particules: integrate decisions D15-D19 in ARCHI, rewrite DRAFT Step A
ARCHI_PARTICULES.md:
- D15 uv_rect, D16 single fixed layout, D17 compaction+indirect draw
- D18 color_range + uv_rects + alpha_scale (spawn randomization, EmitterParams 48 B)
- D19 layout audit: 80 B without padding (storage space, vec3/vec4 align 4),
single shared Particle struct (no ParticleAlive prefix), compact_index 1 u32
per slot via storage binding, indirect_args 16 B
- apply to sections 2/3/4/5/6/7/8/9/10/14/15/17 + new section 18
DRAFT.md (Step A) full rewrite against final decisions:
- Particle 80 B no-padding, 4 pool buffers (data, compact_index,
indirect_args, camera_params), 5-binding layout, empty vertex layout,
draw_indirect, no early-out, SceneGpu gains queue+sample_count
Jérôme Bousquié
8606aba510