Orkuncakilkaya
a71279a7b9
A software light pass over the framebuffer, run in a render phase after drawing the scene: Light.ambient multiplies the scene toward a tint (night/cave mood), Light.point additively accumulates a radial glow with linear falloff clamped per channel, and Light.occlude / Light.clear_occluders cast hard shadows by blocking a light's rays against rectangular occluders. Integer + Q16.16 fixed throughout, so a scene lights identically every run and in a headless render (diffable). Engine in runtime/native/light.ludic, spliced on demand (g_uses_light) like the regex/query runtimes; namespace wired in emit_call.ludic. Ships issue #4 tiers 1 (ambient + additive radial lights) and 2 (hard shadows). Normal-mapped sprites, soft shadows, a day/night directional light, and auto-consuming Light2D/Occluder components are follow-ups (the auto-system hook is tracked by #43). - runtime/native/light.ludic: the light-accumulation engine (isqrt falloff, segment/occluder shadow test, ambient modulate) - examples/library/lighting.ludic: 14 pixel-readback assertions - docs/language/light/: Light.ambient/point/occlude/clear_occluders - tools/x/test.ludic: lighting.ludic in the regression suite Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
32 lines
1.2 KiB
Markdown
32 lines
1.2 KiB
Markdown
---
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id: light-occlude
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name: Light.occlude
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category: light
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kind: namespace-method
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tokens: Light.occlude
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sig: Light.occlude(x, y, width, height)
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tip: Register a rectangle that blocks light — a hard shadow caster.
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order: 3
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ns: Light
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member: occlude
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---
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Registers an axis-aligned rectangle (screen space) that blocks light: for every <a href="light-point"><code>Light.point</code></a> that follows, any pixel whose ray from the light centre crosses this rectangle — or lies inside it — is left in shadow, carving a hard umbra behind the wall. Register the geometry that should cast shadows this frame, then draw the lights. Occluders persist until <a href="light-clear_occluders"><code>Light.clear_occluders</code></a>, so call that once per frame first; up to 64 occluders are kept.
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Parameters:
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- `x`, `y` — the top-left corner, in screen pixels
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- `width`, `height` — the rectangle size in pixels
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```ludic
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program Demo {
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property Wall { x: int = 0, y: int = 0 }
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model Block { Wall }
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handler Render phase Update {
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Screen.clear(0)
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Light.clear_occluders()
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Light.occlude(120, 80, 8, 48) # a pillar
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Light.point(60, 100, 120, Color.rgb(255, 240, 200), 1.0)
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Screen.show()
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}
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}
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```
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