Added stars at L1

crates/resolved-cli/src/main.rs

@@ -11,7 +11,7 @@ use clap::{Args, Parser, Subcommand};
 use resolved::gpu::AdapterChoice;
 use resolved::{
     CameraTier, EarthTexture, Fidelity, Frame, LightingTier, Look, MoonTexture, Preview, Renderer,
-    RendererOptions,
+    RendererOptions, StarCatalog, StarPhotometry,
 };
 
 use crate::scene_file::SceneFile;
@@ -52,13 +52,15 @@ struct RenderArgs {
     #[arg(long)]
     pretty: bool,
     /// Lighting fidelity tier: L0, or L1 (adds Earth's surface, shadows on targets,
-    /// light from Earth and the Moon, eclipses on them, and the Sun's limb darkening;
-    /// needs Blue Marble data).
+    /// light from Earth and the Moon, eclipses on them, the Sun's limb darkening, and
+    /// stars, which camera C1 shows; needs Blue Marble data, and with C1 the star
+    /// catalog).
     #[arg(long, default_value = "L0")]
     lighting: LightingTier,
     /// Camera fidelity tier: C0, or C1 (adds pixels that collect light over their area,
     /// for graded edges and continuous thin parts, lens distortion, lens blur, and the
-    /// Sun, Moon and Earth where light time and aberration make them appear).
+    /// Sun, Moon and Earth where light time and aberration make them appear, and at
+    /// lighting L1 stars).
     #[arg(long, default_value = "C0")]
     camera: CameraTier,
     /// From camera C1: render each pixel as N x N finer ones (1 to 4; default 2), which
@@ -72,7 +74,8 @@ struct RenderArgs {
     #[arg(long, value_name = "FRAMES")]
     timings: Option<usize>,
     /// Directory of data the tiers need (earth/bmng-2004-MM.jpg from
-    /// scripts/fetch-earth.sh, moon/wac-hapke-643.png from scripts/fetch-moon.py).
+    /// scripts/fetch-earth.sh, moon/wac-hapke-643.png from scripts/fetch-moon.py,
+    /// stars/stars.bin from scripts/fetch-stars.py).
     /// Without it: RESOLVED_DATA, then ./data, then the repository's data/.
     #[arg(long, value_name = "DIR")]
     data: Option<PathBuf>,
@@ -124,12 +127,13 @@ fn earth_image(data: Option<&Path>, month: u32) -> Result<PathBuf, String> {
         data,
         &format!("earth/bmng-2004-{month:02}.jpg"),
         "fetch-earth.sh",
+        "lighting L1",
     )
 }
 
 /// `name` from the first data directory that has it; the error names `script`, which
-/// makes it.
-fn data_file(data: Option<&Path>, name: &str, script: &str) -> Result<PathBuf, String> {
+/// makes it, and `tier`, which needs it.
+fn data_file(data: Option<&Path>, name: &str, script: &str, tier: &str) -> Result<PathBuf, String> {
     let tried = data_directories(data);
     tried
         .iter()
@@ -138,7 +142,7 @@ fn data_file(data: Option<&Path>, name: &str, script: &str) -> Result<PathBuf, S
         .ok_or_else(|| {
             let tried: Vec<_> = tried.iter().map(|d| d.display().to_string()).collect();
             format!(
-                "lighting L1 needs {name} (run scripts/{script}, or pass --data DIR); looked in {}",
+                "{tier} needs {name} (run scripts/{script}, or pass --data DIR); looked in {}",
                 tried.join(", ")
             )
         })
@@ -171,6 +175,7 @@ fn render(args: &RenderArgs) -> Result<(), String> {
             args.data.as_deref(),
             "moon/wac-hapke-643.png",
             "fetch-moon.py",
+            "lighting L1",
         )?;
         Some(Arc::new(
             MoonTexture::load(&image).map_err(|e| e.to_string())?,
@@ -178,6 +183,22 @@ fn render(args: &RenderArgs) -> Result<(), String> {
     } else {
         None
     };
+    let stars = if args.lighting >= LightingTier::L1 && args.camera >= CameraTier::C1 {
+        let catalog = data_file(
+            args.data.as_deref(),
+            "stars/stars.bin",
+            "fetch-stars.py",
+            "lighting L1 with camera C1",
+        )?;
+        // Only the stars this exposure can show.
+        let faint = StarPhotometry::new(&camera).faintest_drawn(camera.exposure);
+        Some(Arc::new(
+            StarCatalog::load(&catalog, file.years_since_j2000()?, faint)
+                .map_err(|e| e.to_string())?,
+        ))
+    } else {
+        None
+    };
     let texturing = start.elapsed();
 
     let options = RendererOptions {
@@ -199,6 +220,7 @@ fn render(args: &RenderArgs) -> Result<(), String> {
         shadow_map_size: None,
         dn_in_place: None,
         supersampling: args.supersampling,
+        stars,
     };
     let start = Instant::now();
     let mut renderer = Renderer::new(camera, options).map_err(|e| e.to_string())?;
@@ -260,12 +282,13 @@ fn render(args: &RenderArgs) -> Result<(), String> {
                 v[v.len() / 2]
             };
             println!(
-                "gpu      shadow {:.3} ms, earthshine {:.3} ms, mesh {:.3} ms, bodies {:.3} ms, blur {:.3} ms, sensor {:.3} ms, first to last {:.3} ms (medians)",
+                "gpu      shadow {:.3} ms, earthshine {:.3} ms, mesh {:.3} ms, bodies {:.3} ms, blur {:.3} ms, stars {:.3} ms, sensor {:.3} ms, first to last {:.3} ms (medians)",
                 median(|t| t.shadow),
                 median(|t| t.earthshine),
                 median(|t| t.mesh),
                 median(|t| t.bodies),
                 median(|t| t.blur),
+                median(|t| t.stars),
                 median(|t| t.sensor),
                 median(|t| t.total)
             );

crates/resolved-cli/src/scene_file.rs

@@ -223,6 +223,24 @@ impl SceneFile {
         Ok(None)
     }
 
+    /// Julian years from J2000.0 to the scene's epoch, for the stars' proper motion; 0
+    /// for a scene without one.
+    #[cfg(feature = "astrokit")]
+    pub fn years_since_j2000(&self) -> Result<f64> {
+        let Some(epoch) = &self.epoch else {
+            return Ok(0.0);
+        };
+        let epoch: hifitime::Epoch = epoch.parse().map_err(|e| format!("epoch {epoch:?}: {e}"))?;
+        let j2000 =
+            hifitime::Epoch::from_gregorian_hms(2000, 1, 1, 12, 0, 0, hifitime::TimeScale::TT);
+        Ok((epoch - j2000).to_unit(hifitime::Unit::Day) / 365.25)
+    }
+
+    #[cfg(not(feature = "astrokit"))]
+    pub fn years_since_j2000(&self) -> Result<f64> {
+        Ok(0.0)
+    }
+
     /// The observer's pose.
     pub fn observer(&self) -> Result<Pose> {
         let o = &self.observer;