basalt_api/world/
block.rs

1//! Block state IDs for common Minecraft 1.21.4 blocks.
2//!
3//! These are the default state IDs from the vanilla data generator.
4//! Each block can have multiple states (e.g., grass_block has snowy
5//! and non-snowy variants), but we use the default (non-snowy) state.
6
7/// Air — no block, fully transparent.
8pub const AIR: u16 = 0;
9
10/// Stone — basic underground block.
11pub const STONE: u16 = 1;
12
13/// Dirt — soil block without grass.
14pub const DIRT: u16 = 10;
15
16/// Grass block — dirt with grass on top (default: snowy=false).
17pub const GRASS_BLOCK: u16 = 9;
18
19/// Bedrock — indestructible bottom layer.
20pub const BEDROCK: u16 = 85;
21
22/// Water — still water (default state, level 0).
23pub const WATER: u16 = 86;
24
25/// Sand — beach and desert block.
26pub const SAND: u16 = 118;
27
28/// Gravel — underwater floor block.
29pub const GRAVEL: u16 = 124;
30
31/// Snow block — covers high-altitude terrain tops.
32pub const SNOW_BLOCK: u16 = 5950;
33
34/// Crafting table — default state (1.21.4 block state ID).
35///
36/// Verified against minecraft-data registry. When updating to a new
37/// Minecraft version, verify this constant against the block state data.
38pub const CRAFTING_TABLE: u16 = 4332;
39
40/// Chest — default state (facing north, type single, no waterlog).
41pub const CHEST: u16 = 3010;
42
43/// Range of block states that are chest variants (facing × type × waterlogged).
44const CHEST_MIN: u16 = 3009;
45const CHEST_MAX: u16 = 3032;
46
47/// Returns true if the block state is a crafting table.
48pub fn is_crafting_table(state: u16) -> bool {
49    state == CRAFTING_TABLE
50}
51
52/// Returns true if the block state is any chest variant.
53pub fn is_chest(state: u16) -> bool {
54    (CHEST_MIN..=CHEST_MAX).contains(&state)
55}
56
57/// Returns true if the chest state is a single chest (not part of a double).
58pub fn is_single_chest(state: u16) -> bool {
59    is_chest(state) && chest_type(state) == 0
60}
61
62/// Extracts the facing index from a chest state (0=north, 1=south, 2=west, 3=east).
63pub fn chest_facing(state: u16) -> u16 {
64    if !is_chest(state) {
65        return 0;
66    }
67    (state - CHEST_MIN) / 6
68}
69
70/// Extracts the type from a chest state (0=single, 1=left, 2=right).
71pub fn chest_type(state: u16) -> u16 {
72    if !is_chest(state) {
73        return 0;
74    }
75    ((state - CHEST_MIN) % 6) / 2
76}
77
78/// Builds a chest state from facing, type, and waterlogged=false.
79pub fn chest_state(facing: u16, chest_type: u16) -> u16 {
80    CHEST_MIN + facing * 6 + chest_type * 2 + 1 // +1 for waterlogged=false
81}
82
83/// Returns the adjacent position for double chest pairing based on facing.
84///
85/// For north/south facing: checks east/west (±X).
86/// For east/west facing: checks north/south (±Z).
87/// Returns `(dx1, dz1, dx2, dz2)` — two candidate offsets to check.
88pub fn chest_adjacent_offsets(facing: u16) -> [(i32, i32); 2] {
89    // Right side first (vanilla pairing priority)
90    match facing {
91        0 | 1 => [(1, 0), (-1, 0)], // north/south: east first, then west
92        2 | 3 => [(0, 1), (0, -1)], // west/east: south first, then north
93        _ => [(0, 0), (0, 0)],
94    }
95}
96
97/// Given a facing and the offset direction of the adjacent chest,
98/// returns (type_for_new, type_for_existing).
99///
100/// The "left" chest is the one on the left when looking at the front.
