Coordinates Tutor in MakeCode for Minecraft

 

main screen

We recently developed a game to demonstrate a player’s knowledge of MakeCode Minecraft coordinates. Soon as The Girl started testing it, we realized that a more tutorial program was needed to assist in learning coordinates. Coordinates Tutor — this program — was born..

How to Play Coordinates Tutor

After the user types run in the command window, the Coordinates Tutor will move to a new, pristine  world location, print a compass in the sky for the player’s reference, place a grid of blocks with a cyan glass block at the origin, which is the variable name we give to the 0 0 point in the grid where the X and Z axes intersect.

After initialization, the program will display the left scene then the right to remind the player that in MakeCode Minecraft coding, a coordinate  X is east, Z is south and Y is up. We do not use Y here because it is always the same.

{  X  Y  Z  }.

The positive X axis is east. If one thinks of herself, the player, as facing east, south will be on her right, north on her left, and west behind. Of course, the values X and Z can be negative as well as positive. A negative X is west and a negative Z is north.

When the right scene — {  E   S  } —  is displayed, Coordinates Tutor is waiting for the user to break any block in the grid. Please, break just one block.

broken block

After a block is broken, question marks will flash during the varying time that it takes for the program to search the grid to find the broken block.

When the program finds the broken block, the coordinates of the block will be printed between the brackets. The  broken block will be replaced with a green one, except for the origin block, which will be restored to a cyan block. The green block shown below is at coordinates { – 2 –  2 }.

coor display

At this point, the user may break another block and the program repeats. Coordinates Tutor is patient allowing a user to break blocks until she has absolutely mastered Minecraft coordinates. Then it is time to play Coordinates Game, which works in reverse: that is, when a coordinate is displayed, the user must break the block at the corresponding position on the grid.

The MakeCode Code

The Code Assumes a Flat World

This code assumes a flat world such as that described in MakeCode for Minecraft Sandbox World: Make It Flat and Simple.

Coordinates Tutor Starts with the Run Command

The on-chat run command initializes the program. The steps are:

  1. Teleport the player to an unused part of the world.
  2. Set the variable origin, which will be used as the reference position for all actions as well as the center of the coordinates grid.
  3. Set a position in the sky to be used as left reference point for the coordinate print area.
  4. Run the on-chat command compass to print E, S, W and N in the distant sky. compass runs while the code after it continues because it is an on-chat, not a function.
  5. Run the on-chat command brackets to print squiggly brackets on the left and right sides of where the coordinates will be printed.
  6. Call the function canvas to draw the grid for the coordinates.
  7. Call the function flashXZES, which will display X Z then E S, inside the brackets. This reminds the  player that the left coordinate is X and the right Is Z, or, equivalently, E and S.

run code

The Action Is in the Broken Events

When the player breaks a white, green or cyan stained glass block, which defines the grid, an on-broken event occurs, which for all three events results in the doBrokenEvent being run.

The doBrokenEvent function does the following:

  1. Sets the Boolean variable air_found to false. This variable will be set to true in the function findAir when the broken block is found.
  2. Set nPrints to 0. This variable will be incremented by 1 in one of the print commands launched by the run-chat flash_q.
  3. Launch chat command flash_q, which flashes questions marks inside the coordinate brackets until air_found is set to true in the findAir function.
  4. Call function findAir, which returns only after the broken block is found at which time it runs the chat command postCoordinates.
  5. The chat command postCoordinates prints the coordinate that was found, which is the coordinate of the broken block. postCoordinates is run as a chat, not a function, so that the on-broken event can complete. Although not required, this is neater than having the possibility of a second on-broken event occurring before the prior one has completed.

on break code

Searching for Air

The findAir function, searches the grid starting at coordinate  { -5  -5 } and searching to { 5  5 } for a position in the grid that is air instead of the glass block that was broken. To do the test, it uses the function testTryPositoin to determine air or not. The variable air_found was set to false before the function findAir was called. If air is found, the function testTryPosition sets air_found to true.

find air code

The function testTryPosition tests the Minecraft position to determine whether or not an air block is at that position. If it is not air, it returns doing nothing as air_found is already false. If air is found, it sets air_found to true and sets the airPositoin as well as air_X and air_Z. Note that airPositon has origin added because the Minecraft position is need to place the green block. However, air_X and air_Z are relative to origin; that is they are the coordinates on the grid, e.g. { ,-5  2 } because these variables will be used in posting the coordinate at which air was found. A green glass block is placed at the position at which air was found.

test try position code

The MakeCode Bug that Wasn’t

While coding testTryPosition, I became convinced that there was a MakeCode bug in testing position variables for equality. After some time trying the understand and prove the bug, which included writing a program to test for the bug in a less complex situation, I realized, as I have so many times before, that the bug was in my understanding of position variables. I will not go into the detail here, but take my word for it — if  you want to test a calculated position variable against another, test that all individual coordinates {X Y Z} pairwise for equality instead.

