Entry 43

The title screen from DEMO.PRG: boot, logos, menu, and the hand-off to the desktop

2026-09-23uidecomptest

Filescrates/piney-demotools/test_demo_rs.pydocs/engine/title.md

The game does not boot into the desktop. ccThMother asks for mode 2, ccSetupDemo with DEMO.PRG: first the memory-card check, then the logo movies, the intro stream, and the title menu. New Game from there starts the desktop of 37. A helper agent ported it as piney-demo, reusing the desktop's 2D and 3D machinery, and I re-ran its checks. The reference is the title page.

What it is

ccThDemo runs ccOpening_Control:

• Boot check. PlayBootMemCard / BootMem_Control. With no card it asks whether to start anyway.
• Logos. LogoMain plays three PSS movies (LOGO_B, LOGO_C, LOGO_H) with its skip rule, then the title music.
• Intro. PlayOpeningStream plays stream 0 for 410 frames and fades the menu in from white.
• Menu. NEWGAME, DATALOAD and OPTION, drawn as 3D icons (lit by one omni light) over the animated hexagon backdrop, with the logo and copyright.
• Attract loop. An idle timer fades to black at 2,380 frames and loops back at 2,400.

The crate asks the runtime for movies, the stream, music and mode changes through requests, as the desktop does. The memory card and the system menu are seams.

Findings

• Parody Mode cannot be chosen in Infection. m_ParoFLG is cleared in Init and written nowhere else, in Mutation's DEMO.PRG too, and m_Max_CurNO = 3 stops the cursor before the fourth item anyway. The branch is ported behind a test switch.
• The hand-off. New Game ends the 61-frame screen-out animation, then emits NewGame{parody} and a music fade. Breath(2) follows, then ChangeRequest(3, 7): the desktop.
• The save. ccSaveData::Init(1) runs at boot, NewGame(1) in ccSetupDemo, and NewGame(0) on New Game. NewGame(0) copies charTbl into spcParam and resets play time, words and trade items. None of it touches the desktop's members, so the desktop's fresh state is what New Game hands over.
• Depth. The title's camera puts every model at GS Z of a few thousand. The GS renderer mapped Z as 1 - z/2^32 and lost the order there. The agent found it and I fixed it in piney-gs: depth is now integer GS Z, larger nearer. Against the CPU GS model, the desktop's differing bytes went from 6,177 to 3,459. The title now matches it, except the lit icons, which the CPU model draws unlit.

Checked

tools/test_demo_rs.py runs the game's code in eemu against the port, state by state, 14 tests:

• Cursor and actions. MoveCurNut (40 random runs), SwitchCur, PlayNeutral, ChangeMainAct, and every Set* / Play*.
• Per-frame drawing. AllTransparency bit for bit, AllAnimate (the icon spin bit for bit), AllDraw.
• Timing. The fader after each kind of flash and fade, the idle timer, and LogoMain's movie order, skip rule and waits.
• The rest. The boot check, and ccThDemo itself, breath by breath.

On integration:

• the crate's tests pass (4 unit, 7 on the disc);
• test_demo_rs.py is OK;
• clippy and fmt are clean.

A 150-frame shot shows the menu as above.