Add functionality to get and set event flags

examples/Makefile

@@ -11,6 +11,8 @@ all:
 	$(MAKE) -C gen2_gsball $(MAKECMDGOALS) $(MAKEOVERRIDES)
 	$(MAKE) -C gen2_addItem $(MAKECMDGOALS) $(MAKEOVERRIDES)
 	$(MAKE) -C gen2_removeItem $(MAKECMDGOALS) $(MAKEOVERRIDES)
+	$(MAKE) -C gen2_getEventFlag $(MAKECMDGOALS) $(MAKEOVERRIDES)
+	$(MAKE) -C gen2_setEventFlag $(MAKECMDGOALS) $(MAKEOVERRIDES)
 
 clean:
 	$(MAKE) -C do_stuff_gen1 clean
@@ -22,3 +24,5 @@ clean:
 	$(MAKE) -C gen2_gsball clean
 	$(MAKE) -C gen2_addItem clean
 	$(MAKE) -C gen2_removeItem clean
+	$(MAKE) -C gen2_getEventFlag clean
+	$(MAKE) -C gen2_setEventFlag clean

examples/gen2_addItem/main.cpp

@@ -60,7 +60,7 @@ int main(int argc, char** argv)
 {
     if(argc != 3)
     {
-        fprintf(stderr, "Usage: addDistributionPoke <path/to/rom.gbc> <path/to/file.sav>\n");
+        fprintf(stderr, "Usage: gen2_addItem <path/to/rom.gbc> <path/to/file.sav>\n");
         return 1;
     }
 

examples/gen2_getEventFlag/Makefile

@@ -0,0 +1,48 @@
+# # Compiler flags
+CXXFLAGS := -std=c++11 -fno-rtti -fno-exceptions -fno-unwind-tables -Wall -Wextra -I $(CURDIR) -I $(CURDIR)/../../include -g -Os
+
+# Source files directory
+SRC_DIR := .
+# Build directory
+BUILD_DIR := build
+
+# Source files (add more as needed)
+SRCS := $(shell find $(SRC_DIR) -type f -name '*.cpp')
+# Object files
+OBJS := $(patsubst $(SRC_DIR)/%.cpp,$(BUILD_DIR)/%.o,$(SRCS))
+
+LIBS := -lpokemegb
+ifeq ($(PNG_SUPPORT),1)
+	LIBS += -lpng
+endif
+
+# Ensure necessary directories exist
+# This function ensures the directory for the target exists
+define make_directory
+	@mkdir -p $(dir $@)
+endef
+
+# Target executable
+TARGET := ../../gen2_getEventFlag
+
+# Phony targets
+.PHONY: all clean
+
+# Default target
+all: $(TARGET)
+
+$(TARGET): $(OBJS)
+	$(CXX) $(CXXFLAGS) $^ -o $@ $(LIBS) -L ../../
+
+# Rule to compile source files
+$(BUILD_DIR)/%.o: $(SRC_DIR)/%.cpp | $(BUILD_DIR)
+	$(make_directory)
+	$(CXX) $(CXXFLAGS) -c $< -o $@
+
+# Create the build directory if it doesn't exist
+$(BUILD_DIR):
+	mkdir -p $(BUILD_DIR)
+
+# Clean rule
+clean:
+	rm -rf $(BUILD_DIR) $(TARGET)

