panasyn 0.1.0

A lightweight GPU-accelerated terminal emulator for macOS and Linux.
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use std::collections::VecDeque;
use std::ffi::CString;
use std::os::fd::AsFd;
use std::time::{Duration, Instant};

use nix::poll::{PollFd, PollFlags, PollTimeout, poll};
use nix::pty::{ForkptyResult, Winsize, forkpty};
use nix::sys::signal::Signal;
use nix::sys::wait::{WaitPidFlag, WaitStatus, waitpid};

use crate::ansi;
use crate::renderer::RenderSettings;
use crate::replay::recorder::{ReplayEvent, ReplayEventKind};
use crate::terminal::TerminalState;

const MAX_COALESCED_PTY_CHUNK: usize = 512 * 1024;

struct PtyChunk {
    data: Vec<u8>,
    offset: usize,
}

impl PtyChunk {
    fn new(data: Vec<u8>) -> Self {
        Self { data, offset: 0 }
    }

    fn remaining(&self) -> usize {
        self.data.len().saturating_sub(self.offset)
    }

    fn can_append(&self, len: usize) -> bool {
        self.offset == 0 && self.data.len() + len <= MAX_COALESCED_PTY_CHUNK
    }
}

#[derive(Debug, Clone)]
pub struct BenchSuiteResult {
    pub render: RenderBenchResult,
    pub glyph_shaping: GlyphShapingResult,
    pub pty_backpressure: PtyBackpressureResult,
}

#[derive(Debug, Clone, Default)]
pub struct RenderBenchResult {
    pub frames: usize,
    pub bytes: u64,
    pub parse_ms: f64,
    pub shape_ms: f64,
    pub prepare_ms: f64,
    pub render_ms: f64,
    pub total_frame_ms: f64,
    pub first_frame_ms: f64,
    pub avg_frame_ms: f64,
    pub p95_frame_ms: f64,
    pub max_frame_ms: f64,
    pub steady_avg_frame_ms: f64,
    pub steady_p95_frame_ms: f64,
    pub steady_max_frame_ms: f64,
    pub avg_input_to_render_ms: f64,
    pub p95_input_to_render_ms: f64,
    pub max_input_to_render_ms: f64,
    pub missed_60hz_frames: usize,
    pub steady_missed_60hz_frames: usize,
    pub throughput_mbps: f64,
}

#[derive(Debug, Clone, Default)]
pub struct GlyphShapingResult {
    pub rows: usize,
    pub chars: usize,
    pub total_ms: f64,
    pub rows_per_second: f64,
    pub chars_per_second: f64,
}

#[derive(Debug, Clone, Default)]
pub struct PtyBackpressureResult {
    pub target_bytes: usize,
    pub read_bytes: usize,
    pub parsed_bytes: usize,
    pub wall_ms: f64,
    pub parse_ms: f64,
    pub frames: usize,
    pub peak_queue_bytes: usize,
    pub peak_queue_chunks: usize,
    pub max_frame_parse_ms: f64,
    pub throughput_mbps: f64,
}

#[derive(Debug, Clone, Copy, Default)]
struct RenderTiming {
    shape_ms: f64,
    prepare_ms: f64,
    render_ms: f64,
    total_ms: f64,
}

pub fn run_suite(
    events: &[ReplayEvent],
    cols: u16,
    rows: u16,
    frames: usize,
    pty_bytes: usize,
) -> Result<BenchSuiteResult, Box<dyn std::error::Error>> {
    let settings = RenderSettings::default();
    let render = pollster::block_on(run_render_bench(
        events,
        cols,
        rows,
        frames,
        settings.clone(),
    ))?;
    let glyph_shaping = run_glyph_shaping_bench(&settings, cols as usize, rows as usize);
    let pty_backpressure = run_pty_backpressure_bench(pty_bytes, cols, rows)?;

