BeatUp Engine v0.5

BeatUp Engine v0.5

A gameplay, display and quality-of-life update focused on making matches feel
right on every monitor, giving the editor safer exits, and adding a proper
Challenger mode.

Compatibility: Charts, .bu projects and encrypted patcher files from
v0.4 load unchanged. The 0.7 timing offset default is still the only value
you need to tune, and it can be overridden in master.slk.

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Highlights

• Challenger Mode — pick it from the Patcher gear menu; the song fails if you
  fall below 80% Perfect or exceed 15% Cool+Bad+Miss.
• Borderless fullscreen that actually covers the taskbar, with the display
  mode driven by the chosen resolution.
• 2K and 4K resolutions added, with correct DPI handling so a chosen
  resolution means real pixels on high-DPI monitors.
• Save-on-exit prompts in the editor, patcher and menu so you never lose a
  project by accident.
• .bu file association registered automatically — double-click a project to
  open it.

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Gameplay

Challenger Mode

• Enable it from the gear menu in the Patcher (independent of the Chance
  mode, so it combines with any of them).
• The run fails when either condition is met, evaluated only after 200 notes
  have been played so early-song jitter never ends a run:
  • Perfect ratio drops below 80%, or
  • Cool + Bad + Miss together exceed 15% of the notes played so far.
• On a fail the result card shows "YOU FAILED" with an F rank, and the run is
  clearly marked as a Challenger attempt.

Enter-Chance alignment

• The Enter-Chance note liner, MISS overlays, receptor hit points and receptor
  beams now all share one coordinate system derived from the reference layout.
  Previously the liner used an older grid, so arrows landed next to the receptor
  outline and Perfect felt late in Enter-Chance mode.
• Hit points are now measured from the actual drawn arrow centre inside each
  liner texture (the arrows are not centred in their canvas), fixing a small
  but real offset in normal mode and a larger one in Enter-Chance.
• no_chance icon now shows when Enter is not active.

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Display & Window

• Borderless fullscreen (F11) now covers the whole screen including the
  taskbar, like the borderless mode in modern games.
• Resolution drives the mode: a resolution smaller than the monitor is a
  normal, movable window; a resolution equal to the monitor is fixed, on-top
  borderless fullscreen. F11 reliably toggles between the two and always returns
  to your real windowed resolution.
• New resolutions: 2560×1440 (2K) and 3840×2160 (4K), shown in a two-row
  layout. Resolutions larger than the current monitor are greyed out with a
  tooltip instead of silently shrinking.
• DPI awareness: the process now reports itself as per-monitor DPI aware, so
  1024×768 means real 1024×768 pixels on a 2K/4K monitor instead of being
  stretched by the OS.
• Linear scaling so upscaled game art stays smooth instead of pixelated.
• The window can no longer be dragged while in fullscreen.
• The editor menu bar and the game field now scale and centre to the actual
  resolution instead of being pinned to a fixed 1024×768 area.

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Editor & Menus

Exit confirmations

• Editor: pressing ESC or the window close button while a project is open now
  asks whether to save first — Yes, save writes a .bu next to the music,
  No, discard leaves without saving, Cancel stays. ESC still clears a note
  selection first if one is active.
• Patcher: ESC returns to the menu and the window close button quits, both
  via a confirmation dialog.
• Menu: ESC and the close button now ask before quitting.

.bu file association

• On startup the app registers the .bu extension for the current user (no admin
  rights needed) so a double-click opens the project with its song, notes and
  position restored. The association updates itself if the executable is moved.

Loading & tips

• The loading screen now shows what it is checking (directories, core files,
  assets, score data) with matching progress.
• Random tips appear on the loading screen, the pre-song countdown and the
  pause menu — F11 fullscreen, Ctrl+Alt+1–7 for the Chance, import/export
  hotkeys, Ctrl as Space, the colour-coded grid and more.

Countdown & auto-enter

• The pre-song countdown is centred correctly at any resolution and now uses a
  single clean progress bar instead of several competing indicators.
• Auto-enter (when enabled) is now active from the very start of the
  countdown instead of only after playback begins.

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Fixes

• Fixed Ctrl+drag range selection collapsing when dragging across the centre
  (F↔9 boundary): the selection rectangle now computes its span in screen
  columns instead of raw lane numbers, so it works across both sides.
• Fixed a duplicate sound entry (beat.wav + beat.ogg) causing an ImGui
  ID conflict in the sound settings; duplicate keys are skipped and sliders use
  index-based IDs.
• Fixed the editor menu bar being cut off at 1024px on larger resolutions.
• Fixed the game field sticking to the top-left corner instead of scaling and
  centering.
• Fixed file dialogs opening behind the window in fullscreen (they now use the
  main window as owner).
• Fixed the window close button bypassing the save prompt.

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Compatibility note: all v0.4 content loads without changes, and the 0.7
timing offset default is unchanged.