fix(render): size the tile of a picture's shadow and reflection in points too

Review of #1693 found that cast_effects built the picture content that a shadow,
a glow and a reflection are drawn from without converting a tiled fill to
points, so inside a scaled group the reflection of a tiled picture showed
child-space tiles while its face showed the right ones.

The content now goes through paint::tiled_picture_per_point with per_point_xy,
as the face does.

Test: a tiled picture's reflection in groups scaled 0.25, 1600 and 2x0.5 shows
the same colours as in an unscaled group; it fails without the change.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

ROADMAP.md

@@ -148,7 +148,7 @@ app's JSON control channel (`deckcraft --control PORT`).
 
 | Date | What landed |
 |---|---|
-| 2026-11-02 | Tiled picture fills in groups: a tile (`a:blipFill` with `a:tile`) keeps its size, offset and anchor in slide points whatever the group's child-coordinate scale, uniform or stretched unevenly, nested or flipped (also a group's own tile fill passed to its members, and a picture shape's own tile), and tiles with `rotWithShape="0"` keep their size in points at any zoom, as PowerPoint draws them (measured on its own PNG export of a synthetic probe deck: every grouped case within ~3/255 of the ungrouped control's own difference from PowerPoint, which is ~13/255 from resampling). Before, a group whose child space was ~1800 times smaller than its box showed one flat texel of the texture (a Venn diagram with paper-textured circles and a hatched intersection) |
+| 2026-11-02 | Tiled picture fills in groups: a tile (`a:blipFill` with `a:tile`) keeps its size, offset and anchor in slide points whatever the group's child-coordinate scale, uniform or stretched unevenly, nested or flipped (also a group's own tile fill passed to its members, and a picture shape's own tile, with its shadow and reflection), and tiles with `rotWithShape="0"` keep their size in points at any zoom, as PowerPoint draws them (measured on its own PNG export of a synthetic probe deck: every grouped case within ~3/255 of the ungrouped control's own difference from PowerPoint, which is ~13/255 from resampling). Before, a group whose child space was ~1800 times smaller than its box showed one flat texel of the texture (a Venn diagram with paper-textured circles and a hatched intersection) |
 | 2026-10-31 | No Fill shape interiors allow selection and editing of underlying objects, even when a quick style remains; hit-testing uses the renderer’s fill resolution. Outlines, rotation, text targets and actual fills keep their hit behaviour (#1621) |
 | 2026-10-30 | Print-preview tests use the URL emitted by egui and its exact file path; previews are explicitly removed before the macOS process exits |
 | 2026-10-30 | `slide.actions` lists shape click and hover actions and text-run hyperlinks (including table cells and grouped shapes) for audit; listing never runs an action. The UI pane is a follow-up |

crates/render/src/renderer.rs

@@ -668,9 +668,13 @@ impl Renderer {
         let line = &d.line;
         // Effects below the shape.
         if let Some(e) = &effects {
-            // A picture (or picture fill) casts its shadow from its pixels, not its frame.
+            // A picture (or picture fill) casts its shadow from its pixels, not its frame. A tile
+            // is sized in points on the slide, as the face's is, and so is its shadow and reflection.
             let content = match (&s.kind, &fill) {
-                (ShapeKind::Picture { fill: pf }, _) | (_, Some(Fill::Picture(pf))) => Some(paint::resolved(rctx, pf, None).into_owned()),
+                (ShapeKind::Picture { fill: pf }, _) | (_, Some(Fill::Picture(pf))) => {
+                    let pf = paint::tiled_picture_per_point(pf, self.per_point_xy(m, depth));
+                    Some(paint::resolved(rctx, &pf, None).into_owned())
+                }
                 _ => None,
             };
             // What casts the shadow: the fill as see-through as it is, and the outline.

crates/render/src/tests_wild.rs

@@ -568,6 +568,36 @@ fn a_picture_shapes_own_tile_keeps_its_size_inside_a_scaled_group() {
     }
 }
 
+#[test]
+fn a_tiled_pictures_reflection_keeps_the_tile_size_inside_a_scaled_group() {
+    use deckcraft_model::style::{PictureFill, PictureMode, Reflection};
+    // The reflection mirrors the picture's pixels, so its tiles must be the face's, 60 x 30 pt,
+    // whatever the group's child scale: just below the box it shows the same colours.
+    let reflected = |kx: f64, ky: f64| {
+        let mut p = Presentation::default();
+        let media = p.add_media("t.png", "image/png", half_red_half_blue()).expect("media");
+        let mode = PictureMode::Tile { tx: 0.0, ty: 0.0, sx: 10.0, sy: 10.0, flip: "none".into(), align: "tl".into() };
+        let rf = Reflection { blur: 0.0, start_alpha: 1.0, end_alpha: 0.0, end_pos: 0.5, dist: 0.0 };
+        let img = in_a_scaled_group(kx, ky, p, |w, h| Shape {
+            id: ShapeId(22),
+            xfrm: Some(Xfrm::new(0.0, 0.0, w, h)),
+            kind: ShapeKind::Picture { fill: PictureFill { media, mode, ..Default::default() } },
+            line: no_line(),
+            effects: Some(deckcraft_model::Effects { reflection: Some(rf), ..Default::default() }),
+            ..Default::default()
+        });
+        [img.pixel(115, 163), img.pixel(145, 163), img.pixel(175, 163)]
+    };
+    let plain = reflected(1.0, 1.0);
+    assert!(plain[0][0] > plain[0][2] && plain[1][2] > plain[1][0] && plain[2][0] > plain[2][2], "red, blue, red in the reflection: {plain:?}");
+    for (kx, ky) in [(0.25, 0.25), (1600.0, 1600.0), (2.0, 0.5)] {
+        let got = reflected(kx, ky);
+        for (g, e) in got.iter().zip(&plain) {
+            assert!(close(*g, Rgba::rgb(e[0], e[1], e[2]), 40), "child scale {kx} x {ky}: {got:?} against {plain:?}");
+        }
+    }
+}
+
 #[test]
 fn an_upright_tile_in_a_turned_shape_keeps_its_size_in_points_at_any_zoom() {
     use deckcraft_model::style::{PictureFill, PictureMode};