Merge pull request #1134 from pick2510/fix/3d-in-scaled-groups

crates/render/src/lib.rs

@@ -843,6 +843,15 @@ impl Renderer {
         if depth > 0 && view.determinant().abs() > 1e-12 && view.is_finite() { (view, view.inverse() * m) } else { (m, Affine::IDENTITY) }
     }
 
+    /// Shape-space units per point: a group's child coordinates can scale a shape's box (a legacy
+    /// 1360-unit child space makes one unit hundreds of EMUs), but 3-D sizes kept in points
+    /// (contour width, extrusion depth, bevel) stay points, as PowerPoint draws them. 1 outside a
+    /// group.
+    fn per_point(&self, m: Affine, depth: usize) -> f64 {
+        let k = scale_of(self.line_space(m, depth).1);
+        if k.is_finite() && k > 1e-12 { 1.0 / k } else { 1.0 }
+    }
+
     /// The size and transform a shape's text is set in: inside a group whose child coordinates
     /// scale the shape, the shape's size in slide points and `m` with that scale taken out, so
     /// insets and font sizes stay in points; otherwise `w`, `h` and `m` themselves.
@@ -1049,6 +1058,17 @@ impl Renderer {
             ctx.push_layer(None, None, None, None, None);
             let _ = r;
         }
+        // Shape-space units per point for the 3-D sizes, measured without the camera's turn (which
+        // `shape_at` puts in `m`): its foreshortening is not a child-coordinate scale.
+        let pt = {
+            let turn = effects
+                .as_ref()
+                .and_then(|e| e.raw3d.as_deref())
+                .and_then(camera::from_raw)
+                .and_then(|c| camera::affine(&c, w, h))
+                .filter(|t| t.determinant().abs() > 1e-9);
+            self.per_point(turn.map_or(m, |t| m * t.inverse()), depth)
+        };
         // A 3-D extrusion under a turned camera: the sides, swept behind the face.
         if let Some(raw) = effects.as_ref().and_then(|e| e.raw3d.as_deref())
             && let Some(ex) = extrude::from_raw(raw)
@@ -1062,7 +1082,8 @@ impl Renderer {
             };
             let pre = m * turn.inverse();
             let lit = light::Lighting::from_raw(raw);
-            extrude::draw(ctx, &outline, w, h, &cam, ex.depth, pre, turn, extrude::side_color(rctx, &ex, face), &lit);
+            let d = ex.depth * pt;
+            extrude::draw(ctx, &outline, w, h, &cam, d, pre, turn, extrude::side_color(rctx, &ex, face), &lit);
         }
         // A 3-D contour: a band around the outline, behind the face (and in front of any sides).
         if let Some(raw) = effects.as_ref().and_then(|e| e.raw3d.as_deref())
@@ -1073,7 +1094,7 @@ impl Renderer {
                 _ => None,
             };
             let col = c.color.as_ref().map(|k| rctx.color(k, face)).or(face).unwrap_or(Rgba::rgb(0xff, 0xff, 0xff));
-            extrude::draw_contour(ctx, &outline, m, c.width, col, &light::Lighting::from_raw(raw));
+            extrude::draw_contour(ctx, &outline, m, c.width * pt, col, &light::Lighting::from_raw(raw));
         }
         // Fill.
         match &s.kind {
@@ -1168,6 +1189,7 @@ impl Renderer {
         };
         // A 3-D bevel: the face and a band inside the outline lit as surfaces.
         if let Some(bv) = effects.as_ref().and_then(|e| e.raw3d.as_deref()).and_then(bevel::from_raw) {
+            let bv = bevel::Bevel { w: bv.w * pt, h: bv.h * pt, ..bv };
             let solid = match &fill {
                 Some(Fill::Solid { color: c }) => Some(rctx.color(c, fill_ph)),
                 _ => None,

crates/render/src/tests.rs

@@ -2281,6 +2281,81 @@ fn extrusions_show_their_sides_under_a_turned_camera() {
     assert_eq!(ink(&flat, 0, 960), 0);
 }
 
