fix and improve olmec patch

src/game_api/game_patches.cpp

@@ -69,73 +69,41 @@ bool check_if_ent_type_exists(ENT_TYPE type, int mask)
     return false;
 }
 
+size_t g_olmec_patch_size;
+size_t g_olmec_patch_addr;
 void patch_olmec_kill_crash()
 {
-    /*
-     * The idea: do what's necessary xd
-     */
     static bool once = false;
     if (once)
         return;
 
+    // [patch ... whatever this code does]
+
     const auto offset = get_address("olmec_lookup_crash");
     constexpr auto code_to_move = 7;
     auto memory = Memory::get();
     size_t return_addr;
     {
         // find address to escape to
-
-        auto rva = offset - memory.exe_ptr;
-        // there are two jump that performe long jump, at the end, of it, the is 'mov rax,qword ptr ds:[rdi]', then find jump that's jumps over that code and create sound meta call
-        // this is actually unique pattern
-        auto jump_out_lookup = find_inst(memory.exe(), "\x48\x8B\x45\x50\x48\x83\x78\x60\x00"sv, rva, std::nullopt, "patch_olmec_kill_crash");
+        size_t rva = offset - memory.exe_ptr;
+        // below the patched code there are two jumps that performe long jump, at the end of it there is 'mov rax,qword ptr ds:[rdi]',
+        // from this point find jump that's jumps over sond meta and fmod stuff, the jump ends up on code `mov eax,dword ptr ss:[rbp+10]`, that's our target for return_addr
+        auto jump_out_lookup = find_inst(memory.exe(), "\x48\xC7\x40\x60\x00\x00\x00\x00"sv, rva, rva + 0x69D, "patch_olmec_kill_crash");
         if (jump_out_lookup == 0)
             return;
 
-        // could probably just make static offset from this stuff
-        auto jump_offset_offset = memory.at_exe(jump_out_lookup + 10); // 4 (lookup instruction size) + 1 (jump instruction)
-        auto jump_offset = memory_read<int8_t>(jump_offset_offset);
-        return_addr = jump_offset_offset + 1 + jump_offset; // +1 to get address after the jump
-    }
-    {
-        // patch the cutscene
-
-        const auto function_offset = get_virtual_function_address(VTABLE_OFFSET::THEME_OLMEC, 24); // spawn_effects
-        const auto jump_out_lookup = get_address("olmec_lookup_in_theme");
-        if (jump_out_lookup == 0)
-            return;
-
-        // find first jump (skips the whole funciton)
-        auto end_function_jump = find_inst(memory.exe(), "\x0F\x84"sv, function_offset, function_offset + 0xC3, "patch_olmec_kill_crash");
-        if (end_function_jump == 0)
-            return;
-
-        auto jump_addr = memory.at_exe(end_function_jump);
-        auto addr_to_jump_to = jump_addr + 6 + memory_read<int32_t>(jump_addr + 2);
-        std::string clear_ic8_code = fmt::format(
-            "\x48\xb8{}" // movabs RAX, &clear_cutscene_behavior
-            "\xff\xd0"sv // call   RAX
-        );
-
-        /* The idea:
-         * replace end of the loop jump with jump to the new code
-         * call our own function to clear all the cutscene behaviors
-         * jump to the end of the function
-         * hopefully there isn't something important that we're skipping
-         */
-
-        patch_and_redirect(jump_out_lookup, 5, clear_ic8_code, true, addr_to_jump_to);
+        return_addr = memory.at_exe(jump_out_lookup + 8); // 8 - pattern size
     }
 
     /* The idea:
      * if it's not the end of the array it's looking for olmec, jump back to the oryginal code via jump in `new_code`
      * if it's end of the array (no olmec found) jump to return_addr
      * the place for return_addr was kind of choosen by feel, as the code is complicated
-     * the whole point of the patched code is to find olmec and check it's faze, maybe for the music? no idea
+     * the whole point of the patched code is to find olmec and check it's faze, maybe for the music? no idea, it's a big function
      */
 
     std::string_view new_code{
-        "\x0f\x85\x00\x00\x00\x00"sv}; //   jne (offset needs to be updated after we know the address)
+        "\x0f\x85\x00\x00\x00\x00"sv}; // jne   (offset needs to be updated after we know the address)
 
