magicciv/.project/objectives/p0-07-tech-research-costs.md

id	title	priority	status	scope	updated_at	evidence
p0-07	Tech research costs and science pool pacing	p0	done	game1	2026-04-17	src/simulator/crates/mc-tech/src/lib.rs src/simulator/crates/mc-tech/src/costs.rs src/simulator/crates/mc-turn/src/game_state.rs src/simulator/crates/mc-turn/src/processor.rs src/simulator/api-gdext/src/lib.rs src/game/engine/src/modules/management/turn_processor.gd public/games/age-of-dwarves/data/techs/

Summary

mc-tech has the prerequisite graph and unlock signals with per-tech science cost accumulation. Research gates on both prerequisites and cost; completion decrements the pool by tech.cost and carries overflow to the next tech.

Promoted back to done 2026-04-17: The Rail-1 live-game delegation via GdTechWeb landed under p0-29-gd-tech-bridge.md. The live game now calls Rust for cost-gated research; the parallel GDScript path in turn_processor.gd has been collapsed.

Acceptance

• ✓ cost: u32 field present in all tech JSON files (public/games/age-of-dwarves/data/techs/*.json); era costs 20–320 matching ERA_NOMINAL_COST table in mc-tech/src/costs.rs.
• ✓ science_pool: i64 added to PlayerState (mc-turn/src/game_state.rs:86); accumulates per-turn science via process_science() in processor.rs.
• ✓ Completion via PlayerTechState::add_science() — pool decremented by tech.cost, overflow carries to next tech (mc-turn/src/processor.rs, mc-tech/src/lib.rs).
• ✓ Tuning target verified: full_tree_reachable_within_250_turns_at_normal_yield test passes (28/28 mc-tech tests green, 2026-04-17); formula: culture^1.5 × min(cities,12) × 15 ≈ 339 science/turn → ~155k by T250 vs ~9,600 total tree cost.
• ✓ Live game delegates to mc-tech — turn_processor.gd:156 _process_research replaced by GdTechWeb.process_research(player_json, yield_json, sci_modifier) (12 LOC body, down from ~52). Rail-1 compliance restored. See p0-29-gd-tech-bridge.md for the full bridge landing + the CHANGELOG entry dated 2026-04-17 [ref: p0-29, p0-07].