Print the Broken Block Coordinate

postCoordinate is a simple on-chat command that, if the broken block was found, prints the coordinate between the brackets. If the broken block was not found, which should never happen,  it prints red question marks between the brackets. Most of the code is to adjust the text for whether or not X and Z are negative.

post coordinates code

Simultaneous, Oscillating Print Until … Something Happens

I couldn’t resist explaining how the question marks print at the same time and are reprinted in another color block until the broken block is found. To review this short vid show this working.

The key to the simultaneity is using on-chat commands instead of a function or just doing the print blocks inline.  The changing colors are enabled by the variable nPrnts, which is incremented each time through the print blocks. Because the print blocks are run more or less simultaneously, nPrints must be incremented in only one of the print blocks; otherwise, the colors would get out of sync. The print blocks are in a while loop that tests air_found, which when true,   the prints stop enabling the coordinate of the broken block to be printed in the same spaces.

print q flasher code

Get the Code

Coordinates Tutor  code is shared on Code Connection at this URL

https://makecode.com/_d7PAhvEH98iy

To get and use the code, follow these steps.

Click the Import button import button , which is upper right in the Code Connection window just below the banner. This will open the window shown below.
Import choices

Click the Import URL button Import URL, which is on the right, to open the window shown below.

Import Copy link

Paste the URL supplied for the program you want to use in the space under the text “Copy the URL …”
import url with url

Click the Go ahead! button go ahead button.

The next window you will see will be the MakeCode window with the code downloaded from the URL. At this point, you can treat it like any other code, e.g., run it, save it locally, modify it, publish your changes or whatever else your heat desires.

We have tested several other methods of downloading the code using the URL, for example, pasting the URL in a browser. No joy. For more detailed instruction see our post How to Use Shared MakeCode on Microsoft Code Connection for Minecraft.

Using Minecraft Blocks as Buttons: Block-by-Block Tutorial Video in MakeCode for Minecraft

 

main

Strategy

The strategy for using Minecraft blocks as buttons to control a program is:

  1. Place the buttons on the screen in a place convenient to the player.
  2. In the block on-broken event, use the code that would have been in a on-chat command to do a sequence of actions,
  3. Replace the broken block with another of the same kind.

MakeCode Code

We modified the existing program described in Handy Timer — Block-by-Block Tutorial Video in MakeCode for Minecraft , to illustrate using Minecraft blocks as buttons. Only the changed code is described here.  This code assumes a flat world such as that described in MakeCode for Minecraft Sandbox World: Make It Flat and Simple.

The placeButtons Function

The placeButtons function does exactly what its name implies: it places each button that will be used in lieu of an on-chat command. I like to place the buttons in front of the player within easy reach so that the player need not move to break a block (click a button). In this case we placed red concrete to do the same thing as the stop on-chat command, yellow for the reset command and green for the go command.
Place button code

Call the placeButtons Function

Once the function is built, it must be called from every code that initializes a screen. Here it is called from on start and from moveMe. As explained in the next section, it is also called from each block’s on-broken event.

on start and moveme

Code the on-broken Events

Each block being used as a button must have an on-broken event in which the same code as in the corresponding on-chat command should be run. I like to move the code to a function, which is called from both the on-broken event and the on-chat command. The advantage of putting the code in a function is that if it is modified, it need be changed in only one place.

Each on-broken event must also call placeButtons. Of course, an on-broken event really must replace only the broken button, but the advantage of calling the placeButtons event is that if you want to futz with the location of the buttons, it need be changed only in one place — always a good thing.

all buttons code

Get the Code

Handy Timer with Blocks for Buttons code is shared on Code Connection at this URL

https://makecode.com/_iwCgCd5bsFxY

To get and use the code, follow these steps.

Click the Import button import button , which is upper right in the Code Connection window just below the banner. This will open the window shown below.
Import choices

Click the Import URL button Import URL, which is on the right, to open the window shown below.

Import Copy link

Paste the URL supplied for the program you want to use in the space under the text “Copy the URL …”
import url with url

Click the Go ahead! button go ahead button.