    Ok(BenchSuiteResult {
        render,
        glyph_shaping,
        pty_backpressure,
    })
}

async fn run_render_bench(
    events: &[ReplayEvent],
    cols: u16,
    rows: u16,
    frames: usize,
    settings: RenderSettings,
) -> Result<RenderBenchResult, Box<dyn std::error::Error>> {
    let mut terminal = TerminalState::new(cols as usize, rows as usize, 10_000);
    let mut parser = ansi::Parser::new();
    let mut renderer = OffscreenTextRenderer::new(cols as usize, rows as usize, settings).await?;
    let mut result = RenderBenchResult::default();
    let mut frame_times = Vec::with_capacity(frames);
    let mut input_latencies = Vec::with_capacity(frames);
    let budget_ms = 1000.0 / 60.0;

    let mut pty_events = events
        .iter()
        .filter(|event| matches!(event.kind, ReplayEventKind::PtyBytes(_)));

    for frame_idx in 0..frames {
        let frame_start = Instant::now();
        let event_timestamp = if let Some(event) = pty_events.next() {
            if let ReplayEventKind::PtyBytes(data) = &event.kind {
                let parse_start = Instant::now();
                parser.advance(data, &mut terminal);
                result.parse_ms += elapsed_ms(parse_start);
                result.bytes += data.len() as u64;
            }
            Some(event.timestamp_ms as f64)
        } else {
            None
        };

        let timing = renderer.render(&terminal)?;
        result.shape_ms += timing.shape_ms;
        result.prepare_ms += timing.prepare_ms;
        result.render_ms += timing.render_ms;
        result.total_frame_ms += timing.total_ms;

        let frame_ms = elapsed_ms(frame_start);
        if frame_idx == 0 {
            result.first_frame_ms = frame_ms;
        }
        frame_times.push(frame_ms);
        if frame_ms > budget_ms {
            result.missed_60hz_frames += 1;
            if frame_idx > 0 {
                result.steady_missed_60hz_frames += 1;
            }
        }

        let input_latency = match event_timestamp {
            Some(ts) => {
                let next_vsync = ((ts / budget_ms).floor() + 1.0) * budget_ms;
                (next_vsync - ts) + frame_ms
            }
            None => frame_ms,
        };
        input_latencies.push(input_latency);

        result.frames = frame_idx + 1;
    }

    result.avg_frame_ms = average(&frame_times);
    result.p95_frame_ms = percentile(&frame_times, 0.95);
    result.max_frame_ms = frame_times.iter().copied().fold(0.0, f64::max);
    let steady_frame_times = frame_times.get(1..).unwrap_or(&[]);
    result.steady_avg_frame_ms = average(steady_frame_times);
    result.steady_p95_frame_ms = percentile(steady_frame_times, 0.95);
    result.steady_max_frame_ms = steady_frame_times.iter().copied().fold(0.0, f64::max);
    result.avg_input_to_render_ms = average(&input_latencies);
    result.p95_input_to_render_ms = percentile(&input_latencies, 0.95);
    result.max_input_to_render_ms = input_latencies.iter().copied().fold(0.0, f64::max);
    let seconds = (result.parse_ms + result.shape_ms + result.prepare_ms + result.render_ms)
        .max(f64::EPSILON)
        / 1000.0;
    result.throughput_mbps = (result.bytes as f64 / seconds) / (1024.0 * 1024.0);
    Ok(result)
}

fn run_glyph_shaping_bench(
    settings: &RenderSettings,
    cols: usize,
    rows: usize,
) -> GlyphShapingResult {
    let mut font_system = glyphon::FontSystem::new();
    let metrics = glyphon::Metrics::new(
        settings.font_size,
        settings.font_size * settings.line_height,
    );
    let attrs = attrs_for_family(&settings.font_family);
    let mut buffer = glyphon::Buffer::new(&mut font_system, metrics);
    buffer.set_size(
        &mut font_system,
        Some(cols as f32 * settings.font_size * 0.6),
        Some(metrics.line_height),
    );

