Merge pull request #1337 from HakanSeven12/plot/b1-plot-settings-compat

fix(plot): write page setups in the file format's canonical form

src/app/automation.rs

@@ -294,7 +294,7 @@ impl OpenCADStudio {
         match req["op"].as_str().unwrap_or("") {
             "new" => {
                 let i = self.active_tab;
-                self.tabs[i].scene.clear();
+                self.tabs[i].scene.reset_to_new_drawing();
                 self.tabs[i].scene.material_base_dir = None;
                 self.tabs[i].current_path = None;
                 // The headless session starts on the welcome (Start) tab, which

src/app/document.rs

@@ -1,5 +1,4 @@
 use crate::command::CadCommand;
-use crate::io::linetypes;
 use crate::modules::draw::modify::block_edit::BlockEditSession;
 use crate::modules::draw::modify::refedit::RefEditSession;
 use crate::scene::pick::grip::GripEdit;
@@ -567,24 +566,7 @@ impl DocumentTab {
 
     pub(super) fn new_drawing(n: usize) -> Self {
         let mut scene = Scene::new();
-        linetypes::populate_document(&mut scene.document);
-        // Paper layouts start as A4 landscape.
-        for obj in scene.document.objects.values_mut() {
-            if let acadrust::objects::ObjectType::Layout(l) = obj {
-                if l.name != "Model" {
-                    l.min_limits = (0.0, 0.0);
-                    l.max_limits = (297.0, 210.0);
-                    l.min_extents = (0.0, 0.0, 0.0);
-                    l.max_extents = (297.0, 210.0, 0.0);
-                    l.paper_width = 297.0;
-                    l.paper_height = 210.0;
-                    l.plot_paper_units = 1;
-                    l.plot_scale_numerator = 1.0;
-                    l.plot_scale_denominator = 1.0;
-                    l.paper_size = "ISO_A4_(297.00_x_210.00_MM)".into();
-                }
-            }
-        }
+        scene.populate_new_drawing_defaults();
         Self {
             id: NEXT_DOCUMENT_TAB_ID.fetch_add(1, Ordering::Relaxed),
             scene,

src/app/update/mod.rs

@@ -1508,8 +1508,7 @@ impl OpenCADStudio {
             Message::ClearScene => {
                 let i = self.active_tab;
                 self.push_undo_snapshot(i, "CLEAR");
-                self.tabs[i].scene.clear();
-                crate::io::linetypes::populate_document(&mut self.tabs[i].scene.document);
+                self.tabs[i].scene.reset_to_new_drawing();
                 self.tabs[i].properties = PropertiesPanel::empty();
                 let doc_layers = self.tabs[i].scene.document.layers.clone();
                 let vp_info = self.tabs[i].scene.viewport_list();

src/app/update/viewport.rs

@@ -6033,24 +6033,7 @@ properties={:.1}ms picked={}",
                     if let acadrust::objects::ObjectType::Layout(l) = obj {
                         if l.name == new_name {
                             l.flags = layout_flags;
-                            l.min_limits = (0.0, 0.0);
-                            l.max_limits = (297.0, 210.0);
-                            l.min_extents = (0.0, 0.0, 0.0);
-                            l.max_extents = (297.0, 210.0, 0.0);
-                            l.paper_width = 297.0;
-                            l.paper_height = 210.0;
-                            l.plot_paper_units = 1;
-                            l.plot_scale_numerator = 1.0;
-                            l.plot_scale_denominator = 1.0;
-                            l.plot_scale_type = 16;
-                            l.plot_scale_factor = 1.0;
-                            l.plot_type = 5;
-                            l.plot_flags.use_standard_scale = true;
-                            l.plot_flags.print_lineweights = true;
-                            l.plot_flags.plot_plot_styles = !plot_style.is_empty();
-                            l.plot_flags.show_plot_styles = !plot_style.is_empty();
-                            l.plot_style_sheet = plot_style;
-                            l.paper_size = "ISO_A4_(297.00_x_210.00_MM)".into();
+                            crate::scene::apply_default_page_setup(l, &plot_style);
                             break;
                         }
                     }

