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slow mode
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@pineman
pineman committed Mar 24, 2024
1 parent acc9a9e commit 3deb9f4
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Showing 3 changed files with 75 additions and 18 deletions.
73 changes: 59 additions & 14 deletions fpt-egui/src/main.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -12,7 +12,9 @@ use fpt::ppu::tile::Tile;
use fpt_cli::debugger::Debugger;
use log::info;

const GB_FRAME_IN_SECONDS: f64 = 0.016666666667;
// TODO: the gameboy doesn't run at exactly 60fps
const SIXTY_FPS_FRAMETIME: f64 = 0.016666666667;
const T_CYCLE: f64 = 0.0000002384185791015625;

const TEXTURE_SCALE_FACTOR: f32 = 3.0;

Expand Down Expand Up @@ -83,8 +85,12 @@ pub struct FPT {
bg_map_texture: Option<egui::TextureHandle>,

gb: Rc<RefCell<fpt::Gameboy>>,
db: Debugger,
dbg: Debugger,
paused: bool,
slow_factor_s: String,
slow_factor: f64,
cycles_since_last_frame: u32,
total_cycles: u64,
}

impl Default for FPT {
Expand All @@ -101,8 +107,12 @@ impl Default for FPT {
bg_map: egui::ColorImage::new([BMV_X_SIZE, BMV_Y_SIZE], Color32::TRANSPARENT),
bg_map_texture: None,
gb: gameboy.clone(),
db: Debugger::with_gameboy(gameboy),
dbg: Debugger::with_gameboy(gameboy),
paused: false,
slow_factor_s: "1".to_string(),
slow_factor: 1.0,
cycles_since_last_frame: 0,
total_cycles: 0,
}
}
}
Expand Down Expand Up @@ -138,18 +148,50 @@ impl FPT {
}

fn emulator(&mut self, ui: &mut Ui) {
self.egui_frame_count += 1;
let mut frame: Option<fpt::ppu::Frame> = None;
let delta_time = ui.input(|i| i.unstable_dt) as f64;
self.accum_time += delta_time;
self.egui_frame_count += 1;
if self.accum_time >= GB_FRAME_IN_SECONDS {