    let samples = [
        "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789",
        "src/main.rs:42: warning: GPU frame budget exceeded by 1.2ms",
        "┌────────────┬────────────┬────────────┐",
        "✓ unicode λ shaping -> fi fl ffi <= >= != == ===",
    ];
    let iterations = rows.max(24) * 250;
    let start = Instant::now();
    let mut chars = 0usize;
    for i in 0..iterations {
        let sample = samples[i % samples.len()];
        let line = sample.repeat((cols / sample.chars().count()).max(1));
        chars += line.chars().count();
        buffer.set_text(
            &mut font_system,
            &line,
            &attrs,
            glyphon::Shaping::Advanced,
            None,
        );
        buffer.shape_until_scroll(&mut font_system, false);
    }
    let total_ms = elapsed_ms(start);
    let seconds = (total_ms / 1000.0).max(f64::EPSILON);
    GlyphShapingResult {
        rows: iterations,
        chars,
        total_ms,
        rows_per_second: iterations as f64 / seconds,
        chars_per_second: chars as f64 / seconds,
    }
}

fn run_pty_backpressure_bench(
    target_bytes: usize,
    cols: u16,
    rows: u16,
) -> Result<PtyBackpressureResult, Box<dyn std::error::Error>> {
    let shell = CString::new("/bin/sh")?;
    let arg0 = CString::new("sh")?;
    let arg1 = CString::new("-lc")?;
    let command = CString::new(format!(
        "yes PanasynBackpressure | head -c {}",
        target_bytes
    ))?;
    let winsize = Winsize {
        ws_row: rows,
        ws_col: cols,
        ws_xpixel: 0,
        ws_ypixel: 0,
    };

    // SAFETY: forkpty receives a valid Winsize pointer. The child branch below
    // immediately execs `/bin/sh -lc ...` or exits without touching shared Rust state.
    let forked = unsafe { forkpty(Some(&winsize), None) }?;
    let ForkptyResult::Parent { child, master } = forked else {
        // SAFETY: This is the post-fork child path. The pointers come from
        // CStrings that are still alive, and the process exits if execl fails.
        unsafe {
            libc::execl(
                shell.as_ptr(),
                arg0.as_ptr(),
                arg1.as_ptr(),
                command.as_ptr(),
                std::ptr::null::<libc::c_char>(),
            );
            libc::_exit(127);
        }
    };

    let mut terminal = TerminalState::new(cols as usize, rows as usize, 10_000);
    let mut parser = ansi::Parser::new();
    let mut queue: VecDeque<PtyChunk> = VecDeque::new();
    let mut queued_bytes = 0usize;
    let mut result = PtyBackpressureResult {
        target_bytes,
        ..PtyBackpressureResult::default()
    };
    let mut parse_budget_per_frame = 256 * 1024;
    let min_parse_budget_per_frame = 64 * 1024;
    let max_parse_budget_per_frame = 4 * 1024 * 1024;
    let max_chunks_per_frame = 512usize;
    let frame_period = Duration::from_micros(16_667);
    let frame_budget_ms = frame_period.as_secs_f64() * 1000.0;
    let grow_parse_ms = frame_budget_ms * 0.70;
    let shrink_parse_ms = frame_budget_ms * 0.85;
    let start = Instant::now();
    let mut next_frame = start;
    let mut child_done = false;
    let mut buf = vec![0u8; 128 * 1024];
    const MAX_READ_BATCH_BYTES: usize = 1024 * 1024;

    loop {
        if start.elapsed() > Duration::from_secs(30) {
            terminate_child(child);
            return Err("PTY backpressure benchmark timed out".into());
        }

        let revents = {
            let mut poll_fds = [PollFd::new(
                master.as_fd(),
                PollFlags::POLLIN | PollFlags::POLLHUP,
            )];
            match poll(&mut poll_fds, PollTimeout::ZERO) {
                Ok(_) => poll_fds[0].revents().unwrap_or_else(PollFlags::empty),
                Err(nix::errno::Errno::EINTR) => PollFlags::empty(),
                Err(e) => return Err(Box::new(e)),
            }
        };

