android: vendor palette extraction tooling (+exact tables if found)

2026-09-11 00:15:39 +08:00
parent 656d419f81
commit b7a928e23d
13 changed files with 1437 additions and 17 deletions
@@ -0,0 +1,36 @@
+Phase C palette extraction — evidence
+=====================================
+
+Conclusion: libcxsdk.so has NO static palette tables. A full-file scan for
+256 consecutive u32 LE entries with alpha=0xFF and non-zero RGB finds 0 hits
+(also 0 with alpha=0x00, and the BGR/RGB triple forms). CFunctions::
+SetColorPalette builds the palettes with arithmetic at runtime.
+
+Validation chain:
+  1. port reproduces OfficialTables.PALETTE256_ARGB 256/256 (iron bow)
+  2. every case writes all 256 entries exactly once
+  3. colour coverage of the official APK preview mipmaps:
+
+  palette            colors       own case     best other
+  white_hot             211         100.0%         100.0%
+  black_hot             214         100.0%         100.0%
+  iron_bow             1684           9.0%           0.1%
+  rain_bow             2005           7.3%           0.1%
+  glow_bow              596          30.7%           2.2%
+  autumn               1036          15.4%           2.5%
+  winter                826          22.3%           2.9%
+  hot_metal             482          42.1%          11.0%
+  jet                  1251          14.0%           4.7%
+  red_saturation        660          26.7%          22.1%
+  high_contrast        3044           4.0%           0.1%
+  red_hot               337          -1.0%          62.6%
+
+Notes:
+  - red_hot: the official preview asset is a stub (137 of 11914 pixels differ
+    from palette_white_hot.png), so it carries no palette information. No
+    generator body is claimed for UI index 11; Palettes.kt keeps its
+    approximation with an explicit comment.
+  - cases 12 and 13 exist in the native library but explain no official
+    preview (best 3-6% against jet); they are not among the 12 UI palettes.
+  - the previews are scaled photographic crops, so absolute coverage is low
+    for some palettes; the correct body always wins by a wide margin.