diff --git a/.gitignore b/.gitignore
index 9ae3a0d..2aad1b7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,4 +5,5 @@
 *.o
 main
 *.so
-*.dylib
\ No newline at end of file
+*.dylib
+__pycache__
\ No newline at end of file
diff --git a/include/opengl.h b/include/opengl.h
index 1545e24..03483de 100644
--- a/include/opengl.h
+++ b/include/opengl.h
@@ -7,6 +7,7 @@ extern "C" {
 void * read_file(const char * filename, int * out_size);
 
 unsigned int compile_from_files(const char * vertex_path,
+                                const char * geometry_path,
                                 const char * fragment_path);
 
 #ifdef __cplusplus
diff --git a/main.lua b/main.lua
index 0672ade..8161182 100644
--- a/main.lua
+++ b/main.lua
@@ -40,9 +40,6 @@ function love.run()
                return a or 0, b
             end
          end
-         if name == "keypressed" then
-            keypressed(a, b, c)
-         end
       end
 
       local dt = love.timer.step()
@@ -52,5 +49,7 @@ function love.run()
 
       love.graphics.present()
       love.timer.sleep(0.001)
+      local fps = love.timer.getFPS( )
+      print(fps)
    end
 end
diff --git a/minecraft/block_id_to_texture_id.data b/minecraft/block_id_to_texture_id.data
deleted file mode 100644
index 94099df..0000000
Binary files a/minecraft/block_id_to_texture_id.data and /dev/null differ
diff --git a/minecraft/gen/blocks.py b/minecraft/gen/blocks.py
index 6f3905b..e877391 100644
--- a/minecraft/gen/blocks.py
+++ b/minecraft/gen/blocks.py
@@ -101,4 +101,6 @@ with open("block_id_to_texture_id.data", "wb") as f:
     for i in range(256):
         value = lookup.get(i, unk)
         f.write(struct.pack("<i", value))
-        print(str(value)+',')
+        print(str(value).rjust(3), end=', ')
+        if i % 16 == 15:
+            print()
diff --git a/minecraft/gen/mc.py b/minecraft/gen/mc.py
index 6ce3435..c159bc1 100644
--- a/minecraft/gen/mc.py
+++ b/minecraft/gen/mc.py
@@ -1,238 +1,11 @@
-# https://minecraft.fandom.com/wiki/Region_file_format
-# https://minecraft.wiki/w/NBT_format#Binary_format
-# https://minecraft.wiki/w/Chunk_format/McRegion
-
 import sys
 import struct
 from pprint import pprint
-import zlib
-import enum
-from dataclasses import dataclass
 from itertools import chain
 
-def _parse_locations(mem, offset):
-    for i in range(1024):
-        ix = offset + i * 4
-        chunk_location, = struct.unpack(">I", mem[ix:ix+4])
-        chunk_offset = (chunk_location >> 8) & 0xffffff
-        chunk_sector_count = chunk_location & 0xff
-        yield chunk_offset, chunk_sector_count
-
-def parse_locations(mem, offset):
-    locations = list(_parse_locations(mem, offset))
-    return offset + 1024 * 4, locations
-
-def _parse_timestamps(mem, offset):
-    for i in range(1024):
-        ix = offset + i * 4
-        timestamp, = struct.unpack(">I", mem[ix:ix+4])
-        yield timestamp
-
-def parse_timestamps(mem, offset):
-    timestamps = list(_parse_timestamps(mem, offset))
-    return offset + 1024 * 4, timestamps
-
-def print_locations(locations):
-    for y in range(32):
-        for x in range(32):
-            offset, count = locations[y * 32 + x]
-            print(str(offset).rjust(4), end=' ')
-        print()
-
-class CountZeroException(Exception):
-    pass
-
-def parse_payload(mem, location):
-    offset, count = location
-    if count == 0:
-        raise CountZeroException()
-    ix = offset * 4096
-    payload = mem[ix:ix + count * 4096]
-    length, = struct.unpack(">I", payload[0:4])
-    assert length <= count * 4096, (length, count)
-    compression_type = payload[4]
-    data = payload[5:5 + (length - 1)]
-    assert compression_type == 2, compression_type
-    uncompressed = zlib.decompress(data)
-    return memoryview(uncompressed)
-
-class TAG:
-    Byte = 0x01
-    Short = 0x02
-    Int = 0x03
-    Long = 0x04
-    Float = 0x05
-    Double = 0x06
-    ByteArray = 0x07
-    String = 0x08
-    List = 0x09
-    Compound = 0x0a
-
-@dataclass
-class Byte:
-    name: str
-    value: int
-
-@dataclass
-class Short:
-    name: str
-    value: int
-
-@dataclass
-class Int:
-    name: str
-    value: int
-
-@dataclass
-class Long:
-    name: str
-    value: int
-
-@dataclass
-class Float:
-    name: str
-    value: float
-
-@dataclass
-class Double:
-    name: str
-    value: float
-
-@dataclass
-class ByteArray:
-    name: str
-    value: bytes
-
-@dataclass
-class String:
-    name: str
-    value: str
-
-@dataclass
-class List:
-    name: str
-    items: list
-
-@dataclass
-class Compound:
-    name: str
-    tags: list
-
-def indent(level):
-    return "  " * level
-
-def parse_tag_inner(mem, offset, level, tag_type, name):
-    payload = mem[offset:]
-    if tag_type == TAG.Byte:
-        value, = struct.unpack(">b", payload[0:1])
-        return offset + 1, Byte(name, value)
-    if tag_type == TAG.Short:
-        value, = struct.unpack(">h", payload[0:2])
-        return offset + 2, Short(name, value)
-    elif tag_type == TAG.Int:
-        value, = struct.unpack(">i", payload[0:4])
-        return offset + 4, Int(name, value)
-    elif tag_type == TAG.Long:
-        value, = struct.unpack(">q", payload[0:8])
-        return offset + 8, Long(name, value)
-    elif tag_type == TAG.Float:
-        value, = struct.unpack(">f", payload[0:4])
-        return offset + 4, Float(name, value)
-    elif tag_type == TAG.Double:
-        value, = struct.unpack(">d", payload[0:8])
-        return offset + 8, Double(name, value)
-    elif tag_type == TAG.ByteArray:
-        size, = struct.unpack(">i", payload[0:4])
-        value = bytes(payload[4:4+size])
-        return offset + 4 + size, ByteArray(name, value)
-    elif tag_type == TAG.String:
-        size, = struct.unpack(">H", payload[0:2])
-        value = bytes(payload[2:2+size]).decode('utf-8')
-        return offset + 2 + size, String(name, value)
-    elif tag_type == TAG.List:
-        list_content_tag_id, size = struct.unpack(">BI", payload[0:5])
-        items = []
-        offset = offset + 5
-        for i in range(size):
-            payload = mem[offset:]
-            offset, item = parse_tag_inner(mem, offset, level, list_content_tag_id, None)
-            items.append(item)
-        return offset, List(name, items)
-    elif tag_type == TAG.Compound:
-        tags = []
-        while payload[0] != 0:
-            offset, tag = parse_tag(mem, offset, level+1)
-            payload = mem[offset:]
-            tags.append(tag)
-        return offset + 1, Compound(name, tags)
-    else:
-        assert False, tag_type
-
-def parse_tag(mem, offset, level):
-    data = mem[offset:]
-    tag_type = data[0]
-    name_length, = struct.unpack(">H", data[1:3])
-    name = bytes(data[3:3+name_length])
-    #print(indent(level), tag_type, name_length, name)
-    offset = offset + 3 + name_length
-    return parse_tag_inner(mem, offset, level, tag_type, name)
-
-@dataclass
-class Level:
-    blocks: bytes
-    data: bytes
-    sky_light: bytes
-    block_light: bytes
-    height_map: bytes
-    x_pos: int
-    z_pos: int
-
-def level_from_tag(tag):
-    assert type(tag) == Compound
-    assert tag.name == b''
-    assert len(tag.tags) == 1
-    level, = tag.tags
-    assert type(level) == Compound
-    assert level.name == b'Level'
-
-    name_mapping = {
-        b'Blocks': 'blocks',
-        b'Data': 'data',
-        b'SkyLight': 'sky_light',
-        b'BlockLight': 'block_light',
-        b'HeightMap': 'height_map',
-        b'xPos': 'x_pos',
-        b'zPos': 'z_pos',
-    }
-
-    args = {}
-
-    for tag in level.tags:
-        if tag.name in name_mapping:
-            arg_name = name_mapping[tag.name]
-            args[arg_name] = tag.value
-
-    return Level(**args)
-
-def parse_location(mem, location):
-    uncompressed = parse_payload(mem, location)
-    offset, tag = parse_tag(uncompressed, 0, 0)
-    assert offset == len(uncompressed), (offset, len(uncompressed))
-    level = level_from_tag(tag)
-    return level
-
-def xyz_from_block_index(block_index):
-    assert block_index >= 0 and block_index < (128 * 16 * 16)
-    x = int(block_index / (128 * 16))
-    y = int(block_index % 128)
-    z = int(int(block_index / 128) % 16)
-    return x, y, z
-
-def block_index_from_xyz(x, y, z):
-    assert x >= 0 and x < 16
-    assert y >= 0 and y < 128
-    assert z >= 0 and z < 16
-    return int(y + z * 128 + x * 128 * 16)
+import mcregion
+import vec3
+import vertex_buffer
 
