X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fcanvas%2Fcolors.cc;h=7a108e7f85a36bd4aad3380478df053f9a0228f3;hb=c80e8727dffd2a0958ae377aff5f0e7e2904770f;hp=d83c471c2face7481c16210db55075f63d75a2f1;hpb=a494211e737eb47ffb135400f757a44fae16016f;p=ardour.git diff --git a/libs/canvas/colors.cc b/libs/canvas/colors.cc index d83c471c2f..7a108e7f85 100644 --- a/libs/canvas/colors.cc +++ b/libs/canvas/colors.cc @@ -55,9 +55,9 @@ ArdourCanvas::color_to_hsva (Color color, double& h, double& s, double& v, doubl double cmax; double cmin; double delta; - + color_to_rgba (color, r, g, b, a); - + if (r > g) { cmax = max (r, b); } else { @@ -76,12 +76,12 @@ ArdourCanvas::color_to_hsva (Color color, double& h, double& s, double& v, doubl if (cmax == 0) { // r = g = b == 0 ... v is undefined, s = 0 - s = 0.0; + s = 0.0; h = 0.0; return; } - if (delta != 0.0) { + if (delta != 0.0) { if (cmax == r) { h = fmod ((g - b)/delta, 6.0); } else if (cmax == g) { @@ -89,9 +89,9 @@ ArdourCanvas::color_to_hsva (Color color, double& h, double& s, double& v, doubl } else { h = ((r - g)/delta) + 4; } - + h *= 60.0; - + if (h < 0.0) { /* negative values are legal but confusing, because they alias positive values. @@ -135,7 +135,7 @@ ArdourCanvas::hsva_to_color (double h, double s, double v, double a) return rgba_to_color (x + m, m, c + m, a); } else if (h >= 300.0 && h < 360.0) { return rgba_to_color (c + m, m, x + m, a); - } + } return rgba_to_color (m, m, m, a); } @@ -172,8 +172,8 @@ ArdourCanvas::rgba_to_color (double r, double g, double b, double a) } // Inverse of sRGB "gamma" function. -static inline double -inv_gam_sRGB (double c) +static inline double +inv_gam_sRGB (double c) { if (c <= 0.04045) { return c/12.92; @@ -183,8 +183,8 @@ inv_gam_sRGB (double c) } // sRGB "gamma" function -static inline int -gam_sRGB(double v) +static inline int +gam_sRGB(double v) { if (v <= 0.0031308) { v *= 12.92; @@ -194,7 +194,7 @@ gam_sRGB(double v) return int (v*255+.5); } -static double +static double luminance (uint32_t c) { // sRGB luminance(Y) values @@ -205,9 +205,9 @@ luminance (uint32_t c) double r, g, b, a; ArdourCanvas::color_to_rgba (c, r, g, b, a); - + return (gam_sRGB (rY*inv_gam_sRGB(r) + gY*inv_gam_sRGB(g) + bY*inv_gam_sRGB(b))) / 255.0; -} +} uint32_t ArdourCanvas::contrasting_text_color (uint32_t c) @@ -226,7 +226,7 @@ HSV::HSV () : h (0.0) , s (1.0) , v (1.0) - , a (1.0) + , a (1.0) { } @@ -234,7 +234,7 @@ HSV::HSV (double hh, double ss, double vv, double aa) : h (hh) , s (ss) , v (vv) - , a (aa) + , a (aa) { if (h < 0.0) { /* normalize negative hue values into positive range */ @@ -259,6 +259,7 @@ HSV::HSV (const std::string& str) string HSV::to_string () const { + PBD::LocaleGuard lg; stringstream ss; ss << h << ' '; ss << s << ' '; @@ -341,12 +342,12 @@ HSV HSV::shade (double factor) const { HSV hsv (*this); - + /* algorithm derived from a google palette website and analysis of their color palettes. - basic rule: to make a color darker, increase its saturation - until it reaches 88%, but then additionally reduce value/lightness + basic rule: to make a color darker, increase its saturation + until it reaches 88%, but then additionally reduce value/lightness by a larger amount. invert rule to make a color lighter. @@ -355,12 +356,12 @@ HSV::shade (double factor) const if (factor > 1.0) { if (s < 88) { hsv.v += (hsv.v * (factor * 10.0)); - } + } hsv.s *= factor; } else { if (s < 88) { hsv.v -= (hsv.v * (factor * 10.0)); - } + } hsv.s *= factor; } @@ -420,13 +421,13 @@ HSV::distance (const HSV& other) const if (is_gray() && other.is_gray()) { /* human color perception of achromatics generates about 450 distinct colors. By contrast, CIE94 could give a maximal - perceptual distance of sqrt ((360^2) + 1 + 1) = 360. The 450 + perceptual distance of sqrt ((360^2) + 1 + 1) = 360. The 450 are not evenly spread (Webers Law), so lets use 360 as an approximation of the number of distinct achromatics. - + So, scale up the achromatic difference to give about a maximal distance between v = 1.0 and v = 0.0 of 360. - + A difference of about 0.0055 will generate a return value of 2, which is roughly the limit of human perceptual discrimination for chromatics. @@ -444,7 +445,7 @@ HSV::distance (const HSV& other) const double sL, sA, sB; double oL, oA, oB; double r, g, b, alpha; // Careful, "a" is a field of this - Color c; + Color c; c = hsva_to_color (h, s, v, a); color_to_rgba (c, r, g, b, alpha); @@ -458,7 +459,7 @@ HSV::distance (const HSV& other) const const double whtL = 1.0; const double whtC = 1.0; - const double whtH = 1.0; + const double whtH = 1.0; const double xC1 = sqrt ((sA * sA) + (sB * oB)); const double xC2 = sqrt ((oA * oA) + (oB * oB)); @@ -467,7 +468,7 @@ HSV::distance (const HSV& other) const const double xDE = sqrt (((sL - oL) * (sL - oL)) + ((sA - oA) * (sA - oA)) + ((sB - oB) * (sB - oB))); - + double xDH; if (sqrt (xDE) > (sqrt (abs (xDL)) + sqrt (abs (xDC)))) { @@ -482,7 +483,7 @@ HSV::distance (const HSV& other) const xDL /= whtL; xDC /= whtC * xSC; xDH /= whtH * xSH; - + return sqrt ((xDL * xDL) + (xDC * xDC) + (xDH * xDH)); } @@ -596,7 +597,7 @@ SVAModifier::from_string (string const & str) string SVAModifier::to_string () const { - PBD::LocaleGuard lg ("POSIX"); + PBD::LocaleGuard lg; stringstream ss; switch (type) { @@ -630,7 +631,7 @@ HSV SVAModifier::operator () (HSV& hsv) const { HSV r (hsv); - + switch (type) { case Add: r.s += _s; @@ -658,3 +659,10 @@ SVAModifier::operator () (HSV& hsv) const return r; } +ArdourCanvas::Color +ArdourCanvas::color_at_alpha (ArdourCanvas::Color c, double a) +{ + double r, g, b, unused; + color_to_rgba (c, r, g, b, unused); + return rgba_to_color( r,g,b, a ); +}