[Image references 2/6] Shared image geometry and executable vectors #1825

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opened 2026-08-28 09:43:10 +00:00 by brenno · 0 comments

brenno commented

2026-08-28 09:43:10 +00:00

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Parent: #1801
Depends on: #1824
Completed prerequisite: #1813
Contract: docs/design/IMAGE_CALLOUTS.md, frozen revision 4 (§4 and §9)

Outcome

Provide one Flutter-free geometry contract that every image-reference renderer and the editor can use or verify against. This turns the measurements recorded in the design into permanent, executable repository evidence.

Scope

Implement ImageViewportGeometry for intrinsic image size, slot size, focal point and image zoom.
Map point and region targets from normalised image space to the painted image rectangle.
Report clipping against the visible slot without inventing or clamping callout geometry.
Match the complete cover and zoom transform from §4.1, including the different focal behaviour in both branches and the shared 0..400 zoom clamp.
Create one checked-in vector table used by the pure Dart implementation, real Flutter layout and generated browser CSS.
Keep the geometry service free of Flutter UI dependencies so hit-testing, rendering and export cannot drift into separate formulae.

Acceptance evidence

Landscape, portrait and square images.
Slots at 20%, 40% and 70% of a 16:9 slide.
Zoom inputs 0, 100, 140, 400, a negative value and a value above the maximum.
Focal points at 0, 0.5 and 1 on both axes.
Point targets on all corners and edge midpoints, plus regions with width and height and cases clipped by the slot.
A real browser measurement of the generated CSS and a real Flutter render are compared to the same vectors with an explicit pixel tolerance.
The two previously disproved CSS formulations fail a focused regression test or fixture mutation.
The measurement command is part of the repository-native validation workflow; the 486-case claim must be rerunnable rather than copied from the design document.

Boundaries

No public authoring control and no visible callout feature in this slice.
Do not add a second geometry implementation per renderer.
Do not reproduce the pre-#1813 zoom bug for compatibility; #1813 is fixed on main and the frozen contract is authoritative.

Use small coherent commits for the pure geometry, fixtures, browser proof, Flutter proof and documentation/quality-gate wiring.

Parent: #1801 Depends on: #1824 Completed prerequisite: #1813 Contract: `docs/design/IMAGE_CALLOUTS.md`, frozen revision 4 (§4 and §9) ## Outcome Provide one Flutter-free geometry contract that every image-reference renderer and the editor can use or verify against. This turns the measurements recorded in the design into permanent, executable repository evidence. ## Scope - Implement `ImageViewportGeometry` for intrinsic image size, slot size, focal point and image zoom. - Map point and region targets from normalised image space to the painted image rectangle. - Report clipping against the visible slot without inventing or clamping callout geometry. - Match the complete cover and zoom transform from §4.1, including the different focal behaviour in both branches and the shared `0..400` zoom clamp. - Create one checked-in vector table used by the pure Dart implementation, real Flutter layout and generated browser CSS. - Keep the geometry service free of Flutter UI dependencies so hit-testing, rendering and export cannot drift into separate formulae. ## Acceptance evidence - Landscape, portrait and square images. - Slots at 20%, 40% and 70% of a 16:9 slide. - Zoom inputs `0`, `100`, `140`, `400`, a negative value and a value above the maximum. - Focal points at `0`, `0.5` and `1` on both axes. - Point targets on all corners and edge midpoints, plus regions with width and height and cases clipped by the slot. - A real browser measurement of the generated CSS and a real Flutter render are compared to the same vectors with an explicit pixel tolerance. - The two previously disproved CSS formulations fail a focused regression test or fixture mutation. - The measurement command is part of the repository-native validation workflow; the 486-case claim must be rerunnable rather than copied from the design document. ## Boundaries - No public authoring control and no visible callout feature in this slice. - Do not add a second geometry implementation per renderer. - Do not reproduce the pre-#1813 zoom bug for compatibility; #1813 is fixed on `main` and the frozen contract is authoritative. Use small coherent commits for the pure geometry, fixtures, browser proof, Flutter proof and documentation/quality-gate wiring.

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2026-08-28 09:43:10 +00:00

brenno referenced this issue

2026-08-28 09:45:26 +00:00

[Feature] Map with arrows #1801

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2026-08-28 12:12:59 +00:00