openvistapro/README.md

OpenVistaPro

OpenVistaPro is an early-stage, open-source Rust project to build a modern landscape generator inspired by classic VistaPro.

The goal is not to redistribute or reuse proprietary VistaPro code/assets. The local reference/ directory is intentionally ignored by git and is used only for historical/product research.

Current status

This repository currently contains:

• A Rust binary crate scaffold.
• A first-pass knowledgebase under docs/knowledgebase/.
• An implementation roadmap under docs/plans/.
• Legal and reference-material hygiene notes under docs/legal/ and docs/research/.
• A clean-room terrain import boundary with project-owned ovp-text fixtures, a PNG heightmap script importer, an SRTM/HGT byte importer behind the hgt Cargo feature, and an ESRI ASCII Grid parser behind the ascii-grid-import feature.

Development

cargo build
cargo test
cargo run -- info
cargo run -- scene export --output /tmp/openvistapro-default.ovp.toml
cargo run -- render --preset hill --width 256 --height 256 --output /tmp/openvistapro-hill.png
cargo run -- render --preset hill --scene /tmp/openvistapro-default.ovp.toml --width 256 --height 256 --output /tmp/openvistapro-hill-from-scene.png
cargo run -- render --preset hill --camera-demo --width 256 --height 192 --output /tmp/openvistapro-perspective.png
cargo run --features app --bin openvistapro_app

The optional app shell is gated behind the app feature so default CLI builds stay GPU-free. It opens an eframe/egui window titled OpenVistaPro with scene controls and a CPU-rendered terrain preview.

Importer status:

• heightmap: script execution can import grayscale PNG heightmaps with import heightmap "path.png" and map brightness to elevation.
• ovp-text: project-owned plain-text heightfield fixture format used for import-boundary tests.
• hgt: enabled by the optional hgt Cargo feature; parses SRTM HGT payloads as square grids of big-endian signed 16-bit metre samples. The implementation and tests use open specifications and synthetic/tiny fixtures only.
• esri-ascii-grid: enabled by the optional ascii-grid-import Cargo feature; parses open ESRI ASCII Grid text with synthetic/project-owned fixtures only.
• geotiff: enabled by the optional import-geotiff Cargo feature; parses single-band GeoTIFF elevation tiles in memory via the pure-Rust geotiff-reader crate (no GDAL, no native dependency). It supports a deliberately narrow subset — a single-band raster decoded as f32 — and is reported by openvistapro info only when the feature is built.

All importer tests use tiny synthetic, project-owned fixture data: HGT uses inline synthetic byte arrays, ESRI ASCII Grid uses tiny project-owned text fixtures, and the GeoTIFF tests generate a tiny single-band tile in memory rather than reading committed binaries or real geodata.

To verify the importer feature surface:

cargo test import
cargo test hgt
cargo test hgt --features hgt
cargo test ascii_grid --features ascii-grid-import
cargo run --features hgt --bin openvistapro -- info
cargo run --features ascii-grid-import --bin openvistapro -- info
cargo test --no-default-features
cargo test geotiff --features import-geotiff
cargo run --features import-geotiff --bin openvistapro -- info
cargo test --all-features

The default render mode writes a deterministic top-down elevation preview. Passing --camera-demo switches to the current CPU perspective renderer spike: a simple pinhole-camera raymarcher with bilinear height sampling, fixed step size, sky gradient, and distance haze. It is intended as a readable reference renderer for architecture validation, not a performance target or final visual model.

Scene files use the project-owned .ovp.toml format. Version 1 stores a top-level schema = "openvistapro.scene", version = 1, and a serialized Scene payload containing camera, light, water, tree-line, snow-line, and haze settings. The format is intentionally human-readable while the data model is still evolving.

Script language (MVP)

OpenVistaPro includes a small, line-oriented scripting language for driving terrain and render jobs from a plain-text file (src/script.rs). The grammar is clean-room and project-owned: it is not VistaPro-compatible and deliberately does not mirror the legacy VistaPro scripting syntax.

Each line is a blank line, a # comment (also usable as a trailing comment), or one command:

use preset hill                              # `hill` or `plane`
set thresholds water=0.18 tree=0.42 snow=0.77
import heightmap "data/demo-height.png"      # optional grayscale PNG terrain input
render output "out/demo.png"

Run the checked-in demo script with:

cargo run --bin openvistapro -- script run --input examples/demo.ovps

Script paths are resolved relative to the script file. use preset and import heightmap select the active terrain, set thresholds updates scene bands, and execution writes each render output to a deterministic PNG.

Project principles

• Clean-room implementation: do not decompile, copy, or translate proprietary binaries.
• Use open data formats and openly licensed datasets.
• Preserve the spirit/workflow of VistaPro while designing a modern UX and renderer.
• Start with a small, testable terrain engine before building advanced rendering or UI.