        if revents.contains(PollFlags::POLLIN) {
            let mut read_batch_bytes = 0usize;
            loop {
                match nix::unistd::read(&master, &mut buf) {
                    Ok(0) => {
                        child_done = true;
                        break;
                    }
                    Ok(n) => {
                        result.read_bytes += n;
                        queued_bytes += n;
                        read_batch_bytes += n;
                        push_pty_chunk(&mut queue, &buf[..n]);
                        result.peak_queue_bytes = result.peak_queue_bytes.max(queued_bytes);
                        result.peak_queue_chunks = result.peak_queue_chunks.max(queue.len());
                    }
                    Err(nix::errno::Errno::EINTR) => continue,
                    Err(e) => return Err(Box::new(e)),
                }

                if read_batch_bytes >= MAX_READ_BATCH_BYTES {
                    break;
                }

                let mut poll_fds = [PollFd::new(
                    master.as_fd(),
                    PollFlags::POLLIN | PollFlags::POLLHUP,
                )];
                match poll(&mut poll_fds, PollTimeout::ZERO) {
                    Ok(_) => {
                        let next = poll_fds[0].revents().unwrap_or_else(PollFlags::empty);
                        child_done |= next.contains(PollFlags::POLLHUP);
                        if !next.contains(PollFlags::POLLIN) {
                            break;
                        }
                    }
                    Err(nix::errno::Errno::EINTR) => continue,
                    Err(e) => return Err(Box::new(e)),
                }
            }
        }

        if revents.contains(PollFlags::POLLHUP) {
            child_done = true;
        }

        match waitpid(child, Some(WaitPidFlag::WNOHANG)) {
            Ok(WaitStatus::StillAlive) => {}
            Ok(_) | Err(nix::errno::Errno::ECHILD) => child_done = true,
            Err(e) => return Err(Box::new(e)),
        }

        if Instant::now() >= next_frame {
            let parse_start = Instant::now();
            let parsed = parse_queued_bytes(
                &mut queue,
                &mut queued_bytes,
                parse_budget_per_frame,
                max_chunks_per_frame,
                &mut parser,
                &mut terminal,
            );
            let parse_ms = elapsed_ms(parse_start);
            result.parsed_bytes += parsed;
            result.parse_ms += parse_ms;
            result.max_frame_parse_ms = result.max_frame_parse_ms.max(parse_ms);
            result.frames += 1;
            if queued_bytes > parse_budget_per_frame / 2 && parse_ms < grow_parse_ms {
                parse_budget_per_frame =
                    (parse_budget_per_frame * 2).min(max_parse_budget_per_frame);
            } else if parse_ms > shrink_parse_ms {
                parse_budget_per_frame =
                    (parse_budget_per_frame / 2).max(min_parse_budget_per_frame);
            }
            if result.parsed_bytes >= target_bytes {
                result.wall_ms = elapsed_ms(start);
                terminate_child(child);
                let seconds = (result.wall_ms / 1000.0).max(f64::EPSILON);
                result.throughput_mbps = (result.parsed_bytes as f64 / seconds) / (1024.0 * 1024.0);
                return Ok(result);
            }
            next_frame += frame_period;
        }

        if child_done && queue.is_empty() {
            break;
        }

        if queue.is_empty() {
            std::thread::sleep(Duration::from_millis(1));
        }
    }

    result.wall_ms = elapsed_ms(start);
    let seconds = (result.wall_ms / 1000.0).max(f64::EPSILON);
    result.throughput_mbps = (result.parsed_bytes as f64 / seconds) / (1024.0 * 1024.0);
    Ok(result)
}

fn terminate_child(child: nix::unistd::Pid) {
    let _ = nix::sys::signal::kill(child, Signal::SIGTERM);
    for _ in 0..10 {
        match waitpid(child, Some(WaitPidFlag::WNOHANG)) {
            Ok(WaitStatus::StillAlive) => std::thread::sleep(Duration::from_millis(10)),
            Ok(_) | Err(nix::errno::Errno::ECHILD) => return,
            Err(_) => break,
        }
    }
    let _ = nix::sys::signal::kill(child, Signal::SIGKILL);
    let _ = waitpid(child, Some(WaitPidFlag::WNOHANG));
}