examples/gen2_getEventFlag/main.cpp

@@ -0,0 +1,79 @@
+#include "gen2/Gen2GameReader.h"
+#include "gen1/Gen1Common.h"
+#include "RomReader.h"
+#include "SaveManager.h"
+#include "utils.h"
+
+#include <cstdio>
+#include <cstring>
+#include <cstdlib>
+
+static uint16_t getFlagNumber()
+{
+    char input[100];
+    printf("Enter event flag number: ");
+    if (fgets(input, sizeof(input), stdin) == NULL)
+    {
+        fprintf(stderr, "Error reading input\n");
+        return 0;
+    }
+    // Remove the newline character if it exists
+    input[strcspn(input, "\n")] = '\0';
+
+    return (uint16_t)strtoul(input, 0, 10);
+}
+
+int main(int argc, char** argv)
+{
+    if(argc != 3)
+    {
+        fprintf(stderr, "Usage: gen2_getEventFlag <path/to/rom.gbc> <path/to/file.sav>\n");
+        return 1;
+    }
+
+    uint8_t* romBuffer;
+    uint8_t* saveBuffer;
+    uint32_t romFileSize;
+    uint32_t saveFileSize;
+
+    romBuffer = readFileIntoBuffer(argv[1], romFileSize);
+    if(!romBuffer)
+    {
+        fprintf(stderr, "ERROR: Couldn't read file %s\n", argv[1]);
+        return 1;
+    }
+    saveBuffer = readFileIntoBuffer(argv[2], saveFileSize);
+    if(!saveBuffer)
+    {
+        fprintf(stderr, "ERROR: Couldn't read file %s\n", argv[2]);
+        return 1;
+    }
+
+    GameboyCartridgeHeader cartridgeHeader;
+    BufferBasedRomReader romReader(romBuffer, romFileSize);
+    BufferBasedSaveManager saveManager(saveBuffer, saveFileSize);
+
+    readGameboyCartridgeHeader(romReader, cartridgeHeader);
+
+    //check if we're dealing with gen 1
+    const Gen1GameType gen1Type = gen1_determineGameType(cartridgeHeader);
+    const Gen2GameType gen2Type = gen2_determineGameType(cartridgeHeader);
+    if(gen1Type != Gen1GameType::INVALID)
+    {
+        fprintf(stderr, "ERROR: sorry, this tool only supports gen 2!\n");
+        return 1;
+    }
+    else if(gen2Type == Gen2GameType::INVALID)
+    {
+        fprintf(stderr, "ERROR: this is not a Gen 2 pokémon game!\n");
+        return 1;
+    }
+
+    const uint16_t flagNumber = getFlagNumber();
+
+    Gen2GameReader gameReader(romReader, saveManager, gen2Type);
+    bool result = gameReader.getEventFlag(flagNumber);
+    printf("Flag %hu => %s\n", flagNumber, (result) ? "true" : "false");
+    
+    return 0;
+}

examples/gen2_gsball/main.cpp

@@ -15,7 +15,7 @@ int main(int argc, char** argv)
 {
     if(argc != 3)
     {
-        fprintf(stderr, "Usage: addDistributionPoke <path/to/rom.gbc> <path/to/file.sav>\n");
+        fprintf(stderr, "Usage: gen2_gsball <path/to/rom.gbc> <path/to/file.sav>\n");
         return 1;
     }
 

examples/gen2_removeItem/main.cpp

@@ -60,7 +60,7 @@ int main(int argc, char** argv)
 {
     if(argc != 3)
     {
-        fprintf(stderr, "Usage: addDistributionPoke <path/to/rom.gbc> <path/to/file.sav>\n");
+        fprintf(stderr, "Usage: gen2_removeItem <path/to/rom.gbc> <path/to/file.sav>\n");
         return 1;
     }
 

