refactor(hevc): split prediction_unit into merge, AMVP and store helpers (S3776)

* fix(windows): keep the shortcut icon after an update (#1114)

The MSI's Start menu shortcut took its icon from the WiX <Icon>, which Windows
Installer caches under %APPDATA%\Microsoft\Installer\{ProductCode}\. Every
update is a major upgrade with a new ProductCode, so the old folder is deleted.
A taskbar pin is a copy of the shortcut that the update never touches, so it
kept pointing at the deleted file and lost its icon.

Drop the Icon from the shortcut so it shows the icon embedded in deckcraft.exe,
whose path survives updates. The <Icon> stays for ARPPRODUCTICON. A test keeps
shortcuts from naming an MSI icon again.

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

* contributors: credit Sofia Alves Figueredo by real name

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

* fix(windows): make the Start menu shortcut non-advertised (#1114)

Addresses the review comment: without an MSI Icon, a non-advertised shortcut
targets the installed exe directly and takes its embedded icon.

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

* fix(windows): package.ps1 rejects a deckcraft.exe with no embedded icon (#1114)

The shortcuts now take the exe's own icon, and -SkipBuild packages an existing
exe that may come from a build without DECKCRAFT_REQUIRE_WINRES=1. Count its
icons with ExtractIconEx and stop before WiX when there are none.

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

---------

Co-authored-by: Claude Sonnet 5.5 <noreply@anthropic.com>

ROADMAP.md

@@ -137,6 +137,7 @@ app's JSON control channel (`deckcraft --control PORT`).
 
 | Date | What landed |
 |---|---|
+| 2026-10-25 | Windows installer: the Start menu shortcut takes the icon embedded in `deckcraft.exe` instead of an MSI `<Icon>`, so a taskbar pin keeps its icon after an update (#1114); a pin that already lost it has to be unpinned and pinned again once |
 | 2026-10-24 | AutoFormat as you type: a paragraph that starts with `*`, `-`, `--`, `>`, `<>`, `1.`, `1)`, `I.`, `i.`, `A.`, `a.` or `a)` and a space or tab becomes a bulleted or numbered list in that style; Backspace right after puts the typed text back, and Tools ▸ AutoCorrect and `text.autocorrect {lists}` turn it off |
 | 2026-10-24 | Tables: while the caret is in a cell, dragging into another cell selects that range of cells (shaded, merged cells taken in whole), and Shift+arrow grows or shrinks it; formatting applies to the selected cells only, and Delete clears their text and keeps the table |
 | 2026-10-24 | Preferences ▸ Measurement units: inches or centimetres. The Format pane's Size and Position fields, Shape Format ▸ Size on the ribbon, the Slide Size dialog and the ruler show and take the chosen unit; the deck still stores points (#1326) |
@@ -293,6 +294,7 @@ app's JSON control channel (`deckcraft --control PORT`).
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-25 | trivial | Progress log: Windows shortcut icon survives updates (#1114). Scores and milestone names unchanged |
 | 2026-10-24 | trivial | Progress log: selecting a range of table cells by dragging. Scores and milestone names unchanged |
 | 2026-10-24 | trivial | Progress log: measurement units in centimetres (#1326). Scores unchanged |
 | 2026-10-22 | trivial | Progress log: Animation Pane ▸ Play From. Scores unchanged |