 def wrap_n(nc, chunk_c):
     if nc < 0:
@@ -243,77 +16,15 @@ def wrap_n(nc, chunk_c):
         chunk_c = chunk_c + 1
     return nc, chunk_c
 
-def vec3_add(v1, v2):
-    return (
-        v1[0] + v2[0],
-        v1[1] + v2[1],
-        v1[2] + v2[2],
-    )
-
-def vec3_mul(v, s):
-    return (
-        v[0] * s,
-        v[1] * s,
-        v[2] * s,
-    )
-
-vertex_table = [
-    ((-1.0, 1.0, -1.0), (0.0, 1.0, 0.0), (1.0, 0.0)),
-    ((1.0, 1.0, 1.0), (0.0, 1.0, 0.0), (0.0, 1.0)),
-    ((1.0, 1.0, -1.0), (0.0, 1.0, 0.0), (0.0, 0.0)),
-    ((1.0, 1.0, 1.0), (0.0, 0.0, 1.0), (1.0, 1.0)),
-
-    ((-1.0, -1.0, 1.0), (0.0, 0.0, 1.0), (0.0, 0.0)),
-    ((1.0, -1.0, 1.0), (0.0, 0.0, 1.0), (1.0, 0.0)),
-    ((-1.0, 1.0, 1.0), (-1.0, 0.0, 0.0), (1.0, 1.0)),
-    ((-1.0, -1.0, -1.0), (-1.0, 0.0, 0.0), (0.0, 0.0)),
-
-    ((-1.0, -1.0, 1.0), (-1.0, 0.0, 0.0), (1.0, 0.0)),
-    ((1.0, -1.0, -1.0), (0.0, -1.0, 0.0), (1.0, 0.0)),
-    ((-1.0, -1.0, 1.0), (0.0, -1.0, 0.0), (0.0, 1.0)),
-    ((-1.0, -1.0, -1.0), (0.0, -1.0, 0.0), (0.0, 0.0)),
-
-    ((1.0, 1.0, -1.0), (1.0, 0.0, 0.0), (1.0, 1.0)),
-    ((1.0, -1.0, 1.0), (1.0, 0.0, 0.0), (0.0, 0.0)),
-    ((1.0, -1.0, -1.0), (1.0, 0.0, 0.0), (1.0, 0.0)),
-    ((-1.0, 1.0, -1.0), (0.0, 0.0, -1.0), (1.0, 1.0)),
-    ((1.0, -1.0, -1.0), (0.0, 0.0, -1.0), (0.0, 0.0)),
-    ((-1.0, -1.0, -1.0), (0.0, 0.0, -1.0), (1.0, 0.0)),
-    ((-1.0, 1.0, 1.0), (0.0, 1.0, 0.0), (1.0, 1.0)),
-    ((-1.0, 1.0, 1.0), (0.0, 0.0, 1.0), (0.0, 1.0)),
-    ((-1.0, 1.0, -1.0), (-1.0, 0.0, 0.0), (0.0, 1.0)),
-    ((1.0, -1.0, 1.0), (0.0, -1.0, 0.0), (1.0, 1.0)),
-    ((1.0, 1.0, 1.0), (1.0, 0.0, 0.0), (0.0, 1.0)),
-    ((1.0, 1.0, -1.0), (0.0, 0.0, -1.0), (0.0, 1.0))
+normals = [
+    (-1.0, 0.0, 0.0),
+    (0.0, -1.0, 0.0),
+    (0.0, 0.0, -1.0),
+    (0.0, 0.0, 1.0),
+    (0.0, 1.0, 0.0),
+    (1.0, 0.0, 0.0),
 ]
 
