A12-letter-as-canvas

A12 — letter as canvas

Composes

letter-substitution-handoff (the swap mechanic on the target letter)
pop-in or slide on the rest of the word (lands first)

Layout

canvas: 1080x1920 (or pack-specified)

word_zone:
  anchor: center
  origin: { x: canvas_w/2, y: canvas_h/2 }
  align: center
  font_size: ~display-scale (200+ px)
  font_family: heavy sans (Inter Black or Söhne Breit)

target_letter_index: declared per scene # which letter is the canvas target_letter_slot: width: same as letter glyph height: same as letter glyph content_swap: required


## Choreography

```yaml
phase_1_word_lands:
  start_frame: 0
  effect: slide or pop-in
  duration_frames: 14

phase_2_letter_swap:
  start_frame: 18                        # AFTER word settles
  effect: letter-substitution-handoff
  swap_duration_frames: 12               # crossfade between letter content variants
  swap_count: 1-3                        # how many content variations cycle through

phase_3_hold:
  start_frame: phase_2_end + 4
  duration_frames: ≥ 20

Style pack compatibility

supported: [SP-C, SP-F]
preferred_in: [SP-C]
incompatible: [SP-A, SP-B, SP-D, SP-E, SP-G]

Requires editorial restraint to land. Saturated/playful packs don't fit.

Pack-specific overrides

SP-C (editorial-cinematic)

Word: heavy sans in caps ("MIE", "CARBON", "WHEN").
Target letter content: photograph, icon, or smaller word stack.
Bg: muted cream or sage.
Crop-marks visible in corners.

SP-F (product-demo)

Word: brand name with one letter as content slot.
Target letter hosts an aurora-blob or product mock.

Duration

duration_seconds: [3.0, 5.0]
default: 3.5

Need time for word-land + letter-swap + hold.

Quality Checks

Letter slot is exactly the bounding box of the target letter glyph (not a generic rect).
Content inside the letter is sized to fit the slot — no overflow.
Swap happens AFTER word settles (otherwise the swap is invisible).
Word's other letters don't animate during the swap — only the target letter.

Failure Modes

Letter slot is too small/large. Bbox isn't matching the actual glyph. Use the rendered glyph's measured bounding rect.
Swap is invisible. Word-land and letter-swap fire simultaneously. Add delay.
Word's baseline shifts during swap. Letter substitution must preserve baseline. Use absolute positioning inside the slot.