RPG City Maker Reborn is a Go + Fyne desktop app inspired by the original Roleplaying City Map Generator. It supports large image sizes, deterministic seeded generation, and exporting canvas/heightmap/bump map/masks in modern image formats.

Current Features

Deterministic generation with a user-provided seed (same settings + same seed = same output).
Terrain generation with detail and roughness controls.
Lakes with multiple shapes (circle, oval, procedural) and edge roughness.
Rivers with width range, curviness, width variability, and edge roughness.
Roads with:
- Widths scaled by image size (percent of average image dimension).
- Junction angle constraint. (this needs some work)
- Exit roads.
- Building-driven road count via Buildings Per Road.
- Bridge generation and reduced probability for repeated bridges over the same water body.
- Distribution model that transitions from compact/organic to near full-canvas coverage.
Buildings with:
- Size scaled by image size (percent of average image dimension).
- Shapes: squares, circles, rectangles, mixed, procedural.
- Mixed/procedural shape-ratio sliders.
- Procedural complexity controls (Min, Max, Complexity Ratio).
- Automatic cap of requested building count based on image size and average building size.
Trees with:
- Size scaled by image size (percent of average image dimension).
- Coverage target by map area.
- Clumpiness controlling distribution style (spread vs clustered), not just raw count.
- Trees are removed on water, roads, or buildings.
Export:
- Canvas, heightmap, bump map exports as PNG, JPG, WEBP.
- Mask export package as Folder, tar.gz, or zip.
- Saved masks include lakes, rivers, trees, roads, bridges, and buildings.
Timeout protection: generation steps for lakes, rivers, roads, buildings, and trees continue with partial results if a step exceeds 1 minute, and the UI shows which steps timed out.

Settings

All settings below are currently implemented in the UI.

Setting	Description	Range
Detail	Terrain noise detail level.	`1` to `100`
Roughness	Visual roughness overlay on terrain.	`0` to `100`
Width	Output image width in pixels.	`10` to `8192`
Height	Output image height in pixels.	`10` to `8192`
Seed	Base random seed for deterministic generation.	Any integer
Lakes	Number of lakes to generate.	`0` to `15`
Min Lake Size	Minimum lake size (% of map area heuristic).	`1%` to `100%`
Max Lake Size	Maximum lake size (% of map area heuristic).	`1%` to `100%`
Lake Edge Roughness	Irregularity/noise along lake boundaries.	`0%` to `100%`
Lake Shape	Lake shape mode.	`circle`, `oval`, `procedural`
Rivers	Number of rivers to generate.	`0` to `5`
Min River Width	Minimum river width (% of smaller image dimension).	`1%` to `100%`
Max River Width	Maximum river width (% of smaller image dimension).	`1%` to `100%`
River Curvyness	River path curviness.	`0%` to `100%`
River Width Variability	Width fluctuation along rivers.	`0%` to `100%`
River Edge Roughness	Irregularity/noise along river edges.	`0%` to `100%`
Min Tree Size	Minimum tree size as % of average image dimension `((width+height)/2)`.	`0.2%` to `15%` in `0.2%` steps
Max Tree Size	Maximum tree size as % of average image dimension `((width+height)/2)`.	`0.2%` to `15%` in `0.2%` steps
Tree Coverage	Target coverage of map area by trees.	`1%` to `100%`
Tree Clumpiness	Distribution style of trees (spread vs clustered forest).	`0%` to `100%`
Min Road Width	Minimum road width as % of average image dimension `((width+height)/2)`.	`0.1%` to `5%` in `0.1%` steps
Max Road Width	Maximum road width as % of average image dimension `((width+height)/2)`.	`0.1%` to `5%` in `0.1%` steps
Road Exits	Number of edge-connected exit roads.	`0` to `100`
Minimum Road Angle	Minimum allowed angle between roads at a junction.	`0°` to `180°`
Road Curvyness	Curviness of generated roads.	`0%` to `100%`
Distribution (Roads tab)	Road POI spread from compact center to broad/full-map coverage.	`0%` to `100%`
Number of Buildings	Requested building count before fit-cap.	`0` to `10000`
Min Building Size	Minimum building size as % of average image dimension `((width+height)/2)`.	`0.5%` to `25%` in `0.5%` steps
Max Building Size	Maximum building size as % of average image dimension `((width+height)/2)`.	`0.5%` to `25%` in `0.5%` steps
Building Distribution	How far buildings may spread away from roads: `0%` stays road-adjacent, `100%` becomes fully random map-wide placement.	`0%` to `100%`
Building Shape	Primary building generation mode.	`squares`, `circles`, `rectangles`, `mixed`, `procedural`
Squares / Circles / Rectangles	Shape ratio sliders used by `mixed` and `procedural` building modes.	`0%` to `100%` each (normalized together)
Min Building Complexity	Minimum number of shape components in procedural buildings.	`1` to `6`
Max Building Complexity	Maximum number of shape components in procedural buildings.	`1` to `6`
Building Complexity Ratio	Chance to use a random complexity between min and max.	`0%` to `100%`

Acknowledgments

Inspired by the original Roleplaying City Map Generator
Thanks to the maintainers of Go, Fyne, and other open-source projects that make this one possible.