openroller/docs/re_gc_song_select.md

GC-style song selection

Running the stage player without a stage path opens the graphical song selector backed by data/boot/stage_param.dat:

./tools/run_stage_player.sh

Passing a stage remains the direct reverse/debug path:

./tools/run_stage_player.sh GC/data/stage/ac_oshama_hard.dat

The selector renders the original English selectmusic2 and selectmode2 RVB/MTX scenes. Exact task flow, coordinates, animation bindings, and the container reverse are recorded in docs/re_gc_menu_exe.md from game471.exe itself.

What is already wired:

• the original portrait 720x1280 SELECT MUSIC and SELECT MODE scenes;
• original MovieClip frame labels, display-list depth updates, transforms, alpha fades, and RGB color transforms;
• the original common_eng controller HUD and animated Yume navigator scenes;
• the executable's purple-to-pink background strip, rotating wire sphere, translucent menu geometry, and balloon.dds lower backing layer;
• genre filtering from the catalog genre byte;
• the twelve dynamically linked mc_music_link/mc_index_link carousel slots with their executable positions and opacity table, including original s_j_eng.dds genre headings as real scrolling entries;
• title rows, jacket, source and artist cut directly from each original data/stage/2d/<imageKey>_menu.dds atlas;
• SIMPLE/NORMAL/HARD/EXTRA availability and selected-state MovieClips from the same catalog;
• separate select-music and difficulty states, matching the task transition proven in the executable;
• launch through the selected difficulty's exact ac_* stage ID.

Entries are included only when both their menu atlas and at least one local stage .dat exist. This dump currently yields 887 playable songs from the 924 master catalog records. Only the visible carousel window is uploaded to the GPU, rather than all jackets at once.

Controls:

Up / Down, W / S       previous / next song
PageUp / PageDown      jump by eight songs
Q / E or Tab           genre
Enter or Space         enter difficulty screen
Escape                 close selector

Difficulty state:

```text
Arrows, W / S, A / D   difficulty
Enter or Space         play
Escape                 back to music selection