     auto new_code_addr = patch_and_redirect(offset, code_to_move, new_code, false, return_addr);
     if (new_code_addr == 0)
@@ -144,12 +112,53 @@ void patch_olmec_kill_crash()
     new_code_addr += code_to_move;
     int32_t rel = static_cast<int32_t>(offset + code_to_move - (new_code_addr + 6)); // +6 after the jump
     write_mem_prot(new_code_addr + 2, rel, true);
+
+    // [patch the cutscene]
+
+    const auto patch_addr = get_address("olmec_lookup_in_theme");
+    if (patch_addr == 0)
+        return;
+
+    size_t addr_to_jump_to;
+    {
+        // find end of the function that sets the camera and stuff
+        size_t rva = patch_addr - memory.exe_ptr;
+        size_t rva_jumpout_to = find_inst(memory.exe(), "\x48\x8B\x06"sv, rva, rva + 0xA50, "patch_olmec_kill_crash");
+        if (rva_jumpout_to == 0)
+            return;
+
+        addr_to_jump_to = memory.at_exe(rva_jumpout_to + 14); // +14 just offset to get what we want
+    }
+
+    std::string cutscene_new_code = fmt::format(
+        "\xb9{}"sv                    // mov      ecx, ENT_TYPE
+        "\xba\x80\x00\x00\x00"sv      // mov      edx, 0x80 (MASK::ACTIVEFLOOR)
+        "\x48\xb8{}"sv                // movabs   RAX, &check_if_ent_type_exists
+        "\xff\xd0"sv                  // call     RAX
+        "\x84\xc0"sv                  // test     al, al
+        "\x0f\x85\x00\x00\x00\x00"sv, // jnz      (offset needs to be updated after we know the address)
+        to_le_bytes(to_id("ENT_TYPE_ACTIVEFLOOR_OLMEC")),
+        to_le_bytes((size_t)&check_if_ent_type_exists));
+
+    /* The idea:
+     * same as tiamat
+     */
+    constexpr auto cutscene_code_to_move = 7;
+    g_olmec_patch_size = cutscene_new_code.size() + cutscene_code_to_move; // without the final jump added by patch_and_redirect
+
+    g_olmec_patch_addr = patch_and_redirect(patch_addr, cutscene_code_to_move, cutscene_new_code, false, addr_to_jump_to);
+    if (g_olmec_patch_addr == 0)
+        return;
+
+    auto jump_addr = g_olmec_patch_addr + g_olmec_patch_size;
+    int32_t rel_off = static_cast<int32_t>(patch_addr + cutscene_code_to_move - jump_addr);
+    write_mem_prot(jump_addr - 4, rel_off, true); // update the jump offset
+
     once = true;
 }
 
 size_t g_tiamat_patch_size;
 size_t g_tiamat_patch_addr;
-
 void patch_tiamat_kill_crash()
 {
     static bool once = false;
@@ -193,6 +202,8 @@ void patch_tiamat_kill_crash()
     g_tiamat_patch_size = new_code.size() + copy_over_code_size; // without the final jump added by patch_and_redirect
 
     g_tiamat_patch_addr = patch_and_redirect(patch_addr, copy_over_code_size, new_code, false, return_to_addr);
+    if (g_tiamat_patch_addr == 0)
+        return;
 
     auto jump_addr = g_tiamat_patch_addr + g_tiamat_patch_size;
     int32_t rel = static_cast<int32_t>(patch_addr + copy_over_code_size - jump_addr);
@@ -238,6 +249,9 @@ void patch_liquid_OOB()
         "\x0f\x8C\x00\x00\x00\x00"sv}; //   jl     (same jump as before)
 
     auto new_code_addr = patch_and_redirect(offset, code_to_move, new_code);
+    if (new_code_addr == 0)
+        return;
+
     new_code_addr += code_to_move;
 
     int32_t rel = static_cast<int32_t>(continue_addr - (new_code_addr + 10)); // +10 after the jump
@@ -249,12 +263,12 @@ void patch_liquid_OOB()
 
 void set_skip_olmec_cutscene(bool skip)
 {
-    static const auto jump_out_lookup = get_address("olmec_lookup_in_theme");
-    if (jump_out_lookup == 0)
-        return;
+    patch_olmec_kill_crash(); // just in case
 
+    // simple jump over the tiamat check, nop here just so there is no funny business
+    static const std::string code = fmt::format("\xEB{}\x90"sv, to_le_bytes(static_cast<int8_t>(g_olmec_patch_size - 2)));
     if (skip)
-        write_mem_recoverable("set_skip_olmec_cutscene", jump_out_lookup - 2, "\x90\x90"sv, true);
+        write_mem_recoverable("set_skip_olmec_cutscene", g_olmec_patch_addr, code, true);
     else
         recover_mem("set_skip_olmec_cutscene");
 }

src/game_api/search.cpp

@@ -1986,11 +1986,11 @@ std::unordered_map<std::string_view, AddressRule> g_address_rules{
     },
     {
         "olmec_lookup_in_theme"sv,
-        // find the jump out of olmec lookup loop
+        // find the first jump in the virtual that skips the whole function
         PatternCommandBuffer{}
             .get_virtual_function_address(VTABLE_OFFSET::THEME_OLMEC, (VIRT_FUNC)24) // spawn_effects
-            .find_after_inst("\x48\x03\x58\x28"sv)
-            .offset(0x5)
+            .find_after_inst("83 78 0C 0D"_gh)
+            .offset(0x6) // after the jump instruction
             .at_exe(),
     },
     {

src/game_api/state.cpp

@@ -289,7 +289,7 @@ State& State::get()
             // game patches
             patch_tiamat_kill_crash();
             patch_orbs_limit();
-            //patch_olmec_kill_crash();
+            patch_olmec_kill_crash();
             patch_liquid_OOB();
         }