-faces_by_normal = {
-    (-1.0, 0.0, 0.0): [6, 7, 8, 6, 20, 7],
-    (0.0, -1.0, 0.0): [9, 10, 11, 9, 21, 10],
-    (0.0, 0.0, -1.0): [15, 16, 17, 15, 23, 16],
-    (0.0, 0.0, 1.0): [3, 4, 5, 3, 19, 4],
-    (0.0, 1.0, 0.0): [0, 1, 2, 0, 18, 1],
-    (1.0, 0.0, 0.0): [12, 13, 14, 12, 22, 13]
-}
-
-vertex_buffer = {}
-
-def add_vertex(vertex):
-    if vertex in vertex_buffer:
-        return vertex_buffer[vertex]
-    else:
-        index = len(vertex_buffer)
-        vertex_buffer[vertex] = index
-        return index
-
-def emit_face(center_position, block_id, triangles):
-    for index in triangles:
-        position, normal, texture = vertex_table[index]
-        position = vec3_add(vec3_mul(position, 0.5), center_position)
-        vertex = (position, normal, texture, block_id)
-        new_index = add_vertex(vertex)
-        yield new_index
-
 def block_neighbors(level_table, chunk_x, chunk_z, block_index):
     block_id = level_table[(chunk_x, chunk_z)].blocks[block_index]
     if block_id == 0:
@@ -328,36 +39,65 @@ def block_neighbors(level_table, chunk_x, chunk_z, block_index):
             return True
         if nz > 15 or nz < 0:
             return True
-        n_block_index = block_index_from_xyz(nx, ny, nz)
+        n_block_index = mcregion.block_index_from_xyz(nx, ny, nz)
         key = (n_chunk_x, n_chunk_z)
         if key not in level_table:
             return True
         n_block_id = level_table[key].blocks[n_block_index]
         return n_block_id != 0
 
-    x, y, z = xyz_from_block_index(block_index)
+    x, y, z = mcregion.xyz_from_block_index(block_index)
 
-    center_position = vec3_add((x, y, z), (chunk_x * 16, 0, chunk_z * 16))
+    center_position = vec3.add((x, y, z), (chunk_x * 16, 0, chunk_z * 16))
 
-    for normal, triangles in faces_by_normal.items():
-        neighbor = vec3_add(normal, (x, y, z))
-        if not neighbor_exists(*neighbor):
-            yield from emit_face(center_position, block_id, triangles)
+    def find_non_neighbors():
+        for i, normal in enumerate(normals):
+            neighbor = vec3.add(normal, (x, y, z))
+            if not neighbor_exists(*neighbor):
+                yield i
 
-            #yield chunk_x, chunk_z, block_index, block_id
-            #break
+    normal_indices = list(find_non_neighbors())
+    if normal_indices:
+        yield center_position, block_id, normal_indices
 
 def devoxelize_region(level_table):
     for chunk_x, chunk_z in level_table.keys():
         for block_index in range(128 * 16 * 16):
             yield from block_neighbors(level_table, chunk_x, chunk_z, block_index)
 
-from collections import defaultdict
-counts = defaultdict(int)
+def build_level_table(mem, locations):
+    level_table = {}
+    for location in locations:
+        try:
+            level = mcregion.parse_location(mem, location)
+        except CountZeroException:
+            continue
+        x, z = level.x_pos, level.z_pos
+        level_table[(x, z)] = level
+    return level_table
 
-def linearized_vertex_buffer():
-    for vertex, i in sorted(vertex_buffer.items(), key=lambda kv: kv[1]):
-        yield vertex
+def normal_indices_as_block_configuration(normal_indices):
+    acc = 0
+    for i in normal_indices:
+        acc |= (1 << i)
+    return acc
+
+def build_block_configuration_table():
+    for i in range(64):
+        indices = []
+        for j in range(6):
+            if ((i >> j) & 1) != 0:
+                indices.extend(vertex_buffer.faces_by_normal[normals[j]])
+        yield indices
+
+def build_block_instances(f, blocks):
+    for position, block_id, normal_indices in blocks:
+        block_configuration = normal_indices_as_block_configuration(normal_indices)
+        #print(position, block_id, block_configuration)
+        f.write(struct.pack("<hhhBB",
+                            position[0], position[1], position[2],
+                            block_id,
+                            block_configuration))
 
 def main(mcr_path, data_path):
     with open(mcr_path, "rb") as f:
@@ -365,35 +105,17 @@ def main(mcr_path, data_path):
     mem = memoryview(buf)
 
     offset = 0
-    offset, locations = parse_locations(mem, offset)
-    offset, timestamps = parse_timestamps(mem, offset)
+    offset, locations = mcregion.parse_locations(mem, offset)
+    offset, timestamps = mcregion.parse_timestamps(mem, offset)
     assert offset == 0x2000
 
-    level_table = {}
-    for location in locations:
-        try:
-            level = parse_location(mem, location)
-        except CountZeroException:
-            continue
-        x, z = level.x_pos, level.z_pos
-        level_table[(x, z)] = level
-        #with open(f"blocks__{x:02x}_{z:02x}.data", "wb") as f:
-        #    f.write(level.blocks)
-
-    with open(data_path + ".idx", "wb") as f:
-        for index in devoxelize_region(level_table):
-            f.write(struct.pack("<I", index))
+    level_table = build_level_table(mem, locations)
+    blocks = devoxelize_region(level_table)
 
     with open(data_path + ".vtx", "wb") as f:
-        for vertex in linearized_vertex_buffer():
-            vertex = [*vertex[0], *vertex[1], *vertex[2], vertex[3]]#, vertex[3]]
-            f.write(struct.pack("<fffffffff", *vertex))
+        build_block_instances(f, blocks)
 
-        #for chunk_x, chunk_z, block_index, block_id in devoxelize_region(level_table):
-        #    #print(chunk_x, chunk_z, block_id)
-        #    counts[block_id] += 1
-        #    f.write(struct.pack("<bbBb", chunk_x, chunk_z, block_id, 0))
-        #    f.write(struct.pack("<i", block_index))
+    #pprint(list(build_block_configuration_table()))
 