examples/gen2_setEventFlag/Makefile

@@ -0,0 +1,48 @@
+# # Compiler flags
+CXXFLAGS := -std=c++11 -fno-rtti -fno-exceptions -fno-unwind-tables -Wall -Wextra -I $(CURDIR) -I $(CURDIR)/../../include -g -Os
+
+# Source files directory
+SRC_DIR := .
+# Build directory
+BUILD_DIR := build
+
+# Source files (add more as needed)
+SRCS := $(shell find $(SRC_DIR) -type f -name '*.cpp')
+# Object files
+OBJS := $(patsubst $(SRC_DIR)/%.cpp,$(BUILD_DIR)/%.o,$(SRCS))
+
+LIBS := -lpokemegb
+ifeq ($(PNG_SUPPORT),1)
+	LIBS += -lpng
+endif
+
+# Ensure necessary directories exist
+# This function ensures the directory for the target exists
+define make_directory
+	@mkdir -p $(dir $@)
+endef
+
+# Target executable
+TARGET := ../../gen2_setEventFlag
+
+# Phony targets
+.PHONY: all clean
+
+# Default target
+all: $(TARGET)
+
+$(TARGET): $(OBJS)
+	$(CXX) $(CXXFLAGS) $^ -o $@ $(LIBS) -L ../../
+
+# Rule to compile source files
+$(BUILD_DIR)/%.o: $(SRC_DIR)/%.cpp | $(BUILD_DIR)
+	$(make_directory)
+	$(CXX) $(CXXFLAGS) -c $< -o $@
+
+# Create the build directory if it doesn't exist
+$(BUILD_DIR):
+	mkdir -p $(BUILD_DIR)
+
+# Clean rule
+clean:
+	rm -rf $(BUILD_DIR) $(TARGET)

examples/gen2_setEventFlag/main.cpp

@@ -0,0 +1,111 @@
+#include "gen2/Gen2GameReader.h"
+#include "gen1/Gen1Common.h"
+#include "RomReader.h"
+#include "SaveManager.h"
+#include "utils.h"
+
+#include <cstdio>
+#include <cstring>
+#include <cstdlib>
+
+static uint16_t getFlagNumber()
+{
+    char input[100];
+    printf("Enter event flag number: ");
+    if (fgets(input, sizeof(input), stdin) == NULL)
+    {
+        fprintf(stderr, "Error reading input\n");
+        return 0;
+    }
+    // Remove the newline character if it exists
+    input[strcspn(input, "\n")] = '\0';
+
+    return (uint16_t)strtoul(input, 0, 10);
+}
+
+static uint16_t getFlagValue()
+{
+    char input[100];
+    printf("Enter new value (0-1): ");
+    if (fgets(input, sizeof(input), stdin) == NULL)
+    {
+        fprintf(stderr, "Error reading input\n");
+        return 0;
+    }
+    // Remove the newline character if it exists
+    input[strcspn(input, "\n")] = '\0';
+
+    return (uint16_t)strtoul(input, 0, 10);
+}
+
+int main(int argc, char** argv)
+{
+    if(argc != 3)
+    {
+        fprintf(stderr, "Usage: gen2_setEventFlag <path/to/rom.gbc> <path/to/file.sav>\n");
+        return 1;
+    }
+
+    uint8_t* romBuffer;
+    uint8_t* saveBuffer;
+    uint32_t romFileSize;
+    uint32_t saveFileSize;
+
+    romBuffer = readFileIntoBuffer(argv[1], romFileSize);
+    if(!romBuffer)
+    {
+        fprintf(stderr, "ERROR: Couldn't read file %s\n", argv[1]);
+        return 1;
+    }
+    saveBuffer = readFileIntoBuffer(argv[2], saveFileSize);
+    if(!saveBuffer)
+    {
+        fprintf(stderr, "ERROR: Couldn't read file %s\n", argv[2]);
+        return 1;
+    }
+
+    GameboyCartridgeHeader cartridgeHeader;
+    BufferBasedRomReader romReader(romBuffer, romFileSize);
+    BufferBasedSaveManager saveManager(saveBuffer, saveFileSize);
+
+    readGameboyCartridgeHeader(romReader, cartridgeHeader);
+
+    //check if we're dealing with gen 1
+    const Gen1GameType gen1Type = gen1_determineGameType(cartridgeHeader);
+    const Gen2GameType gen2Type = gen2_determineGameType(cartridgeHeader);
+    if(gen1Type != Gen1GameType::INVALID)
+    {
+        fprintf(stderr, "ERROR: sorry, this tool only supports gen 2!\n");
+        return 1;
+    }
+    else if(gen2Type == Gen2GameType::INVALID)
+    {
+        fprintf(stderr, "ERROR: this is not a Gen 2 pokémon game!\n");
+        return 1;
+    }
+
+    const uint16_t flagNumber = getFlagNumber();
+    const uint16_t flagValue = getFlagValue();
+
+    if(flagValue != 0 && flagValue != 1)
+    {
+        fprintf(stderr, "ERROR: wrong value %hu\n", flagValue);
+        return 1;
+    }
+
+    Gen2GameReader gameReader(romReader, saveManager, gen2Type);
+    gameReader.setEventFlag(flagNumber, static_cast<bool>(flagValue));
+    gameReader.finishSave();
+    printf("Flag %hu => %s\n", flagNumber, (static_cast<bool>(flagValue)) ? "true" : "false");
+    
+    FILE* f = fopen(argv[2], "w");
+    fwrite(saveBuffer, 1, saveFileSize, f);
+    fclose(f);
+
+    free(romBuffer);
+    free(saveBuffer);
+    romBuffer = 0;
+    saveBuffer = 0;
+
+    return 0;
+}

