Run-length zero compression for RTA.

Common/RLEZ.hpp

@@ -0,0 +1,66 @@
+#pragma once
+
+#include <vector>
+#include <stdexcept>
+#include <cstdint>
+
+namespace RLEZ
+{
+    inline std::vector<uint8_t> Decompress(const std::vector<uint8_t>& input)
+    {
+        std::vector<uint8_t> output;
+        size_t read = 0;
+
+        while (read < input.size())
+        {
+            uint8_t byte = input[read++];
+            output.push_back(byte);
+
+            if (byte == 0x00)
+            {
+                if (read >= input.size())
+                {
+                    break;
+                }
+
+                uint8_t count = input[read++];
+                output.insert(output.end(), count, 0x00);
+            }
+        }
+
+        return output;
+    }
+
+    inline std::vector<uint8_t> Compress(const std::vector<uint8_t>& input)
+    {
+        std::vector<uint8_t> output;
+        size_t i = 0;
+
+        while (i < input.size())
+        {
+            if (input[i] != 0x00)
+            {
+                output.push_back(input[i]);
+                ++i;
+            }
+            else
+            {
+                // Start of a zero run — count how many consecutive 0x00s
+                size_t zeroCount = 0;
+                size_t start = i;
+
+                while (i < input.size() && input[i] == 0x00 && zeroCount < 255)
+                {
+                    ++i;
+                    ++zeroCount;
+                }
+
+                // Emit zero-run marker and count (DO NOT emit any 0x00s literally)
+                output.push_back(0x00);
+                output.push_back(static_cast<uint8_t>(zeroCount));
+            }
+        }
+
+        return output;
+    }
+}