brightness reduction in colormap gen

misc/generate_colormap_constant.py

@@ -2,27 +2,38 @@
 
 import numpy as np
 import matplotlib.cm
+import matplotlib.pyplot as plt
+import colorsys
 
 nValues = 500;
 
 # get a matplotlib colormap
-# cmapName = 'Spectral'
-# cmap = matplotlib.cm.get_cmap(cmapName)
+cmapName = 'hsv'
+cmap = plt.get_cmap(cmapName)
 
 # get a cmocean colormap
-import cmocean
-cmapName = 'phase'
-cmap = cmocean.cm.phase
+# import cmocean
+# cmapName = 'phase'
+# cmap = cmocean.cm.phase
 
 
 print("static const Colormap CM_" + cmapName.upper() + " = {")
 print("    \"" + cmapName + "\",")
 
+def reduce_brightness_rgb(color, factor):
+    r, g, b = color
+    h, l, s = colorsys.rgb_to_hls(r, g, b)
+    l = max(0, l * factor)  # Ensure lightness remains non-negative
+    r, g, b = colorsys.hls_to_rgb(h, l, s)
+    return tuple(x for x in (r, g, b))
+
 dataStr = "{"
 for i in range(nValues):
 
     floatInd = float(i) / (nValues-1)
     color = cmap(floatInd)
+    color = (color[0], color[1], color[2])
+    # color = reduce_brightness_rgb(color, 0.85) # optional: dim bright colormaps a little
 
     dataStr += "{" + str(color[0]) + "," + str(color[1]) + "," + str(color[2]) + "},"