Update readme

README.md

@@ -3,29 +3,73 @@ PyAnvilEditor
 A python based library for loading and saving minecraft world files. The project includes a method for creating, editing, and saving nbt files as well as a method for loading worlds and editing the chunks and blocks within them.
 
 ## NBT
-The `nbt` module can load uncompressed binary data in nbt format. Calling `parse_nbt` on a stream of binary data will return a `CompoundTag` encoding the data in the stream. NBT decoding for Minecraft 1.13 includes the following tags:
-- `ByteTag`
-- `ShortTag`
-- `IntTag`
-- `LongTag`
-- `FloatTag`
-- `DoubleTag`
-- `ByteArray`
-- `IntArray`
-- `LongArray`
-- `StringTag`
-- `ListTag`
-- `CompundTag`
-
-Calling `serialize` on an nbt tag with a file stream will write the binary data of the nbt tag to the file.
+The `nbt` module is designed to load and save uncompressed binary data in nbt format. Calling `parse_nbt` on a stream of binary data will return a `CompoundTag` containing the data in the stream. NBT decoding for Minecraft 1.13 includes the following tags:
+- `ByteTag`: 8 bit, signed
+- `ShortTag`: 16 bit, signed
+- `IntTag`: 32 bit, signed
+- `LongTag`: 64 bit, signed
+- `FloatTag`: 32 bit, signed
+- `DoubleTag`: 64 bit, signed
+- `ByteArray`: List of nameless 8 bit signed numbers
+- `IntArray`: List of nameless 32 bit signed numbers
+- `LongArray`: List of nameless 64 bit signed numbers
+- `StringTag`: List of bytes representing UTF-8 chars
+- `ListTag`: List any other tag
+- `CompundTag`: Unordered list of named tags of any type
+
+Calling `serialize` on an nbt tag with a file stream will write the binary data of the nbt tag to the file. The `stream.Output` class can also be used to emulate a file buffer.
+
+For example, to get the name of a region from the `level.dat` file of a region folder:
+```python
+import nbt, stream, gzip
+
+# Open the file for reading in binary mode (level.dat is just gzipped)
+with gzip.open('level.dat', mode='rb') as level:
+    # Read the file in to an input stream
+    in_stream = stream.InputStream(level.read())
+    # Decode the stream
+    level_data = nbt.parse_nbt(in_stream)
+    # Get the value of Data > LevelName
+    lvl_name = level_data.get("Data").get("LevelName").get()
+    # lvl_name is now a string containing the name of the level used
+
+```
 
 ## World
 The `world` module allows the modification and saving of a whole world file. An example of getting a single block using the world module might look like the following:
-```
+```python
 import world
-myWorld = world.World("myWorld")
-myBlockPos = (15, 10, 25)
-myBlock = myWorld.get_block(myBlockPos)
+
+# Load the world folder relative to the current working dir
+with world.World('myWorld') as myWorld:
+    # All locations are stored as tuples
+    myBlockPos = (15, 10, 25)
+    # Get the block object at the given location
+    myBlock = myWorld.get_block(myBlockPos)
+    # Set the state of the block to an iron block
+    myBlock.set_state(world.BlockState('minecraft:iron_block', {}))
+
+# Once the with closes, the world is saved
 ```
 
-`myBlock` now contains the name and properties of the block state at the given location.
+## Canvas
+The `canvas` module allows for easy drawing within a world object. The canvas can draw:
+- Squares
+- Disks
+- Cubes
+- Spheres
+- Pyramids
+
+To use the canvas, we simply make a new instance an pass in the world we want to use:
+```python
+import world, canvas
+
+# Load the world folder relative to the current working dir
+with world.World('myWorld') as myWorld:
+    # create the canvas to draw on
+    cvs = canvas.Canvas(myWorld)
+    # draw a disk centered at (10, 10, 10) and made of gold ore block
+    cvs.brush(world.BlockState('minecraft:gold_ore', {})).disk((10, 10, 10))
+
+# Once the world is closed, the changes have been saved and can be viewed in game
+```