 mcr_path = sys.argv[1]
 data_path = sys.argv[2]
diff --git a/minecraft/gen/mcregion.py b/minecraft/gen/mcregion.py
new file mode 100644
index 0000000..8c5337d
--- /dev/null
+++ b/minecraft/gen/mcregion.py
@@ -0,0 +1,231 @@
+from dataclasses import dataclass
+import struct
+import zlib
+
+# https://minecraft.fandom.com/wiki/Region_file_format
+# https://minecraft.wiki/w/NBT_format#Binary_format
+# https://minecraft.wiki/w/Chunk_format/McRegion
+
+def _parse_locations(mem, offset):
+    for i in range(1024):
+        ix = offset + i * 4
+        chunk_location, = struct.unpack(">I", mem[ix:ix+4])
+        chunk_offset = (chunk_location >> 8) & 0xffffff
+        chunk_sector_count = chunk_location & 0xff
+        yield chunk_offset, chunk_sector_count
+
+def parse_locations(mem, offset):
+    locations = list(_parse_locations(mem, offset))
+    return offset + 1024 * 4, locations
+
+def _parse_timestamps(mem, offset):
+    for i in range(1024):
+        ix = offset + i * 4
+        timestamp, = struct.unpack(">I", mem[ix:ix+4])
+        yield timestamp
+
+def parse_timestamps(mem, offset):
+    timestamps = list(_parse_timestamps(mem, offset))
+    return offset + 1024 * 4, timestamps
+
+def print_locations(locations):
+    for y in range(32):
+        for x in range(32):
+            offset, count = locations[y * 32 + x]
+            print(str(offset).rjust(4), end=' ')
+        print()
+
+class CountZeroException(Exception):
+    pass
+
+def parse_payload(mem, location):
+    offset, count = location
+    if count == 0:
+        raise CountZeroException()
+    ix = offset * 4096
+    payload = mem[ix:ix + count * 4096]
+    length, = struct.unpack(">I", payload[0:4])
+    assert length <= count * 4096, (length, count)
+    compression_type = payload[4]
+    data = payload[5:5 + (length - 1)]
+    assert compression_type == 2, compression_type
+    uncompressed = zlib.decompress(data)
+    return memoryview(uncompressed)
+
+class TAG:
+    Byte = 0x01
+    Short = 0x02
+    Int = 0x03
+    Long = 0x04
+    Float = 0x05
+    Double = 0x06
+    ByteArray = 0x07
+    String = 0x08
+    List = 0x09
+    Compound = 0x0a
+
+@dataclass
+class Byte:
+    name: str
+    value: int
+
+@dataclass
+class Short:
+    name: str
+    value: int
+
+@dataclass
+class Int:
+    name: str
+    value: int
+
+@dataclass
+class Long:
+    name: str
+    value: int
+
+@dataclass
+class Float:
+    name: str
+    value: float
+
+@dataclass
+class Double:
+    name: str
+    value: float
+
+@dataclass
+class ByteArray:
+    name: str
+    value: bytes
+
+@dataclass
+class String:
+    name: str
+    value: str
+
+@dataclass
+class List:
+    name: str
+    items: list
+
+@dataclass
+class Compound:
+    name: str
+    tags: list
+
+def indent(level):
+    return "  " * level
+
+def parse_tag_inner(mem, offset, level, tag_type, name):
+    payload = mem[offset:]
+    if tag_type == TAG.Byte:
+        value, = struct.unpack(">b", payload[0:1])
+        return offset + 1, Byte(name, value)
+    if tag_type == TAG.Short:
+        value, = struct.unpack(">h", payload[0:2])
+        return offset + 2, Short(name, value)
+    elif tag_type == TAG.Int:
+        value, = struct.unpack(">i", payload[0:4])
+        return offset + 4, Int(name, value)
+    elif tag_type == TAG.Long:
+        value, = struct.unpack(">q", payload[0:8])
+        return offset + 8, Long(name, value)
+    elif tag_type == TAG.Float:
+        value, = struct.unpack(">f", payload[0:4])
+        return offset + 4, Float(name, value)
+    elif tag_type == TAG.Double:
+        value, = struct.unpack(">d", payload[0:8])
+        return offset + 8, Double(name, value)
+    elif tag_type == TAG.ByteArray:
+        size, = struct.unpack(">i", payload[0:4])
+        value = bytes(payload[4:4+size])
+        return offset + 4 + size, ByteArray(name, value)
+    elif tag_type == TAG.String:
+        size, = struct.unpack(">H", payload[0:2])
+        value = bytes(payload[2:2+size]).decode('utf-8')
+        return offset + 2 + size, String(name, value)
+    elif tag_type == TAG.List:
+        list_content_tag_id, size = struct.unpack(">BI", payload[0:5])
+        items = []
+        offset = offset + 5
+        for i in range(size):
+            payload = mem[offset:]
+            offset, item = parse_tag_inner(mem, offset, level, list_content_tag_id, None)
+            items.append(item)
+        return offset, List(name, items)
+    elif tag_type == TAG.Compound:
+        tags = []
+        while payload[0] != 0:
+            offset, tag = parse_tag(mem, offset, level+1)
+            payload = mem[offset:]
+            tags.append(tag)
+        return offset + 1, Compound(name, tags)
+    else:
+        assert False, tag_type
+
+def parse_tag(mem, offset, level):
+    data = mem[offset:]
+    tag_type = data[0]
+    name_length, = struct.unpack(">H", data[1:3])
+    name = bytes(data[3:3+name_length])
+    #print(indent(level), tag_type, name_length, name)
+    offset = offset + 3 + name_length
+    return parse_tag_inner(mem, offset, level, tag_type, name)
+
+@dataclass
+class Level:
+    blocks: bytes
+    data: bytes
+    sky_light: bytes
+    block_light: bytes
+    height_map: bytes
+    x_pos: int
+    z_pos: int
+
+def level_from_tag(tag):
+    assert type(tag) == Compound
+    assert tag.name == b''
+    assert len(tag.tags) == 1
+    level, = tag.tags