// if self.slow_factor != 1.0 {
if true {
let cycles = self.accum_time.div_euclid(T_CYCLE * self.slow_factor) as u32;
self.accum_time -= cycles as f64 * T_CYCLE * self.slow_factor;
for _ in 0..cycles {
// TODO: care for double speed mode
self.gb.borrow_mut().cpu_mut().t_cycle();
self.gb.borrow_mut().ppu_mut().step(1);
self.cycles_since_last_frame += 1;
if self.cycles_since_last_frame == self.gb.borrow().cycles_in_one_frame() {
frame = {
let mut ppu_frame_copy: fpt::ppu::Frame = [0; 23040]; // should be optimized away?
ppu_frame_copy.copy_from_slice(self.gb.borrow_mut().get_frame());
Option::from(ppu_frame_copy)
};
self.gb_frame_count += 1;
self.cycles_since_last_frame = 0;
}
}
self.total_cycles += cycles as u64;
if let Some(frame) = frame {
for z in 0..(WIDTH * HEIGHT) {
let x = z % WIDTH;
let y = z / WIDTH;
self.image[(x, y)] = PALETTE[frame[z] as usize];
}
}
} else if self.accum_time >= SIXTY_FPS_FRAMETIME {
self.accum_time -= SIXTY_FPS_FRAMETIME;
self.gb_frame_count += 1;
self.accum_time -= GB_FRAME_IN_SECONDS;
self.cycles_since_last_frame = 0;
self.total_cycles += 70224;
self.gb.borrow_mut().frame();
// I didn't manage to work with a reference from self.gb.borrow().frame()
// because that borrows self immutably,
// and then `self.image[(x, y)] = ... frame[z] ...` borrows self mutably and reads frame
let frame = {
let mut ppu_frame_copy: fpt::ppu::Frame = [0; 23040]; // should be optimized away?
ppu_frame_copy.copy_from_slice(self.gb.borrow_mut().frame());
ppu_frame_copy.copy_from_slice(self.gb.borrow_mut().get_frame());
ppu_frame_copy
};
for z in 0..(WIDTH * HEIGHT) {
Expand All @@ -176,7 +218,7 @@ impl FPT {
if _ccc {
info!("time_taken2 {:.8}", time_taken);
}
let sleep_time = GB_FRAME_IN_SECONDS - time_taken;
let sleep_time = SIXTY_FPS_FRAMETIME - time_taken;
info!("sleep_time {:.8}", sleep_time);
if sleep_time < 0.0 {
ctx.request_repaint();
Expand All @@ -202,7 +244,7 @@ impl FPT {
stat!("time" : "{:.8}", time);
stat!("dt" : "{:.8}", delta_time);
stat!("accum. time" : "{:.8}", self.accum_time);
stat!("Ideal count" : "{:.3}", time / GB_FRAME_IN_SECONDS);
stat!("Ideal count" : "{:.3}", time / SIXTY_FPS_FRAMETIME);
stat!("Frame count" : "{}" , self.gb_frame_count);
stat!("UI updates" : "{}" , self.egui_frame_count);
});
Expand All @@ -225,11 +267,14 @@ impl FPT {
egui::ScrollArea::vertical()
.id_source("debug_panel")
.show(ui, |ui| {
ui.heading("VRAM");
ui.horizontal(|ui| {
ui.heading("VRAM");
ui.with_layout(Layout::right_to_left(Align::Max), |ui| {
// ui.with_layout(Layout::right_to_left(Align::Max), |ui| {
ui.monospace("Slow factor:");
ui.add(egui::TextEdit::singleline(&mut self.slow_factor_s).desired_width(16.0));
self.slow_factor = self.slow_factor_s.parse().unwrap_or(1.0);
ui.checkbox(&mut self.paused, "Paused")
});
// });
});
ui.separator();
ui.horizontal_wrapped(|ui| {
Expand Down Expand Up @@ -410,12 +455,12 @@ impl FPT {
self.paused = false;
}
ui.with_layout(Layout::right_to_left(Align::Max), |ui| {
ui.monospace(self.db.pc().to_string());
ui.monospace(self.dbg.pc().to_string());
ui.label("PC: ");
});
});
ui.separator();
let breakpoints_string = self.db.list_breakpoints();
let breakpoints_string = self.dbg.list_breakpoints();
if breakpoints_string.is_empty() {
ui.centered_and_justified(|ui| ui.label("No breakpoints (WIP)"));
} else {
Expand Down
16 changes: 14 additions & 2 deletions fpt/src/lib.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,13 @@ impl Gameboy {
&mut self.cpu
}

pub fn ppu(&self) -> &Ppu {
&self.ppu
}
pub fn ppu_mut(&mut self) -> &mut Ppu {
&mut self.ppu
}

pub fn instruction(&mut self) -> u32 {
let cycles = self.cpu.instruction() as u32;
// TODO: care for double speed mode (need to run half as much dots)
Expand All @@ -54,8 +61,8 @@ impl Gameboy {

pub fn frame(&mut self) -> &Frame {
for _ in 0..DOTS_IN_ONE_FRAME {
// TODO: care for double speed mode (need to run two cpu cycles)
self.cpu.cycle();
// TODO: care for double speed mode (need to run two cpu t_cycles)
self.cpu.t_cycle();
self.ppu.step(1);
}
self.ppu.get_frame()
Expand All @@ -64,4 +71,9 @@ impl Gameboy {
pub fn get_frame(&self) -> &Frame {
self.ppu.get_frame()
}

pub fn cycles_in_one_frame(&self) -> u32 {
// TODO: care for double speed mode
DOTS_IN_ONE_FRAME
}
}
4 changes: 2 additions & 2 deletions fpt/src/lr35902.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -555,7 +555,7 @@ impl LR35902 {
}

/// Run one t-cycle - from actual crystal @ 4 or 8 MHz (double speed mode)
pub fn cycle(&mut self) {
pub fn t_cycle(&mut self) {
let instruction = self.decode();
self.set_inst_cycle_count(self.inst_cycle_count() + 1);
// Only actually mutate CPU state on the last t-cycle of the instruction
Expand Down Expand Up @@ -583,7 +583,7 @@ impl LR35902 {
pub fn instruction(&mut self) -> u8 {
let instruction = self.decode();
for _ in 0..instruction.cycles {
self.cycle();
self.t_cycle();
}
instruction.cycles
}
Expand Down

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