Function mapToColor

utils/src/colormap.cpp:1188–1219

* Map a given value to a RGB value in the given colormap. */

 * Map a given value <x> to a RGB value in the given colormap.
 */
std::array<double, 3> mapToColor(double x, double min, double max, const std::string& colormap_name) {

    // Normalize value to [0,1] range.
    x = std::max(std::min(x, max), min);
    x = (x - min) / (max - min);

    // Determine the colormap.
    std::vector<std::pair<double, Vector3>> colormap;
    if (colormap_name == "coolwarm") {
        colormap = COOLWARM;
    } else if (colormap_name == "seismic") {
        colormap = SEISMIC;
    } else if (colormap_name == "hot") {
        colormap = HOT;
    }

    // Find the two colors in the colormap that x falls in between.
    int v1 = 1;
    while (colormap[v1].first < x) {
        v1 += 1;
    }
    v1 -= 1;
    int v2 = v1 + 1;

    Vector3 c1 = colormap[v1].second;
    Vector3 c2 = colormap[v2].second;

    // Interpolate between the two colors.
    Vector3 c = c1 + (c2 - c1) * (x - colormap[v1].first) / (colormap[v2].first - colormap[v1].first);
    std::array<double, 3> color = {c[0], c[1], c[2]};
    return color;
}

/*
 * Computes the hue, saturation, and value of the RGB color model.