47 lines
3.7 KiB
Markdown
47 lines
3.7 KiB
Markdown
# AGENT INSTRUCTIONS
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This crate (`hcie-io`) provides image I/O, KRA import/export, and SVG loading for the HCIE engine.
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## Permissions
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- All files are editable. No source-code lock rules are in effect.
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- `examples/` and `tests/` remain editable for GUI and integration testing.
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## Dependencies
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- Workspace-level `hcie-blend`, `hcie-composite`, `hcie-protocol`, and `hcie-tile` are used where applicable.
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## GUI Test (`examples/gui.rs`)
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- **Zoom**: Scroll wheel (exponential), Ctrl+scroll (10% step), buttons (-, +, 1:1, Reset)
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- **Pan**: Middle mouse drag
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- **Layer Visibility**: Eye button toggles, changes trigger re-composite
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- **Checkerboard**: Transparent canvas background, layer thumbnails show transparency
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- **Compositing**: Uses `hcie-composite` + `hcie-blend` for real blend-mode compositing
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- **Layer Thumbnails**: Nearest-neighbor resize, dirty flag updates only changed layers
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- **PSD/KRA**: Bottom layers at bottom of layer panel, composited image respects visibility
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- **Save**: Writes composited buffer to disk in chosen format
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## Info
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Read before change psd functions : Adobe Photoshop File Formats Specification.txt
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## Session Progress (2026-06-02)
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### Completed
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- **`effective_size()`** (`shadow.rs:32`): Clamps effect sizes to canvas `max_dim`, zeros effects with `size > 2*max_dim`. Fixes garbage size=131077 values from PSD parsing artifacts. Applied to all 8 effect types (bevel, satin, inner glow, inner shadow, stroke, drop shadow, outer glow, outside stroke).
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- **Regional MAE analysis**: Added to `test_emboss_optimize` — tile-based (32×32), per-channel, opaque-only, and horizontal/vertical line scanning for detailed pixel comparison.
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- **`.bak` restore**: Restored clean `shadow.rs` from backup, re-applied `effective_size` and `max_size` fixes.
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### Root Cause Analysis — Inner Bevel Plateau
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- **NDL plateau**: On simple shapes (rectangle), the height field gradient is constant across the bevel slope, so `N·L` produces a constant value → flat highlight/shadow plateau.
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- **Photoshop's algorithm**: Uses profile+direction approach — shadow=`|dir_weight| × (1-profile) × depth`, highlight=`|dir_weight| × profile × depth`, where `profile = min(dist_to_edge / size, 1.0)` and `dir_weight` = gradient·light. This produces linear transitions on simple shapes.
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- **Hybrid challenge**: Profile+direction works for emboss (opaque MAE 40.5→29.1 w/o NDL blur) but broke Sultan (4.27→7.40). Sultan needs NDL for its complex shapes. A hybrid approach (`NDL × w + profile × (1-w)`) blended before blur collapsed because the 25px lighting blur washes out the profile contribution.
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- **Key experiment**: With separate shadow/highlight buffers and NO extra blur, emboss edge matches perfectly (R=53 vs ref=53 at x=66), showing the profile+direction approach is correct. But Sultan needs the blur for smooth corners.
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### Open Issues
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- **Emboss MAE**: 120.9 (opaque 40.5). Plateau on Inner Bevel for simple shapes is unsolved.
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- **Sultan**: MAE=23.6 (NDL gradient-based bevel).
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- **Bevel algorithm**: Needs fundamental redesign — combine NDL (for complex shapes) with height-ratio (for linear edge transitions on simple shapes). The challenge is the 25px blur destroys profile-based corrections. Possible solutions: apply profile correction AFTER blur, or use adaptive blur based on gradient consistency.
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### Key Files
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- `hcie-fx/src/shadow.rs` — `effective_size()` at line 32, all effect calls use it. `generate_bevel_emboss()` at line 652 (NDL-based).
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- `hcie-io/src/test_psd_composite.rs` — `test_emboss_optimize()` at line 1228.
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- `/home/hc/Pictures/_psd_stil_test/emboss.psd` — Test PSD (256×256, InnerBevel, depth=100, size=29).
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- `/home/hc/Pictures/_psd_stil_test/emboss.png` — Reference PNG.
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- `/tmp/emboss_debug/` — Debug output. |