Platform map and Android verification
May 13, 2026 · View on GitHub
English-only companion to the submodule READMEs. Strategy names here are conceptual until you paste the submodule API you integrate. Migrating unified Android labels (FIXED / DEFAULT / BALANCED): MIGRATION.md.
Authoritative Compose math + prefix catalogue: appdimens-dynamic/DOCUMENTATION/ — MATHEMATICS-AND-CALCULUS.md, README.md, COMPOSE-API-CONVENTIONS.md.
flowchart LR
concept["Scaling concept"] --> submodule["Submodule README"]
submodule --> surface["Codegen or resources"]
Submodule status snapshot
Always reconfirm semver in the submodule README before pinning — this column is a coarse "production-ready?" indicator only.
| Submodule | Platform | Status |
|---|---|---|
appdimens-dynamic | Android (Compose + Kotlin + Java) | Production |
appdimens-sdps | Android (XML + Compose) | Production |
appdimens-ssps | Android (XML + Compose, text) | Production |
appdimens-games | Android (Kotlin + NDK + OpenGL ES) | Work in progress |
appdimens-ios | iOS / macOS (UIKit + SwiftUI + Metal) | Work in progress |
appdimens-dynamic-kmp | Kotlin Multiplatform | Work in progress |
appdimens-flutter | Flutter (Android / iOS / Web / desktop) | Work in progress |
appdimens-react-native | React Native | Work in progress |
appdimens-web | Web (vanilla / React / Vue / Svelte / Angular) | Work in progress |
Concept → binding (all stacks)
Concrete syntax lives beside the source — not in this table. Snapshot for orientation only:
| Concept | Android Compose (appdimens-dynamic) | iOS (AppDimens) | Web (webdimens) | Flutter (appdimens) | React Native (appdimens-react-native) |
|---|---|---|---|---|---|
| Hybrid BALANCED curve | auto — asdp, ahdp, awdp, assp, … auto.md | AppDimens.shared.balanced(_).toPoints() | balanced(_) builder | .fixed, .fx per Flutter submodule | balanced(_) |
| SDP-style baseline (DEFAULT / FIXED narrative) | scaled — sdp, wdp, hdp, ssp, sem, … scaled.md | Submodule README | defaultScaling-style helpers where published | Same fixed-style helpers | defaultScaling(_) |
| Logarithmic damping | Prefer explicit logarithmic or AR-aware scaled tokens — no mythical defaultDp | defaultScaling, logarithmic | defaultScaling, logarithmic | builder-specific | Helpers as exposed |
| PERCENTAGE / legacy DYNAMIC | percent — psdp, pwdp, phdp, … percent.md | percentage(_) | percentage(_) | Dynamic builders .dy | percentage(_) |
| Raw XML SDP/SSP | Separate artifacts appdimens-sdps, appdimens-ssps | — | — | — | — |
| Native games | appdimens-games façade | submodule Metal layer | — | — | — |
| Builder smart chaining | Compose tree uses explicit tokens (sdp, asdp, …) — no fused smart().forElement | .smart(_).forElement(_) variants | Equivalent hooks where published | Equivalent hooks | Equivalent hooks |
Physical units (mm / cm / inch) — across stacks
Real-world measurements where they matter (kiosks, AR, accessibility touch targets). Each cell links to the submodule entry point.
| Concept | Android Compose / code | iOS | Flutter | React Native | Web |
|---|---|---|---|---|---|
| Millimetres | 10.mm (Compose); DimenPhysicalUnits.toDpFromMm(10f) (physical-units.md) | AppDimensPhysicalUnits.mm(10) | AppDimensPhysicalUnits.mmToPixels(10, context) | physicalUnits.mm(10) | webdimens.mm(10) |
| Centimetres | 8.cm (Compose) | AppDimensPhysicalUnits.cm(8) | AppDimensPhysicalUnits.cmToPixels(8, context) | physicalUnits.cm(8) | webdimens.cm(8) |
| Inches | 5.inch (Compose) | AppDimensPhysicalUnits.inch(5) | AppDimensPhysicalUnits.inchToPixels(5, context) | physicalUnits.inch(5) | webdimens.inch(5) |
The Android implementation uses displayMetrics.xdpi / ydpi — see physical-units.md for the formal definition and per-axis caveats.
