CityGen 0.3.0 (Windows)

CityGen 0.3.0 Release Notes

Released on August 20, 2026.

This release follows the Tkinter-to-Qt migration with a structural cleanup of the
Qt GUI layer, a reduction of surrounding tooling debt, and a renderer palette fix.
Unlike 0.2.x, this release does change generated output: biome-tinted blocks
(leaves, grass, vines, water) now render in colour instead of gray, and the
WorldEdit auto-copy step has been removed.

Highlights

• The 1,100-line gui/qt_app.py was split into focused modules, and the Qt image
  viewer gained a public overlay API so dialogs no longer reach into its internals.
• The renderer palette now honours Minecraft's biome tinting, so leaves and grass
  are green and water is blue instead of gray.
• clear_cache.py moved into tools/ and now also clears build, packaging, and
  test caches.
• Dead code left over from the Tkinter era was removed, and the WorldEdit
  auto-copy step was retired.

What Changed

GUI structure

• Split gui/qt_app.py into theme, workers, widgets, region_dialog,
  tabs, and app.
• Flattened the Qt image-viewer factory into module-level classes with a direct
  PySide6 import, and gave QtImageViewer a public overlay API
  (image_rect, set_overlay_rect, clear_overlay) so the region-selector
  dialog no longer touches private members.
• Replaced string-matched error handling with typed SeedError/ConfigError,
  and the hand-rolled argument loop with argparse (adds --help and a real
  --no-custom-theme flag).
• Centralized the brand palette and the label-to-value selector mapping, made the
  button-icon helper idempotent, and switched to the static QFontDatabase API.
• Added headless GUI unit tests covering argument parsing, style configuration,
  and widget value round-trips.

Renderer

• The palette generator (tools/update_render_colors.py) now reads each model
  face's tintindex and multiplies grayscale colormap masks by a representative
  biome tint (plains foliage/grass, default water; birch and spruce use their
  fixed constants).
• Tinting is gated on the source texture actually being grayscale and on an
  explicit allow-list, so pre-coloured blocks (cherry and azalea leaves) are left
  untouched.
• src/engine/color_render.csv was regenerated from the 26.2 client jar.

Tooling and cleanup

• Removed the WorldEdit auto-copy step and the MC_CITY_WORLDEDIT_SCHEM override.
  The final city schematic is still written to artifacts/city/production/ as a
  WorldEdit-ready .schem.
• Moved clear_cache.py into tools/ and expanded it to also clear build/,
  dist/, *.egg-info/, .pytest_cache/, and the startup error log.
• Deduplicated numba across the speed/build dependency extras.

Fixes

• Replaced the deprecated QFontDatabase() instance call with the static form.
• Corrected stale "Tkinter" references in entry-point docstrings and comments.

Upgrade notes

• Renders will look different: foliage and water now show their in-game colours.
  Regenerate any previews or city renders to pick up the new palette.
• The WorldEdit auto-copy is gone. If you relied on MC_CITY_WORLDEDIT_SCHEM,
  copy the schematic from artifacts/city/production/ yourself instead.
• clear_cache.py now lives at tools/clear_cache.py; update any scripts that
  invoked it.
• Local tooling that imported gui.qt_app should import from the new modules
  (gui.app, gui.tabs, gui.widgets, ...).
• The --custom-qt-theme flag was removed (the theme is on by default); use
  --no-custom-theme to opt out.

Verification

• python -m pytest
• python packaging/build_windows_release.py --clean
• Launch the built executable and confirm the GUI opens and renders show green
  foliage.