sij/mapnik
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

fix initialization of hue and sat in rgb2hsl + fix rounding in hsl2rgb to be stable on 32 bit systems (no change on 64 bit) - refs #1954

Browse source
This commit is contained in:
Dane Springmeyer 2013-07-19 00:22:52 -04:00
parent 87a2787a40
commit a834d2941a
1 changed files with 5 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
include/mapnik/util/hsl.hpp
View file

@ -36,7 +36,7 @@ static inline void rgb2hsl(unsigned char red, unsigned char green, unsigned char
double min = std::min(r,std::min(g,b));
double delta = max - min;
double gamma = max + min;
h = s = l = gamma / 2.0;
h = 0.0, s = 0.0, l = gamma / 2.0;
if (delta > 0.0) {
s = l > 0.5 ? delta / (2.0 - gamma) : delta / gamma;
if (max == r && max != g) h = (g - b) / delta + (g < b ? 6.0 : 0.0);
@ -47,7 +47,6 @@ static inline void rgb2hsl(unsigned char red, unsigned char green, unsigned char
}
static inline double hueToRGB(double m1, double m2, double h) {
// poor mans fmod
if(h < 0) h += 1;
if(h > 1) h -= 1;
if (h * 6 < 1) return m1 + (m2 - m1) * h * 6;
@ -59,13 +58,13 @@ static inline double hueToRGB(double m1, double m2, double h) {
static inline void hsl2rgb(double h, double s, double l,
unsigned char & r, unsigned char & g, unsigned char & b) {
if (!s) {
r = g = b = static_cast<unsigned char>(l * 255);
r = g = b = static_cast<unsigned char>(std::floor((l * 255.0)+.5));
}
double m2 = (l <= 0.5) ? l * (s + 1) : l + s - l * s;
double m1 = l * 2 - m2;
r = static_cast<unsigned char>(hueToRGB(m1, m2, h + 0.33333) * 255);
g = static_cast<unsigned char>(hueToRGB(m1, m2, h) * 255);
b = static_cast<unsigned char>(hueToRGB(m1, m2, h - 0.33333) * 255);
r = static_cast<unsigned char>(std::floor((hueToRGB(m1, m2, h + 0.33333) * 255.0)+.5));
g = static_cast<unsigned char>(std::floor((hueToRGB(m1, m2, h) * 255.0)+.5));
b = static_cast<unsigned char>(std::floor((hueToRGB(m1, m2, h - 0.33333) * 255.0)+.5));
}
}