# Verification Note: pdftract-tuky (Phase 3.1: Graphics State Machine coordinator)

## Summary

All 8 children of the Phase 3.1 Graphics State Machine coordinator are closed. This coordinator delivers the complete graphics state infrastructure consumed by all other Phase 3 operations.

## Acceptance Criteria Status

### 1. All 8 children closed ✅

All children verified closed:
- pdftract-1jlpy: Page /Rotate normalization (commit 606e162)
- pdftract-1os1: q/Q stack with depth limit 64 (closed)
- pdftract-1vxh: BT/ET text object lifecycle (closed)
- pdftract-44f6: GraphicsState struct + Color enum (closed)
- pdftract-4dmp: Text state operators (Tc Tw Tz TL Ts Tr) (closed)
- pdftract-4ubed: Color operators (rg RG k K cs scn) (closed)
- pdftract-4x0y: Font binding (Tf) + text positioning operators (Td TD Tm T*) (closed)
- pdftract-p7yll: CTM operator (cm) (closed)

### 2. q/Q 64 levels deep succeeds; 65th level emits GSTATE_STACK_OVERFLOW ✅

Verified by tests in `src/graphics_state/stack.rs`:
- `test_64_nested_q_calls_succeed`: Pushes 64 times, all succeed
- `test_gstate_stack_depth_limit`: 65th push fails and emits diagnostic
- `test_max_depth_is_64`: Verifies stack limit

### 3. Td chain accumulates correctly ✅

Verified by `test_td_chain` in `src/graphics_state/state.rs`:
```rust
// BT 100 200 Td 50 0 Td ET should yield translation (150, 200)
state.begin_text();
state.move_text(100.0, 200.0);
state.move_text(50.0, 0.0);
// Result: (150, 200) ✅
```

### 4. Tm followed by Td: Td is relative to previous text_line_matrix ✅

Implementation in `src/graphics_state/state.rs`:
- `set_text_matrix`: Sets both text_matrix and text_line_matrix
- `move_text`: Updates text_line_matrix first, then copies to text_matrix

This matches ISO 32000-1 Table 108 specification.

### 5. /Rotate 90 normalization ✅

Child bead pdftract-1jlpy (commit 606e162) implements page rotation normalization. The implementation:
- Handles /Rotate 0/90/180/270 degrees
- Applies inverse rotation matrix to all glyph bboxes after content stream execution
- Emits INVALID_ROTATE diagnostic for illegal rotation values

### 6. Color operators tracked ✅

Verified by tests in `crates/pdftract-core/src/graphics_state.rs`:
- `test_set_fill_gray`, `test_set_fill_rgb`, `test_set_fill_cmyk`
- `test_set_stroke_gray`, `test_set_stroke_rgb`, `test_set_stroke_cmyk`
- `test_color_space_component_count`
- `test_set_fill_color_space`, `test_set_stroke_color_space`
- `test_set_fill_color_named_spot`

## Test Results

All 72 graphics_state tests pass:
```
Summary [   0.049s] 72 tests run: 72 passed, 2612 skipped
```

## Changes Made

Fixed one incorrect test expectation in `crates/pdftract-core/src/graphics_state.rs`:
- `test_color_device_rgb_clamped`: Corrected expected value from "#ff8080" to "#ff0080"
  (The G value -0.5 should clamp to 0.0, not 0.5)

## Coordinator Status

The Phase 3.1 Graphics State Machine is complete and ready for consumption by Phase 3.2-3.5.