Copyright © 2015 – Curt Hill Minecraft Blocks Properties and Methods.

Copyright © 2015 – Curt Hill

Minecraft Blocks

Properties and Methods

Introduction• Blocks are basic to Minecraft• The environment is constructed

from blocks• We have seen how to construct

blocks and to give them textures• We now delve into some of their

properties and methods • Most properties have a set method


Recall• There are several things that you

should recall from the first mod presentation– Making a derivation of Block– Building the constructor– Invoking the ancestral constructor with

super– Setting the name– Setting the texture– Putting into a tab– Registering the block

• We will not redo those hereCopyright © 2015 – Curt Hill

Generally• The properties and methods are

generally in Block• We change using a set method

– Sometimes there is a get method, other times not

• If this is a derived class we may go after properties directly

• Sometimes the property has a different type than the set method

• We may add properties and methods but do not expect the game to use them


Hardness

• blockHardness is a float• setHardness(float) is the method• Determines difficulty in breaking

the block– Higher numbers indicate harder items

• The next screen has a partial table of hardnesses


Hardness


Block Hardness Block Hardness Block Hardness

Grass 0 Melon 1.0 Iron bars 5.0

Fire 0 Stone 1.5 Anvil 5.0

TNT 0 Wood 2.0 Block Iron 5

Snow 0.2 Bricks 2.0 Block Coal 5

Glass pane

0.3 Craft Table

2.5 Obsidian 50

Ladder 0.4 Gold ore 3.0 Lava 100

Ice 0.5 Coal Ore 3.0 Bedrock Infinite

Reality

• Hardness determines how many time you must hit it depending on tool– (In reality, we have hardness and

brittleness and others as well – consider glass and iron)

• The hardness determines the wear on tools


Resistance• How does it hold up to a blast• Field is float blockResistance• Method is setResistance(float)• Resistance is similar to hardness

– The higher the number the less damage

• The resistance and hardness values do not have to correlate


Resistance


Block Resistance

Block Resistance Block Resistance

Grass 0 Melon 5 Iron bars 30

Fire 0 Wood 10 Block Coal

30

TNT 0 Craft Table

12.5 Block Iron

30

Snow 1 Gold ore 15 Lava 500

Glass pane

1.5 Coal Ore 15 Obsidian 6000

Ladder 2 Stone 30 Anvil 6000

Ice 2.5 Bricks 30 Bedrock 18,000,000

Sounds

• What sound does the block make• stepSound is Block.SoundType• Method: setStepSound

(Block.SoundType)• There are several static sounds• See the next table


Static Sounds


soundTypeAnvil soundTypeMetal

soundTypeCloth soundTypePiston

soundTypeGlass soundTypeSandsoundTypeGrass

soundTypeSnow

soundTypeGravel

soundTypeStone

soundTypeLadder

soundTypeWood

Opacity• How much light may pass through the

block• boolean opaque

– No method sets this– boolean isOpaqueCube() shows

• int lightOpacity– setLightOpacity(int) – Also int getLightOpacity()

• Opaque is 16, translucent is 0• The texture must allow light through• This may affect reflectivity


Light Level• How much light does this emit?

– Normally none

• int lightValue• setLightLevel (float)• No light is 0, full sunlight is 1.0• Notice local variable and method do

not match– It appears that 0 is no light and 15 is

full– Exceeding 0-1 bounds gives the

rendering engine fitsCopyright © 2015 – Curt Hill

Luninescent Block


Behavior• Most of what we have seen so far

are static properties• We typically set them near to

construction time and then never touch them again

• Next we look at dynamic things– Harvesting– Event handlers

• These do not typically work in creative modeg


The Harvest

• Harvesting is when a block is broken and yields an item

• This is managed by a several things:– Method setHarvestLevel– Overridden method getItemDropped– Overridden method quantityDropped


Harvest Level

• What tool at what level breaks the block

• setHarvestLevel(String, int)• The string is a tool name• The int determines how long it

takes• Any registered tool should work


Dropping an Item

• Once the block is broken two methods are called to drop something

• quantityDropped returns the integer number to make

• getItemDropped returns an Item handle

• Both of these should be prefixed by @Override


quantityDropped

• Signature:public int quantityDropped (Random r);