101pub fn chest_double_types(facing: u16, dx: i32, dz: i32) -> (u16, u16) {
102    // (new_type, existing_type)
103    match facing {
104        0 => {
105            // North-facing: front faces north, viewed from south
106            if dx < 0 { (2, 1) } else { (1, 2) } // west neighbor: new=right, existing=left
107        }
108        1 => {
109            // South-facing: front faces south, viewed from north
110            if dx < 0 { (1, 2) } else { (2, 1) }
111        }
112        2 => {
113            // West-facing: front faces west, viewed from east
114            if dz < 0 { (1, 2) } else { (2, 1) }
115        }
116        3 => {
117            // East-facing: front faces east, viewed from west
118            if dz < 0 { (2, 1) } else { (1, 2) }
119        }
120        _ => (0, 0),
121    }
122}
123
124/// Returns the chest block state for a given player yaw (facing the player).
125///
126/// The chest faces the player: if the player is looking north (yaw ~180),
127/// the chest faces south so the player sees the front.
128pub fn chest_state_for_yaw(yaw: f32) -> u16 {
129    // Normalize yaw to 0-360
130    let yaw = ((yaw % 360.0) + 360.0) % 360.0;
131    // Chest states: base 3009, facing*6 + type*2 + waterlogged
132    // type=single(0), waterlogged=false(1)
133    // facing: 0=north, 1=south, 2=west, 3=east
134    let facing = match yaw as u16 {
135        0..=45 | 316..=360 => 0, // player faces south → chest faces north
136        46..=135 => 3,           // player faces west → chest faces east
137        136..=225 => 1,          // player faces north → chest faces south
138        226..=315 => 2,          // player faces east → chest faces west
139        _ => 0,
140    };
141    3009 + facing * 6 + 1 // +1 for waterlogged=false
142}
143
144/// Maximum item ID in the lookup table.
145const MAX_ITEM_ID: usize = 1384;
146
147/// Lookup table mapping item registry IDs to default block state IDs.
148/// Generated from minecraft-data 1.21.4. Entries with value `u16::MAX`
149/// indicate items that do not have a corresponding block.
150#[rustfmt::skip]
151const ITEM_TO_BLOCK_STATE: [u16; 1385] = [
152        0,    1,    2,    3,    4,    5,    6,    7,25918,25920,26331,23329,22094,22098,22112,22184,
153    22916,22505,22509,22523,22595,22917,22921,22935,23007,23328,25781,    9,   10,   11,   13,25915,
154    25916,19621,19604,   14,   15,   16,   17,   18,   19,   20,   21,   25,   26,   27,19679,19680,
155       28,   29,   31,   33,   35,   37,   39,   41,   43,   50,   85,  118,  119,  125,  123,  124,
156      133,  134,  131,  132,23955,23956,  129,  130, 5904, 5906, 8285, 8286,  563,  564, 4329, 4330,
157      135,10023,20461,11624,27571,27572,27573,27696,22044,22045, 2135,23951, 2134, 4331,20460,23952,
158    23953,23954,23964,23963,23962,23961,23960,23959,23958,23957,24220,24140,24060,23980,24310,24304,
159    24298,24292,24313,24315,24314,24316,23968,23967,23966,23965,24320,24319,24318,24317,24572,24492,
160    24412,24332,24662,24656,24650,24644,  137,  140,  143,  146,  149,  152,  158,  155,  161,  164,
161      166,19610,19593,  169,  193,  172,  175,  178,  181,  184,  187,  190,  196,19613,19596,  226,
162      229,  232,  235,  238,  241,  244,  247,  250,19619,19602,  199,  202,  205,  208,  211,  214,
163      217,   23,  220,  223,19616,19599,  279,  307,  335,  363,  391,  419,  447,  475,  503,  531,
164      559,  560,  561,  562,23330,  565,  578,  579,  580, 2047, 2048, 2049,25837,25838, 2050, 2051,
165    13946, 2090, 2091, 2092, 2093, 2094, 2095, 2096, 2097, 2098, 2099, 2100, 2101, 2102, 2103, 2104,
166     2105, 2118,27862,27863, 2120, 2121, 2122, 2123, 2124, 2125, 2126, 2127, 2128, 2129, 2131, 2130,