The next window you will see will be the MakeCode window with the code downloaded from the URL. At this point, you can treat it like any other code, e.g., run it, save it locally, modify it, publish your changes or whatever else your heat desires.

We have tested several other methods of downloading the code using the URL, for example, pasting the URL in a browser. No joy. For more detailed instruction see our post How to Use Shared MakeCode on Microsoft Code Connection for Minecraft.

More Grandma’s Chickens 2.0: A Makecode for Minecraft Game

 

Grandma’s Chickens is a game in which the player kills as many chickens as possible racing against the lightning strikes that may kill  chickens  and ocelots that may  eat them before the player can score a kill. Also, lightning might strike the fence making a hole through which chickens can escape.

A cowardly (or impatient) player will choose to use the sword, which is provided in the player inventory. In this case, chickens are killed with a single strike and the fence and ground will not be destroyed accidently. A more difficult version is to use the hand rather than the sword. In this case, it takes a few strikes to kill each chicken and it is frustratingly easy to accidently make holes in the fence or ground. During all this action, the score is updated in the sky. The game can be varied using the on-chat arguments for the size of the fence, the number of chickens and the number of ocelots.

Field GrandmasChickens

Strategy for the Design of the Grandma’s Chickens Game

The strategy for building Grandma’s Chickens was to spawn chickens and ocelots at random positions inside a wooden fence with the player at the center. The player can start killing chickens while they are being  spawned. The on-chicken-killed event keeps score and every few kills randomly spawns a lightning bolt at a random position inside and including the fence. If lightning strikes the fence, a hole is burned in the fence through which chickens can escape. When a chicken is killed, the score is updated by the on-chicken-killed event and printed in the sky.

The Code for Grandma’s Chickens

The key code is the on-chat command “run” and the on-chicken-killed event.

The steps for then on-chat command “run” and described in the following paragraphs.

Step 1: Set the global variable origin, which will be where the west-north corner of the fence is positioned.

Step 2: Store the arguments in global variables– nBLocksPerFenceSide, nChickens and nOcelots. Check the variables for allowed values, switching to defaults if needed. Say these values before and after the validity checks to be sure there is not a problem, like the one described in a MakeCode for Minecraft on Chat Command Arguments Problem (Bug?). Notice that if no arguments are given — “run” — the values are all zero and the defaults are used.

GrandmasChickes Code 1
Grandma’s Chickens Part 1 of 4

Step 3: Calculate fence parameters including the west-north corner (same as origin), the opposing east-south corner  and the center. If the argument for the number of blocks per side is even, increase it d by 1 so that it is odd. This enables an exact center block for the fence; that is, the center block has the exact same number of blocks on the left, right, in front and behind. Yes, I realize that this is being a bit too meticulous. It’s a programmer thing.

GrandmasChickes Code 2

Grandma’s Chickens Run —  Part 2 of 4

Step 4: Move the player to just outside the fence so she will not be in the way. Yes, I know that this is probably not necessary.

Step 5: Build the fence according to the previously calculated parameters.

Step 6: Call the function makeEastPointerFromOrigin, which helps the programmer visualize the fence construction.

Step 7: Give the player a sword to provide the option of striking chickens with a more powerful weapon than just the hand. Using a sword makes the game easier to play, but personally, I prefer the more difficult version using the hand.

Step 8: Initialize the score to zero and print it in the sky.

GrandmasChickes Code 3

Grandma’s Chickens Run —  Part 3 of 4

Step 9: Set the boundaries for spawning chickens and ocelots one block inside the fence. Spawn the number of chickens and ocelots specified by the global variables nChickens and nOcelots, which were set to the values passed in the on-chat arguments or to the default values if on-chat had no arguments or were invalid values.

GrandmasChickes Code 4

Grandma’s Chickens Run —  Part 4 of 4

Grandmas chickens on start On start initializes the values for the global variables. Here it was automatically generated by MakeCode as JavaScript statements. 

An essential part of the Grandma’s Chickens game is the on-animal-chicken-killed event, which  is run when a chicken is killed by the player. Each time the event is triggered, 1 is added to the score and the score is printed in the sky. A random number is picked from the sequence 0, 1, 2. If the random number is 1, a lightning -bolt projectile is spawned at or inside the fence. The number 1 is arbitrary and could have been any of the three number 0, 1 or 2. It simply enables a 1 in 3 chance of the lightning striking.  If the lightning hits the fence, it burns a hole in the fence through which chickens and ocelots can escape. The lightning also sets fire to the grass, which can be annoying when one is in a panic to kill chickens.