+#[test]
+fn group_child_scale_does_not_scale_3d_depth_contours_or_bevels() {
+    // A legacy group child space (here 100 points per unit) scales the shapes' boxes, but
+    // extrusion depths, contour widths and bevels are points: a 1 pt contour on a small extruded
+    // cube in such a group was drawn hundreds of points wide, a band across the whole slide.
+    let mut deck = extruded_deck();
+    let bevelled = Shape {
+        id: ShapeId(704),
+        xfrm: Some(Xfrm::new(40.0, 340.0, 170.0, 130.0)),
+        geom: Geom::preset("rect"),
+        style: Some(ShapeStyle::accent(deckcraft_color::SchemeSlot::Accent1)),
+        effects: Some(deckcraft_model::Effects {
+            raw3d: Some(r#"<a:scene3d><a:camera prst="orthographicFront"/><a:lightRig rig="threePt" dir="t"/></a:scene3d><a:sp3d><a:bevelT w="254000" h="254000"/></a:sp3d>"#.into()),
+            ..Default::default()
+        }),
+        ..Default::default()
+    };
+    std::sync::Arc::make_mut(&mut deck.slides[0]).shapes.push(bevelled);
+    let shapes = deck.slides[0].shapes.clone();
+    let grouped = |k: f64| {
+        let children = shapes
+            .iter()
+            .map(|s| {
+                let x = s.xfrm.unwrap_or_default();
+                Shape { xfrm: Some(Xfrm::new(x.x / k, x.y / k, x.w / k, x.h / k)), ..s.clone() }
+            })
+            .collect();
+        let group = Shape {
+            id: ShapeId(10),
+            xfrm: Some(Xfrm::new(0.0, 0.0, 960.0, 540.0)),
+            kind: ShapeKind::Group { children, child: Xfrm::new(0.0, 0.0, 960.0 / k, 540.0 / k) },
+            ..Default::default()
+        };
+        render_slide(&deck_with(vec![group]), 0, &RenderOpts { scale: 1.0, ..Default::default() })
+    };
+    let reference = grouped(1.0);
+    let ink = |img: &Image| img.pixels.as_chunks::<4>().0.iter().filter(|p| **p != [255, 255, 255, 255]).count();
+    let drawn = ink(&reference);
+    assert!(drawn > 20_000, "the reference draws the shapes: {drawn}");
+    let scaled = grouped(100.0);
+    let (n, d) = (ink(&scaled), differing(&reference, &scaled));
+    assert!(n.abs_diff(drawn) * 20 < drawn, "{n} inked pixels against {drawn}");
+    assert!(d * 20 < drawn, "{d} differing values against {drawn} inked pixels");
+}
+
+#[test]
+fn a_turned_camera_in_a_one_to_one_group_draws_its_3d_sizes_as_outside_one() {
+    // The camera's turn is part of the shape's transform; its foreshortening is not a group scale,
+    // so a 1:1 group must not change extrusion depths, contours or bevels under a turned camera.
+    let mut deck = extruded_deck();
+    let bevelled = Shape {
+        id: ShapeId(705),
+        xfrm: Some(Xfrm::new(40.0, 340.0, 170.0, 130.0)),
+        geom: Geom::preset("rect"),
+        style: Some(ShapeStyle::accent(deckcraft_color::SchemeSlot::Accent1)),
+        effects: Some(deckcraft_model::Effects {
+            raw3d: Some(r#"<a:scene3d><a:camera prst="isometricOffAxis1Right"/><a:lightRig rig="threePt" dir="t"/></a:scene3d><a:sp3d extrusionH="254000" contourW="38100"><a:bevelT w="254000" h="254000"/></a:sp3d>"#.into()),
+            ..Default::default()
+        }),
+        ..Default::default()
+    };
+    std::sync::Arc::make_mut(&mut deck.slides[0]).shapes.push(bevelled);
+    let opts = RenderOpts { scale: 1.0, ..Default::default() };
+    let alone = render_slide(&deck, 0, &opts);
+    let group = Shape {
+        id: ShapeId(10),
+        xfrm: Some(Xfrm::new(0.0, 0.0, 960.0, 540.0)),
+        kind: ShapeKind::Group { children: deck.slides[0].shapes.clone(), child: Xfrm::new(0.0, 0.0, 960.0, 540.0) },
+        ..Default::default()
+    };
+    let grouped = render_slide(&deck_with(vec![group]), 0, &opts);
+    let d = differing(&alone, &grouped);
+    assert!(d < 200, "{d} values differ between the shapes alone and in a 1:1 group");
+}
+
 #[test]
 fn table_rows_below_the_slide_are_not_laid_out_and_the_slide_looks_the_same() {
     // A fuzzed deck's 200 x 200 table of long text took 70 s to draw, most of it off the slide.