feat: complete freehand sketch workflow

Co-authored-by: ramox81 <184937705+ramox81@users.noreply.github.com>

src/io/mod.rs

@@ -1784,6 +1784,7 @@ fn fix_current_style_names(doc: &mut CadDocument) {
             doc.header.current_mleader_style_name = v;
         }
     }
+    reflect_sketch_settings(doc);
 }
 
 /// Find the handle of the `DictionaryVariable` registered under `name` in any
@@ -1818,6 +1819,32 @@ pub(crate) fn drawing_variable(doc: &CadDocument, name: &str) -> Option<String>
     vardict_value(doc, name)
 }
 
+fn reflect_sketch_settings(doc: &mut CadDocument) {
+    let sketch_type = vardict_value(doc, "SKPOLY")
+        .and_then(|value| value.parse::<i16>().ok())
+        .unwrap_or(doc.header.sketch_type)
+        .clamp(0, 2);
+    let increment = vardict_value(doc, "SKETCHINC")
+        .and_then(|value| value.parse::<f64>().ok())
+        .filter(|value| value.is_finite() && *value > 0.0)
+        .unwrap_or(doc.header.sketch_increment);
+    let tolerance = vardict_value(doc, "SKTOLERANCE")
+        .and_then(|value| value.parse::<f64>().ok())
+        .filter(|value| value.is_finite() && (0.0..=1.0).contains(value))
+        .unwrap_or(doc.header.sketch_tolerance);
+    doc.header.sketch_type = sketch_type;
+    doc.header.sketch_increment = if increment.is_finite() && increment > 0.0 {
+        increment
+    } else {
+        0.1
+    };
+    doc.header.sketch_tolerance = if tolerance.is_finite() {
+        tolerance.clamp(0.0, 1.0)
+    } else {
+        0.5
+    };
+}
+
 /// Write a drawing variable, creating the variable dictionary and record when
 /// needed so new drawings preserve the value too.
 pub(crate) fn set_drawing_variable(doc: &mut CadDocument, name: &str, value: &str) {
@@ -1859,6 +1886,31 @@ pub(crate) fn set_drawing_variable(doc: &mut CadDocument, name: &str, value: &st
     }
 }
 
+pub(crate) fn set_sketch_settings(
+    doc: &mut CadDocument,
+    sketch_type: i16,
+    increment: f64,
+    tolerance: f64,
+) {
+    let sketch_type = sketch_type.clamp(0, 2);
+    let increment = if increment.is_finite() && increment > 0.0 {
+        increment
+    } else {
+        0.1
+    };
+    let tolerance = if tolerance.is_finite() {
+        tolerance.clamp(0.0, 1.0)
+    } else {
+        0.5
+    };
+    doc.header.sketch_type = sketch_type;
+    doc.header.sketch_increment = increment;
+    doc.header.sketch_tolerance = tolerance;
+    set_drawing_variable(doc, "SKPOLY", &sketch_type.to_string());
+    set_drawing_variable(doc, "SKETCHINC", &increment.to_string());
+    set_drawing_variable(doc, "SKTOLERANCE", &tolerance.to_string());
+}
+
 /// The layout tab that was active when the drawing was saved — the `CTAB`
 /// system variable (stored in the variable dictionary as a `DICTIONARYVAR`).
 /// `None` when the file recorded no current tab.
@@ -1919,6 +1971,10 @@ fn sync_current_styles_on_save(doc: &mut CadDocument) {
     set_drawing_variable(doc, "CMLEADERSTYLE", &mleader);
     let annotation = doc.header.current_annotation_scale.clone();
     set_drawing_variable(doc, "CANNOSCALE", &annotation);
+    let sketch_type = doc.header.sketch_type;
+    let increment = doc.header.sketch_increment;
+    let tolerance = doc.header.sketch_tolerance;
+    set_sketch_settings(doc, sketch_type, increment, tolerance);
 }
 
 // ── Corrupt-entity guard ──────────────────────────────────────────────────