diff options
Diffstat (limited to 'wx+/image_tools.h')
| -rw-r--r-- | wx+/image_tools.h | 50 |
1 files changed, 49 insertions, 1 deletions
diff --git a/wx+/image_tools.h b/wx+/image_tools.h index 8a2a43ed..772189a6 100644 --- a/wx+/image_tools.h +++ b/wx+/image_tools.h @@ -27,6 +27,7 @@ bool isEqual(const wxBitmap& lhs, const wxBitmap& rhs); //pixel-wise equality (r wxColor gradient(const wxColor& from, const wxColor& to, double fraction); //maps fraction within [0, 1] to an intermediate color +wxColour hsvColor(double h, double s, double v); //h within [0, 360), s, v within [0, 1] @@ -164,7 +165,54 @@ wxColor gradient(const wxColor& from, const wxColor& to, double fraction) from.Blue () + (to.Blue () - from.Blue ()) * fraction, from.Alpha() + (to.Alpha() - from.Alpha()) * fraction); } -} +inline +wxColour hsvColor(double h, double s, double v) //h within [0, 360), s, v within [0, 1] +{ + //http://de.wikipedia.org/wiki/HSV-Farbraum + + //make input values fit into bounds + if (h > 360) + h -= static_cast<int>(h / 360) * 360; + else if (h < 0) + h -= static_cast<int>(h / 360) * 360 - 360; + numeric::confine<double>(s, 0, 1); + numeric::confine<double>(v, 0, 1); + //------------------------------------ + const int h_i = h / 60; + const float f = h / 60 - h_i; + + auto polish = [](double val) -> unsigned char + { + int result = numeric::round(val * 255); + numeric::confine(result, 0, 255); + return static_cast<unsigned char>(result); + }; + + const unsigned char p = polish(v * (1 - s)); + const unsigned char q = polish(v * (1 - s * f)); + const unsigned char t = polish(v * (1 - s * (1 - f))); + const unsigned char vi = polish(v); + + switch (h_i) + { + case 0: + return wxColour(vi, t, p); + case 1: + return wxColour(q, vi, p); + case 2: + return wxColour(p, vi, t); + case 3: + return wxColour(p, q, vi); + case 4: + return wxColour(t, p, vi); + case 5: + return wxColour(vi, p, q); + } + assert(false); + return *wxBLACK; +} +} + #endif //IMAGE_TOOLS_HEADER_45782456427634254 |