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Fix math and add dump_state option
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@mbStavola
mbStavola committed Oct 15, 2017
1 parent b47f310 commit 3cb940a
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Showing 3 changed files with 56 additions and 65 deletions.
3 changes: 3 additions & 0 deletions .idea/misc.xml
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104 changes: 47 additions & 57 deletions src/emulator.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -63,31 +63,7 @@ impl System {
}
}

pub fn run_cli(&mut self) -> Result<(), ()> {
println!("PC\tDELAY\tSOUND\tOP\tARG1\tARG2\tARG3");
println!("--\t-----\t-----\t--\t----\t----\t----");
loop {
let first_address = self.program_counter as usize;
let second_address = (self.program_counter + 1) as usize;

let first_byte = self.memory[first_address];
let second_byte = self.memory[second_address];

print!("{:#04x}\t{}\t{}\t", self.program_counter, self.delay_timer, self.sound_timer);
match Opcode::from(first_byte, second_byte) {
Ok(opcode) => {
println!("{:?}", opcode);
self.process_opcode(opcode)?;
}
Err((first, second)) => {
println!("DATA\t{:x}{:x}", first.0, second.0);
self.program_counter += WORD_SIZE;
}
}
}
}

pub fn run_gui(&mut self) -> Result<(), ()> {
pub fn run(&mut self, dump_state: bool) -> Result<(), ()> {
let mut tick_rate = 16;
let mut running = true;
let mut paused = false;
Expand Down Expand Up @@ -119,19 +95,9 @@ impl System {
tick_rate += 4;
}
Some(InputAction::DebugInfo) => {
print!("PC[{:#04x}]\tDELAY[{}]\tSOUND[{}]\tI[{:#03x}]", self.program_counter, self.delay_timer, self.sound_timer, self.address_register);
for i in 0x0..0x10 {
print!("\tV{:X}[{}]", i, self.get_register(i));
if !dump_state {
self.print_debug();
}

let first_address = self.program_counter as usize;
let second_address = (self.program_counter + 1) as usize;

let first_byte = self.memory[first_address];
let second_byte = self.memory[second_address];

let op = Opcode::from(first_byte, second_byte).unwrap();
println!("\t{:?}", op);
}
_ => {}
}
Expand All @@ -140,6 +106,10 @@ impl System {
continue;
}

if dump_state {
self.print_debug();
}

let first_address = self.program_counter as usize;
let second_address = (self.program_counter + 1) as usize;

Expand All @@ -156,6 +126,22 @@ impl System {
Err(())
}

fn print_debug(&mut self) {
print!("PC[{:#04x}]\tDELAY[{}]\tSOUND[{}]\tI[{:#03x}]", self.program_counter, self.delay_timer, self.sound_timer, self.address_register);
for i in 0x0..0x10 {
print!("\tV{:X}[{}]", i, self.get_register(i));
}

let first_address = self.program_counter as usize;
let second_address = (self.program_counter + 1) as usize;

let first_byte = self.memory[first_address];
let second_byte = self.memory[second_address];

let op = Opcode::from(first_byte, second_byte).unwrap();
println!("\t{:?}", op);
}

fn process_opcode(&mut self, opcode: Opcode) -> Result<(), ()> {
match opcode {
Opcode::Call(_) => {
Expand Down Expand Up @@ -207,7 +193,14 @@ impl System {
}
Opcode::AddAssign(register, constant) => {
let value = self.get_register(register);
self.set_register(register, value.wrapping_add(constant));

let mut result = if let Some(result) = value.checked_add(constant) {
result
} else {
(value as u16 + constant as u16) as u8
};

self.set_register(register, result);
self.program_counter += WORD_SIZE;
}
Opcode::Copy(to, from) => {
Expand All @@ -234,19 +227,18 @@ impl System {
self.program_counter += WORD_SIZE;
}
Opcode::AddAssignReg(first, second) => {
let first_value = self.get_register(first) as u16;
let second_value = self.get_register(second) as u16;

let mut result = first_value + second_value;
let first_value = self.get_register(first);
let second_value = self.get_register(second);

if result > 255 {
result = result & 0xFF;
self.set_flag_register(0x1);
} else {
let mut result = if let Some(result) = first_value.checked_add(second_value) {
self.set_flag_register(0x0);
}
result
} else {
self.set_flag_register(0x1);
(first_value as u16 + second_value as u16) as u8
};

self.set_register(first, result as u8);
self.set_register(first, result);


self.program_counter += WORD_SIZE;
Expand All @@ -255,14 +247,13 @@ impl System {
let first_value = self.get_register(first);
let second_value = self.get_register(second);

if first_value > second_value {
if first_value >= second_value {
self.set_flag_register(0x1);
} else {
self.set_flag_register(0x0);
}

let result = first_value.wrapping_sub(second_value);
self.set_register(first, result);
self.set_register(first, first_value.wrapping_sub(second_value));

self.program_counter += WORD_SIZE;
}
Expand All @@ -282,14 +273,13 @@ impl System {
let first_value = self.get_register(first);
let second_value = self.get_register(second);

if second_value > first_value {
if second_value >= first_value {
self.set_flag_register(0x1);
} else {
self.set_flag_register(0x0);
}

let result = second_value.wrapping_sub(first_value);
self.set_register(first, result);
self.set_register(first, second_value.wrapping_sub(first_value));

self.program_counter += WORD_SIZE;
}
Expand Down Expand Up @@ -429,9 +419,9 @@ impl System {
let memory_location = self.address_register;
let value = self.get_register(register) as u16;

let ones = value & 0xF;
let tens = (value & 0xF0) >> 4;
let hundreds = (value & 0xF00) >> 8;
let ones = value / 100;
let tens = (value / 10) % 10;
let hundreds = (value % 100) % 10;

self.set_memory(memory_location, ones as u8);
self.set_memory(memory_location + 1, tens as u8);
Expand Down
14 changes: 6 additions & 8 deletions src/main.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -34,9 +34,9 @@ fn main() {
)
.subcommand(clap::SubCommand::with_name("disassemble"))
.subcommand(clap::SubCommand::with_name("run")
.arg(Arg::with_name("cli")
.long("cli")
.help("Launch in cli mode")
.arg(Arg::with_name("debug")
.long("debug")
.help("Continuously dump emulator state to the command line")
.takes_value(false)
.required(false)
)
Expand All @@ -54,11 +54,9 @@ fn main() {
Some("run") => {
let mut system = System::new(buffer);

if matches.subcommand_matches("run").unwrap().is_present("cli") {
system.run_cli();
} else {
system.run_gui();
}
let dump_state = matches.subcommand_matches("run").unwrap()
.is_present("debug");
system.run(dump_state);
}
_ => {
println!("ERROR: command invalid or not provided")
Expand Down

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