get gamma corrected value

snippets/dev/gamma_correction_linear_to_srgb.py

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+## color gamma correction using linear to SRGB
+## Allow to get screen displayed color values from a color prop (i.e. can be used in OpenGL draw)
+
+from math import pow
+
+def linear_to_srgb(color_linear):
+    """
+    Convert a linear color value to sRGB using the approximate gamma 2.2.
+    Optionally handles an alpha channel, which is passed through unchanged.
+
+    Parameters:
+    color_linear (tuple): A tuple of three or four floats representing the linear RGB values, optionally with alpha.
+
+    Returns:
+    tuple: A tuple of three or four floats representing the sRGB values, optionally with alpha.
+    """
+    def convert_channel(c):
+        if c <= 0.0031308:
+            return 12.92 * c
+        else:
+            return 1.055 * pow(c, 1/2.4) - 0.055
+
+    # Apply gamma correction to RGB channels
+    color_srgb = tuple(convert_channel(c) for c in color_linear[:3])
+
+    # If an alpha channel is present, append it to the output
+    if len(color_linear) == 4:
+        color_srgb += (color_linear[3],)
+
+    return color_srgb
+
+## example by getting color from a material:
+# color = bpy.data.materials['material_name'].node_tree.nodes["Principled BSDF"].inputs[0].default_value[:]
+
+color = [0.270500, 0.270500, 0.270500, 1.0] # (format doing Ctrl+C over a color property)
+print(linear_to_srgb(color))
+# >> (0.5568648270521792, 0.5568648270521792, 0.5568648270521792, 1.0)