Sources of truth: appdimens-dynamic README · Flutter appdimens.dart · Web WebDimensBuilder.ts · RN AppDimensBuilder.ts · iOS examples / USAGE_GUIDE.md.
appdimens-dynamic roster (Gradle strategy ↔ Compose import)
Older hub prose used ENUM-like headings. appdimens-dynamic implements each kernel as its own Gradle source package:
| Cross-platform wording | Gradle strategy | Compose import sketch | Doc |
|---|---|---|---|
| BALANCED | auto | com.appdimens.dynamic.compose.auto.* | auto.md |
| DEFAULT / FIXED | scaled | compose.scaled.* (sdp, wdp, hdp, ssp) | scaled.md |
| PERCENTAGE / legacy DYNAMIC | percent | compose.percent.* | percent.md |
| Steven’s law knob | power | compose.power.* | power.md |
| Clamp / band typography | fluid | compose.fluid.* | fluid.md |
| Weber–Fechner style | logarithmic | compose.logarithmic.* | logarithmic.md |
| Blend vs linear | interpolated | compose.interpolated.* | interpolated.md |
| Hypotenuse feel | diagonal | compose.diagonal.* | diagonal.md |
| W+H pacing | perimeter | compose.perimeter.* | perimeter.md |
| Letterbox | fit | compose.fit.* | fit.md |
| Cover | fill | compose.fill.* | fill.md |
| Density knobs | density | compose.density.* | density.md |
| Constraint resize | resize | compose.resize.*, ResizeBound | resize.md |
| NONE | — | Plain Dp/Sp or guard rails | — |
Prefix naming rules: COMPOSE-API-CONVENTIONS.md
Constants checked against Kotlin
Compared with DesignScaleConstants.kt:
| Constant | Value | Meaning |
|---|---|---|
BASE_WIDTH_DP | 300f | Reference width denominator |
BASE_HEIGHT_DP | 533f | Companion height baseline |
REFERENCE_ASPECT_RATIO | 1.78f | AR normalization for multipliers |
| Diagonal baseline | \sqrt{$300^{2}$+533^2} ≈ 611.63 dp | For diagonal strategy |
| Perimeter baseline | 833 dp | For perimeter strategy |
auto hinge | measured axis 480 dp (DimenAutoDp.kt) | BALANCED narrative |
auto ln gain | 0.4f | Log damping coefficient |
Heavy linear algebra layouts live in MATHEMATICS-AND-CALCULUS.md §§3–4. Performance notes echo from submodule library/PERFORMANCE.md.
auto (BALANCED) kernel recap
Kotlin path calculateAutoDpCompose (DimenAutoDp.kt) with inv = 1/300, transition = 480, sensitivity = 0.4:
- If axis
dim ≤ 480 dp:scale = dim × inv(linear segment identical to SDP thinking on phones). - If
dim > 480 dp:scale = transition·inv + sensitivity·ln(1 + (dim - transition)·inv).
Output before optional AR suffix a is base × scale × (aspect ratio multiplier). Matches submodule DOCUMENTATION/auto.md.
scaled, percent, Smart builders
scaled: Plain linear scale when AR compensation is OFF; f.arMultiplier path when documented suffixes flip AR on (scaled.md).
percent: Matches percent.md §4 matrices (axis dp × global inverse).
Smart inference: Kotlin does not ship smart(...).forElement(...) wrappers; other stacks may—keep Android guidance explicitly strategy-per-call. Strategy selection order summarized in README (scaled → percent → auto when reading older tables).
Regression coverage: StrategyModuleFormulasTest.kt in appdimens-dynamic (MATHEMATICS-AND-CALCULUS.md §6).
Cross-platform numeric parity (historical QA snapshot)
For the audited reference row 48 dp base on a ~720 dp-wide canvas, stacks that shipped the canonical kernel landed within ~0.1 dp of each other:
| Platform family | Narrative curve | Result |
|---|---|---|
| Audited snapshots (Android/iOS/Web/Flutter/RN) | Hybrid BALANCED | ~69.7 dp |
| Same cohort | Phone-first DEFAULT prose | ~79.2 dp |
| Same cohort | Proportional / axis-heavy storyline | ~115.2 dp |
Treat this as reassurance that narratives match reference implementations — not a pledge about every nightly build on every roadmap module. Always run your submodule tests before pinning.
Sources of truth (per submodule)
When prose in this hub disagrees with the submodule, the submodule wins. Use this list when porting concepts, verifying signatures, or filing shipping bugs.
- Android
appdimens-dynamic— README ·DOCUMENTATION/README.md·MATHEMATICS-AND-CALCULUS.md·COMPOSE-API-CONVENTIONS.md·PERFORMANCE.md·R8-PROGUARD.md - Android
appdimens-sdps— README - Android
appdimens-ssps— README - Android
appdimens-games— submodule root ·appdimens_games/ - Apple
appdimens-ios— submodule root (UIKit + SwiftUI + Metal) - Kotlin Multiplatform
appdimens-dynamic-kmp— submodule root - Flutter
appdimens-flutter— submodule root ·lib/src/ - React Native
appdimens-react-native— submodule root ·src/core/ - Web
webdimens— submodule root ·src/core/
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