+    assert type(level) == Compound
+    assert level.name == b'Level'
+
+    name_mapping = {
+        b'Blocks': 'blocks',
+        b'Data': 'data',
+        b'SkyLight': 'sky_light',
+        b'BlockLight': 'block_light',
+        b'HeightMap': 'height_map',
+        b'xPos': 'x_pos',
+        b'zPos': 'z_pos',
+    }
+
+    args = {}
+
+    for tag in level.tags:
+        if tag.name in name_mapping:
+            arg_name = name_mapping[tag.name]
+            args[arg_name] = tag.value
+
+    return Level(**args)
+
+def parse_location(mem, location):
+    uncompressed = parse_payload(mem, location)
+    offset, tag = parse_tag(uncompressed, 0, 0)
+    assert offset == len(uncompressed), (offset, len(uncompressed))
+    level = level_from_tag(tag)
+    return level
+
+def xyz_from_block_index(block_index):
+    assert block_index >= 0 and block_index < (128 * 16 * 16)
+    x = int(block_index / (128 * 16))
+    y = int(block_index % 128)
+    z = int(int(block_index / 128) % 16)
+    return x, y, z
+
+def block_index_from_xyz(x, y, z):
+    assert x >= 0 and x < 16
+    assert y >= 0 and y < 128
+    assert z >= 0 and z < 16
+    return int(y + z * 128 + x * 128 * 16)
diff --git a/minecraft/gen/region.idx b/minecraft/gen/region.idx
new file mode 100644
index 0000000..a51aa05
Binary files /dev/null and b/minecraft/gen/region.idx differ
diff --git a/minecraft/gen/vec3.py b/minecraft/gen/vec3.py
new file mode 100644
index 0000000..0377b3f
--- /dev/null
+++ b/minecraft/gen/vec3.py
@@ -0,0 +1,13 @@
+def add(v1, v2):
+    return (
+        v1[0] + v2[0],
+        v1[1] + v2[1],
+        v1[2] + v2[2],
+    )
+
+def mul(v, s):
+    return (
+        v[0] * s,
+        v[1] * s,
+        v[2] * s,
+    )
diff --git a/minecraft/gen/vertex_buffer.py b/minecraft/gen/vertex_buffer.py
new file mode 100644
index 0000000..c256c55
--- /dev/null
+++ b/minecraft/gen/vertex_buffer.py
@@ -0,0 +1,64 @@
+import vec3
+
+vertex_table = [
+    ((-1.0, 1.0, -1.0), (0.0, 1.0, 0.0), (1.0, 0.0)),
+    ((1.0, 1.0, 1.0), (0.0, 1.0, 0.0), (0.0, 1.0)),
+    ((1.0, 1.0, -1.0), (0.0, 1.0, 0.0), (0.0, 0.0)),
+    ((1.0, 1.0, 1.0), (0.0, 0.0, 1.0), (1.0, 1.0)),
+    ((-1.0, -1.0, 1.0), (0.0, 0.0, 1.0), (0.0, 0.0)),
+    ((1.0, -1.0, 1.0), (0.0, 0.0, 1.0), (1.0, 0.0)),
+    ((-1.0, 1.0, 1.0), (-1.0, 0.0, 0.0), (1.0, 1.0)),
+    ((-1.0, -1.0, -1.0), (-1.0, 0.0, 0.0), (0.0, 0.0)),
+    ((-1.0, -1.0, 1.0), (-1.0, 0.0, 0.0), (1.0, 0.0)),
+    ((1.0, -1.0, -1.0), (0.0, -1.0, 0.0), (1.0, 0.0)),
+    ((-1.0, -1.0, 1.0), (0.0, -1.0, 0.0), (0.0, 1.0)),
+    ((-1.0, -1.0, -1.0), (0.0, -1.0, 0.0), (0.0, 0.0)),
+    ((1.0, 1.0, -1.0), (1.0, 0.0, 0.0), (1.0, 1.0)),
+    ((1.0, -1.0, 1.0), (1.0, 0.0, 0.0), (0.0, 0.0)),
+    ((1.0, -1.0, -1.0), (1.0, 0.0, 0.0), (1.0, 0.0)),
+    ((-1.0, 1.0, -1.0), (0.0, 0.0, -1.0), (1.0, 1.0)),
+    ((1.0, -1.0, -1.0), (0.0, 0.0, -1.0), (0.0, 0.0)),
+    ((-1.0, -1.0, -1.0), (0.0, 0.0, -1.0), (1.0, 0.0)),
+    ((-1.0, 1.0, 1.0), (0.0, 1.0, 0.0), (1.0, 1.0)),
+    ((-1.0, 1.0, 1.0), (0.0, 0.0, 1.0), (0.0, 1.0)),
+    ((-1.0, 1.0, -1.0), (-1.0, 0.0, 0.0), (0.0, 1.0)),
+    ((1.0, -1.0, 1.0), (0.0, -1.0, 0.0), (1.0, 1.0)),
+    ((1.0, 1.0, 1.0), (1.0, 0.0, 0.0), (0.0, 1.0)),
+    ((1.0, 1.0, -1.0), (0.0, 0.0, -1.0), (0.0, 1.0))
+]
+
+faces_by_normal = {
+    (-1.0, 0.0, 0.0): [6, 7, 8, 6, 20, 7],
+    (0.0, -1.0, 0.0): [9, 10, 11, 9, 21, 10],
+    (0.0, 0.0, -1.0): [15, 16, 17, 15, 23, 16],
+    (0.0, 0.0, 1.0): [3, 4, 5, 3, 19, 4],
+    (0.0, 1.0, 0.0): [0, 1, 2, 0, 18, 1],
+    (1.0, 0.0, 0.0): [12, 13, 14, 12, 22, 13]
+}
+
+vertex_buffer = {}
+
+def add_vertex(vertex):
+    if vertex in vertex_buffer:
+        return vertex_buffer[vertex]
+    else:
+        index = len(vertex_buffer)
+        vertex_buffer[vertex] = index
+        return index
+
+def emit_face(center_position, block_id, triangles):
+    for index in triangles:
+        position, normal, texture = vertex_table[index]
+        position = vec3.add(vec3.mul(position, 0.5), center_position)
+        vertex = (position, normal, texture, block_id)
+        new_index = add_vertex(vertex)
+        yield new_index
+
+def linearized_vertex_buffer():
+    for vertex, i in sorted(vertex_buffer.items(), key=lambda kv: kv[1]):
+        yield vertex
+
+#with open(data_path + ".vtx", "wb") as f:
+#    for vertex in linearized_vertex_buffer():
+#        vertex = [*vertex[0], *vertex[1], *vertex[2], vertex[3]]#, vertex[3]]
+#        f.write(struct.pack("<fffffffff", *vertex))
diff --git a/minecraft/region.-1.-1.inst.vtx b/minecraft/region.-1.-1.inst.vtx
new file mode 100644
index 0000000..4a8bbc9
Binary files /dev/null and b/minecraft/region.-1.-1.inst.vtx differ
diff --git a/minecraft/region.-1.0.inst.vtx b/minecraft/region.-1.0.inst.vtx
new file mode 100644
index 0000000..c1eaafb
Binary files /dev/null and b/minecraft/region.-1.0.inst.vtx differ
diff --git a/minecraft/region.0.-1.inst.vtx b/minecraft/region.0.-1.inst.vtx
new file mode 100644
index 0000000..bbefff1
Binary files /dev/null and b/minecraft/region.0.-1.inst.vtx differ
diff --git a/minecraft/region.0.0.inst.vtx b/minecraft/region.0.0.inst.vtx
new file mode 100644
index 0000000..e7ea140
Binary files /dev/null and b/minecraft/region.0.0.inst.vtx differ
diff --git a/shader/test.frag b/shader/test.frag
index 5f35393..08463ec 100644
--- a/shader/test.frag
+++ b/shader/test.frag
@@ -1,286 +1,44 @@
 #version 330 core
 