167     2119,13521,25836, 2132, 2133,19622,19605,19678,19607,19608,19624,19651, 5968,13773,25840,25839,
168    25856,27698,27860,27697,25914,25858,25900,13958,12044,12050,12056,12062,12068,12074,12080,12086,
169    12092,12098,12104,19684,19690,12110,12116,12122,12128,12134,12140,12146,12152,12158,12164,12170,
170    12176,12182,12188,11588,11594,11600,12193,12194,12192,12191, 2136, 2139, 2203,27596, 2396, 2397,
171     2398,13351,13416,13417,13423,13425,13438, 2916, 2926, 3010, 4332, 4341, 4350, 4742, 4780, 5941,
172     5949, 5950, 5951, 5967, 5985, 6017,12514,12546,12578,12610,12642,12674,12706,12738,12770,19728,
173    19760, 7044, 6035, 6039, 6018, 6019, 6020, 6022, 6025,27570, 6027, 6032, 6776, 6777, 6778, 6779,
174     6780, 6781,27568, 6770, 6771, 6772, 6773, 6774, 6775,27153,27565,26742,27566,27564,27586, 6782,
175     6846, 6910, 7005, 7009, 7043, 7045, 7101, 7229, 7357, 7633, 7634, 7646, 7718, 7724, 8045, 7401,
176     7481, 7561, 7631, 7632, 8046,21736,21735, 8078, 8090,23812,23940,23942,23950, 8163, 8185, 8189,
177    13507, 8190, 8216, 8288, 8439, 2940, 8451, 8531, 8611,10694,10774,10854,10934,11014,11094,11174,
178    19964,20044, 8686, 8692, 8696, 9020,15176,15500,15824,16148,16472,16796,17120,17444,17768,18092,
179    18416,18740,19064,20557,21414,20977,26010,26421,27243,26832, 9906, 9910, 9914,10035,10034,21737,
180    10037,10050,10155,10156,10157,10158,10159,10160,10161,10162,10163,10164,10165,10166,10167,10168,
181    10169,10170,11245,11277,11605,11607,11608,11609,11610,11611,11612,11613,11614,11615,11616,11617,
182    11618,11619,11620,11621,11622,11623,11625,13526,11627,11629,11631,11633,11635,11637, 6114, 6115,
183     6116, 6117, 6118, 6119, 6120, 6121, 6122, 6123, 6124, 6125, 6126, 6127, 6128, 6129,10202,10234,
184    10266,10298,10330,10362,10394,10426,10458,10490,10522,10554,10586,10618,10650,10682,11342,11343,
185    11344,11356,11436,11516,11603,11958,11959,11960,11972,13534,13546,13556,13557,19606,13558,13560,
186    13562,13579,13585,13591,13597,13603,13609,13615,13621,13627,13633,13639,13645,13651,13657,13663,
187    13669,13675,13677,13681,13685,13689,13693,13697,13701,13705,13709,13713,13717,13721,13725,13729,
188    13733,13737,13741,13742,13743,13744,13745,13746,13747,13748,13749,13750,13751,13752,13753,13754,
189    13755,13756,13757,13758,13759,13760,13761,13762,13763,13764,13765,13766,13767,13768,13769,13770,
190    13771,13772,13801,13813,13816,13817,13818,13819,13820,13821,13822,13823,13824,13825,13836,13838,
191    13840,13842,13844,13828,13830,13832,13834,13826,13856,13858,13860,13862,13864,13846,13848,13850,
192    13852,13854,13954,13955,13986,14066,14146,14226,14306,14386,14466,14546,14626,14706,14786,14866,
193    14946,15026,25932,26343,27165,26754,15098,15104,15110,15116,15122,15128,15134,15140,15146,15152,
194    15158,15164,15170,26004,26415,27237,26826,19416,65535, 5907,10022, 6053, 9975, 2060, 2041,11243,
195    20458,13568,10024,  567,10144,19466,20394, 5802,25756,10006,23333,23429, 8304, 9919, 2138, 8192,
196      582, 5926,21396, 9395, 9419, 9443, 9467, 9491, 9515, 9539, 9563, 9587, 9611,20122,20146, 5818,
197    21386, 9942, 9958, 5884, 5886, 5888, 5890, 5892, 5894, 5896, 5898, 5900, 5902,19694,19696, 5830,
198     4688,12782,12846,12910,12974,13038,13102,13166,13230,13294,20172,20236,24676,24740,24868,24804,
199    24932,24996,25124,25060,11293, 6145, 6209, 6273, 6337, 6401, 6465, 6529, 6593, 6657, 6721,19776,
200    19840,25192,25256,25384,25320,25448,25512,25640,25576, 7365,12202,12234,12266,12298,12330,12362,
201    12394,12426,12458,19896,19928, 2000, 2024, 4750,10132,65535,65535,65535,65535,65535,65535,65535,
202    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
203    65535,65535,65535,65535,65535,65535,65535,20370,20383,65535,65535,65535,65535,65535,65535,65535,
