The Curse of Monkey Island demo

The local original demo comes from the Windows 98 A-D distribution linked in sources.md. The package and playable files remain local-only.

The bundled README identifies demo 1.0 and requires Windows 95, a Pentium, 16 MB RAM, CD-ROM, and a mouse. CURSE.EXE is the original launcher: a real emulated launch displayed Play, Install DirectX, Readme, Troubleshooting, and Exit. It reached the child-launch yield without a game-copy wizard. The top artwork panel was initially blank; the etched-static fix below restores it. The registered app runs COMI.EXE with the original 11 companion files.

Functional acceptance

test/test-comi-gameplay.js uses the frozen headless CLI, skips the opening dialogue with Escape, and clicks the hold floor at (250,390). Before and after screenshots show Guybrush standing at the right wall and then walking toward the center. The test measures his distinctive cream-shirt palette pixels, requiring a leftward displacement greater than 60 pixels, rather than counting cannon animation or mouse-cursor changes as player movement. The verified run measured x=438 to x=335 and exited cleanly.

Screenshots are written to COMI_SCREENSHOT_DIR or the temporary directory wine-assembly-comi-gameplay. The test pins the original executable hash; its palette assertion is specific to that demo and scene.

The regression also right-clicks to open the inventory chest, closes it, then holds the left button over the small pirate to open the verb coin. Both captures were visually inspected. Region-specific brown chest and gold coin pixel thresholds assert those controls appeared; selecting a verb and completing the demo's puzzle remain unverified.

Launcher artwork investigation

The blank panel is not evidence of an absent bitmap resource. CURSE.EXE contains bitmap resource 184, and its launch trace calls LoadImageA for that resource with dimensions 240x197 and LR_CREATEDIBSECTION, followed by a successful BitBlt into the dialog at (0,3). A static child occupies the same rectangle. Trace control paints and DC targeting before deciding whether loading, rasterization, or a later repaint loses the artwork.

The resource header is a 40-byte BITMAPINFOHEADER: 320x240, 8bpp, BI_RGB, 76800 pixel bytes (raw PE offset 0x2cefc). The overlapping dialog-102 static is control 1003, style 0x50000012, not SS_BITMAP. --trace-ctrl confirms it paints at screen (199,77) with extent 240x197. The LoadImage result selected into the source DC is nonzero (0x410005). These observations narrow the next probe to actual bitmap pixels and destination/repaint behavior; a successful BitBlt return alone does not prove visible rendering. The bounded 80-step probe exits cleanly.

Etched frame fix

The cause was static-control painting: a four-bit type mask changed SS_ETCHEDFRAME (0x12) into SS_RIGHT (0x02), then its text-label fill erased the parent's artwork. Preserve five type bits and handle etched horizontal, vertical, and full frames with EDGE_ETCHED and the appropriate border flags, without BF_MIDDLE. This follows the static-control style contract.

test/test-static-bitmap-control.js seeds colored interior pixels and checks all three etched styles across repeated paints, including which edges change. It failed gray before the fix and passes afterward, alongside the existing resource/dynamic bitmap coverage. The original launcher now shows the moon, sea, and Guybrush in his boat; its capture was inspected. The art region changed from zero to 38238 chromatic pixels. Canonical and compat builds pass, as does the full COMI movement/inventory/verb-coin test against the new build. This verifies artwork presence, not exact LoadImage scaling fidelity or every launcher button.

Hot loop: the destination-blended LUT at exe+0x40340e

The #1 hot block across three profiling windows, at 11.62 / 11.72 / 11.68% of block entries (spread 0.11pp — flat, unlike most hot-loop measurements), and 35.12 / 35.24 / 35.14% for the region within ±0x60.

0040340e  mov dl,[eax]          ; src index
00403410  inc eax
00403411  cmp dl,0xff
00403414  jz short 0x40343a     ; transparent
00403416  cmp dl,0x8
00403419  jnb short 0x403438    ; opaque passthrough
0040341e  mov bl,dl
00403422  shl ebx,0x8
00403425  mov dl,[ecx-0x1]      ; dst index
00403429  mov dl,[ebx+edx+0x4d30d0]   ; 64KB blend table
00403430  mov [ecx-0x1],dl
00403433  jnz short 0x40340e

A destination-blended 2D lookup, dst = tbl[(src<<8)|dst], table at 0x4d30d0. Both branches target addresses past the back edge, so they are loop exits with no internal edge — which makes this a SELFEXIT, not a self-loop, and therefore invisible to $loop_match_block: the decoder splits the block at the first jz. See §22 of loop-idiom-superops-design.md.

tools/find-ck-lut-nests.js classifies it LUT8_NOKEY. tools/match-loops.js on COMI: 956 loops, 58 matched (6.1%), 203 multi-branch declines.