExtendedBlockStorage extendedblockstorage2 = this.storageArrays[j1 >> 4];

                        if (extendedblockstorage2 != null)
                        {
                            extendedblockstorage2.setExtSkylightValue(x, j1 & 15, z, 15);
                            this.worldObj.notifyLightSet(new BlockPos((this.xPosition << 4) + x, j1, (this.zPosition << 4) + z));
                        }
                    }
                }
                else
                {
                    for (int i1 = i; i1 < j; ++i1)
                    {
                        ExtendedBlockStorage extendedblockstorage = this.storageArrays[i1 >> 4];

                        if (extendedblockstorage != null)
                        {
                            extendedblockstorage.setExtSkylightValue(x, i1 & 15, z, 0);
                            this.worldObj.notifyLightSet(new BlockPos((this.xPosition << 4) + x, i1, (this.zPosition << 4) + z));
                        }
                    }
                }

                int k1 = 15;

                while (j > 0 && k1 > 0)
                {
                    --j;
                    int i2 = this.getBlockLightOpacity(x, j, z);