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chore(ppu): improve code quality

This commit is contained in:
Rekai Nyangadzayi Musuka 2021-04-28 17:59:30 -05:00
parent 7620633116
commit 8a06fe9ff8
1 changed files with 49 additions and 32 deletions
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71
src/ppu.rs
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@ -194,29 +194,46 @@ impl Ppu {
let window_y = self.pos.window_y;
let is_window = self.control.window_enabled() && window_y <= line_y;
// Determine whether we need to enable sprite fetching
let mut obj_attr = None;
let iter = &mut self.obj_buffer.iter();
for attr in self.obj_buffer.iter().flatten() {
let obj_attr = loop {
match iter.flatten().next() {
Some(attr) => {
if attr.x <= (self.x_pos + 8) {
// self.fetcher.obj.resume(); TODO: Try running only when there's a sprite
self.fetcher.bg.reset();
self.fetcher.bg.pause();
self.fifo.pause();
obj_attr = Some(*attr);
break;
break Some(*attr);
}
}
None => break None,
}
};
// // Determine whether we need to enable sprite fetching
// let mut obj_attr = None;
// for attr in self.obj_buffer.iter().flatten() {
// if attr.x <= (self.x_pos + 8) {
// // self.fetcher.obj.resume(); TODO: Try running only when there's a sprite
// self.fetcher.bg.reset();
// self.fetcher.bg.pause();
// self.fifo.pause();
// obj_attr = Some(*attr);
// break;
// }
// }
if let Some(attr) = obj_attr {
match self.fetcher.obj.state {
TileNumber => {
self.fetcher.obj.tile.with_id(attr.tile_index);
self.fetcher.obj.next(SleepZero);
self.fetcher.obj.next(ToLowByteSleep);
}
SleepZero => self.fetcher.obj.next(TileDataLow),
TileDataLow => {
ToLowByteSleep => self.fetcher.obj.next(TileLowByte),
TileLowByte => {
let obj_size = self.control.obj_size().as_u8();
let addr = PixelFetcher::get_obj_low_addr(&attr, &self.pos, obj_size);
@ -224,10 +241,10 @@ impl Ppu {
let byte = self.read_byte(addr);
self.fetcher.obj.tile.with_low_byte(byte);
self.fetcher.obj.next(SleepOne);
self.fetcher.obj.next(ToHighByteSleep);
}
SleepOne => self.fetcher.obj.next(TileDataHigh),
TileDataHigh => {
ToHighByteSleep => self.fetcher.obj.next(TileHighByte),
TileHighByte => {
let obj_size = self.control.obj_size().as_u8();
let addr = PixelFetcher::get_obj_low_addr(&attr, &self.pos, obj_size);
@ -235,9 +252,9 @@ impl Ppu {
let byte = self.read_byte(addr + 1);
self.fetcher.obj.tile.with_high_byte(byte);
self.fetcher.obj.next(SleepTwo);
self.fetcher.obj.next(ToFifoSleep);
}
SleepTwo => self.fetcher.obj.next(SendToFifoOne),
ToFifoSleep => self.fetcher.obj.next(SendToFifoOne),
SendToFifoOne => {
// Load into Fifo
let maybe_low = self.fetcher.obj.tile.low;
@ -301,27 +318,27 @@ impl Ppu {
self.fetcher.bg.tile.with_id(id);
// Move on to the Next state in 2 T-cycles
self.fetcher.bg.next(SleepZero);
self.fetcher.bg.next(ToLowByteSleep);
}
SleepZero => self.fetcher.bg.next(TileDataLow),
TileDataLow => {
ToLowByteSleep => self.fetcher.bg.next(TileLowByte),
TileLowByte => {
let addr = self.fetcher.bg_byte_low_addr(control, pos, is_window);
let low = self.read_byte(addr);
self.fetcher.bg.tile.with_low_byte(low);
self.fetcher.bg.next(SleepOne);
self.fetcher.bg.next(ToHighByteSleep);
}
SleepOne => self.fetcher.bg.next(TileDataHigh),
TileDataHigh => {
ToHighByteSleep => self.fetcher.bg.next(TileHighByte),
TileHighByte => {
let addr = self.fetcher.bg_byte_low_addr(control, pos, is_window);
let high = self.read_byte(addr + 1);
self.fetcher.bg.tile.with_high_byte(high);
self.fetcher.bg.next(SleepTwo);
self.fetcher.bg.next(ToFifoSleep);
}
SleepTwo => self.fetcher.bg.next(SendToFifoOne),
ToFifoSleep => self.fetcher.bg.next(SendToFifoOne),
SendToFifoOne => {
self.fetcher.bg.next(SendToFifoTwo);
}
@ -840,11 +857,11 @@ impl WindowLineCounter {
#[derive(Debug, Clone, Copy)]
pub enum FetcherState {
TileNumber,
SleepZero,
TileDataLow,
SleepOne,
TileDataHigh,
SleepTwo,
ToLowByteSleep,
TileLowByte,
ToHighByteSleep,
TileHighByte,
ToFifoSleep,
SendToFifoOne,
SendToFifoTwo,
}