From 7ecfff3e0d3c249a6cb2bd0d7dd9831162893c16 Mon Sep 17 00:00:00 2001
From: Denis-Cosmin NUTIU <dnutiu@bitdefender.com>
Date: Mon, 2 Dec 2024 23:39:22 +0200
Subject: [PATCH] implement clear display instruction

---
 src/display.rs     |  4 ++--
 src/emulator.rs    | 25 +++++++++++++++++++++----
 src/instruction.rs |  2 +-
 3 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/src/display.rs b/src/display.rs
index bfed099..c2ed33b 100644
--- a/src/display.rs
+++ b/src/display.rs
@@ -7,7 +7,7 @@ const DISPLAY_HEIGHT: usize = 32;
 /// Display trait
 pub trait Display {
     /// Re-draws the display.
-    fn redraw(&self);
+    fn clear(&self);
     /// Draws the display.
     fn draw(&mut self);
 }
@@ -28,7 +28,7 @@ impl TerminalDisplay {
 
 impl Display for TerminalDisplay {
     /// Re-draws the display.
-    fn redraw(&self) {
+    fn clear(&self) {
         // ANSI Escape code to move cursor to row 1 column 1
         // See https://stackoverflow.com/a/4062051
         print!("{esc}[2J{esc}[1;1H", esc = 27 as char);
diff --git a/src/emulator.rs b/src/emulator.rs
index 9e1e723..d71ca42 100644
--- a/src/emulator.rs
+++ b/src/emulator.rs
@@ -2,7 +2,7 @@ use crate::display::Display;
 use crate::instruction::Instruction;
 use crate::stack::Stack;
 use anyhow::anyhow;
-use log::{debug, info};
+use log::{debug, info, warn};
 use std::fs::File;
 use std::io::Read;
 use std::path::Path;
@@ -103,12 +103,29 @@ where
             let instruction = self.fetch_instruction()?;
             self.program_counter += 2;
 
-            debug!("PC={} {:04x}", self.program_counter, instruction)
+            debug!("PC={} {:04x}", self.program_counter, instruction);
 
             // decode & execute
-            //let decode = self.decode_instruction(instruction);
+            self.execute_instruction(instruction)?;
+        }
+        Ok(())
+    }
 
-            // execute
+    fn execute_instruction(&mut self, instruction: Instruction) -> Result<(), anyhow::Error> {
+        match instruction.raw() {
+            // Clear Display
+            0x00E0 => {
+                info!("clear display");
+                self.display.clear()
+            }
+            // Jump
+            0x1000..=0x1FFF => {
+                info!("jump to {}", instruction);
+            }
+            // Unknown instruction
+            _ => {
+                warn!("Unknown instruction: {:04x}, skipping.", instruction);
+            }
         }
         Ok(())
     }
diff --git a/src/instruction.rs b/src/instruction.rs
index c0e9bad..9993145 100644
--- a/src/instruction.rs
+++ b/src/instruction.rs
@@ -23,7 +23,7 @@ impl Instruction {
 impl Display for Instruction {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         f.write_str(&format!(
-            "Instruction: [{:02x}, {:02x}]",
+            "<Instruction: [{:02x}{:02x}]>",
             ((self.data & 0xFF00) >> 8u8) as u8,
             (self.data & 0x00FF) as u8
         ))