azalea/codegen/lib/code/shapes.py

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