Okay, so, I want to create a block which changes depending on if other blocks of the same block are next to it

 

Like with fences and redstone wire

 

If you've got redstone wire and place another redstone wire next to it, it changes to the line and the corners/crosses if you put more next to it

 

how does that work?

 

I know it's something to do with

 

    private void notifyWireNeighborsOfNeighborChange(World par1World, int par2, int par3, int par4)
    {
        if (par1World.getBlockId(par2, par3, par4) == this.blockID)
        {
            par1World.notifyBlocksOfNeighborChange(par2, par3, par4, this.blockID);
            par1World.notifyBlocksOfNeighborChange(par2 - 1, par3, par4, this.blockID);
            par1World.notifyBlocksOfNeighborChange(par2 + 1, par3, par4, this.blockID);
            par1World.notifyBlocksOfNeighborChange(par2, par3, par4 - 1, this.blockID);
            par1World.notifyBlocksOfNeighborChange(par2, par3, par4 + 1, this.blockID);
            par1World.notifyBlocksOfNeighborChange(par2, par3 - 1, par4, this.blockID);
            par1World.notifyBlocksOfNeighborChange(par2, par3 + 1, par4, this.blockID);
        }
    }

    /**
     * Called whenever the block is added into the world. Args: world, x, y, z
     */
    public void onBlockAdded(World par1World, int par2, int par3, int par4)
    {
        super.onBlockAdded(par1World, par2, par3, par4);

        if (!par1World.isRemote)
        {
            this.updateAndPropagateCurrentStrength(par1World, par2, par3, par4);
            par1World.notifyBlocksOfNeighborChange(par2, par3 + 1, par4, this.blockID);
            par1World.notifyBlocksOfNeighborChange(par2, par3 - 1, par4, this.blockID);
            this.notifyWireNeighborsOfNeighborChange(par1World, par2 - 1, par3, par4);
            this.notifyWireNeighborsOfNeighborChange(par1World, par2 + 1, par3, par4);
            this.notifyWireNeighborsOfNeighborChange(par1World, par2, par3, par4 - 1);
            this.notifyWireNeighborsOfNeighborChange(par1World, par2, par3, par4 + 1);

            if (par1World.isBlockNormalCube(par2 - 1, par3, par4))
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2 - 1, par3 + 1, par4);
            }
            else
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2 - 1, par3 - 1, par4);
            }

            if (par1World.isBlockNormalCube(par2 + 1, par3, par4))
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2 + 1, par3 + 1, par4);
            }
            else
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2 + 1, par3 - 1, par4);
            }

            if (par1World.isBlockNormalCube(par2, par3, par4 - 1))
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2, par3 + 1, par4 - 1);
            }
            else
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2, par3 - 1, par4 - 1);
            }

            if (par1World.isBlockNormalCube(par2, par3, par4 + 1))
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2, par3 + 1, par4 + 1);
            }
            else
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2, par3 - 1, par4 + 1);
            }
        }
    }

    /**
     * ejects contained items into the world, and notifies neighbours of an update, as appropriate
     */
    public void breakBlock(World par1World, int par2, int par3, int par4, int par5, int par6)
    {
        super.breakBlock(par1World, par2, par3, par4, par5, par6);

        if (!par1World.isRemote)
        {
            par1World.notifyBlocksOfNeighborChange(par2, par3 + 1, par4, this.blockID);
            par1World.notifyBlocksOfNeighborChange(par2, par3 - 1, par4, this.blockID);
            par1World.notifyBlocksOfNeighborChange(par2 + 1, par3, par4, this.blockID);
            par1World.notifyBlocksOfNeighborChange(par2 - 1, par3, par4, this.blockID);
            par1World.notifyBlocksOfNeighborChange(par2, par3, par4 + 1, this.blockID);
            par1World.notifyBlocksOfNeighborChange(par2, par3, par4 - 1, this.blockID);
            this.updateAndPropagateCurrentStrength(par1World, par2, par3, par4);
            this.notifyWireNeighborsOfNeighborChange(par1World, par2 - 1, par3, par4);
            this.notifyWireNeighborsOfNeighborChange(par1World, par2 + 1, par3, par4);
            this.notifyWireNeighborsOfNeighborChange(par1World, par2, par3, par4 - 1);
            this.notifyWireNeighborsOfNeighborChange(par1World, par2, par3, par4 + 1);