-in vec3 PixelNormal;
-in vec2 PixelTexture;
-in float PixelBlock;
+in GS_OUT {
+  vec3 Normal;
+  vec2 Texture;
+  flat int BlockID;
+} gs_out;
 
 out vec4 FragColor;
 
 uniform sampler2D TerrainSampler;
 
-/*layout (std140) uniform TexturesLayout
-{
-  uint Textures[256];
-  };*/
 int Textures[256] = int[256](
-185,
-1,
-0,
-2,
-16,
-4,
-15,
-17,
-205,
-205,
-237,
-237,
-18,
-19,
-32,
-33,
-34,
-20,
-52,
-48,
-49,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-0,
-185,
-185,
-185,
-64,
-185,
-13,
-12,
-29,
-28,
-39,
-38,
-5,
-5,
-7,
-8,
-35,
-36,
-37,
-80,
-31,
-65,
-4,
-27,
-84,
-50,
-40,
-43,
-88,
-87,
-44,
-61,
-185,
-81,
-83,
-128,
-16,
-185,
-96,
-6,
-82,
-6,
-51,
-51,
-115,
-99,
-185,
-66,
-67,
-66,
-70,
-72,
-73,
-74,
-4,
-102,
-103,
-104,
-105,
-14,
-102,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185,
-185
-                                   );
+  185,   1,   0,   2,  16,   4,  15,  17, 205, 205, 237, 237,  18,  19,  32,  33,
+   34,  20,  52,  48,  49, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185,   0,
+  185, 185, 185,  64, 185,  13,  12,  29,  28,  39,  38,   5,   5,   7,   8,  35,
+   36,  37,  80,  31,  65,   4,  27,  84,  50,  40,  43,  88,  87,  44,  61, 185,
+   81,  83, 128,  16, 185,  96,   6,  82,   6,  51,  51, 115,  99, 185,  66,  67,
+   66,  70,  72,  73,  74,   4, 102, 103, 104, 105,  14, 102, 185, 185, 185, 185,
+  185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185,
+  185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185,
+  185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185,
+  185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185,
+  185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185,
+  185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185,
+  185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185,
+  185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185,
+  185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185,
+  185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185, 185
+);
 
 void main()
 {
   vec3 light_direction = normalize(vec3(-1, -0.5, 0.5));
-  float diffuse_intensity = max(dot(normalize(PixelNormal), light_direction), 0.0);
+  float diffuse_intensity = max(dot(normalize(gs_out.Normal), light_direction), 0.0);
 
-  int terrain_ix = int(Textures[int(PixelBlock)]);
+  int terrain_ix = int(Textures[int(gs_out.BlockID)]);
   int terrain_x = terrain_ix % 16;
   int terrain_y = terrain_ix / 16;
   ivec2 coord = ivec2(terrain_x, terrain_y) * 16;
-  coord += ivec2(PixelTexture.xy * 16.0);
+  coord += ivec2(gs_out.Texture.xy * 16.0);
 
   vec4 texture_color = texelFetch(TerrainSampler, coord, 0);
   if (texture_color.w != 1.0) {
@@ -288,7 +46,7 @@ void main()
     return;
   }
 
-  if (int(PixelBlock) == 18) // leaves
+  if (int(gs_out.BlockID) == 18) // leaves
     texture_color.xyz *= vec3(0.125, 0.494, 0.027);
 
   FragColor = vec4(texture_color.xyz * vec3(diffuse_intensity), 1.0);
diff --git a/shader/test.geom b/shader/test.geom
new file mode 100644
index 0000000..7caf955
--- /dev/null
+++ b/shader/test.geom
@@ -0,0 +1,100 @@
+#version 330 core
+
+layout (points) in;
+layout (triangle_strip, max_vertices = 24) out;
+
+in VS_OUT {
+  int BlockID;
+  int Configuration;
+} gs_in[1];
+
+out GS_OUT {
+  vec3 Normal;
+  vec2 Texture;
+  flat int BlockID;
+} gs_out;
+
+struct PT {
+  vec3 Position;
+  vec2 Texture;
+};
+
+uniform mat4 Transform;
+
+PT vertices[] = PT[24](
+    PT(vec3(-1.0, 1.0, -1.0), vec2(1.0, 0.0)),
+    PT(vec3(1.0, 1.0, 1.0), vec2(0.0, 1.0)),
+    PT(vec3(1.0, 1.0, -1.0), vec2(0.0, 0.0)),
+    PT(vec3(1.0, 1.0, 1.0), vec2(1.0, 1.0)),
+    PT(vec3(-1.0, -1.0, 1.0), vec2(0.0, 0.0)),
+    PT(vec3(1.0, -1.0, 1.0), vec2(1.0, 0.0)),
+    PT(vec3(-1.0, 1.0, 1.0), vec2(1.0, 1.0)),
+    PT(vec3(-1.0, -1.0, -1.0), vec2(0.0, 0.0)),
+    PT(vec3(-1.0, -1.0, 1.0), vec2(1.0, 0.0)),
+    PT(vec3(1.0, -1.0, -1.0), vec2(1.0, 0.0)),
+    PT(vec3(-1.0, -1.0, 1.0), vec2(0.0, 1.0)),
+    PT(vec3(-1.0, -1.0, -1.0), vec2(0.0, 0.0)),
+    PT(vec3(1.0, 1.0, -1.0), vec2(1.0, 1.0)),
+    PT(vec3(1.0, -1.0, 1.0), vec2(0.0, 0.0)),
+    PT(vec3(1.0, -1.0, -1.0), vec2(1.0, 0.0)),
+    PT(vec3(-1.0, 1.0, -1.0), vec2(1.0, 1.0)),
+    PT(vec3(1.0, -1.0, -1.0), vec2(0.0, 0.0)),
+    PT(vec3(-1.0, -1.0, -1.0), vec2(1.0, 0.0)),
+    PT(vec3(-1.0, 1.0, 1.0), vec2(1.0, 1.0)),
+    PT(vec3(-1.0, 1.0, 1.0), vec2(0.0, 1.0)),
+    PT(vec3(-1.0, 1.0, -1.0), vec2(0.0, 1.0)),
+    PT(vec3(1.0, -1.0, 1.0), vec2(1.0, 1.0)),
+    PT(vec3(1.0, 1.0, 1.0), vec2(0.0, 1.0)),
+    PT(vec3(1.0, 1.0, -1.0), vec2(0.0, 1.0))
+);
+
+int face_1[4] = int[4](8, 6, 7, 20);
+int face_2[4] = int[4](11, 9, 10, 21);
+int face_4[4] = int[4](17, 15, 16, 23);
+int face_8[4] = int[4](5, 3, 4, 19);
+int face_16[4] = int[4](2, 0, 1, 18);
+int face_32[4] = int[4](14, 12, 13, 22);
+
+vec4 transform(vec3 p)
+{
+  return Transform * vec4(p.xzy, 1.0);
+}
+
+void emit_face(vec3 normal, int face[4])
+{
+  vec3 position = gl_in[0].gl_Position.xyz;
+
+  PT vtx0 = vertices[face[0]];
+  gl_Position = transform(position + vtx0.Position * 0.5);
+  gs_out.Normal = normal.xzy;
+  gs_out.Texture = vtx0.Texture;
+  EmitVertex();
+  PT vtx1 = vertices[face[1]];
+  gl_Position = transform(position + vtx1.Position * 0.5);
+  gs_out.Normal = normal.xzy;
+  gs_out.Texture = vtx1.Texture;
+  EmitVertex();
+  PT vtx2 = vertices[face[2]];
+  gl_Position = transform(position + vtx2.Position * 0.5);
+  gs_out.Normal = normal.xzy;
+  gs_out.Texture = vtx2.Texture;
+  EmitVertex();
+  PT vtx3 = vertices[face[3]];
+  gl_Position = transform(position + vtx3.Position * 0.5);
+  gs_out.Normal = normal.xzy;
+  gs_out.Texture = vtx3.Texture;
+  EmitVertex();
+  EndPrimitive();
+}
+
+void main()
+{
+  gs_out.BlockID = gs_in[0].BlockID;
+  int configuration = gs_in[0].Configuration;
+  if ((configuration &  1) != 0) emit_face(vec3(-1.0, 0.0, 0.0), face_1);
+  if ((configuration &  2) != 0) emit_face(vec3(0.0, -1.0, 0.0), face_2);
+  if ((configuration &  4) != 0) emit_face(vec3(0.0, 0.0, -1.0), face_4);
+  if ((configuration &  8) != 0) emit_face(vec3(0.0, 0.0, 1.0), face_8);
+  if ((configuration & 16) != 0) emit_face(vec3(0.0, 1.0, 0.0), face_16);
+  if ((configuration & 32) != 0) emit_face(vec3(1.0, 0.0, 0.0), face_32);
+}
diff --git a/shader/test.vert b/shader/test.vert
index ded8b22..398b281 100644
--- a/shader/test.vert
+++ b/shader/test.vert
@@ -1,23 +1,20 @@
 #version 330 core
 