src/scene/entity.rs

@@ -2709,4 +2709,25 @@ impl Scene {
         self.named_parameters = crate::scene::named_parameters::ParameterTable::new();
         self.bump_geometry();
     }
+
+    /// Reset to the drawing File → New produces. Every path that starts a
+    /// fresh drawing (the New tab, CLEAR, the automation `new` op) goes
+    /// through here so they all agree on what a blank drawing contains.
+    pub fn reset_to_new_drawing(&mut self) {
+        self.clear();
+        self.populate_new_drawing_defaults();
+    }
+
+    /// What a blank document gets on top of the codec's defaults: the
+    /// standard linetypes and a compatible page setup on every paper layout.
+    pub fn populate_new_drawing_defaults(&mut self) {
+        crate::io::linetypes::populate_document(&mut self.document);
+        for obj in self.document.objects.values_mut() {
+            if let acadrust::objects::ObjectType::Layout(l) = obj {
+                if l.name != "Model" {
+                    crate::scene::apply_default_page_setup(l, "");
+                }
+            }
+        }
+    }
 }

src/scene/mod.rs

@@ -33,6 +33,7 @@ pub(crate) mod centermark;
 pub(crate) mod dimension_assoc;
 pub(crate) mod dimension_assoc_chain;
 pub use dimension_assoc::{ReferenceStatus, ResolvedReference};
+pub use page_setup::{apply_default_page_setup, rotated_margins};
 mod dwg_native_constraints;
 mod entity;
 #[cfg(test)]
@@ -4378,13 +4379,8 @@ impl Scene {
             None
         })?;
         // `paper_limits()` already swaps the sheet for a 90°/270° rotation, so the
-        // margins must rotate to the same edges: a margin on a physical side moves
-        // to the displayed side that side rotates onto.
-        let (ml, mb, mr, mt) = match rot {
-            1 | 3 => (bottom, left, top, right),
-            2 => (right, top, left, bottom),
-            _ => (left, bottom, right, top),
-        };
+        // margins must rotate to the same edges.
+        let (ml, mb, mr, mt) = page_setup::rotated_margins((left, bottom, right, top), rot);
         // Plot margins are millimetres like the paper size; scale them into the
         // layout's paper-space units so the inset matches the (already scaled)
         // sheet rect. Without this an inch paper space insets an ~8-inch sheet
@@ -4970,6 +4966,78 @@ impl Scene {
         .then_some(owner)
     }
 