fn push_pty_chunk(queue: &mut VecDeque<PtyChunk>, bytes: &[u8]) {
    if bytes.is_empty() {
        return;
    }
    if let Some(last) = queue.back_mut()
        && last.can_append(bytes.len())
    {
        last.data.extend_from_slice(bytes);
        return;
    }
    queue.push_back(PtyChunk::new(bytes.to_vec()));
}

fn parse_queued_bytes(
    queue: &mut VecDeque<PtyChunk>,
    queued_bytes: &mut usize,
    byte_budget: usize,
    chunk_budget: usize,
    parser: &mut ansi::Parser,
    terminal: &mut TerminalState,
) -> usize {
    let mut parsed = 0usize;
    let mut chunks = 0usize;
    while parsed < byte_budget && chunks < chunk_budget {
        let Some(chunk) = queue.front_mut() else {
            break;
        };
        let remaining_budget = byte_budget - parsed;
        let parse_len = chunk.remaining().min(remaining_budget);
        let start = chunk.offset;
        let end = start + parse_len;
        parser.advance(&chunk.data[start..end], terminal);
        chunk.offset = end;
        parsed += parse_len;
        *queued_bytes = queued_bytes.saturating_sub(parse_len);
        chunks += 1;
        if queue.front().is_some_and(|chunk| chunk.remaining() == 0) {
            queue.pop_front();
        } else {
            break;
        }
    }
    parsed
}

struct OffscreenTextRenderer {
    device: wgpu::Device,
    queue: wgpu::Queue,
    _cache: glyphon::Cache,
    atlas: glyphon::TextAtlas,
    viewport: glyphon::Viewport,
    font_system: glyphon::FontSystem,
    swash_cache: glyphon::SwashCache,
    text_renderer: glyphon::TextRenderer,
    row_buffers: Vec<glyphon::Buffer>,
    texture_view: wgpu::TextureView,
    width: u32,
    height: u32,
    rows: usize,
    metrics: glyphon::Metrics,
    buffer_w: f32,
    settings: RenderSettings,
}

impl OffscreenTextRenderer {
    async fn new(
        cols: usize,
        rows: usize,
        settings: RenderSettings,
    ) -> Result<Self, Box<dyn std::error::Error>> {
        let (cell_w, cell_h, font_size) = cell_dimensions(&settings);
        let width = (cols as f32 * cell_w + cell_w * 4.0).ceil().max(1.0) as u32;
        let height = (rows as f32 * cell_h + cell_h * 2.0).ceil().max(1.0) as u32;
        let instance = wgpu::Instance::new(wgpu::InstanceDescriptor {
            backends: crate::platform::platform_backends(),
            ..wgpu::InstanceDescriptor::new_without_display_handle()
        });
        let adapter = request_offscreen_adapter(&instance).await?;
        let (device, queue) = adapter
            .request_device(&wgpu::DeviceDescriptor {
                label: Some("panasyn bench device"),
                required_features: wgpu::Features::empty(),
                required_limits: wgpu::Limits::default(),
                experimental_features: wgpu::ExperimentalFeatures::default(),
                memory_hints: wgpu::MemoryHints::Performance,
                trace: wgpu::Trace::default(),
            })
            .await?;
        let format = wgpu::TextureFormat::Bgra8UnormSrgb;
        let texture = device.create_texture(&wgpu::TextureDescriptor {
            label: Some("panasyn bench target"),
            size: wgpu::Extent3d {
                width,
                height,
                depth_or_array_layers: 1,
            },
            mip_level_count: 1,
            sample_count: 1,
            dimension: wgpu::TextureDimension::D2,
            format,
            usage: wgpu::TextureUsages::RENDER_ATTACHMENT,
            view_formats: &[],
        });
        let texture_view = texture.create_view(&wgpu::TextureViewDescriptor::default());
        let mut font_system = glyphon::FontSystem::new();
        let cache = glyphon::Cache::new(&device);
        let mut atlas = glyphon::TextAtlas::new(&device, &queue, &cache, format);
        let mut viewport = glyphon::Viewport::new(&device, &cache);
        viewport.update(&queue, glyphon::Resolution { width, height });
        let swash_cache = glyphon::SwashCache::new();
        let metrics = glyphon::Metrics::new(font_size, cell_h);
        let buffer_w = cols as f32 * cell_w;
        let attrs = attrs_for_family(&settings.font_family);
        let blanks = " ".repeat(cols);
        let mut row_buffers = Vec::with_capacity(rows);
        for _ in 0..rows {
            let mut buffer = glyphon::Buffer::new(&mut font_system, metrics);
            buffer.set_size(&mut font_system, Some(buffer_w), Some(metrics.line_height));
            buffer.set_text(
                &mut font_system,
                &blanks,
                &attrs,
                glyphon::Shaping::Advanced,
                None,
            );
            buffer.shape_until_scroll(&mut font_system, false);
            row_buffers.push(buffer);
        }
        let text_renderer = glyphon::TextRenderer::new(
            &mut atlas,
            &device,
            wgpu::MultisampleState::default(),
            None,
        );