include/gen2/Gen2GameReader.h

@@ -183,6 +183,15 @@ public:
      * @brief Unlocks the GS Ball event in Pokemon crystal
      */
     void unlockGsBallEvent();
+
+    /**
+     * @brief Retrieves the value of the given event flag
+     */
+    bool getEventFlag(uint16_t flagNumber);
+    /**
+     * @brief Sets the value of the given event flag number
+     */
+    void setEventFlag(uint16_t flagNumber, bool enabled);
 protected:
 private:
     IRomReader &romReader_;

src/gen2/Gen2GameReader.cpp

@@ -9,6 +9,9 @@
 #define CRYSTAL_PICS_FIX 0x36
 #define CRYSTAL_BANK_PICS_1 72
 
+#define EVENT_FLAGS_OFFSET_GOLDSILVER 0x261F
+#define EVENT_FLAGS_OFFSET_CRYSTAL 0x2600
+
 static const uint8_t crystalPicsBanks[] = {
     CRYSTAL_BANK_PICS_1 + 0,
     CRYSTAL_BANK_PICS_1 + 1,
@@ -696,4 +699,42 @@ void Gen2GameReader::unlockGsBallEvent()
     saveManager_.writeByte(0xB);
     saveManager_.seek(0x3E44);
     saveManager_.writeByte(0xB);
+}
+
+bool Gen2GameReader::getEventFlag(uint16_t flagNumber)
+{
+    const uint16_t saveOffset = (isGameCrystal()) ? EVENT_FLAGS_OFFSET_CRYSTAL : EVENT_FLAGS_OFFSET_GOLDSILVER;
+    uint8_t byteVal;
+    const uint8_t flag = 1 << (flagNumber % 8);
+
+    saveManager_.seek(saveOffset + (flagNumber / 8));
+    saveManager_.readByte(byteVal);
+
+    return (byteVal & flag);
+}
+
+#include <cstdio>
+
+void Gen2GameReader::setEventFlag(uint16_t flagNumber, bool enabled)
+{
+    const uint16_t saveOffset = (isGameCrystal()) ? EVENT_FLAGS_OFFSET_CRYSTAL : EVENT_FLAGS_OFFSET_GOLDSILVER;
+    uint8_t byteVal;
+    uint8_t resultVal;
+    const uint8_t flag = 1 << (flagNumber % 8);
+
+    saveManager_.seek(saveOffset + (flagNumber / 8));
+    saveManager_.readByte(byteVal);
+    saveManager_.rewind(1);
+
+    // first calculate the value of the byte with the bit reset to 0
+    resultVal = byteVal & (~flag);
+
+    // now apply the flag if enabled == true
+    if(enabled)
+    {
+        resultVal |= flag;
+    }
+    printf("%s: flagNumber %hu, enabled: %d, orig byte: 0x%02x, new byte 0x%02x\n", __FUNCTION__, flagNumber, enabled, byteVal, resultVal);
+
+    saveManager_.writeByte(resultVal);
 }