+    /// Millimetres in one unit of the paper side of this drawing's scale
+    /// family: 25.4 for an imperial drawing (whose `1/8" = 1'-0"` style scales
+    /// measure paper in inches), 1 for a metric one. Plot-scale factors built
+    /// from [`Scene::scale_list`] are expressed per this unit; page setups
+    /// store theirs per the layout's own paper unit, so the two are converted
+    /// through this value.
+    pub(crate) fn scale_family_unit_mm(&self) -> f64 {
+        if self.prefers_imperial_scales() == Some(true) {
+            25.4
+        } else {
+            1.0
+        }
+    }
+
+    /// The `paper : drawing` ratio behind a scale-list name, from the
+    /// drawing's own `Scale` object when it has one, otherwise from the
+    /// built-in family. A ratio keeps the plot scale readable in a page setup
+    /// (`1 : 250` rather than `0.004 : 1`).
+    pub(crate) fn scale_ratio(&self, name: &str) -> Option<(f64, f64)> {
+        use acadrust::objects::ObjectType;
+        let stored = self.document.objects.values().find_map(|o| match o {
+            ObjectType::Scale(s) if !s.is_temporary && s.name.eq_ignore_ascii_case(name) => {
+                Some((s.paper_units, s.drawing_units))
+            }
+            _ => None,
+        });
+        stored
+            .or_else(|| Self::parse_scale_name_ratio(name))
+            .filter(|(paper, drawing)| *paper > 0.0 && *drawing > 0.0)
+    }
+
+    /// The `paper : drawing` ratio spelled by a scale name: `1:250` gives
+    /// `(1, 250)`, an architectural `1/8" = 1'-0"` gives `(0.125, 12)` in
+    /// inches. Anything else is not a scale name.
+    pub(crate) fn parse_scale_name_ratio(name: &str) -> Option<(f64, f64)> {
+        if let Some((paper, drawing)) = name.split_once(':') {
+            let paper: f64 = paper.trim().parse().ok()?;
+            let drawing: f64 = drawing.trim().parse().ok()?;
+            return (paper > 0.0 && drawing > 0.0).then_some((paper, drawing));
+        }
+        let (paper, drawing) = name.split_once('=')?;
+        let paper = Self::parse_feet_inches(paper)?;
+        let drawing = Self::parse_feet_inches(drawing)?;
+        (paper > 0.0 && drawing > 0.0).then_some((paper, drawing))
+    }
+
+    /// Inches in a `F'-I"` / `I"` / `F'` length, where the inch part may be a
+    /// fraction (`3/32"`).
+    fn parse_feet_inches(text: &str) -> Option<f64> {
+        let text = text.trim();
+        let (feet, inches) = match text.split_once('\'') {
+            Some((feet, rest)) => (
+                feet.trim().parse::<f64>().ok()?,
+                rest.trim_start_matches('-').trim(),
+            ),
+            None => (0.0, text),
+        };
+        let inches = inches.trim_end_matches('"').trim();
+        let inches = if inches.is_empty() {
+            0.0
+        } else if let Some((num, den)) = inches.split_once('/') {
+            let den: f64 = den.trim().parse().ok()?;
+            if den <= 0.0 {
+                return None;
+            }
+            num.trim().parse::<f64>().ok()? / den
+        } else {
+            inches.parse::<f64>().ok()?
+        };
+        Some(feet * 12.0 + inches)
+    }
+
     /// Handle of the real (non-temporary) `Scale` object with this display name.
     /// Scales are matched by their `name` field, not the dictionary key — some
     /// files key the entries by an internal identifier (`*A1`, `A0`, …) that

src/scene/page_setup.rs

@@ -5,9 +5,60 @@
 //! dictionary + objects consistent so the result round-trips through DWG/DXF.
 
 use super::Scene;
-use acadrust::objects::{Dictionary, ObjectType, PlotSettings};
+use acadrust::objects::{Dictionary, Layout, ObjectType, PlotSettings};
 use acadrust::Handle;
 
