implement-pyray-isometric-rendering

name	implement-pyray-isometric-rendering
description	Implement deterministic 2D/2.5D isometric projection, culling, depth ordering, animation selection, and render passes in pyray. Use for the world-rendering phase only.

Implement isometric rendering

Scope

Implement only G21 isometric projection/inverse, culling, stable depth planning, tick-based animation selection, render passes, and drawing-port behavior.

Inputs

• Absolute FORGE_ROOT and external GAME_ROOT with passing G20 gate.
• Current source-tree/runtime/platform/catalog hashes and G21 writable surface.
• Selected world ID, release ID, and verified bundle hash for reference scenes.
• Immutable render-state contract, isometric coordinate/elevation convention, semantic asset bindings, and representative reference scenes.
• G20 drawing port and viewport contract; G23 native resources may be fallbacks.

Outputs

• Game-owned pure projection/inverse helpers and render-command planner/renderer.
• Projection, depth-tie, pivot, culling, pass-order, and scene tests.
• Forge-owned G21 completion record outside GAME_ROOT.

Invariants

• Keep src/isoworld, locks, bundles, and authoritative state immutable.
• Consume immutable render state only; do not poll input, advance simulation, load resources, or let native handles enter render planning.
• Keep inverse projection pure for later G22 picking.
• Invoke only the screen-UI pass position; G24 owns UI layout and behavior.
• Never copy AGENTS.md, .agents, Forge skills, or phase evidence into GAME_ROOT.

Workflow

1. Read the rendering gate in docs/GAME_IMPLEMENTATION_PHASES.md.
2. Consume immutable render state; never read or mutate authoritative world state.
3. Own pure projection/inverse helpers and use authored pivots/elevation.
4. Cull before emitting draw commands and sort by explicit stable depth keys.
5. Render terrain, overlays, merged entities, foreground, and effects, then invoke the G24-owned screen-UI pass.
6. Test projection, depth ties, pivots, culling, and tick-based animation frames.

Completion

Complete when projection/inverse round trips, stable depth/culling/pass tests and representative scene checks pass with primitive fallbacks, the shared headless suite and clean-game audit pass, and evidence is recorded outside GAME_ROOT.