dnutiu/chip8-rust
dnutiu/chip8-rust
1
1
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

refactor the pattern matching

Browse source
This commit is contained in:
Denis-Cosmin Nutiu 2024-12-04 23:12:11 +02:00
parent d63f5580be
commit 2f4e615ab3
1 changed files with 16 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

22
src/instruction.rs
View file

@ -54,30 +54,34 @@ impl Instruction {
/// Decodes the raw instruction data into a processor instruction.
fn decode_instruction(data: u16) -> ProcessorInstruction {
match data {
let digit1 = Self::grab_zeroth_nibble(data);
let digit2 = Self::grab_first_nibble(data);
let digit3 = Self::grab_middle_nibble(data);
let digit4 = Self::grab_first_nibble(data);
match (digit1, digit2, digit3, digit4) {
// Clear Display
0x00E0 => ProcessorInstruction::ClearScreen,
(0, 0, 0xE, 0) => ProcessorInstruction::ClearScreen,
// Jump
0x1000..=0x1FFF => {
(0x1, _, _, _) => {
// 1NNN
ProcessorInstruction::Jump(Self::grab_inner_data(data))
}
// Set Register
0x6000..=0x6FFF => {
(0x6, _, _, _) => {
// 6XNN
ProcessorInstruction::SetRegister(
Self::grab_first_nibble(data),
Self::grab_last_byte(data),
)
}
0x7000..=0x7FFF => {
(0x7, _, _, _) => {
// 7XNN
ProcessorInstruction::AddValueToRegister(
Self::grab_first_nibble(data),
Self::grab_last_byte(data),
)
}
0xD000..=0xDFFF => {
(0xD, _, _, _) => {
// DXYN
ProcessorInstruction::Draw(
Self::grab_first_nibble(data),
@ -100,6 +104,12 @@ impl Instruction {
(data & 0x00FF) as u8
}
/// Grabs the zeroth nibble from the data.
fn grab_zeroth_nibble(data: u16) -> u8 {
((data & 0xF000) >> 12) as u8
}
/// Grabs the first nibble from the data.
fn grab_first_nibble(data: u16) -> u8 {
((data & 0x0F00) >> 8) as u8