snapshot --camera and saved views; grid: false / axes: false for headless renders (#1313)

solidcraft-cli snapshot takes --camera JSON and --view with a saved view name (through view.apply, as the MCP screenshot does), plus --no-grid and --no-axes; the MCP screenshot and ui.render take grid/axes, the headless render skips a hidden origin axis, and the app's ui.render follows the Grid and Origin switches. Closes #1245.

apps/solidcraft-cli/src/main.rs

@@ -6,7 +6,7 @@
 //! solidcraft-cli script <design.solidcraft> [--out script.json]     the design's history as a command script
 //! solidcraft-cli bench-open <design.solidcraft | part.step> [--parse-only] [--display LEVEL [--edit NAME EXPR]] loading timings as JSON lines
 //! solidcraft-cli bench-agent [--scale F] [--save F] [--script-out F] a ~1,300-body design built command by command, timed
-//! solidcraft-cli snapshot <script|design> [--in design|part.step] --out shot.png [--width W] [--height H] [--view iso|front|top|…]
+//! solidcraft-cli snapshot <script|design> [--in design|part.step] --out shot.png [--width W] [--height H] [--view iso|front|top|…|NAME | --camera JSON] [--no-grid] [--no-axes]
 //! solidcraft-cli exec <command> [json-params]                 run one command on an empty design
 //! solidcraft-cli commands                                     the command registry as JSON
 //! solidcraft-cli recipe <recipe.json>                         translate an oracle recipe to a script
@@ -34,7 +34,8 @@ use serde_json::{Value, json};
 mod app_icon;
 
 use solidcraft_engine::Session;
-use solidcraft_engine::render::{StandardView, render_png};
+use solidcraft_engine::render::render_png;
+use solidcraft_engine::view::Guides;
 
 const USAGE: &str = "usage:
   solidcraft-cli run <script.json|design.solidcraft|part.step> [--in design.solidcraft|part.step] [--out FILE]... [--save FILE] [--quiet] [--results] [--json-out FILE] [--allow-errors]
@@ -47,9 +48,12 @@ const USAGE: &str = "usage:
       (the design's history as a command script that eval and run replay)
   solidcraft-cli bench-open <design.solidcraft | part.step> [--parse-only] [--display LEVEL [--edit NAME EXPR]]
   solidcraft-cli bench-agent [--scale F] [--save design.solidcraft] [--script-out script.json]
-  solidcraft-cli snapshot <script|design> [--in design.solidcraft|part.step] --out shot.png [--width W] [--height H] [--view iso|front|back|top|bottom|left|right]
+  solidcraft-cli snapshot <script|design> [--in design.solidcraft|part.step] --out shot.png [--width W] [--height H] [--view NAME | --camera JSON] [--no-grid] [--no-axes]
   solidcraft-cli snapshot --in <design.solidcraft|part.step> --out shot.png ...
-      (as with run, --in starts from a design and the script runs on top of it; an option snapshot doesn't take is an error)
+      (as with run, --in starts from a design and the script runs on top of it; an option snapshot doesn't take is an error;
+       --view: iso, front, back, top, bottom, left, right, or the name of a view saved in the design with view.save;
+       --camera: {target: [x,y,z], yaw, pitch, distance, fov?} in mm and radians, as the MCP screenshot takes it (docs/mcp.md);
+       --no-grid and --no-axes leave the ground grid (on Z 0) and the origin's axes out of the picture)
   solidcraft-cli render <script|design> --out image.png [--setup NAME] [--width W] [--height H] [--transparent] [--overwrite] [--timeout SECONDS]
   solidcraft-cli exec <command> [json-params]
   solidcraft-cli commands
@@ -172,7 +176,7 @@ fn positional(args: &[String]) -> Option<&String> {
     let mut i = 0;
     while let Some(a) = args.get(i) {
         if a.starts_with("--") {
-            i += if matches!(a.as_str(), "--quiet" | "--results" | "--allow-errors") { 1 } else { 2 };
+            i += if matches!(a.as_str(), "--quiet" | "--results" | "--allow-errors" | "--no-grid" | "--no-axes") { 1 } else { 2 };
             continue;
         }
         return Some(a);
@@ -266,7 +270,7 @@ fn open(base: Option<&str>, path: Option<&String>) -> Result<Session, String> {
 
