First public commit.

lenser/ti99/palette.py

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+"""TI-99/4A TMS9918A Video Display Processor palette (15 colours + transparent)."""
+
+from __future__ import annotations
+
+import numpy as np
+
+from ..palette import srgb_to_lab
+
+# TMS9918A colours, index 0 = transparent (we never use it for pixels).
+# Common measured RGB values.
+TMS9918 = np.array([
+    (0x00, 0x00, 0x00),   # 0  transparent (treated as black for matching)
+    (0x00, 0x00, 0x00),   # 1  black
+    (0x21, 0xc8, 0x42),   # 2  medium green
+    (0x5e, 0xdc, 0x78),   # 3  light green
+    (0x54, 0x55, 0xed),   # 4  dark blue
+    (0x7d, 0x76, 0xfc),   # 5  light blue
+    (0xd4, 0x52, 0x4d),   # 6  dark red
+    (0x42, 0xeb, 0xf5),   # 7  cyan
+    (0xfc, 0x55, 0x54),   # 8  medium red
+    (0xff, 0x79, 0x78),   # 9  light red
+    (0xd4, 0xc1, 0x54),   # 10 dark yellow
+    (0xe6, 0xce, 0x80),   # 11 light yellow
+    (0x21, 0xb0, 0x3b),   # 12 dark green
+    (0xc9, 0x5b, 0xba),   # 13 magenta
+    (0xcc, 0xcc, 0xcc),   # 14 grey
+    (0xff, 0xff, 0xff),   # 15 white
+], dtype=np.float64)
+
+# Palette indices usable as pixel colours (1..15).
+USABLE = list(range(1, 16))
+
+
+def get_palette() -> np.ndarray:
+    return TMS9918
+
+
+def palette_lab() -> np.ndarray:
+    return srgb_to_lab(TMS9918)