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3 commits

Author SHA1 Message Date
Erik
9957070cab feat(render): Phase G.1/G.2 — SceneLighting UBO + sky renderer + shader integration
Wire the existing LightManager + WorldTimeService state into visible
rendering. Every draw call (terrain, static mesh, instanced mesh, sky)
now shares one SceneLighting UBO at binding=1 carrying:
  - 8 Light slots (Directional / Point / Spot, retail hard-cutoff)
  - Ambient RGB + active light count
  - Fog start/end/mode + color + lightning flash scalar
  - Camera world position + day fraction

The CPU side (SceneLightingUbo in Core.Lighting) is a POD struct that
gets BufferSubData'd once per frame from GameWindow.OnRender. Shaders
read the block via `layout(std140, binding = 1) uniform SceneLighting`
— no per-program uniform uploads.

Shader changes:
  - mesh.frag + mesh_instanced.frag accumulate 8 dynamic lights per
    fragment using the retail no-attenuation hard-cutoff model
    (r13 §10.2 / §13.1). Sun reads slot 0; spots use hard cos-cone test.
    Additive lightning flash + linear fog layered on top. Saturate
    clamps per-channel to 1.0.
  - terrain.vert bakes AdjustPlanes sun+ambient per vertex using the
    retail MIN_FACTOR = 0.08 ambient floor (r13 §7). terrain.frag adds
    fog + flash on top of the baked vertex color.
  - mesh.vert + mesh_instanced.vert emit vWorldPos so the fragment
    stage can do per-pixel lighting against world-space positions.
  - New sky.vert / sky.frag pair — unlit, scroll-UV, camera-centered,
    with its own 0.1..1e6 far plane. Ports WorldBuilder's skybox.

SkyRenderer (new file in App/Rendering/Sky/) ports WorldBuilder's
SkyboxRenderManager verbatim for the C# idiom: zeroed view translation,
dedicated projection, depth mask off, iterate each visible SkyObject
in the day group, apply arc transform (Z rot for heading + Y rot for
arc sweep), feed TexVelocityX/Y as a scrolling UV offset, apply
per-keyframe SkyObjectReplace overrides (mesh swap + transparency +
luminosity) for overcast / dusk cloud variants.

GameWindow integration:
  - OnLoad parses Region (0x13000000) into LoadedSkyDesc and hot-swaps
    WorldTime's provider to the dat-accurate keyframes. Seeds to noon
    for offline rendering. Creates the SceneLightingUboBinding and the
    SkyRenderer.
  - OnRender: set clear color from atmosphere fog, tick WeatherSystem,
    spawn/stop rain/snow camera-local emitters on kind change, feed
    sun to LightManager (zero intensity indoors — r13 §13.7), tick
    LightManager against viewer pos, build + upload the UBO, draw
    sky before terrain, draw terrain + static + instanced using the
    shared UBO.

5 new UBO packing tests (struct sizes, slot population, 8-light cap,
directional slot 0).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-19 10:39:48 +02:00
Erik
31d3a4678f fix(lighting): port ACME lighting constants replacing guessed values
Replace guessed sun direction (0.5, 0.4, 0.6) with ACME's verified
value (0.5, 0.3, -0.3) from GameScene.cs:238. Replace hardcoded
ambient/diffuse (0.25/0.75) with ACME's ambient intensity 0.45 from
LandscapeEditorSettings.cs:108.

Terrain shaders now match ACME Landscape.vert/frag pattern:
- Vertex shader computes Lambert term with xLightDirection uniform
- Fragment shader applies: color * (clamp(lambert, 0, 1) + xAmbient)

Static object shader matches ACME StaticObject.vert:
- LightingFactor = max(dot(N, -L), 0) + ambient
- Removed separate uDiffuseIntensity (ACME doesn't have one)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-13 22:01:28 +02:00
Erik
6a55838a10 perf(rendering): true DrawElementsInstanced — one draw call per (GfxObj × sub-mesh)
Replaces the per-entity glUniform uModel path with a shared instance VBO and
DrawElementsInstanced. All instance model matrices are uploaded to GPU once per
frame; the VAO's per-instance attribute pointers (locations 3–6, divisor=1) are
updated with a byte-offset re-point per group so a single VBO serves all groups
without requiring DrawElementsInstancedBaseInstance (not in Silk.NET 2.23).

Changes:
- InstancedMeshRenderer: add _instanceVbo, _instanceBuffer scratch; EnsureUploaded
  sets up mat4 instance attrs (locs 3–6) from the shared VBO; Draw builds the flat
  float[] of all instance matrices once then calls DrawElementsInstanced per sub-mesh.
  Drops the unused uint TerrainLayer attribute (loc 3 from vertex VBO) — mesh shaders
  never used it. Adds InstanceGroup helper to track per-group buffer offsets.
- mesh_instanced.frag: replace sampler2DArray+uTextureLayer with sampler2D uDiffuse,
  matching the existing TextureCache / individual-texture pipeline.
- mesh_instanced.vert+frag: track as committed files (were untracked).
- Shader.cs: add SetVec3 helper needed for uLightDirection uniform.
- GameWindow.cs: switch mesh shader load from mesh.vert/.frag to
  mesh_instanced.vert/.frag.

Visual output is identical: same entities, same textures, same lighting constants
(SUN_DIR=(0.5,0.4,0.6), AMBIENT=0.25, DIFFUSE=0.75 — moved from frag to vert).
Build: clean. Tests: 431/431 green.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-13 18:51:49 +02:00