        Ok(Self {
            device,
            queue,
            _cache: cache,
            atlas,
            viewport,
            font_system,
            swash_cache,
            text_renderer,
            row_buffers,
            texture_view,
            width,
            height,
            rows,
            metrics,
            buffer_w,
            settings,
        })
    }

    fn render(
        &mut self,
        terminal: &TerminalState,
    ) -> Result<RenderTiming, Box<dyn std::error::Error>> {
        let total_start = Instant::now();
        let shape_start = Instant::now();
        let attrs = attrs_for_family(&self.settings.font_family);
        for row in 0..self.rows {
            let text = if row < terminal.grid.rows() {
                terminal.grid.row_text(row)
            } else {
                String::new()
            };
            let buffer = &mut self.row_buffers[row];
            buffer.set_size(
                &mut self.font_system,
                Some(self.buffer_w),
                Some(self.metrics.line_height),
            );
            buffer.set_text(
                &mut self.font_system,
                &text,
                &attrs,
                glyphon::Shaping::Advanced,
                None,
            );
            buffer.shape_until_scroll(&mut self.font_system, false);
        }
        let shape_ms = elapsed_ms(shape_start);

        let text_areas: Vec<glyphon::TextArea> = self
            .row_buffers
            .iter()
            .enumerate()
            .map(|(row, buffer)| glyphon::TextArea {
                buffer,
                left: self.settings.font_size * 1.2,
                top: self.settings.font_size * self.settings.line_height * (row + 1) as f32,
                scale: 1.0,
                bounds: glyphon::TextBounds {
                    left: 0,
                    top: 0,
                    right: self.width as i32,
                    bottom: self.height as i32,
                },
                default_color: glyphon::Color::rgb(0xCC, 0xCC, 0xCC),
                custom_glyphs: &[],
            })
            .collect();

        let prepare_start = Instant::now();
        self.text_renderer
            .prepare(
                &self.device,
                &self.queue,
                &mut self.font_system,
                &mut self.atlas,
                &self.viewport,
                text_areas,
                &mut self.swash_cache,
            )
            .map_err(|e| format!("offscreen render prepare failed: {e}"))?;
        let prepare_ms = elapsed_ms(prepare_start);

        let render_start = Instant::now();
        let mut encoder = self
            .device
            .create_command_encoder(&wgpu::CommandEncoderDescriptor {
                label: Some("panasyn bench encoder"),
            });
        {
            let mut pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
                label: Some("panasyn bench pass"),
                color_attachments: &[Some(wgpu::RenderPassColorAttachment {
                    view: &self.texture_view,
                    depth_slice: None,
                    resolve_target: None,
                    ops: wgpu::Operations {
                        load: wgpu::LoadOp::Clear(wgpu::Color::BLACK),
                        store: wgpu::StoreOp::Store,
                    },
                })],
                depth_stencil_attachment: None,
                timestamp_writes: None,
                occlusion_query_set: None,
                multiview_mask: None,
            });
            self.text_renderer
                .render(&self.atlas, &self.viewport, &mut pass)
                .map_err(|e| format!("offscreen render pass failed: {e}"))?;
        }
        self.queue.submit(Some(encoder.finish()));
        let _ = self.device.poll(wgpu::PollType::wait_indefinitely());
        let render_ms = elapsed_ms(render_start);

