From 8de34f6091679b0cc7f7b21547cdabc9a503b24c Mon Sep 17 00:00:00 2001
From: Tiger <tiger@stargazer-developments.com>
Date: Sun, 10 Sep 2023 09:48:26 +0200
Subject: [PATCH] Implemented 0x3XKK

---
 include/chip8.h               |  7 +++++++
 include/instruction_handler.h |  5 +++++
 src/chip8.cpp                 |  4 ++++
 src/instruction_handler.cpp   | 16 +++++++++++++++-
 4 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/include/chip8.h b/include/chip8.h
index cc5ac2e..4e7e126 100644
--- a/include/chip8.h
+++ b/include/chip8.h
@@ -80,5 +80,12 @@ public:
      * @return
      */
     [[nodiscard]] unsigned short getProgramCounter() const;
+
+    /**
+     * Gets a value from the register (V)
+     * @param i The index
+     * @return
+     */
+    unsigned short getRegister(unsigned char i);
 };
 #endif //CHIP8_CHIP8_H
diff --git a/include/instruction_handler.h b/include/instruction_handler.h
index 30f4545..af82804 100644
--- a/include/instruction_handler.h
+++ b/include/instruction_handler.h
@@ -34,6 +34,11 @@ private:
      * Handles Chip8 instruction 0x2000
      */
     static void handle2000(Chip8&, Instruction);
+
+    /**
+     * Handles Chip8 instruction 0x3000
+     */
+    static void handle3000(Chip8&, Instruction);
 public:
     InstructionHandler();
 
diff --git a/src/chip8.cpp b/src/chip8.cpp
index 03ff5db..3560831 100644
--- a/src/chip8.cpp
+++ b/src/chip8.cpp
@@ -65,3 +65,7 @@ void Chip8::setProgramCounter(unsigned short value) {
 unsigned short Chip8::getProgramCounter() const {
     return this->pc;
 }
+
+unsigned short Chip8::getRegister(unsigned char reg) {
+    return this->v[reg];
+}
diff --git a/src/instruction_handler.cpp b/src/instruction_handler.cpp
index ffa736c..4a27605 100644
--- a/src/instruction_handler.cpp
+++ b/src/instruction_handler.cpp
@@ -4,6 +4,8 @@
 InstructionHandler::InstructionHandler() {
     this->handlers[0x0000] = handle0000;
     this->handlers[0x1000] = handle1000;
+    this->handlers[0x2000] = handle2000;
+    this->handlers[0x3000] = handle3000;
 }
 
 /**
@@ -58,7 +60,7 @@ void InstructionHandler::handle1000(Chip8& chip8, Instruction instruction) {
 
 /**
  * Handles the 0x2NNN Chip8 instruction which is used to call a subroutine at NNN.
- * This will increments the stack pointer and puts PC on top of the stack.
+ * This will increments the stack pointer and puts the program counter on top of the stack.
  *
  * @param chip8 The Chip8 instance
  * @param instruction The Instruction instance
@@ -68,3 +70,15 @@ void InstructionHandler::handle2000(Chip8& chip8, Instruction instruction) {
     chip8.setProgramCounter(instruction.nnn());
 }
 
+/**
+ * Handles the 0x3XKK Chip8 instruction which is used to skip the next instruction if V[x] == kk.
+ * This will compare V[x] to kk and increases the program counter by 2 if they are equal.
+ *
+ * @param chip8 The Chip8 instance
+ * @param instruction The Instruction instance
+ */
+void InstructionHandler::handle3000(Chip8& chip8, Instruction instruction) {
+    if (chip8.getRegister(instruction.x()) == instruction.kk()) {
+        chip8.setProgramCounter(chip8.getProgramCounter() + 2);
+    }
+}
\ No newline at end of file