apps/deckcraft/src/main.rs

@@ -430,4 +430,27 @@ mod tests {
         assert_eq!(mac, win, "macOS and Windows offer different file types");
         assert_eq!(mac, linux, "macOS and Linux offer different file types");
     }
+
+    /// #1114: a shortcut that names an MSI `<Icon>` shows a blank icon once an update deletes the
+    /// cached copy of it, and a taskbar pin (a copy of the shortcut) is never repaired. Shortcuts
+    /// take the icon embedded in `deckcraft.exe`; only `ARPPRODUCTICON` uses the MSI `<Icon>`.
+    #[test]
+    fn windows_shortcuts_use_the_icon_embedded_in_the_exe() {
+        let wxs = include_str!("../../../packaging/windows/deckcraft.wxs");
+        let shortcuts: Vec<&str> = wxs.split("<Shortcut").skip(1).filter_map(|s| s.split("/>").next()).collect();
+        assert!(!shortcuts.is_empty(), "deckcraft.wxs has no shortcut");
+        for shortcut in shortcuts {
+            assert!(!shortcut.contains("Icon="), "a shortcut names an MSI <Icon>:{shortcut}");
+        }
+        assert!(wxs.contains("<Property Id=\"ARPPRODUCTICON\""), "Apps and features keeps its icon");
+    }
+
+    /// The shortcuts take the exe's own icon, and `package.ps1 -SkipBuild` packages an existing
+    /// exe without `DECKCRAFT_REQUIRE_WINRES`, so the script has to refuse one with no icon.
+    #[test]
+    fn the_windows_package_script_rejects_an_exe_without_an_icon() {
+        let script = include_str!("../../../packaging/windows/package.ps1");
+        assert!(script.contains("ExtractIconEx"), "package.ps1 does not count the exe's icons");
+        assert!(script.contains("has no embedded icon"), "package.ps1 does not reject an iconless exe");
+    }
 }

contributors/people.toml

@@ -65,3 +65,6 @@ sync_github_name = true
 
 [people.Katacc]
 sync_github_name = true
+
+[people.SofiaAFigueredo]
+real_name = "Sofia Alves Figueredo"