+/// Give a freshly created paper layout the page setup a new drawing starts
+/// with — ISO A4 landscape on no plotter, plotted 1:1 as a layout — stored the
+/// way the file format expects it: the portrait medium under its canonical
+/// name with the orientation in the rotation code. `plot_style` names the
+/// plot style table to attach, or is empty.
+pub fn apply_default_page_setup(layout: &mut Layout, plot_style: &str) {
+    use acadrust::objects::{PlotPaperUnits, PlotRotation, PlotType, ScaledType};
+    let a4 = crate::io::paper_catalog::default_paper();
+    let (paper_width, paper_height) = a4.portrait_mm();
+    layout.min_limits = (0.0, 0.0);
+    layout.max_limits = (paper_height, paper_width);
+    layout.min_extents = (0.0, 0.0, 0.0);
+    layout.max_extents = (paper_height, paper_width, 0.0);
+    layout.paper_width = paper_width;
+    layout.paper_height = paper_height;
+    layout.plot_rotation = PlotRotation::Degrees90.to_code();
+    layout.plot_paper_units = PlotPaperUnits::Millimeters.to_code();
+    layout.plot_type = PlotType::Layout.to_code();
+    layout.plot_scale_type = ScaledType::OneToOne.to_code();
+    layout.plot_scale_numerator = 1.0;
+    layout.plot_scale_denominator = 1.0;
+    layout.plot_scale_factor = 1.0;
+    layout.plot_flags.use_standard_scale = true;
+    layout.plot_flags.print_lineweights = true;
+    layout.plot_flags.draw_viewports_first = true;
+    layout.plot_flags.plot_plot_styles = !plot_style.is_empty();
+    layout.plot_flags.show_plot_styles = !plot_style.is_empty();
+    layout.plot_style_sheet = plot_style.to_string();
+    layout.paper_size = a4.canonical.to_string();
+    layout.plot_printer_name = crate::io::plot_device::PlotDevice::None.canonical_name();
+}
+
+/// The unprintable margins of a sheet as they appear on the rotated layout,
+/// `(left, bottom, right, top)`. Stored margins belong to the medium's own
+/// edges; a plot rotated by a quarter turn (`rotation` is the file's 0–3
+/// code) shows the medium turned on the layout, so each margin moves to the
+/// edge its side lands on — verified against limits written by the
+/// commercial application: at 90° the medium's top margin is the layout's
+/// left one and its left margin the layout's bottom one.
+pub fn rotated_margins(
+    (left, bottom, right, top): (f64, f64, f64, f64),
+    rotation: i16,
+) -> (f64, f64, f64, f64) {
+    match rotation {
+        1 => (top, left, bottom, right),
+        2 => (right, top, left, bottom),
+        3 => (bottom, right, top, left),
+        _ => (left, bottom, right, top),
+    }
+}
+
 impl Scene {
     /// Handle of the `ACAD_PLOTSETTINGS` dictionary, located robustly.
     ///

tests/fixtures/plot/README.md

@@ -0,0 +1,29 @@
+Page-setup fixtures saved by a commercial CAD application (2016 release, DXF
+AC1027 and the matching DWG). Provided by Panos for the plotting parity track;
+the drawing holds one 10 m line (`$INSUNITS` = 6, metres) and three paper
+layouts, each with a viewport of that line and its dimension:
+
+| Layout | Device | Media (`4`) | `44`×`45` | `73` | `72` | `142`/`143` | `147` | `75` |
+|---|---|---|---|---|---|---|---|---|
+| `A4 1-100` | `DWG To PDF.pc3` | `ISO_A4_(297.00_x_210.00_MM)` | 297 × 210 | 0 | mm | 1 / 1 | 25.4 | 16 |
+| `A3 - plotter` | system printer `HPB602DE (HP OfficeJet Pro 7740 series)` | `A3` | 297.01 × 419.99 | 1 | mm | 1 / 1 | 25.4 | 16 |
+| `ARCH D - PLOTTER` | the application's second PDF plotter configuration (`… PDF (High Quality Print).pc3`) | `ARCH_D_(36.00_x_24.00_Inches)` | 914.4 × 609.6 | 0 | in | 1 / 25.4 | 0.03937 | 16 |
+
+What the file establishes (see `src/app/update/file.rs`, `plot_settings_from_dialog`):
+
+- A landscape sheet is written either as the driver's own landscape medium
+  with rotation 0 (the PDF driver lists both orientations) or as a portrait
+  medium with rotation 90 (system printers) — rotation is relative to the
+  medium's orientation, and the medium's exact driver dimensions are kept.
+- Margins (`40`–`43`, mm) belong to the medium's own edges: the PDF driver's
+  A4 has 5.79375 left/right and 17.79375 bottom/top. Layout limits (`10`/`20`)
+  put the sheet at minus the *displayed* margins: at rotation 90 the medium's
+  top margin (20.02) becomes the layout's left one, its left margin (5.00) the
+  layout's bottom one.
+- Plot flags `70` = 672 on every layout: draw viewports first, print
+  lineweights, plot with plot styles — the "use standard scale" bit stays clear
+  even with a standard code in `75`; the model tab (fit to paper) sets it.
+- `147` is `142/143` × 25.4 on millimetre page setups and `142/143` itself on
+  inch ones.
+- An inch page setup over a millimetre paper space stores "1:1" as
+  `1 in = 25.4 units` (`75` = 16 kept).