Round display support (gabbro): round template variants and arc status

## Goal Make the Pebble Round 2 a device the app was designed for rather than tolerated on. 260x260 round, but a circle of that size inscribes only about 184x184 - so a screen with more total pixels than emery has less usable area for grids. ## Acceptance criteria - [ ] `HERO1` centred with ~170 px digits - the template that suits a circle best - [ ] `HERO2` hero centred, the two cells inset to the chord width at their vertical position - [ ] `QUAD` inset to the inscribed square, cells about 92x92 - [ ] **`GRID6` falls back to `QUAD` on `gabbro`**, as it does on `basalt` - [ ] **Status becomes an arc** along the top bezel using `graphics_draw_arc()` and `gpoint_from_polar()`, with glyphs placed radially - a straight strip has almost no width on a circle - [ ] `NAV` centred turn arrow with arc-aligned text - [ ] `MAP` round-native: a heading-up centred map, which suits a circle better than a rectangle - [ ] Variants selected with `PBL_ROUND` / `PBL_IF_ROUND_ELSE()`, never with runtime screen-size checks - [ ] **No hard-coded coordinates anywhere** - everything derived from `layer_get_bounds()` - [ ] `gbitmap_get_data_row_info()` used wherever the framebuffer is touched directly; rows are shorter near the top and bottom of a round display - [ ] `text_layer_enable_screen_text_flow_and_paging()` enabled for text that can overflow, so it follows the curve rather than clipping - [ ] Every page verified in the `gabbro` emulator and, where hardware allows, on device ## Files - `watchapp/src/c/page_render.c` - `watchapp/src/c/status_bar.c` ## Notes Rectangular layouts do NOT auto-adapt to round - the SDK's automatic scaling is chalk to gabbro, which is round to round. See docs/DESIGN.md section 3 and docs/DECISIONS.md D24. ## Update — 2026-09-01: moved to Phase 1b, and the DPI figure was wrong Moved to **Phase 1b — Generalise the display** (D32). Round support is not cancelled; it is better designed after a few real rides on the rectangle than before the first one, and it was landing before #4 had confirmed the transport the whole architecture depends on. **Correction: the Round 2 is ~200 DPI, not 283.** 260 px across a 1.3″ diagonal is about 200 — the same density as the Time 2 (200 × 228 over 1.5″ ≈ 202 DPI). See the D24 correction. - [ ] A digit specified in pixels is the **same physical size on both watches**, so no per-device type scale is needed — but `gabbro` text cannot be smaller in pixels either, because the density it was credited with is not there - [ ] Digit sizes come from the procedural renderer (D33), so the round variants need no extra font resources - [ ] `QUAD`'s emphasised slot 1 (D29) works within the inscribed square - [ ] Template geometry covered by the host-side tests in #68 — "no slot exceeds its bounds on `emery`, `gabbro` or `basalt`" as an assertion rather than a look in the emulator

robert commented

2026-08-31 18:06:56 +02:00

(Migrated from git.butzei.de)

Goal

Make the Pebble Round 2 a device the app was designed for rather than tolerated on. 260x260 round, but a circle of that size inscribes only about 184x184 - so a screen with more total pixels than emery has less usable area for grids.

Acceptance criteria

HERO1 centred with ~170 px digits - the template that suits a circle best
HERO2 hero centred, the two cells inset to the chord width at their vertical position
QUAD inset to the inscribed square, cells about 92x92
GRID6 falls back to QUAD on gabbro, as it does on basalt
Status becomes an arc along the top bezel using graphics_draw_arc() and gpoint_from_polar(), with glyphs placed radially - a straight strip has almost no width on a circle
NAV centred turn arrow with arc-aligned text
MAP round-native: a heading-up centred map, which suits a circle better than a rectangle
Variants selected with PBL_ROUND / PBL_IF_ROUND_ELSE(), never with runtime screen-size checks
No hard-coded coordinates anywhere - everything derived from layer_get_bounds()
gbitmap_get_data_row_info() used wherever the framebuffer is touched directly; rows are shorter near the top and bottom of a round display
text_layer_enable_screen_text_flow_and_paging() enabled for text that can overflow, so it follows the curve rather than clipping
Every page verified in the gabbro emulator and, where hardware allows, on device

Files

watchapp/src/c/page_render.c
watchapp/src/c/status_bar.c

Notes

Rectangular layouts do NOT auto-adapt to round - the SDK's automatic scaling is chalk to gabbro, which is round to round. See docs/DESIGN.md section 3 and docs/DECISIONS.md D24.

Update — 2026-09-01: moved to Phase 1b, and the DPI figure was wrong

Moved to Phase 1b — Generalise the display (D32). Round support is not cancelled; it is better
designed after a few real rides on the rectangle than before the first one, and it was landing before
#4 had confirmed the transport the whole architecture depends on.

Correction: the Round 2 is ~200 DPI, not 283. 260 px across a 1.3″ diagonal is about 200 — the
same density as the Time 2 (200 × 228 over 1.5″ ≈ 202 DPI). See the D24 correction.

A digit specified in pixels is the same physical size on both watches, so no per-device type
scale is needed — but gabbro text cannot be smaller in pixels either, because the density it
was credited with is not there
Digit sizes come from the procedural renderer (D33), so the round variants need no extra font
resources
QUAD's emphasised slot 1 (D29) works within the inscribed square
Template geometry covered by the host-side tests in #68 — "no slot exceeds its bounds on
emery, gabbro or basalt" as an assertion rather than a look in the emulator

Rows
Columns

Round display support (gabbro): round template variants and arc status #62

Goal

Acceptance criteria

Files

Notes

Update — 2026-09-01: moved to Phase 1b, and the DPI figure was wrong