gasm_host/
headless.rs

1//! Headless runs: N frames with virtual time, scripted input and (optionally)
2//! hashes of everything the guest presents. Reproducible: the same module and
3//! options give the same hashes on every runner (runners/web/headless.mjs).
4
5use std::time::{Duration, Instant};
6
7use crate::gfx::{Gfx, HEADLESS_SIZE};
8use crate::host::{Stop, VirtualClock};
9use crate::present::Present;
10use crate::script::{Script, ScriptState};
11use crate::session::Session;
12
13pub struct Options {
14    pub frames: u64,
15    /// render on the GPU (offscreen) and write the last frame as PNG
16    pub screenshot: Option<String>,
17    /// also write the last 2D frame as the window would show it: `present` at `window` size
18    pub screenshot_filtered: Option<String>,
19    pub present: Present,
20    pub window: (u32, u32),
21    pub script: Script,
22    /// pace frames at the guest's rate
23    pub realtime: bool,
24    pub hash: bool,
25}
26
27/// What a run produced (`print` writes the hash lines scripts compare).
28pub struct Report {
29    pub frames: u64,
30    pub presented: u64,
31    pub size: (usize, usize),
32    pub video_hash: u32,
33    pub audio_hash: u32,
34    pub audio_frames: u64,
35    pub frame_rate: f64,
36    pub seconds: f64,
37    /// the guest called proc_exit(code)
38    pub exit: Option<i32>,
39}
40
41impl Report {
42    /// The hash lines (stdout): a contract between runners and scripts.
43    pub fn print(&self) {
44        println!("frames={} presented={} size={}x{}", self.frames, self.presented, self.size.0, self.size.1);
45        println!("video_fnv32={:08x} audio_fnv32={:08x} audio_frames={}", self.video_hash, self.audio_hash, self.audio_frames);
46    }
47}
48
49pub fn run(session: Session, opts: &Options) -> Result<Report, String> {
50    // Render on the GPU only when a screenshot is wanted; otherwise a null backend.
51    let gpu = opts.screenshot.is_some() || opts.screenshot_filtered.is_some();
52    let gfx = match gpu {
53        true => Gfx::offscreen(HEADLESS_SIZE.0, HEADLESS_SIZE.1).unwrap_or_else(|e| {
54            eprintln!("[gasm] no GPU for screenshots ({e}); gfx output will be blank");
55            Gfx::null()
56        }),
57        false => Gfx::null(),
58    };
59    if let Some(t) = crate::host::static_title(&session.wasm) {
60        eprintln!("[gasm] title: {t} (gasm.title)");
61    }
62    let mut game = match session.start(None, gfx, true, opts.hash) {
63        Ok(g) => g,
64        Err(Stop::Exit(code)) => {
65            return Ok(Report { frames: 0, presented: 0, size: (0, 0), video_hash: 0x811c_9dc5, audio_hash: 0x811c_9dc5, audio_frames: 0, frame_rate: 60.0, seconds: 0.0, exit: Some(code) });
66        }
67        Err(Stop::Trap(e)) => return Err(e),
68    };
69    let t0 = Instant::now();
70    let mut exit = None;
71    let mut ran = 0;
72    let mut clock = VirtualClock::default();
73    let mut script_state = ScriptState::default();
74    for i in 0..opts.frames {
75        let host = game.host_mut();
76        let rate = host.frame_rate;
77        host.virtual_time_ms = Some(clock.at(i, rate));
78        host.pads = [opts.script.pad(i), 0, 0, 0];
79        host.text = Some(opts.script.text(i));
80        let (w, h) = host.gfx.size();
81        let mode = host.input_mode;
82        host.input = opts.script.raw(i, &mut script_state, (w as f32, h as f32), mode);
83        host.show_frame = gpu && i + 1 == opts.frames;
84        ran = i + 1;
85        let result = game.frame();
86        let host = game.host_mut();
87        if std::mem::take(&mut host.title_changed) {
88            eprintln!("[gasm] title: {}", host.title.as_deref().unwrap_or("(default)"));
89        }
90        match result {
91            Ok(()) => {}
92            Err(Stop::Exit(code)) => {
93                exit = Some(code);
94                break;
95            }
96            Err(Stop::Trap(e)) => return Err(format!("frame {i}: {e}")),
97        }
98        if opts.realtime {
99            let due = t0 + Duration::from_secs_f64((i + 1) as f64 / game.host().frame_rate);
100            if let Some(wait) = due.checked_duration_since(Instant::now()) {
101                std::thread::sleep(wait);
102            }
103        }
104    }
105    if exit.is_none() {
106        game.exit();
107    }
108    if let Some(path) = &opts.screenshot_filtered {
109        let h = game.host_mut();
110        let img = match h.gfx.used {
111            true => h.gfx.read_offscreen(), // gfx guests render at drawable size: no filter
112            false if h.width > 0 => {
113                let rgba = std::mem::take(&mut h.rgba);
114                h.gfx.present = opts.present;
115                let img = h.gfx.render_video(&rgba, h.width as u32, h.height as u32, h.aspect, opts.window);
116                h.rgba = rgba;
117                img
118            }
119            false => None,
120        };
121        if let Some((w, hgt, rgba)) = img {
122            write_png(path, w, hgt, &rgba)?;
123            eprintln!("[gasm] wrote {path}");
124        }
125    }
126    let h = game.host();
127    if let Some(path) = &opts.screenshot {
128        let (w, hgt, rgba) = match h.gfx.read_offscreen() {
129            Some(img) if h.gfx.used => img,
130            _ => (h.width as u32, h.height as u32, h.rgba.clone()),
131        };
132        if w > 0 {
133            write_png(path, w, hgt, &rgba)?;
134            eprintln!("[gasm] wrote {path}");
135        }
136    }
137    Ok(Report {
138        frames: ran,
139        presented: h.frames_presented,
140        size: (h.width, h.height),
141        video_hash: h.video_hash.0,
142        audio_hash: h.audio_hash.0,
143        audio_frames: h.audio_frames,
144        frame_rate: h.frame_rate,
145        seconds: t0.elapsed().as_secs_f64(),
146        exit,
147    })
148}
149
150pub fn write_png(path: &str, w: u32, h: u32, rgba: &[u8]) -> Result<(), String> {
151    let file = std::fs::File::create(path).map_err(|e| format!("{path}: {e}"))?;
152    let mut enc = png::Encoder::new(std::io::BufWriter::new(file), w, h);
153    enc.set_color(png::ColorType::Rgba);
154    enc.set_depth(png::BitDepth::Eight);
155    let mut writer = enc.write_header().map_err(|e| e.to_string())?;
156    writer.write_image_data(rgba).map_err(|e| e.to_string())
157}
gasm_host/headless.rs

gasm_host/
headless.rs
