ASCII Terrain Renderer

Project roadmap

1. 01

   Define the output

   ~1h

   Write README.md: the command (terrain --width 80 --height 40 --seed 42 --scale 20), the height bands and their characters and colors (for example ~ blue for deep water, . yellow for sand, " green for grass, ^ grey for rock and * white for snow), and an example output. Set up a CMake project. Done when: README.md shows the options and an example.

2. 02

   Store the height map

   ~1h

   Write a HeightMap class with a width, a height and heights as floats between 0 and 1 in a std::vector, with at(x, y) that checks bounds. Parse and validate the command-line options (sizes between 10 and 300, a positive scale). Fill the map with plain random values from std::mt19937 seeded with the seed, just to test it. Done when: the map is created with the requested size and seed.

3. 03

   Generate smooth terrain with noise

   ~2h

   Implement value noise: random values on a coarse grid, smoothly interpolated between grid points (with a smoothstep curve). Add several layers (octaves), each with double the detail and half the strength, and normalize the result to 0 to 1. Done when: the same seed always gives the same map, and the map shows smooth hills instead of static.

4. 04

   Render with colors and shading

   ~2h

   Map each height to a band's character and color using ANSI escape codes, with --no-color for plain output. Add shading: compare each point's height with its neighbor towards the light, and make slopes facing the light brighter and those facing away darker. Done when: the terminal shows a colorful, shaded landscape.

5. 05

   Add options and export

   ~1h

   Add --sea-level to shift the water line and --out map.txt to save the map (without colors), and print the share of each terrain type below the map. Handle a terminal narrower than the map with a warning. Done when: changing the sea level visibly floods or drains the map, and the saved file matches the screen.

6. 06

   Test it

   ~1.5h

   Write tests (with doctest or Catch2): the same seed gives the same map, different seeds give different maps, heights always stay between 0 and 1, the band mapping for boundary values, and option validation. Done when: all tests pass.

Resources

• ArticleRed Blob Games: making maps with noise
• ArticleThe Book of Shaders: noise (with interactive examples)
• Docsstd::mersenne_twister_engine (cppreference)
• ArticleANSI escape codes (Wikipedia)
• DocsCMake tutorial