Canvas: a trackpad swipe turns the page

A sideways flick changes slides when the slide fits the window, and any
flick does so during the show. One gesture turns one page. A zoomed slide
still pans. Pinch-zoom is unchanged.

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/gaps.md

@@ -1,6 +1,6 @@
 # Where DeckCraft falls short of PowerPoint
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-13 · **Change:** minor (3-D bevel, camera and face lighting rendered; previous: minor, IME composition and CJK interface text landed, #101; previous: minor, core-workflow alpha gate added; stage stays alpha; before that: major, first itemized gap list; full re-measure against PowerPoint for Mac 16.113.4 and the open GitHub issues) · **Target:** Microsoft PowerPoint for Mac 16.113 (Microsoft 365)
+> **Last reviewed:** 2026-10-14 · **Last updated:** 2026-10-14 · **Change:** minor (a trackpad swipe turns the page in the editor and the show; pinch-zoom remains; previous: minor, 3-D bevel, camera and face lighting rendered) · **Target:** Microsoft PowerPoint for Mac 16.113 (Microsoft 365)
 
 Every known shortfall, one entry each, ranked by how much it stops someone who presents with
 PowerPoint from switching. This is the work list: pick from the top. Numbers are summarized in
@@ -217,7 +217,8 @@ Detail in [hardware-parity.md](hardware-parity.md).
   or wgpu path).
 - **Software-only video decode**; PowerPoint uses VideoToolbox/Media Foundation. 8–14 h (copy
   FilmCraft's hardware decode).
-- **No pen pressure or tilt for ink**; no pinch-zoom or trackpad gestures. 3–6 h.
+- **No pen pressure or tilt for ink**; no pinch-zoom. A trackpad swipe turns the page when the
+  slide fits the window, and during the show. 2–4 h for pinch-zoom.
 
 ## Localization
 
@@ -256,6 +257,7 @@ Detail in [localization-parity.md](localization-parity.md).
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-14 | minor | A trackpad swipe (and the mouse wheel, in the show) turns the page. Pinch-zoom remains |
 | 2026-10-13 | minor | Shape, picture and table rendering checked against PowerPoint on ~150 synthetic edge-case slides; 3-D bevels, cameras and face lighting now render approximately (gap narrowed to extrusion, rigs and the 3-D pane) |
 | 2026-10-12 | minor | IME composition in slide text and notes, and CJK interface text with real glyphs (#101): the IME gap is now Korean on the web and table-cell underlines |
 | 2026-10-12 | minor | EMF/WMF text, pattern and hatch brushes drawn; legacy OLE and ActiveX previews shown; the SVG gap keeps only EMF clip regions |

docs/hardware-parity.md

@@ -1,6 +1,6 @@
 # Hardware parity with PowerPoint
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-12 · **Change:** minor (IME input, #101; previous: major, created from the renderer, media and windowing code) · **Target:** Microsoft PowerPoint for Mac 16.113 (Microsoft 365); PowerPoint for Windows where noted
+> **Last reviewed:** 2026-10-14 · **Last updated:** 2026-10-14 · **Change:** minor (a trackpad swipe turns the page; pinch-zoom remains; previous: minor, IME input, #101) · **Target:** Microsoft PowerPoint for Mac 16.113 (Microsoft 365); PowerPoint for Windows where noted
 
 What hardware PowerPoint uses and what DeckCraft uses, per platform. Dimension score: **~40%
 ready** (estimated), **25–45 h** to parity. Performance (unmeasured, ~55%) is tracked here too
@@ -43,7 +43,8 @@ because it mostly follows from hardware use.
 |---|---|---|
 | Keyboard and presentation clickers (Page Up/Down, B, Esc) | yes | yes |
 | Mouse and trackpad scroll | yes | yes |
-| Pinch to zoom, two-finger gestures | yes | no |
+| Pinch to zoom | yes | no |
+| Two-finger swipe between slides | yes | yes: when the slide fits the window, and during the show. A zoomed slide still pans |
 | Pen pressure and tilt for ink (Apple Pencil via Sidecar, Windows Ink) | yes | no: ink strokes have constant width |
 | Touch screens (Windows) | yes | basic pointer only |
 | IME input methods for CJK text | yes | yes: composed in place, underlined, candidate window at the caret (#101) |
@@ -71,5 +72,6 @@ outlines every frame (#67, fix open), and the decoders run in software.
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-14 | minor | A sideways trackpad swipe turns the page in Normal view (when the slide fits) and in the show. Pinch-zoom is unchanged |
 | 2026-10-12 | minor | IME input methods (#101) |
 | 2026-10-10 | major | Created: rendering, media, displays, input and performance against PowerPoint 16.113 |

docs/slideshow-parity.md

@@ -1,6 +1,6 @@
 # Slide show and presenter view: parity with PowerPoint
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-10 · **Change:** major (created; measured from `crates/ui-egui/src/show.rs` and `crates/anim/src/show.rs` against PowerPoint 16.113's Slide Show tab and menu) · **Target:** Microsoft PowerPoint for Mac 16.113 (Microsoft 365)
+> **Last reviewed:** 2026-10-14 · **Last updated:** 2026-10-14 · **Change:** minor (a trackpad swipe or mouse wheel turns the page during the show; previous: major, created) · **Target:** Microsoft PowerPoint for Mac 16.113 (Microsoft 365)
 
 Presenting is the job PowerPoint is hired for. This doc covers the show window, presenter view,
 rehearsal and recording. Transition and animation playback are in
@@ -14,6 +14,7 @@ ready** (estimated), **10–16 h** to parity.
 |---|---|---|---|
 | Play from Start / from Current Slide (F5, Shift+F5, Cmd+Enter) | yes | yes | |
 | Next/previous by click, arrows, Space, Page Up/Down, Enter, Backspace | yes | yes | #17 reported arrows not working in v0.3.0 AppImage; recheck |
+| Next/previous by trackpad swipe or mouse wheel | yes | yes | One flick turns one page. The pen ignores the flick |
 | Go to slide (number + Enter), first/last | yes | yes | |
 | Black / white screen (B / W) | yes | yes | |
 | End screen, Esc to leave | yes | yes | |