From 4247945df13507fb07a4746263bb702d6fbe04cd Mon Sep 17 00:00:00 2001
From: mat <github@matdoes.dev>
Date: Sun, 18 Sep 2022 23:13:45 -0500
Subject: start work on optimizing block macros

---
 azalea-core/src/bitset.rs | 50 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

(limited to 'azalea-core/src')

diff --git a/azalea-core/src/bitset.rs b/azalea-core/src/bitset.rs
index 2ffd5657..6f0a27ca 100644
--- a/azalea-core/src/bitset.rs
+++ b/azalea-core/src/bitset.rs
@@ -7,6 +7,8 @@ pub struct BitSet {
     data: Vec<u64>,
 }
 
+const ADDRESS_BITS_PER_WORD: usize = 6;
+
 // the Index trait requires us to return a reference, but we can't do that
 impl BitSet {
     pub fn new(size: usize) -> Self {
@@ -18,6 +20,54 @@ impl BitSet {
     pub fn index(&self, index: usize) -> bool {
         (self.data[index / 64] & (1u64 << (index % 64))) != 0
     }
+
+    // private static int wordIndex(int bitIndex) {
+    //     return bitIndex >> ADDRESS_BITS_PER_WORD;
+    // }
+    pub fn word_index(bit_index: usize) -> usize {
+        bit_index >> ADDRESS_BITS_PER_WORD
+    }
+
+    pub fn clear_from_to(&mut self, from: usize, to: usize) {
+        assert!(from <= to);
+        assert!(to <= self.data.len() * 64);
+        assert!(to > 0);
+
+        if from == to {
+            return;
+        }
+
+        // int startWordIndex = wordIndex(fromIndex);
+        // if (startWordIndex >= wordsInUse)
+        //     return;
+
+        // int endWordIndex = wordIndex(toIndex - 1);
+        // if (endWordIndex >= wordsInUse) {
+        //     toIndex = length();
+        //     endWordIndex = wordsInUse - 1;
+        // }
+
+        // long firstWordMask = WORD_MASK << fromIndex;
+        // long lastWordMask  = WORD_MASK >>> -toIndex;
+        // if (startWordIndex == endWordIndex) {
+        //     // Case 1: One word
+        //     words[startWordIndex] &= ~(firstWordMask & lastWordMask);
+        // } else {
+        //     // Case 2: Multiple words
+        //     // Handle first word
+        //     words[startWordIndex] &= ~firstWordMask;
+
+        //     // Handle intermediate words, if any
+        //     for (int i = startWordIndex+1; i < endWordIndex; i++)
+        //         words[i] = 0;
+
+        //     // Handle last word
+        //     words[endWordIndex] &= ~lastWordMask;
+        // }
+
+        // recalculateWordsInUse();
+        // checkInvariants();
+    }
 }
 
 impl McBufReadable for BitSet {
-- 
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