[Project] Css: Fix HSL conversion

diff --git a/src/libserver/css/css_value.cxx b/src/libserver/css/css_value.cxx
index f00543615c3f823d7d2959314b0a3ca43e41eb1a..c0ed9242c15a8fb567d942fbf2efef1b20cd75ec 100644 (file)
--- a/src/libserver/css/css_value.cxx
+++ b/src/libserver/css/css_value.cxx
@@ -158,17 +158,11 @@ constexpr static inline auto h_component_convert(const css_parser_token &tok)
                        else if (dbl < 0) {
                                dbl = 0;
                        }
-                       ret = (dbl / 100.0) * 360.0;
+                       ret = (dbl / 100.0);
                }
                else {
-                       if (dbl > 360) {
-                               dbl = 360;
-                       }
-                       else if (dbl < 0) {
-                               dbl = 0;
-                       }
-
-                       ret = dbl;
+                       dbl = ((((int)dbl % 360) + 360) % 360); /* Deal with rotations */
+                       ret = dbl / 360.0; /* Normalize to 0..1 */
                }
        }
 
@@ -210,6 +204,8 @@ constexpr static inline auto sl_component_convert(const css_parser_token &tok)
 static inline auto hsl_to_rgb(double h, double s, double l)
        -> css_color
 {
+       css_color ret;
+
        constexpr auto hue2rgb = [](auto p, auto q, auto t) -> auto {
                if (t < 0.0) {
                        t += 1.0;
@@ -217,25 +213,33 @@ static inline auto hsl_to_rgb(double h, double s, double l)
                if (t > 1.0) {
                        t -= 1.0;
                }
-               if (t < 1.0/6.0) {
+               if (t * 6. < 1.0) {
                        return p + (q - p) * 6.0 * t;
                }
-               if (t < 0.5) {
+               if (t * 2. < 1) {
                        return q;
                }
-               if (t < 2.0/3.0) {
+               if (t * 3. < 2.) {
                        return p + (q - p) * (2.0/3.0 - t) * 6.0;
                }
-               return p * 255.0;
+               return p;
        };
 
-       css_color ret;
+       if (s == 0) {
+               /* Achromatic */
+               ret.r = l;
+               ret.g = l;
+               ret.b = l;
+       }
+       else {
+               auto q = l <= 0.5 ? l * (1.0 + s) : l + s - l * s;
+               auto p = 2.0 * l - q;
+               ret.r = (std::uint8_t) (hue2rgb(p, q, h + 1.0 / 3.0) * 255);
+               ret.g = (std::uint8_t) (hue2rgb(p, q, h) * 255);
+               ret.b = (std::uint8_t) (hue2rgb(p, q, h - 1.0 / 3.0) * 255);
+       }
 
-       auto q = l < 0.5 ? l * (1.0 + s) : l + s - l * s;
-       auto p = 2.0 * l - q;
-       ret.r = (std::uint8_t)hue2rgb(p, q, h + 1.0/3.0);
-       ret.g = (std::uint8_t)hue2rgb(p, q, h);
-       ret.b = (std::uint8_t)hue2rgb(p, q, h - 1.0/3.0);
+       ret.alpha = 255;
 
        return ret;
 }

diff --git a/src/libserver/css/css_value.hxx b/src/libserver/css/css_value.hxx
index a8152ed101c3001667fc4df5f57c8f8725491e20..5f9fa0cee958faea9bc13d38022b830fee59ffa4 100644 (file)
--- a/src/libserver/css/css_value.hxx
+++ b/src/libserver/css/css_value.hxx
@@ -36,7 +36,7 @@ struct alignas(int) css_color {
 
        std::uint8_t alpha;
 
-       constexpr css_color(std::uint8_t _r, std::uint8_t _g, std::uint8_t _b, std::uint8_t _alpha = 255) :
+       css_color(std::uint8_t _r, std::uint8_t _g, std::uint8_t _b, std::uint8_t _alpha = 255) :
                r(_r), g(_g), b(_b), alpha(_alpha) {}
        css_color() = default;
 };