204    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
205    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
206    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
207    65535,65535,65535,65535,65535, 4333,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
208    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
209    65535,65535,65535,65535,65535, 4358, 4390, 4422, 4518, 4454, 4486, 4550, 4582, 4614, 4646,20290,
210    20322, 4962, 5026, 5090, 5282, 5154, 5218, 5346, 5410, 5602, 5666, 5474, 5538,65535,65535,65535,
211    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,13800,65535,65535,65535,
212    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
213    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
214    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
215    65535,65535,65535,65535, 6043, 1734, 1750, 1766, 1782, 1798, 1814, 1830, 1846, 1862, 1878, 1894,
216     1910, 1926, 1942, 1958, 1974,65535,27648,65535,65535,65535,65535,65535,65535,65535,65535,65535,
217    65535,65535,65535,65535,65535,65535, 8159,65535,65535,65535,65535,65535,65535, 8171, 8172,65535,
218    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
219    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
220    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
221    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
222    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
223    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535, 9341,65535,65535,65535,65535,
224    65535,65535, 9642, 9682, 9762, 9722, 9802, 9842, 9882,65535,65535,65535,65535,65535,65535,65535,
225    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
226    65535,11638,11654,11670,11686,11702,11718,11734,11750,11766,11782,11798,11814,11830,11846,11862,
227    11878,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
228    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
229    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,19417,65535,65535,
230    65535,65535,65535,65535,65535,65535,65535,65535,65535,20385,19422,19434,19442,19449,19450,19455,
231    19479,19480,19485,19519,19523,65535,65535,19527,19559,19623,65535,20410,20434,65535,20459,20472,
232    20462,20473,20881,20485,21298,20884,21382,21310,20887,20885,20891,20905,20886,20463,21741,21757,
233    21773,21789,21805,21821,21837,21853,21869,21885,21901,21917,21933,21949,21965,21981,21997,22091,
234    22079,22067,22055,25766,27577,27580,27583,27585,65535,65535,65535,65535,65535,65535,65535,65535,
235    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
236    65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,65535,
237    65535,65535,65535,65535,25690,25692,25694,25696,25698,25700,25702,25704,25708,25712,25716,25720,
238    25724,25728,25732,25736,27657,65535,65535,27667,65535,
239];
240
241/// Returns whether a block state ID represents a solid (collidable) block.
242///
243/// Solid blocks prevent entity movement through them. Air, water, and
244/// a few other blocks are non-solid. This is a simplified check — a
245/// full implementation would use the block registry's collision shape.
246pub fn is_solid(state: u16) -> bool {
247    // Non-solid blocks: air, water, lava, and their variants
248    // This is a conservative approximation — in vanilla, collision
249    // shapes are per-block-state, but for basic physics this suffices.
250    !matches!(state, AIR | WATER)
251}
252
253/// Maps a Minecraft item registry ID to the default block state ID.
254///
255/// Returns `None` if the item does not have a corresponding block
256/// (e.g., swords, food, spawn eggs). The mapping covers all 943
257/// vanilla 1.21.4 blocks with matching items.