Grandmas Chickens kill
grandmas chickens giveswords

The function giveMeSwords first clears the player’s inventory and then gives the player a sword that can be used to kill chickens more efficiently than just the hand. A function was chosen to implement this code rather than coding it inline, so that other items could be easily added to the player inventory to experiment with the game without cluttering the main code. For example, I have considered providing fence blocks so that the player can repair the fence.

Don’t Worry About the Chickens

I know you might be concerned about all those chickens being killed. Don’t be. They were born to be eaten by the hungry folks in the Minecraft world. On the humble farm where I grew up, chickens were feast food. I can still remember the anticipation of a festive meal when my mother was in the yard plucking the chicken feathers from a fine bird that my father had just killed.

Of course, We Are Working on Grandma’s Chickens 3.0

We have lots of ideas for making Grandma’s Chickens even more interesting and fun. We hope you have some, too. We would very much like for you to build on our code.

Get the Code

Grandma’s Chickens 2.0  code is shared on Code Connection at this URL

 https://makecode.com/_RFUKHraM7Tbp

To get and use the code, follow these steps.

Click the Import button import button , which is upper right in the Code Connection window just below the banner. This will open the window shown below.
Import choices

Click the Import URL button Import URL, which is on the right, to open the window shown below.

Import Copy link

Paste the URL supplied for the program you want to use in the space under the text “Copy the URL …”
import url with url

Click the Go ahead! button go ahead button.

The next window you will see will be the MakeCode window with the code downloaded from the URL. At this point, you can treat it like any other code, e.g., run it, save it locally, modify it, publish your changes or whatever else your heat desires.

We have tested several other methods of downloading the code using the URL, for example, pasting the URL in a browser. No joy. For more detailed instruction see our post How to Use Shared MakeCode on Microsoft Code Connection for Minecraft.

Bang! — Simulating an On-TNT-Exploded Event in MakeCode for Minecraft

 

Bang Code

The Bang program  places TNT in the ground of a flat world. It then places a  flint and steel item in the player inventory. The player is teleported to within a few blocks above the TNT so that the TNT can be ignited. 

I wanted the player to be way high above the TNT area so that the full effect of the explosion could be seen. After igniting the TNT, it is hard to manually fly the player rapidly enough and high enough to catch the full view. What I needed was a TNT-Exploded event that, when triggered, would teleport the player high enough to get the desired view. But after reading, searching and experimenting, I didn’t find a way to do this with MakeCode’s built-in events (e.g., on block destroyed).

My solution was to simulate a TNT-Exploded event. The key idea was that after the event is enabled, it repeatedly tests the block under origin. The block is originally grass,  then replaced by TNT, and  when the TNT explodes, it is destroyed and replaced by air. When the event is enabled and the test for air succeeds, the TNT has exploded and the player is teleported high in the sky.

Before running bang, be sure the player is flying; otherwise, she will fall all the way to  bedrock after the teleport. I would like to find a way to programmatically put the player in flying mode, but haven’t found it as of this writing.

The implementation of the TNT-Exploded event uses the global variable TNT_eventEnabled, which is false until the TNT is in place and the player is in position to ignite it. Once the event is enabled, the forever loop, which runs repeatedly, proceeds to test for air under origin. When air is found, the player is teleported sky high and the event is disabled so that it will run only once for each run of bang.

Event

Bang is a companion program to Flat Fixer. Using the two programs, Bang can make a mess and Flat Fixer can clean it up again and again and …

Get the Code

Bang! code is shared on Code Connection at this URL

https://makecode.com/_LC4dzUPe4bYg

To get and use the code, follow these steps.

Click the Import button import button , which is upper right in the Code Connection window just below the banner. This will open the window shown below.
Import choices

Click the Import URL button Import URL, which is on the right, to open the window shown below.

Import Copy link

Paste the URL supplied for the program you want to use in the space under the text “Copy the URL …”
import url with url

Click the Go ahead! button go ahead button.

The next window you will see will be the MakeCode window with the code downloaded from the URL. At this point, you can treat it like any other code, e.g., run it, save it locally, modify it, publish your changes or whatever else your heat desires.

We have tested several other methods of downloading the code using the URL, for example, pasting the URL in a browser. No joy. For more detailed instruction see our post How to Use Shared MakeCode on Microsoft Code Connection for Minecraft.