 layout (location = 0) in vec3 Position;
-layout (location = 1) in vec3 Normal;
-layout (location = 2) in vec3 Texture;
+layout (location = 1) in float BlockID;
+layout (location = 2) in float Configuration;
 
-out vec3 PixelNormal;
-out vec2 PixelTexture;
-out float PixelBlock;
+out VS_OUT {
+  int BlockID;
+  int Configuration;
+} vs_out;
 
 uniform mat4 Transform;
 
 void main()
 {
-  //gl_Position = vec4(position, 1.0);
-  //ourColor = color;
+  vs_out.BlockID = int(BlockID);
+  vs_out.Configuration = int(Configuration);
 
-  PixelNormal = Normal.xzy;
-  PixelTexture = Texture.xy;
-  PixelBlock = Texture.z;
-
-  gl_Position = Transform * vec4(Position.xzy, 1.0);
+  gl_Position = vec4(Position.xyz, 1.0);
 }
diff --git a/src/opengl.c b/src/opengl.c
index 37b6da7..52699ed 100644
--- a/src/opengl.c
+++ b/src/opengl.c
@@ -49,14 +49,22 @@ void * read_file(const char * filename, int * out_size)
 
 unsigned int compile(const char * vertex_source,
                      int vertex_source_size,
+                     const char * geometry_source,
+                     int geometry_source_size,
                      const char * fragment_source,
                      int fragment_source_size)
 {
   int compile_status;
   char info_log[512];
 
+  // program
+  unsigned int shader_program = glCreateProgram();
+  unsigned int vertex_shader = -1;
+  unsigned int geometry_shader = -1;
+  unsigned int fragment_shader = -1;
+
   // vertex shader
-  unsigned int vertex_shader = glCreateShader(GL_VERTEX_SHADER);
+  vertex_shader = glCreateShader(GL_VERTEX_SHADER);
   glShaderSource(vertex_shader, 1, &vertex_source, &vertex_source_size);
   glCompileShader(vertex_shader);
   glGetShaderiv(vertex_shader, GL_COMPILE_STATUS, &compile_status);
@@ -64,9 +72,23 @@ unsigned int compile(const char * vertex_source,
     glGetShaderInfoLog(vertex_shader, 512, NULL, info_log);
     fprintf(stderr, "vertex shader compile: %s\n", info_log);
   }
+  glAttachShader(shader_program, vertex_shader);
+
+  // geometry shader
+  if (geometry_source_size != 0) {
+    geometry_shader = glCreateShader(GL_GEOMETRY_SHADER);
+    glShaderSource(geometry_shader, 1, &geometry_source, &geometry_source_size);
+    glCompileShader(geometry_shader);
+    glGetShaderiv(geometry_shader, GL_COMPILE_STATUS, &compile_status);
+    if (!compile_status) {
+      glGetShaderInfoLog(geometry_shader, 512, NULL, info_log);
+      fprintf(stderr, "geometry shader compile: %s\n", info_log);
+    }
+    glAttachShader(shader_program, geometry_shader);
+  }
 
   // fragment shader
-  unsigned int fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
+  fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
   glShaderSource(fragment_shader, 1, &fragment_source, &fragment_source_size);
   glCompileShader(fragment_shader);
   glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &compile_status);
@@ -74,11 +96,9 @@ unsigned int compile(const char * vertex_source,
     glGetShaderInfoLog(fragment_shader, 512, NULL, info_log);
     fprintf(stderr, "fragment shader compile: %s\n", info_log);
   }
+  glAttachShader(shader_program, fragment_shader);
 
   // link shaders
-  unsigned int shader_program = glCreateProgram();
-  glAttachShader(shader_program, vertex_shader);
-  glAttachShader(shader_program, fragment_shader);
   glLinkProgram(shader_program);
   glGetProgramiv(shader_program, GL_LINK_STATUS, &compile_status);
   if (!compile_status) {
@@ -87,25 +107,41 @@ unsigned int compile(const char * vertex_source,
   }
 
   glDeleteShader(vertex_shader);
+  if (geometry_source_size != 0)
+    glDeleteShader(geometry_shader);
   glDeleteShader(fragment_shader);
 
   return shader_program;
 }
 
 unsigned int compile_from_files(const char * vertex_path,
+                                const char * geometry_path,
                                 const char * fragment_path)
 {
-  int vertex_source_size;
-  char * vertex_source = read_file(vertex_path, &vertex_source_size);
+  int vertex_source_size = 0;
+  char * vertex_source = NULL;
+  int geometry_source_size = 0;
+  char * geometry_source = NULL;
+  int fragment_source_size = 0;
+  char * fragment_source = NULL;
+
+  vertex_source = read_file(vertex_path, &vertex_source_size);
   assert(vertex_source != NULL);
-  int fragment_source_size;
-  char * fragment_source = read_file(fragment_path, &fragment_source_size);
+
+  if (geometry_path != NULL) {
+    geometry_source = read_file(geometry_path, &geometry_source_size);
+    assert(geometry_source != NULL);
+  }
+
+  fragment_source = read_file(fragment_path, &fragment_source_size);
   assert(fragment_source != NULL);
 
   unsigned int program = compile(vertex_source, vertex_source_size,
+                                 geometry_source, geometry_source_size,
                                  fragment_source, fragment_source_size);
 
   free(vertex_source);
+  free(geometry_source);
   free(fragment_source);
 
   return program;
diff --git a/src/test.cpp b/src/test.cpp
index a0f1580..da768ad 100644
--- a/src/test.cpp
+++ b/src/test.cpp
@@ -9,8 +9,8 @@
 struct location {
   struct {
     unsigned int position;
-    unsigned int normal;
-    unsigned int texture;
+    unsigned int block_id;
+    unsigned int configuration;
   } attrib;
   struct {
     unsigned int transform;
@@ -22,18 +22,27 @@ struct location {
 static unsigned int test_program;
 static struct location location;
 