• We will consider Random next• Use random to determine how

many you return• There are others as well


Random

• This is not part of the game, but is in java.util.Random

• Gives a variety of random number forms

• Has a variety of methods that give random values


Random Methods• Has a variety of methods of form:

– nextX()– Where x is a type– nextInt, nextBoolean, nextDouble, etc– These give a uniform distribution

• nextInt(int n) gives integer in range 0-(n-1)

• nextGaussian gives a normally distributed double in range 0-1


GetItemDropped• Signature:public Item getItemDropped (int meta, Random random, int fortune)

• Where:– meta is metadata about the item– fortune is intended to increase

production

• The return is a registered item– An unregistered item crashes the

systemCopyright © 2015 – Curt Hill

The Item• You may return any item you want

that is registered• If there is only one type of Item to

return then have a static variable hold it

• You may use the Random variable to choose one of several items to return

• This is where GameRegistry.findItem can be used


Example


The Ons• There are a variety of methods

that start with on• These are all event handlers• They all need to be prefixed by

@Override• Typically they need to also call the

super.on… method to make sure other functions continue

• Today we look at two– onEntityWalking– onEntityCollidedWithBlock


onEntityCollidedWithBlock

• This event occurs when an entity collides with this block

• The signature:public void onEntityCollidedWithBlock( World w, int p_1, int p_2, int p_3, Entity ent)


onEntityWalking

• This event occurs when an entity walks over the block

• The signature:public void onEntityWalking( World w, int p_1, int p_2, int p_3, Entity ent)


Some others of interest


• onBlockExploded (World w, int x, int y, int z, Explosion exp)

• onNeighborChange (IBlockAccess world, int x, int y, int z, int tileX, int tileY, int tileZ)

An Example

• What will follow is some code on a new block: LightBlock

• This uses several of these properties and methods


Light Block Beginnings


public class LightBlock extends Block{

// For harvestItem drop=null;// For light output boolean bright = false;

Light Block Constructor


public LightBlock(Material mat){ super(mat); setBlockName("LightBlock"); setBlockTextureName( CurtMod.MODID + ":LightBlock"); setCreativeTab( CreativeTabs.tabBlock); setHarvestLevel("pickaxe",8); setStepSound(Block.soundTypeMetal); setLightLevel(0.05f); drop = CurtModItems.curtItem;}

// For harvestItem drop=null;// For light output boolean bright = false;

getItemDropped


@Overridepublic Item getItemDropped( int meta, Random random, int fortune){ return drop;}

Better


@Overridepublic Item getItemDropped(int meta, Random random, int fortune){Item drop=null;int r = random.nextInt(3);switch(r){ case 0: drop = GameRegistry.findItem( "minecraft", "feather"); break;… case 2: drop = GameRegistry.findItem( "minecraft", "emerald"); break; } // Case end return drop;}

quantityDropped


@Overridepublic int quantityDropped (Random random){ // range is [1-4] int result = random.nextInt(3)+1; return result; } // quantity dropped

Collisions 1


public class LightBlock@Overridepublic void onEntityCollidedWithBlock (World w, int p_1, int p_2, int p_3, Entity ent){ super.onEntityCollidedWithBlock (w,p_1, p_2, p_3,ent); // See next page

Collisions 2


// Flip the light emittingfloat light;if(bright) light = 0.05F;else light = 0.95F;bright = !bright;setLightLevel(light);}

Walked on


@Overridepublic void onEntityWalking( World w, int p_1, int p_2, int p_3, Entity ent){ super.onEntityWalking( w, p_1,p_2,p_3,ent); float light; if(bright) light = 0.05F; else light = 0.95F; bright = !bright; setLightLevel(light);}

More to Come

• Another thing that is fundamental to the play of the game is recipes– How are simpler things transformed

into tools?

• This we must cover in another presentation


Date post:	29-Dec-2015
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Copyright © 2015 – Curt Hill Minecraft Blocks Properties and Methods.

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