From 42e54f1344af46447bd0b759c391b02c673549ae Mon Sep 17 00:00:00 2001
From: Riyyi <riyyi3@gmail.com>
Date: Sun, 21 Aug 2022 19:54:02 +0200
Subject: [PATCH] Emulator: Add support for memory banks to memory spaces

---
 src/emu.cpp | 34 +++++++++++++++++++++++++++-------
 src/emu.h   | 17 +++++++++++++----
 2 files changed, 40 insertions(+), 11 deletions(-)

diff --git a/src/emu.cpp b/src/emu.cpp
index f3b6d85..24e6b9b 100644
--- a/src/emu.cpp
+++ b/src/emu.cpp
@@ -41,18 +41,38 @@ void Emu::addProcessingUnit(std::string_view name, ProcessingUnit* processing_un
 	m_processing_units.emplace(name, processing_unit);
 }
 
-void Emu::addMemorySpace(std::string_view name, uint32_t size)
+void Emu::addMemorySpace(std::string_view name, uint32_t start_address, uint32_t end_adress, uint32_t amount_of_banks)
 {
-	std::vector<uint32_t> memory(size);
-	m_memory_spaces.emplace(name, memory);
+	uint32_t bank_length = 1 + end_adress - start_address;
+	MemorySpace memory_space {
+		.memory = BankedMemory(amount_of_banks, std::vector<uint32_t>(bank_length)),
+		.active_bank = 0,
+		.start_address = start_address,
+		.end_address = end_adress,
+	};
+
+	m_memory_spaces.emplace(name, memory_space);
 }
 
-void Emu::writeMemory(std::string_view memory_space, uint32_t location, uint32_t value)
+void Emu::writeMemory(uint32_t address, uint32_t value)
 {
-	m_memory_spaces[memory_space][location] = value;
+	for (auto& memory_space : m_memory_spaces) {
+		auto memory = memory_space.second;
+		if (address >= memory.start_address && address <= memory.end_address) {
+			memory.memory[memory.active_bank][address] = value;
+		}
+	}
 }
 
-uint32_t Emu::readMemory(std::string_view memory_space, uint32_t location)
+uint32_t Emu::readMemory(uint32_t address)
 {
-	return m_memory_spaces[memory_space][location];
+	for (auto& memory_space : m_memory_spaces) {
+		auto memory = memory_space.second;
+		if (address >= memory.start_address && address <= memory.end_address) {
+			return memory.memory[memory.active_bank][address];
+			break;
+		}
+	}
+
+	return 0;
 }
diff --git a/src/emu.h b/src/emu.h
index d7623cc..de8ebbf 100644
--- a/src/emu.h
+++ b/src/emu.h
@@ -17,6 +17,15 @@
 #include "ruc/singleton.h"
 #include "ruc/timer.h"
 
+using BankedMemory = std::vector<std::vector<uint32_t>>;
+
+struct MemorySpace {
+	BankedMemory memory;
+	uint32_t active_bank { 0 };
+	uint32_t start_address { 0 };
+	uint32_t end_address { 0 };
+};
+
 class Emu final : public ruc::Singleton<Emu> {
 public:
 	Emu(s) {}
@@ -26,10 +35,10 @@ public:
 	void update();
 
 	void addProcessingUnit(std::string_view name, ProcessingUnit* processing_unit);
-	void addMemorySpace(std::string_view name, uint32_t size);
+	void addMemorySpace(std::string_view name, uint32_t start_address, uint32_t end_address, uint32_t amount_of_banks = 1);
 
-	void writeMemory(std::string_view memory_space, uint32_t location, uint32_t value);
-	uint32_t readMemory(std::string_view memory_space, uint32_t location);
+	void writeMemory(uint32_t address, uint32_t value);
+	uint32_t readMemory(uint32_t address);
 
 	// -------------------------------------
 
@@ -47,7 +56,7 @@ private:
 	ruc::Timer m_timer;
 
 	std::unordered_map<std::string_view, ProcessingUnit*> m_processing_units;
-	std::unordered_map<std::string_view, std::vector<uint32_t>> m_memory_spaces;
+	std::unordered_map<std::string_view, MemorySpace> m_memory_spaces;
 
 	std::string m_bootrom;
 };