        Ok(RenderTiming {
            shape_ms,
            prepare_ms,
            render_ms,
            total_ms: elapsed_ms(total_start),
        })
    }
}

async fn request_offscreen_adapter(
    instance: &wgpu::Instance,
) -> Result<wgpu::Adapter, Box<dyn std::error::Error>> {
    let options = |power_preference| wgpu::RequestAdapterOptions {
        power_preference,
        compatible_surface: None,
        force_fallback_adapter: false,
    };
    match instance
        .request_adapter(&options(wgpu::PowerPreference::HighPerformance))
        .await
    {
        Ok(adapter) => Ok(adapter),
        Err(high_performance_error) => instance
            .request_adapter(&options(wgpu::PowerPreference::LowPower))
            .await
            .map_err(|_| Box::new(high_performance_error) as Box<dyn std::error::Error>),
    }
}

pub fn print_suite(path: &str, result: &BenchSuiteResult, machine: bool) {
    if machine {
        println!(
            "BENCH_SUITE recording={} frames={} bytes={} throughput_mbps={:.4} \
             first_frame_ms={:.4} avg_frame_ms={:.4} p95_frame_ms={:.4} max_frame_ms={:.4} missed_60hz={} \
             steady_avg_frame_ms={:.4} steady_p95_frame_ms={:.4} steady_max_frame_ms={:.4} steady_missed_60hz={} \
             avg_latency_ms={:.4} p95_latency_ms={:.4} max_latency_ms={:.4} \
             shape_ms={:.4} prepare_ms={:.4} render_ms={:.4} \
             glyph_rows_per_s={:.2} glyph_chars_per_s={:.2} \
             pty_target_bytes={} pty_read_bytes={} pty_parsed_bytes={} \
             pty_wall_ms={:.4} pty_parse_ms={:.4} pty_frames={} \
             pty_max_frame_parse_ms={:.4} pty_peak_queue_bytes={} pty_peak_queue_chunks={} \
             pty_throughput_mbps={:.4}",
            path,
            result.render.frames,
            result.render.bytes,
            result.render.throughput_mbps,
            result.render.first_frame_ms,
            result.render.avg_frame_ms,
            result.render.p95_frame_ms,
            result.render.max_frame_ms,
            result.render.missed_60hz_frames,
            result.render.steady_avg_frame_ms,
            result.render.steady_p95_frame_ms,
            result.render.steady_max_frame_ms,
            result.render.steady_missed_60hz_frames,
            result.render.avg_input_to_render_ms,
            result.render.p95_input_to_render_ms,
            result.render.max_input_to_render_ms,
            result.render.shape_ms,
            result.render.prepare_ms,
            result.render.render_ms,
            result.glyph_shaping.rows_per_second,
            result.glyph_shaping.chars_per_second,
            result.pty_backpressure.target_bytes,
            result.pty_backpressure.read_bytes,
            result.pty_backpressure.parsed_bytes,
            result.pty_backpressure.wall_ms,
            result.pty_backpressure.parse_ms,
            result.pty_backpressure.frames,
            result.pty_backpressure.max_frame_parse_ms,
            result.pty_backpressure.peak_queue_bytes,
            result.pty_backpressure.peak_queue_chunks,
            result.pty_backpressure.throughput_mbps,
        );
        return;
    }

