Hi there,

A huge thank you to all who turned up in NUI, Galway today. There was a great turn out and it was a very successful event. CoderDojo Athenry was very well represented and we especially want to thank parents for their commitment, we know its hard to keep everything going. A special thank you to our Core mentors who turned up today and really helped with the smooth running of the event.

Here are the “Cheat Sheets” from the Scratch session today in case any one would like them. Scratch_CheatSheet.pdf

Hi again everyone,

This week we improved on our Ghostcatcher game from last week.

We introduced two new concepts which we haven’t used before, animation and broadcasting.

Using a simple technique of changing between costumes and having a waiting time we can animate our Sprites. In our case, we animated the Ghosts so they were blinking or sticking out their tongue. You could of course use this technique to have a sprite look like they are walking etc.

We also then had our first introduction to Broadcasting, which is a way of exchanging data/messages between our sprites.

We used Broadcasting to send a message from the Ghosts (that they have been eaten) to be received by the Pacman, who then will change costumes i.e. Open and close its mouth.

Hope you all enjoyed the session and we will be using animation and broadcasting over the next couple of months.

Here are this weeks notes in PDF CDA-S4-Week_04-BetterGhostCatcher.pdf

Hope I see a lot of you next week in NUI, Galway, it should be a great day!!

To prepare for MineVention, a handful of you will be making Java mods. This is the first of the posts showing you what to do.

You need to download the following:

• Eclipse Standard from http://www.eclipse.org/downloads/
• Forge SRC for 1.7.2: http://files.minecraftforge.net/maven/net/minecraftforge/forge/1.7.2-10.12.0.999/forge-1.7.2-10.12.0.999-src.zip
• Eclipse should include Java, but if it does not, you may need to download the Java Development Kit (JDK) SE (standard edition) from http://java.oracle.com (note: don’t just download the JRE, Java Runtime Environment, as you will be developing Java programs, not just running them)

The steps to install the Forge Java modding environment are below.

To install Eclipse:

• Eclipse does not have an installer: you just unzip and run it.
• Create a folder C:\Eclipse, copy your Eclipse zip file into it, and extract it
• In the sub-folder, find Eclipse.exe: make a shortcut to it on your desktop
• Start it up and make sure it works
• We can write a first “Hello World” program: see below.

To install Forge: http://www.minecraftforge.net/wiki/Installation/Source

• Extract the Forge .zip file to a new folder -> C:\Forge
• Open a Command Prompt/CMD window

In that CMD window, navigate to C:\Forge. Use cd .. a few times to go up a level to C:, and cd Forge to go to the Forge folder.
Now run this command (followed by the second gradlew command, see below):
gradlew.bat setupDecompWorkspace –refresh-dependencies

Let the installer download all necessary files. This takes 20-30 minutes. Watch out for errors!

• It will download MCP (Minecraft Coders Pack) automatically, as well as libraries
• It will then download assets. These are non-code elements of Minecraft, e.g. language files, music files, record audio, sounds and more. These are now stored in a folder called “assets” under the “.minecraft” folder.
• Finally, it will begin decompiling the Minecraft source code. When finished, you will have a new folder inside your “forge” folder called “mcp”.
• Finally, create an Eclipse workspace for Forge with this command:
  gradlew.bat eclipse

Start up Eclipse and select the workspace that Forge created, in the Eclipse folder under Forge:

Note: if the workspace is empty, make sure that you ran the command gradlew eclipse and that you selected the correct folder.

Press the green Run icon: you should see messages in the Eclipse console window and Minecraft will launch and will initially have 3 mods.

This week in Scratch Advanced we looked at two areas of scratch that are really useful to get the hang of if you want to build cool games.

Custom Blocks

Scratch comes with many blocks built in, but custom blocks let you actually create your own blocks that you can re-use over and over.  Using custom blocks can make your scripts much tidier and shorter and easier to write.  They are similar to broadcasts, but better because you can pass values to them to make them behave differently.

To create a custom block you go to the “more blocks” menu and add a block.

Give the block a name that describes what it is doing – in the example here I call it “jump”

You can see this is really handy and lets us add jump to our sprite easily without having to copy lots of code around.  You can make it even better by adding “inputs” to the block.

To add an input expand the “options” on the block and click the input for the data type you want – in the case of jump, height might make sense as shown below.

Now we have a jump block that will let us use the block for a normal jump and a super jump – maybe after a powerup or whatever.  You can see how handy this could be for anything you want to do over and over!  If you find yourself writing similar code in more than one place for a sprite, it might be a good time to think about writing a custom block.  One thing we didn’t mention on Saturday which is worth a look is the option for “run without screen refresh”.  When this is pressed, a block will run very quickly and only update the screen when it’s done.  This can be a way to speed up things like drawing programs.  Try it out on the jump example above to see what it does.  When it’s clicked, it will look like the sprite doesn’t do anything.. this is because he jumped up and right down again only updating when the block was finished – and he was right back where he started!.

Writing a Square Block

On Saturday, we used custom blocks to write a function to draw a square using a pen.   Then we showed how easy it was to create nice patterns by just calling the block different ways.

The code we came up with for the block was:

We spent a fair bit of time thinking about X and Y coordinates in Scratch and how to figure out where to move your sprite to get the shapes you want.  One example of how to use our new block is below.  Lots of the clever scratchers came up with much cooler ones than this though!!