Make the HSV pickers keep the same luminance no matter what the saturation is. Makes...

[movit] / util.cpp

diff --git a/util.cpp b/util.cpp
index 08298c7701b9146fcbd76b9330170b458a80f28b..1c47e11787a8c9781d662334430a2220aef47bf0 100644 (file)
--- a/util.cpp
+++ b/util.cpp
@@ -46,6 +46,21 @@ void hsv2rgb(float h, float s, float v, float *r, float *g, float *b)
        *b += m;
 }
 
+void hsv2rgb_normalized(float h, float s, float v, float *r, float *g, float *b)
+{
+       float ref_r, ref_g, ref_b;
+       hsv2rgb(h, s, v, r, g, b);
+       hsv2rgb(h, 0.0f, v, &ref_r, &ref_g, &ref_b);
+       float lum = 0.2126 * *r + 0.7152 * *g + 0.0722 * *b;
+       float ref_lum = 0.2126 * ref_r + 0.7152 * ref_g + 0.0722 * ref_b;
+       if (lum > 1e-3) {
+               float fac = ref_lum / lum;
+               *r *= fac;
+               *g *= fac;
+               *b *= fac;
+       }
+}
+
 std::string read_file(const std::string &filename)
 {
        static char buf[131072];