Question

I need to create a colorbar like THIS
I use a scaled array of floats between 0 and 1.

Now I want to compute the RGB color from this float. How to do it? Want to write it in C/c++ so I think I need 2 functions.

The first function to build the colorbar with one parameter like STEPSIZE and the second function need the value and must just return the array index of the colorbar.

I couldn’t find it on google, so please help me.

Answer 1

RGB uses bytes, so assuming your array of floats is something like

float scaledColor[3]; // 0 = R, etc., all 0.0 < scaledColor[x] < 1.0

then you can do:

unsigned char r = (unsigned char)(255 * scaledColor[0]);
unsigned char g = (unsigned char)(255 * scaledColor[1]);
unsigned char b = (unsigned char)(255 * scaledColor[2]);

This will of course only work if the values in the floats are really in the range from 0.0 to 1.0.