            if (par1World.isBlockNormalCube(par2 - 1, par3, par4))
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2 - 1, par3 + 1, par4);
            }
            else
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2 - 1, par3 - 1, par4);
            }

            if (par1World.isBlockNormalCube(par2 + 1, par3, par4))
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2 + 1, par3 + 1, par4);
            }
            else
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2 + 1, par3 - 1, par4);
            }

            if (par1World.isBlockNormalCube(par2, par3, par4 - 1))
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2, par3 + 1, par4 - 1);
            }
            else
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2, par3 - 1, par4 - 1);
            }

            if (par1World.isBlockNormalCube(par2, par3, par4 + 1))
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2, par3 + 1, par4 + 1);
            }
            else
            {
                this.notifyWireNeighborsOfNeighborChange(par1World, par2, par3 - 1, par4 + 1);
            }
        }
    }

 

 

and the textures are

 

    public void registerIcons(IconRegister par1IconRegister)
    {
        this.field_94413_c = par1IconRegister.registerIcon(this.func_111023_E() + "_" + "cross");
        this.field_94410_cO = par1IconRegister.registerIcon(this.func_111023_E() + "_" + "line");
        this.field_94411_cP = par1IconRegister.registerIcon(this.func_111023_E() + "_" + "cross_overlay");
        this.field_94412_cQ = par1IconRegister.registerIcon(this.func_111023_E() + "_" + "line_overlay");
        this.blockIcon = this.field_94413_c;
    }

    @SideOnly(Side.CLIENT)
    public static Icon func_94409_b(String par0Str)
    {
        return par0Str.equals("cross") ? Block.redstoneWire.field_94413_c : (par0Str.equals("line") ? Block.redstoneWire.field_94410_cO : (par0Str.equals("cross_overlay") ? Block.redstoneWire.field_94411_cP : (par0Str.equals("line_overlay") ? Block.redstoneWire.field_94412_cQ : null)));
    }

 

 

but I don't really get how it works

more in that I don't really get how it knows what texture to use

 

can anyone point me in the direction of a tutorial or explain how this sorta thing works?

Hi

 

The answers you're looking for are probably in here:

RenderBlocks.renderBlockRedstoneWire()

There is a section near the top that figures out how many neighbouring redstone blocks there are:

        boolean flag = BlockRedstoneWire.isPowerProviderOrWire(this.blockAccess, par2 - 1, par3, par4, 1) || !this.blockAccess.isBlockNormalCube(par2 - 1, par3, par4) && BlockRedstoneWire.isPowerProviderOrWire(this.blockAccess, par2 - 1, par3 - 1, par4, -1);
        boolean flag1 = BlockRedstoneWire.isPowerProviderOrWire(this.blockAccess, par2 + 1, par3, par4, 3) || !this.blockAccess.isBlockNormalCube(par2 + 1, par3, par4) && BlockRedstoneWire.isPowerProviderOrWire(this.blockAccess, par2 + 1, par3 - 1, par4, -1);
        boolean flag2 = BlockRedstoneWire.isPowerProviderOrWire(this.blockAccess, par2, par3, par4 - 1, 2) || !this.blockAccess.isBlockNormalCube(par2, par3, par4 - 1) && BlockRedstoneWire.isPowerProviderOrWire(this.blockAccess, par2, par3 - 1, par4 - 1, -1);
        boolean flag3 = BlockRedstoneWire.isPowerProviderOrWire(this.blockAccess, par2, par3, par4 + 1, 0) || !this.blockAccess.isBlockNormalCube(par2, par3, par4 + 1) && BlockRedstoneWire.isPowerProviderOrWire(this.blockAccess, par2, par3 - 1, par4 + 1, -1);
{etc}

par2, par3, par4 correspond to [x,y,z].

 

Based on these flags, the rendering code chooses the right icons to render (using tessellator.addVertexWithUV()...)

See also http://greyminecraftcoder.blogspot.com.au/2013/08/the-tessellator.html

 

Ah, awesome

I'll have a look into that thanks