crates/hevc/src/slicedec.rs

@@ -1366,84 +1366,106 @@ impl<'a> SliceDecoder<'a> {
 
     /// prediction_unit(): parse, derive motion, store it and predict. Returns merge_flag.
     fn prediction_unit(&mut self, g: PbGeom, part: PartMode, skip: bool) -> Result<bool> {
-        let PbGeom { xc, yc, ncb, xp, yp, w, h, part_idx } = g;
         let merge = if skip { true } else { self.dd(MERGE_FLAG) == 1 };
         let mvf = if merge {
-            let idx = if self.sh.max_num_merge_cand > 1 {
-                let mut i = 0;
-                if self.dd(MERGE_IDX) == 1 {
-                    i = 1;
-                    while i < self.sh.max_num_merge_cand - 1 && self.bypass() == 1 {
-                        i += 1;
-                    }
-                }
-                i
-            } else {
-                0
-            };
-            self.derive_merge(PbGeom { xc, yc, ncb, xp, yp, w, h, part_idx }, part, idx as usize)
+            let idx = self.merge_idx();
+            self.derive_merge(g, part, idx as usize)
         } else {
-            let pred_idc = if self.sh.is_b() {
-                if w + h != 12 {
-                    let depth = self.pic.blk_at(xc, yc).depth as usize;
-                    if self.dd(INTER_PRED_IDC + depth) == 1 { 2 } else { self.dd(INTER_PRED_IDC + 4) }
-                } else {
-                    self.dd(INTER_PRED_IDC + 4)
-                }
-            } else {
-                0
-            };
-            let mut ref_idx = [-1i8; 2];
-            let mut mvd = [[0i32; 2]; 2];
-            let mut mvp_flag = [0u32; 2];
-            for l in 0..2 {
-                let used = if l == 0 { pred_idc != 1 } else { pred_idc != 0 };
-                if !used {
-                    continue;
-                }
-                let nref = self.sh.num_ref_idx[l];
-                let mut ri = 0;
-                if nref > 1 {
-                    while ri < nref - 1 {
-                        let bin = if ri < 2 { self.dd(REF_IDX + ri as usize) } else { self.bypass() };
-                        if bin == 0 {
-                            break;
-                        }
-                        ri += 1;
-                    }
-                }
-                ref_idx[l] = ri as i8;
-                if l == 1 && self.sh.mvd_l1_zero && pred_idc == 2 {
-                    mvd[1] = [0, 0];
-                } else {
-                    mvd[l] = self.mvd_coding()?;
-                }
-                mvp_flag[l] = self.dd(MVP_FLAG);
-            }
-            let mut f = MvField { mv: [[0; 2]; 2], ref_idx };
-            for l in 0..2 {
-                if ref_idx[l] < 0 {
-                    continue;
-                }
-                let mvp = self.derive_amvp(PbGeom { xc, yc, ncb, xp, yp, w, h, part_idx }, l, ref_idx[l] as usize, mvp_flag[l] as usize);
-                // mvLX = (mvp + mvd) wrapped to 16 bits (8-94)
-                f.mv[l] = [(mvp[0] as i32 + mvd[l][0]) as i16, (mvp[1] as i32 + mvd[l][1]) as i16];
-            }
-            f
+            self.amvp_motion(g)?
         };
         for l in 0..2 {
             if mvf.ref_idx[l] >= 0 {
                 ensure!((mvf.ref_idx[l] as usize) < self.refs[l].len(), "reference index out of range");
             }
         }
-        // store motion
+        self.store_motion(g.xp, g.yp, g.w, g.h, mvf);
+        self.motion_compensate(g.xp, g.yp, g.w as usize, g.h as usize, &mvf);
+        Ok(merge)
+    }
+
+    /// merge_idx(): the merge candidate index, truncated unary (0 when there is one candidate).
+    fn merge_idx(&mut self) -> u32 {
+        if self.sh.max_num_merge_cand <= 1 {
+            return 0;
+        }
+        let mut i = 0;
+        if self.dd(MERGE_IDX) == 1 {
+            i = 1;
+            while i < self.sh.max_num_merge_cand - 1 && self.bypass() == 1 {
+                i += 1;
+            }
+        }
+        i
+    }
+
+    /// inter_pred_idc: 0 = list 0, 1 = list 1, 2 = both.
+    fn inter_pred_idc(&mut self, xc: i32, yc: i32, w: i32, h: i32) -> u32 {
+        if !self.sh.is_b() {
+            return 0;
+        }
+        if w + h != 12 {
+            let depth = self.pic.blk_at(xc, yc).depth as usize;
+            if self.dd(INTER_PRED_IDC + depth) == 1 { 2 } else { self.dd(INTER_PRED_IDC + 4) }
+        } else {
+            self.dd(INTER_PRED_IDC + 4)
+        }
+    }
+
+    /// ref_idx_lX: truncated unary, the first two bins context-coded.
+    fn ref_idx(&mut self, l: usize) -> u32 {
+        let nref = self.sh.num_ref_idx[l];
+        let mut ri = 0;
+        if nref > 1 {
+            while ri < nref - 1 {
+                let bin = if ri < 2 { self.dd(REF_IDX + ri as usize) } else { self.bypass() };
+                if bin == 0 {
+                    break;
+                }
+                ri += 1;
+            }
+        }
+        ri
+    }
+
+    /// The AMVP branch: parse each used list's reference index, mvd and predictor flag, then add
+    /// every mvd to its predictor.
+    fn amvp_motion(&mut self, g: PbGeom) -> Result<MvField> {
+        let pred_idc = self.inter_pred_idc(g.xc, g.yc, g.w, g.h);
+        let mut ref_idx = [-1i8; 2];
+        let mut mvd = [[0i32; 2]; 2];
+        let mut mvp_flag = [0u32; 2];
+        for l in 0..2 {
+            let used = if l == 0 { pred_idc != 1 } else { pred_idc != 0 };
+            if !used {
+                continue;
+            }
+            ref_idx[l] = self.ref_idx(l) as i8;
+            if l == 1 && self.sh.mvd_l1_zero && pred_idc == 2 {
+                mvd[1] = [0, 0];
+            } else {
+                mvd[l] = self.mvd_coding()?;
+            }
+            mvp_flag[l] = self.dd(MVP_FLAG);
+        }
+        let mut f = MvField { mv: [[0; 2]; 2], ref_idx };
+        for l in 0..2 {
+            if ref_idx[l] < 0 {
+                continue;
+            }
+            let mvp = self.derive_amvp(g, l, ref_idx[l] as usize, mvp_flag[l] as usize);
+            // mvLX = (mvp + mvd) wrapped to 16 bits (8-94)
+            f.mv[l] = [(mvp[0] as i32 + mvd[l][0]) as i16, (mvp[1] as i32 + mvd[l][1]) as i16];
+        }
+        Ok(f)
+    }
+
+    /// Writes a prediction block's motion into the picture's 4x4 motion field.
+    fn store_motion(&mut self, xp: i32, yp: i32, w: i32, h: i32, mvf: MvField) {
         let w4 = self.pic.w4;
         for by in (yp >> 2)..((yp + h) >> 2) {
             let o = by as usize * w4;
             self.pic.mvf[o + (xp >> 2) as usize..o + ((xp + w) >> 2) as usize].fill(mvf);
         }
-        self.motion_compensate(xp, yp, w as usize, h as usize, &mvf);
-        Ok(merge)
     }
 