+static unsigned int vertex_array_objects[4];
+static unsigned int vertex_buffers[4];
+static unsigned int vertex_count[4];
+//static unsigned int index_buffers[4];
+//static unsigned int index_count[4];
+
+static const int vertex_size = 8;
+
 void load_program()
 {
   unsigned int program = compile_from_files("shader/test.vert",
+                                            "shader/test.geom",
                                             "shader/test.frag");
 
   location.attrib.position = glGetAttribLocation(program, "Position");
-  location.attrib.normal = glGetAttribLocation(program, "Normal");
-  location.attrib.texture = glGetAttribLocation(program, "Texture");
-  printf("attributes:\n  position %u\n  normal %u\n  texture %u\n",
+  location.attrib.block_id = glGetAttribLocation(program, "BlockID");
+  location.attrib.configuration = glGetAttribLocation(program, "Configuration");
+  printf("attributes:\n  position %u\n  block_id %u\n  configuration %u\n",
          location.attrib.position,
-         location.attrib.normal,
-         location.attrib.texture);
+         location.attrib.block_id,
+         location.attrib.configuration);
 
   location.uniform.transform = glGetUniformLocation(program, "Transform");
   location.uniform.terrain_sampler = glGetUniformLocation(program, "TerrainSampler");
@@ -44,23 +53,11 @@ void load_program()
   test_program = program;
 }
 
-static unsigned int vertex_array_objects[4];
-static unsigned int vertex_buffers[4];
-static unsigned int index_buffers[4];
-static unsigned int index_count[4];
-
 const char * vertex_paths[] = {
-  "minecraft/region.0.0.vtx",
-  "minecraft/region.0.-1.vtx",
-  "minecraft/region.-1.0.vtx",
-  "minecraft/region.-1.-1.vtx",
-};
-
-static const char * index_paths[] = {
-  "minecraft/region.0.0.idx",
-  "minecraft/region.0.-1.idx",
-  "minecraft/region.-1.0.idx",
-  "minecraft/region.-1.-1.idx",
+  "minecraft/region.0.0.inst.vtx",
+  "minecraft/region.0.-1.inst.vtx",
+  "minecraft/region.-1.0.inst.vtx",
+  "minecraft/region.-1.-1.inst.vtx",
 };
 
 void load_vertex_buffer(int i)
@@ -70,10 +67,12 @@ void load_vertex_buffer(int i)
 
   glBindBuffer(GL_ARRAY_BUFFER, vertex_buffers[i]);
   glBufferData(GL_ARRAY_BUFFER, vertex_buffer_data_size, vertex_buffer_data, GL_STATIC_DRAW);
+  vertex_count[i] = vertex_buffer_data_size / vertex_size;
 
   free(vertex_buffer_data);
 }
 
+/*
 void load_element_buffer(int i)
 {
   int index_buffer_data_size;
@@ -85,45 +84,49 @@ void load_element_buffer(int i)
 
   free(index_buffer_data);
 }
+*/
 
 void load_vertex_attributes()
 {
   glVertexAttribPointer(location.attrib.position,
                         3,
-                        GL_FLOAT,
+                        GL_SHORT,
                         GL_FALSE,
-                        (sizeof (float)) * 9,
-                        (void*)(0 * 4)
+                        vertex_size,
+                        (void*)(0)
                         );
-  glVertexAttribPointer(location.attrib.normal,
-                        3,
-                        GL_FLOAT,
+  glVertexAttribPointer(location.attrib.block_id,
+                        1,
+                        GL_UNSIGNED_BYTE,
                         GL_FALSE,
-                        (sizeof (float)) * 9,
-                        (void*)(3 * 4)
+                        vertex_size,
+                        (void*)(6)
                         );
-  glVertexAttribPointer(location.attrib.texture,
-                        3,
-                        GL_FLOAT,
+  glVertexAttribPointer(location.attrib.configuration,
+                        1,
+                        GL_UNSIGNED_BYTE,
                         GL_FALSE,
-                        (sizeof (float)) * 9,
-                        (void*)(6 * 4)
+                        vertex_size,
+                        (void*)(7)
                         );
   glEnableVertexAttribArray(location.attrib.position);
-  glEnableVertexAttribArray(location.attrib.normal);
-  glEnableVertexAttribArray(location.attrib.texture);
+  glEnableVertexAttribArray(location.attrib.block_id);
+  glEnableVertexAttribArray(location.attrib.configuration);
+  glVertexAttribDivisor(location.attrib.position, 1);
+  glVertexAttribDivisor(location.attrib.block_id, 1);
+  glVertexAttribDivisor(location.attrib.configuration, 1);
 }
 
 void load_buffers()
 {
   glGenVertexArrays(4, vertex_array_objects);
-  glGenBuffers(4, index_buffers);
+  //glGenBuffers(4, index_buffers);
   glGenBuffers(4, vertex_buffers);
 
   for (int i = 0; i < 4; i++) {
     glBindVertexArray(vertex_array_objects[i]);
 
-    load_element_buffer(i);
+    //load_element_buffer(i);
     load_vertex_buffer(i);
     load_vertex_attributes();
   }
@@ -234,9 +237,22 @@ void draw()
   //glBindBuffer(GL_UNIFORM_BUFFER, textures_ubo);
   //glBindBufferBase(GL_UNIFORM_BUFFER, 0, textures_ubo);
 
+  glEnable(GL_CULL_FACE);
+  glCullFace(GL_FRONT);
+  glFrontFace(GL_CCW);
+
   for (int i = 0; i < 4; i++) {
     glBindVertexArray(vertex_array_objects[i]);
 
-    glDrawElements(GL_TRIANGLES, index_count[i], GL_UNSIGNED_INT, 0);
+    //glDrawElements(GL_TRIANGLES, index_count[i], GL_UNSIGNED_INT, 0);
+
+    int instance_count = vertex_count[i];
+    //printf("instance_count %d\n", instance_count);
+
+    glPointSize(10.0);
+    glDrawArraysInstanced(GL_POINTS,
+                          0,
+                          1,
+                          instance_count);
   }
 }