 /// Refuses an option `cmd` doesn't take, and one missing its value: a typo, or another
 /// command's option, would otherwise be ignored without a word.
-fn known_flags(cmd: &str, args: &[String], valued: &[&str]) -> Result<(), String> {
+fn known_flags(cmd: &str, args: &[String], valued: &[&str], switches: &[&str]) -> Result<(), String> {
     let mut i = 0;
     while let Some(a) = args.get(i) {
         if valued.contains(&a.as_str()) {
@@ -274,8 +278,8 @@ fn known_flags(cmd: &str, args: &[String], valued: &[&str]) -> Result<(), String
                 Some(v) if !v.starts_with("--") => i += 2,
                 _ => return Err(format!("{cmd}: {a} needs a value")),
             }
-        } else if a.starts_with("--") {
-            return Err(format!("{cmd} doesn't take {a} (it takes {})", valued.join(", ")));
+        } else if a.starts_with("--") && !switches.contains(&a.as_str()) {
+            return Err(format!("{cmd} doesn't take {a} (it takes {})", [valued, switches].concat().join(", ")));
         } else {
             i += 1;
         }
@@ -331,19 +335,35 @@ fn cmd_script(args: &[String]) -> Result<(), String> {
 }
 
 fn cmd_snapshot(args: &[String]) -> Result<(), String> {
-    known_flags("snapshot", args, &["--in", "--out", "--width", "--height", "--view"])?;
+    known_flags("snapshot", args, &["--in", "--out", "--width", "--height", "--view", "--camera"], &["--no-grid", "--no-axes"])?;
+    if positional(args).is_none() && flag(args, "--in").is_none() {
+        return Err(USAGE.to_string());
+    }
     let out = flag(args, "--out").ok_or("snapshot needs --out FILE.png")?;
     let size = |name: &str, default: usize| match flag(args, name) {
         None => Ok(default),
         Some(x) => x.parse().ok().filter(|n| (16..=8192).contains(n)).ok_or_else(|| format!("{name} must be 16 to 8192 pixels, not `{x}`")),
     };
     let (w, h) = (size("--width", 1280)?, size("--height", 800)?);
-    let s = open(flag(args, "--in"), positional(args))?;
-    let mut cam = solidcraft_engine::view::home_camera(&s);
-    if let Some(v) = flag(args, "--view") {
-        cam.set_view(StandardView::parse(v).ok_or_else(|| format!("unknown view `{v}`"))?);
+    let mut s = open(flag(args, "--in"), positional(args))?;
+    // The camera choices of the MCP `screenshot`, through the same command (`view.apply`): a
+    // standard view, a view saved in the design, or an explicit camera. A script that applies a
+    // view itself sets the camera too; without any, the iso view framing the model.
+    match (flag(args, "--view"), flag(args, "--camera")) {
+        (Some(_), Some(_)) => return Err("snapshot: give --view or --camera, not both".into()),
+        (Some(v), None) => {
+            let hint = "standard views: iso, front, back, top, bottom, left, right";
+            s.execute("view.apply", &json!({"view": v})).map_err(|e| format!("--view {v}: {e} ({hint}; or a view saved with view.save)"))?;
+        }
+        (None, Some(c)) => {
+            let camera: Value = serde_json::from_str(c).map_err(|e| format!("--camera: not JSON: {e}"))?;
+            s.execute("view.apply", &json!({"camera": camera})).map_err(|e| format!("--camera: {e}"))?;
+        }
+        (None, None) => {}
     }
-    let scene = solidcraft_engine::view::scene(&s, &cam);
+    let cam = s.camera.unwrap_or_else(|| solidcraft_engine::view::home_camera(&s));
+    let guides = Guides { grid: !args.iter().any(|a| a == "--no-grid"), axes: !args.iter().any(|a| a == "--no-axes") };
+    let scene = solidcraft_engine::view::scene_with_guides(&s, &cam, s.section, guides);
     let png = render_png(&scene, &cam, w, h).ok_or("render failed")?;
     std::fs::write(out, &png).map_err(|e| format!("{out}: {e}"))?;
     println!("{}", pretty(&json!({"path": out, "width": w, "height": h, "bytes": png.len()})));