     fn mvd_coding(&mut self) -> Result<[i32; 2]> {

packaging/windows/deckcraft.wxs

@@ -58,9 +58,15 @@
       <Component Id="DeckcraftApp" Guid="D87EA444-41A4-4C19-922E-66D1A29461FF">
         <File Id="DeckcraftNotice" Source="$(var.BinDir)\NOTICE" KeyPath="no" />
         <File Id="DeckcraftExe" Source="$(var.BinDir)\deckcraft.exe" KeyPath="yes">
+          <!-- No Icon here, so the shortcut shows the icon embedded in deckcraft.exe (build.rs). An
+               MSI Icon is cached under %APPDATA%\Microsoft\Installer\{ProductCode}\, and every
+               update is a major upgrade with a new ProductCode that deletes the old folder. A
+               taskbar pin is a copy of this shortcut that the update never touches, so it kept
+               pointing at the deleted file and lost its icon (#1114). The exe's path survives
+               updates; the shortcut is not advertised, so it targets that path and its icon is the
+               exe's own. The Icon above stays for ARPPRODUCTICON (Apps and features). -->
           <Shortcut Id="StartMenuShortcut" Directory="ProgramMenuFolder" Name="DeckCraft"
-              Description="DeckCraft presentations and slide shows" WorkingDirectory="INSTALLFOLDER" Advertise="yes"
-              Icon="DeckcraftIcon.ico" IconIndex="0" />
+              Description="DeckCraft presentations and slide shows" WorkingDirectory="INSTALLFOLDER" Advertise="no" />
         </File>
 
         <!-- .deckcraft: DeckCraft's own format. -->

packaging/windows/package.ps1

@@ -83,6 +83,15 @@ foreach ($check in @(@('deckcraft.exe', 2), @('deckcraft-cli.exe', 3))) {
   if ($h.Subsystem -ne $check[1]) { throw "$($check[0]) has PE subsystem $($h.Subsystem), expected $($check[1])" }
   Write-Output "ok $($check[0]): $Arch, PE subsystem $($h.Subsystem)"
 }
+
+# The Start menu shortcut is not advertised and names no MSI icon, so it shows the icon embedded in
+# deckcraft.exe (#1114). -SkipBuild takes whatever binary is already there, which may come from a
+# build without DECKCRAFT_REQUIRE_WINRES=1 whose resource compilation failed: refuse an exe with no
+# icon instead of shipping shortcuts with a generic one. ExtractIconEx with index -1 counts them.
+Add-Type -Namespace DeckCraft -Name Shell -MemberDefinition '[DllImport("shell32.dll", CharSet = CharSet.Unicode)] public static extern uint ExtractIconEx(string file, int index, IntPtr[] large, IntPtr[] small, uint icons);'
+$Icons = [DeckCraft.Shell]::ExtractIconEx((Join-Path $Bin 'deckcraft.exe'), -1, $null, $null, 0)
+if ($Icons -eq 0) { throw 'deckcraft.exe has no embedded icon: rebuild it with DECKCRAFT_REQUIRE_WINRES=1 (omit -SkipBuild)' }
+Write-Output "ok deckcraft.exe: $Icons embedded icon group(s)"
 $Stage = Join-Path $TargetDir "windows-package\$Arch"
 Remove-Item -Recurse -Force $Stage -ErrorAction SilentlyContinue
 New-Item -ItemType Directory -Force -Path $Stage | Out-Null