From f03f5cbeb7eeab3f3bf8858503a39282a832dc62 Mon Sep 17 00:00:00 2001
From: Mauro Junior <45118493+jetrotal@users.noreply.github.com>
Date: Thu, 9 Jan 2025 14:05:05 -0300
Subject: [PATCH] Maniac Patch/CallCommand Update - Support Expressions

---
 src/game_interpreter.cpp | 28 ++++------------------------
 src/maniac_patch.cpp     | 29 +++++++++++++++++++++++++++++
 src/maniac_patch.h       |  3 +++
 3 files changed, 36 insertions(+), 24 deletions(-)

diff --git a/src/game_interpreter.cpp b/src/game_interpreter.cpp
index f949b71204..3a4ae98ff0 100644
--- a/src/game_interpreter.cpp
+++ b/src/game_interpreter.cpp
@@ -5123,31 +5123,11 @@ bool Game_Interpreter::CommandManiacCallCommand(lcf::rpg::EventCommand const& co
 
 	case 4: { // Expression mode - interprets its own parameters as Maniac Expressions
 
-		//TODO - LEARN HOW THIS ACTUALLY WORKS
-		break;
-
-		auto expression_params = MakeSpan(com.parameters).subspan(5);
-
-		// Based on the encoding pattern, each expression seems to be encoded separately 
-		// and the parameters are already split into the format ParseExpression expects
-		output_args.reserve(5); // Reserve space for typical expression array elements
+		auto values = ManiacPatch::ParseExpressions(MakeSpan(com.parameters).subspan(5), *this);
 
-		// Find end of expressions (when encountering a value that breaks the pattern)
-		size_t param_count = expression_params.size();
-		size_t current_param = 0;
+		output_args.reserve(values.size());
+		output_args.insert(output_args.end(), values.begin(), values.end());
 
-		while (current_param < param_count) {
-			// Try to get all bytes until we hit the end or an invalid expression marker
-			auto remaining_params = MakeSpan(expression_params).subspan(current_param);
-
-			// ParseExpression will handle breaking down each parameter into bytes
-			int32_t result = ManiacPatch::ParseExpression(remaining_params, *this);
-			output_args.push_back(result);
-
-			// Move to next expression based on the pattern of bytes used
-			// Need to figure out exact number of parameters used by ParseExpression
-			current_param += 1; // This needs to be adjusted based on how many parameters each expression consumes
-		}
 		break;
 	}
 
@@ -5168,7 +5148,7 @@ bool Game_Interpreter::CommandManiacCallCommand(lcf::rpg::EventCommand const& co
 	for (int i = 0; i < cmd.parameters.size(); i++) params_str += " " + std::to_string(output_args[i]);
 	Output::Warning("Command parameters: {}", params_str);
 	Output::Info("--------------------\n");
-	*/
+	//*/
 
 	// Our implementation pushes a new frame containing the command instead of invoking it directly.
 	// This is incompatible to Maniacs but has a better compatibility with our code.
diff --git a/src/maniac_patch.cpp b/src/maniac_patch.cpp
index 0ed805adf9..2548776e0d 100644
--- a/src/maniac_patch.cpp
+++ b/src/maniac_patch.cpp
@@ -570,6 +570,35 @@ int32_t ManiacPatch::ParseExpression(Span<const int32_t> op_codes, const Game_Ba
 	return Process(beg, ops.end(), interpreter);
 }
 
+std::vector<int32_t> ManiacPatch::ParseExpressions(Span<const int32_t> op_codes, const Game_BaseInterpreterContext& interpreter) {
+	std::vector<int32_t> ops;
+	for (auto& o : op_codes) {
+		auto uo = static_cast<uint32_t>(o);
+		ops.push_back(static_cast<int32_t>(uo & 0x000000FF));
+		ops.push_back(static_cast<int32_t>((uo & 0x0000FF00) >> 8));
+		ops.push_back(static_cast<int32_t>((uo & 0x00FF0000) >> 16));
+		ops.push_back(static_cast<int32_t>((uo & 0xFF000000) >> 24));
+	}
+
+	if (ops.empty()) {
+		return {};
+	}
+
+	auto it = ops.begin();
+
+	std::vector<int32_t> results;
+
+	while (true) {
+		results.push_back(Process(it, ops.end(), interpreter));
+
+		if (it != ops.end() && static_cast<Op>(*it) == Op::Null) {
+			break;
+		}
+	}
+
+	return results;
+}
+
 std::array<bool, 50> ManiacPatch::GetKeyRange() {
 	std::array<Input::Keys::InputKey, 50> keys = {
 		Input::Keys::A,
diff --git a/src/maniac_patch.h b/src/maniac_patch.h
index 789834fcf9..2b5c2c4edd 100644
--- a/src/maniac_patch.h
+++ b/src/maniac_patch.h
@@ -21,6 +21,7 @@
 
 #include <array>
 #include <cstdint>
+#include <vector>
 #include "span.h"
 
 #include "game_strings.h"
@@ -29,6 +30,8 @@ class Game_BaseInterpreterContext;
 
 namespace ManiacPatch {
 	int32_t ParseExpression(Span<const int32_t> op_codes, const Game_BaseInterpreterContext& interpreter);
+	std::vector<int32_t> ParseExpressions(Span<const int32_t> op_codes, const Game_BaseInterpreterContext& interpreter);
+
 
 	std::array<bool, 50> GetKeyRange();