1 files changed, 110 insertions, 0 deletions
diff --git a/codegen/lib/code/shapes.py b/codegen/lib/code/shapes.py
new file mode 100644
index 00000000..e65e4028
--- /dev/null
+++ b/codegen/lib/code/shapes.py
@@ -0,0 +1,110 @@
+from lib.utils import get_dir_location, to_camel_case
+from lib.code.utils import clean_property_name
+from .blocks import get_property_struct_name
+from ..mappings import Mappings
+
+COLLISION_BLOCKS_RS_DIR = get_dir_location(
+    '../azalea-physics/src/collision/blocks.rs')
+
+
+def generate_block_shapes(blocks: dict, shapes: dict, block_states_report, block_datas_burger, mappings: Mappings):
+    code = generate_block_shapes_code(blocks, shapes, block_states_report, block_datas_burger, mappings)
+    with open(COLLISION_BLOCKS_RS_DIR, 'w') as f:
+        f.write(code)
+
+
+def generate_block_shapes_code(blocks: dict, shapes: dict, block_states_report, block_datas_burger, mappings: Mappings):
+    # look at downloads/generator-mod-*/blockCollisionShapes.json for format of blocks and shapes
+
+    generated_shape_code = ''
+    # we make several lazy_static! blocks so it doesn't complain about
+    # recursion and hopefully the compiler can paralleize it?
+    generated_shape_code += 'lazy_static! {'
+    for i, (shape_id, shape) in enumerate(sorted(shapes.items(), key=lambda shape: int(shape[0]))):
+        if i > 0 and i % 10 == 0:
+            generated_shape_code += '}\nlazy_static! {'
+        generated_shape_code += generate_code_for_shape(shape_id, shape)
+    generated_shape_code += '}'
+
+    # BlockState::PurpurStairs_NorthTopStraightTrue => &SHAPE24,
+    generated_match_inner_code = ''
+    shape_ids_to_variants = {}
+    for block_id, shape_ids in blocks.items():
+        if isinstance(shape_ids, int):
+            shape_ids = [shape_ids]
+        block_report_data = block_states_report['minecraft:' + block_id]
+        block_data_burger = block_datas_burger[block_id]
+
+        for possible_state, shape_id in zip(block_report_data['states'], shape_ids):
+            variant_values = []
+            for value in tuple(possible_state.get('properties', {}).values()):
+                variant_values.append(to_camel_case(value))
+            
+            if variant_values == []:
+                variant_name = to_camel_case(block_id)
+            else:
+                variant_name = f'{to_camel_case(block_id)}_{"".join(variant_values)}'
+
+            if shape_id not in shape_ids_to_variants:
+                shape_ids_to_variants[shape_id] = []
+            shape_ids_to_variants[shape_id].append(f'BlockState::{variant_name}')
+    # shape 1 is the most common so we have a _ => &SHAPE1 at the end
+    del shape_ids_to_variants[1]
+    for shape_id, variants in shape_ids_to_variants.items():
+        generated_match_inner_code += f'{"|".join(variants)} => &SHAPE{shape_id},\n'
+
+
+    return f'''
+//! Autogenerated block collisions for every block
+
+// This file is generated from codegen/lib/code/block_shapes.py. If you want to
+// modify it, change that file.
+
+#![allow(clippy::explicit_auto_deref)]
+
+use super::VoxelShape;
+use crate::collision::{{self, Shapes}};
+use azalea_block::*;
+use lazy_static::lazy_static;
+
+trait BlockWithShape {{
+    fn shape(&self) -> &'static VoxelShape;
+}}
+
+{generated_shape_code}
+
+impl BlockWithShape for BlockState {{
+    fn shape(&self) -> &'static VoxelShape {{
+        match self {{
+            {generated_match_inner_code}_ => &SHAPE1
+        }}
+    }}
+}}
+'''
+
+
+def generate_code_for_shape(shape_id: str, parts: list[list[float]]):
+    def make_arguments(part: list[float]):
+        return ', '.join(map(lambda n: str(n).rstrip('0'), part))
+    code = ''
+    code += f'static ref SHAPE{shape_id}: VoxelShape = '
+    steps = []
+    if parts == []:
+        steps.append('collision::empty_shape()')
+    else:
+        steps.append(f'collision::box_shape({make_arguments(parts[0])})')
+        for part in parts[1:]:
+            steps.append(
+                f'Shapes::or(s, collision::box_shape({make_arguments(part)}))')
+
+    if len(steps) == 1:
+        code += steps[0]
+    else:
+        code += '{\n'
+        for step in steps[:-1]:
+            code += f'    let s = {step};\n'
+        code += f'    {steps[-1]}\n'
+        code += '};\n'
+    return code
+
+