    println!("=== Panasyn Bench Suite ===");
    println!("  Recording:             {}", path);
    println!("  Frames rendered:        {}", result.render.frames);
    println!(
        "  Parse/render bytes:     {} ({:.2} KB)",
        result.render.bytes,
        result.render.bytes as f64 / 1024.0
    );
    println!("  Parse time:             {:.3} ms", result.render.parse_ms);
    println!("  Glyph shape time:       {:.3} ms", result.render.shape_ms);
    println!(
        "  GPU prepare time:       {:.3} ms",
        result.render.prepare_ms
    );
    println!(
        "  GPU render+wait time:   {:.3} ms",
        result.render.render_ms
    );
    println!(
        "  Full throughput:        {:.2} MB/s",
        result.render.throughput_mbps
    );
    println!(
        "  Frame pacing:           avg={:.3}ms p95={:.3}ms max={:.3}ms missed_60hz={}",
        result.render.avg_frame_ms,
        result.render.p95_frame_ms,
        result.render.max_frame_ms,
        result.render.missed_60hz_frames
    );
    println!(
        "  Steady frame pacing:    first={:.3}ms avg={:.3}ms p95={:.3}ms max={:.3}ms missed_60hz={}",
        result.render.first_frame_ms,
        result.render.steady_avg_frame_ms,
        result.render.steady_p95_frame_ms,
        result.render.steady_max_frame_ms,
        result.render.steady_missed_60hz_frames
    );
    println!(
        "  Input-to-render model:  avg={:.3}ms p95={:.3}ms max={:.3}ms",
        result.render.avg_input_to_render_ms,
        result.render.p95_input_to_render_ms,
        result.render.max_input_to_render_ms
    );
    println!();
    println!("=== Glyph Shaping ===");
    println!("  Rows:                  {}", result.glyph_shaping.rows);
    println!("  Chars:                 {}", result.glyph_shaping.chars);
    println!(
        "  Total time:            {:.3} ms",
        result.glyph_shaping.total_ms
    );
    println!(
        "  Throughput:            {:.0} rows/s, {:.0} chars/s",
        result.glyph_shaping.rows_per_second, result.glyph_shaping.chars_per_second
    );
    println!();
    println!("=== PTY Backpressure ===");
    println!(
        "  Target bytes:          {}",
        result.pty_backpressure.target_bytes
    );
    println!(
        "  Read bytes:            {}",
        result.pty_backpressure.read_bytes
    );
    println!(
        "  Parsed bytes:          {}",
        result.pty_backpressure.parsed_bytes
    );
    println!(
        "  Wall time:             {:.3} ms",
        result.pty_backpressure.wall_ms
    );
    println!(
        "  Parse time:            {:.3} ms",
        result.pty_backpressure.parse_ms
    );
    println!(
        "  Peak queue:            {} bytes across {} chunks",
        result.pty_backpressure.peak_queue_bytes, result.pty_backpressure.peak_queue_chunks
    );
    println!(
        "  Max frame parse:       {:.3} ms",
        result.pty_backpressure.max_frame_parse_ms
    );
    println!(
        "  Throughput:            {:.2} MB/s",
        result.pty_backpressure.throughput_mbps
    );
}

fn attrs_for_family(font_family: &str) -> glyphon::Attrs<'_> {
    let family = font_family.trim();
    if family.is_empty() {
        glyphon::Attrs::new().family(glyphon::Family::Monospace)
    } else {
        glyphon::Attrs::new().family(glyphon::Family::Name(family))
    }
}

fn cell_dimensions(settings: &RenderSettings) -> (f32, f32, f32) {
    let font_size = settings.font_size.clamp(6.0, 96.0);
    let line_height = settings.line_height.clamp(1.0, 3.0);
    (
        (font_size * 0.6).ceil(),
        (font_size * line_height).ceil(),
        font_size,
    )
}

fn elapsed_ms(start: Instant) -> f64 {
    start.elapsed().as_secs_f64() * 1000.0
}

fn average(values: &[f64]) -> f64 {
    if values.is_empty() {
        0.0
    } else {
        values.iter().sum::<f64>() / values.len() as f64
    }
}

fn percentile(values: &[f64], q: f64) -> f64 {
    if values.is_empty() {
        return 0.0;
    }
    let mut sorted = values.to_vec();
    sorted.sort_by(|a, b| a.total_cmp(b));
    let idx = ((sorted.len() - 1) as f64 * q.clamp(0.0, 1.0)).round() as usize;
    sorted[idx]
}