258pub fn item_to_default_block_state(item_id: i32) -> Option<u16> {
259    if item_id < 0 || item_id as usize > MAX_ITEM_ID {
260        return None;
261    }
262    let state = ITEM_TO_BLOCK_STATE[item_id as usize];
263    if state == u16::MAX { None } else { Some(state) }
264}
265
266/// Returns the item ID that a block state drops when broken.
267///
268/// Performs a reverse lookup of the [`item_to_default_block_state`]
269/// table. Returns `None` for block states with no matching item
270/// (e.g., air, technical blocks) or non-default block state variants.
271pub fn block_state_to_item_id(state: u16) -> Option<i32> {
272    if state == 0 {
273        return None; // air drops nothing
274    }
275    // Blocks with multiple state variants: map any variant to the item
276    if is_chest(state) {
277        return Some(313); // chest item ID
278    }
279    for (item_id, &block_state) in ITEM_TO_BLOCK_STATE.iter().enumerate() {
280        if block_state == state {
281            return Some(item_id as i32);
282        }
283    }
284    None
285}
286
287#[cfg(test)]
288mod tests {
289    use super::*;
290
291    #[test]
292    fn stone_item_maps_to_stone_block() {
293        assert_eq!(item_to_default_block_state(1), Some(STONE));
294    }
295
296    #[test]
297    fn dirt_item_maps_to_dirt_block() {
298        assert_eq!(item_to_default_block_state(28), Some(DIRT));
299    }
300
301    #[test]
302    fn air_item_maps_to_air_block() {
303        assert_eq!(item_to_default_block_state(0), Some(AIR));
304    }
305
306    #[test]
307    fn negative_item_id_returns_none() {
308        assert_eq!(item_to_default_block_state(-1), None);
309    }
310
311    #[test]
312    fn out_of_range_item_id_returns_none() {
313        assert_eq!(item_to_default_block_state(99999), None);
314    }
315
316    #[test]
317    fn non_block_item_returns_none() {
318        // Item IDs in the 65535 sentinel range (e.g., swords, food)
319        // Check a known non-block item
320        assert_eq!(item_to_default_block_state(MAX_ITEM_ID as i32), None);
321    }
322
323    #[test]
324    fn bedrock_mapping() {
325        assert_eq!(item_to_default_block_state(58), Some(BEDROCK));
326    }
327
328    #[test]
329    fn stone_block_drops_stone_item() {
330        assert_eq!(block_state_to_item_id(STONE), Some(1));
331    }
332
333    #[test]
334    fn air_drops_nothing() {
335        assert_eq!(block_state_to_item_id(AIR), None);
336    }
337
338    #[test]
339    fn all_terrain_blocks_have_reverse_mapping() {
340        // Every block the terrain generators use must produce a drop
341        assert!(block_state_to_item_id(STONE).is_some(), "stone");
342        assert!(block_state_to_item_id(DIRT).is_some(), "dirt");
343        assert!(block_state_to_item_id(GRASS_BLOCK).is_some(), "grass_block");
344        assert!(block_state_to_item_id(SAND).is_some(), "sand");
345        assert!(block_state_to_item_id(GRAVEL).is_some(), "gravel");
346        assert!(block_state_to_item_id(BEDROCK).is_some(), "bedrock");
347        assert!(block_state_to_item_id(SNOW_BLOCK).is_some(), "snow_block");
348    }
349
350    #[test]
351    fn is_crafting_table_matches_constant() {
352        assert!(is_crafting_table(CRAFTING_TABLE));
353    }
354
355    #[test]
356    fn is_crafting_table_rejects_air() {
357        assert!(!is_crafting_table(AIR));
358    }
359
360    #[test]
361    fn roundtrip_item_to_block_to_item() {
362        // Stone: item 1 -> block state 1 -> item 1
363        let state = item_to_default_block_state(1).unwrap();
364        assert_eq!(block_state_to_item_id(state), Some(1));
365    }
366}
basalt_api/world/block.rs

basalt_api/world/
block.rs
