From 7abb0e27c16e0a5baabe2039cd69434377832e73 Mon Sep 17 00:00:00 2001
From: 123 <128890349+MacoriDev@users.noreply.github.com>
Date: Sun, 31 May 2026 09:02:22 +0900
Subject: [PATCH] Update main.cpp

---
 src/main.cpp | 63 ++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 49 insertions(+), 14 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index f71c43e..627aed6 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,38 +1,73 @@
 #include <cstdint>
 #include <cstring>
+#include <cstddef>
 #include <sys/mman.h>
+#include <unistd.h>
+
 #include "pl/Gloss.h"
 #include "pl/Signature.h"
 
-static const char* GFX_GAMMA_SIGNATURE = "? ? ? 52 ? ? ? 2F ? ? ? 1E ? ? ? 72 ? ? ? 1E ? ? ? D1 03 01 27 1E ? ? ? D1 E0 03 15 AA ? ? ? 52 ? ? ? 52";
+static const char* GFX_GAMMA_SIGNATURE =
+    "? ? ? 52 ? ? ? 2F ? ? ? 1E ? ? ? 72 ? ? ? 1E ? ? ? D1 "
+    "03 01 27 1E ? ? ? D1 E0 03 15 AA ? ? ? 52 ? ? ? 52";
+
+constexpr uint32_t FULLBRIGHT_GAMMA = 100;
+
+static constexpr uint32_t MakeMovW8(uint32_t imm) {
+    return 0x52800000u | ((imm & 0xFFFFu) << 5) | 8u;
+}
 
-constexpr uint32_t MOV_W8_10   = 0x52800148;
+constexpr uint32_t MOV_W8_FULLBRIGHT = MakeMovW8(FULLBRIGHT_GAMMA);
 constexpr uint32_t SCVTF_S2_W8 = 0x1E220102;
+constexpr uint32_t EXPECTED_FMOV_S2_1 = 0x1E2E1002;
+constexpr ptrdiff_t OFFSET_GAMMA_CONST = 12;
+constexpr ptrdiff_t OFFSET_FMOV        = 16;
 
-constexpr ptrdiff_t OFFSET_MOVK = 12;
-constexpr ptrdiff_t OFFSET_FMOV = 16;
+static bool ReadInsn(uintptr_t addr, uint32_t& out) {
+    std::memcpy(&out, reinterpret_cast<void*>(addr), sizeof(out));
+    return true;
+}
 
 static bool PatchMemory(void* addr, uint32_t insn) {
-    uintptr_t page_start = (uintptr_t)addr & ~(uintptr_t)4095;
-    size_t    page_size  = (sizeof(insn) + 4095) & ~(size_t)4095;
-    if (mprotect((void*)page_start, page_size, PROT_READ | PROT_WRITE | PROT_EXEC) != 0)
+    uintptr_t p = reinterpret_cast<uintptr_t>(addr);
+
+    long page_size_long = sysconf(_SC_PAGESIZE);
+    uintptr_t page_size = page_size_long > 0 ? static_cast<uintptr_t>(page_size_long) : 4096;
+
+    uintptr_t page_start = p & ~(page_size - 1);
+    uintptr_t page_end   = (p + sizeof(insn) + page_size - 1) & ~(page_size - 1);
+    size_t len = page_end - page_start;
+
+    if (mprotect(reinterpret_cast<void*>(page_start), len, PROT_READ | PROT_WRITE | PROT_EXEC) != 0)
         return false;
-    memcpy(addr, &insn, sizeof(insn));
-    __builtin___clear_cache((char*)addr, (char*)addr + sizeof(insn));
-    mprotect((void*)page_start, page_size, PROT_READ | PROT_EXEC);
+
+    std::memcpy(addr, &insn, sizeof(insn));
+    __builtin___clear_cache(reinterpret_cast<char*>(addr),
+                            reinterpret_cast<char*>(addr) + sizeof(insn));
+
+    mprotect(reinterpret_cast<void*>(page_start), len, PROT_READ | PROT_EXEC);
     return true;
 }
 
 static bool PatchGfxGamma() {
-    uintptr_t base = pl::signature::pl_resolve_signature(GFX_GAMMA_SIGNATURE, "libminecraftpe.so");
+    uintptr_t base = pl::signature::pl_resolve_signature(
+        GFX_GAMMA_SIGNATURE,
+        "libminecraftpe.so"
+    );
+
     if (base == 0)
         return false;
 
-    if (*reinterpret_cast<uint32_t*>(base + OFFSET_FMOV) != 0x1E2E1002)
+    uint32_t old_fmov = 0;
+    ReadInsn(base + OFFSET_FMOV, old_fmov);
+
+    if (old_fmov != EXPECTED_FMOV_S2_1)
         return false;
 
-    return PatchMemory(reinterpret_cast<void*>(base + OFFSET_MOVK), MOV_W8_10)
-        && PatchMemory(reinterpret_cast<void*>(base + OFFSET_FMOV), SCVTF_S2_W8);
+    bool ok1 = PatchMemory(reinterpret_cast<void*>(base + OFFSET_GAMMA_CONST), MOV_W8_FULLBRIGHT);
+    bool ok2 = PatchMemory(reinterpret_cast<void*>(base + OFFSET_FMOV), SCVTF_S2_W8);
+
+    return ok1 && ok2;
 }
 
 __attribute__((constructor))