669 lines
12 KiB
C++
669 lines
12 KiB
C++
/*
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Copyright (C) 2014 Paul Davis
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <algorithm>
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#include <sstream>
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#include <cmath>
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#include <stdint.h>
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#include <cfloat>
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#include "pbd/failed_constructor.h"
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#include "pbd/locale_guard.h"
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#include "pbd/string_convert.h"
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#include "canvas/colors.h"
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#include "canvas/colorspace.h"
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using namespace std;
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using namespace ArdourCanvas;
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using std::max;
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using std::min;
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ArdourCanvas::Color
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ArdourCanvas::change_alpha (Color c, double a)
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{
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return ((c & ~0xff) | (lrintf (a*255.0) & 0xff));
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}
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void
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ArdourCanvas::color_to_hsv (Color color, double& h, double& s, double& v)
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{
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double a;
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color_to_hsva (color, h, s, v, a);
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}
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void
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ArdourCanvas::color_to_hsva (Color color, double& h, double& s, double& v, double& a)
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{
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double r, g, b;
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double cmax;
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double cmin;
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double delta;
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color_to_rgba (color, r, g, b, a);
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if (r > g) {
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cmax = max (r, b);
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} else {
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cmax = max (g, b);
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}
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if (r < g) {
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cmin = min (r, b);
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} else {
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cmin = min (g, b);
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}
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v = cmax;
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delta = cmax - cmin;
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if (cmax == 0) {
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// r = g = b == 0 ... v is undefined, s = 0
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s = 0.0;
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h = 0.0;
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return;
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}
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if (delta != 0.0) {
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if (cmax == r) {
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h = fmod ((g - b)/delta, 6.0);
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} else if (cmax == g) {
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h = ((b - r)/delta) + 2;
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} else {
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h = ((r - g)/delta) + 4;
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}
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h *= 60.0;
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if (h < 0.0) {
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/* negative values are legal but confusing, because
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they alias positive values.
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*/
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h = 360 + h;
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}
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}
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if (delta == 0 || cmax == 0) {
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s = 0;
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} else {
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s = delta / cmax;
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}
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}
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ArdourCanvas::Color
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ArdourCanvas::hsva_to_color (double h, double s, double v, double a)
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{
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s = min (1.0, max (0.0, s));
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v = min (1.0, max (0.0, v));
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if (s == 0) {
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return rgba_to_color (v, v, v, a);
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}
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h = fmod (h + 360.0, 360.0);
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double c = v * s;
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double x = c * (1.0 - fabs(fmod(h / 60.0, 2) - 1.0));
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double m = v - c;
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if (h >= 0.0 && h < 60.0) {
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return rgba_to_color (c + m, x + m, m, a);
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} else if (h >= 60.0 && h < 120.0) {
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return rgba_to_color (x + m, c + m, m, a);
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} else if (h >= 120.0 && h < 180.0) {
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return rgba_to_color (m, c + m, x + m, a);
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} else if (h >= 180.0 && h < 240.0) {
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return rgba_to_color (m, x + m, c + m, a);
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} else if (h >= 240.0 && h < 300.0) {
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return rgba_to_color (x + m, m, c + m, a);
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} else if (h >= 300.0 && h < 360.0) {
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return rgba_to_color (c + m, m, x + m, a);
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}
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return rgba_to_color (m, m, m, a);
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}
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void
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ArdourCanvas::color_to_rgba (Color color, double& r, double& g, double& b, double& a)
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{
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r = ((color >> 24) & 0xff) / 255.0;
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g = ((color >> 16) & 0xff) / 255.0;
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b = ((color >> 8) & 0xff) / 255.0;
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a = ((color >> 0) & 0xff) / 255.0;
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}
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ArdourCanvas::Color
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ArdourCanvas::rgba_to_color (double r, double g, double b, double a)
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{
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/* clamp to [0 .. 1] range */
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r = min (1.0, max (0.0, r));
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g = min (1.0, max (0.0, g));
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b = min (1.0, max (0.0, b));
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a = min (1.0, max (0.0, a));
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/* convert to [0..255] range */
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unsigned int rc, gc, bc, ac;
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rc = rint (r * 255.0);
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gc = rint (g * 255.0);
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bc = rint (b * 255.0);
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ac = rint (a * 255.0);
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/* build-an-integer */
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return (rc << 24) | (gc << 16) | (bc << 8) | ac;
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}
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// Inverse of sRGB "gamma" function.
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static inline double
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inv_gam_sRGB (double c)
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{
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if (c <= 0.04045) {
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return c/12.92;
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} else {
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return pow(((c+0.055)/(1.055)),2.4);
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}
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}
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// sRGB "gamma" function
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static inline int
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gam_sRGB(double v)
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{
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if (v <= 0.0031308) {
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v *= 12.92;
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} else {
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v = 1.055 * pow (v, 1.0 / 2.4) - 0.055;
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}
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return int (v*255+.5);
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}
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static double
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luminance (uint32_t c)
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{
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// sRGB luminance(Y) values
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const double rY = 0.212655;
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const double gY = 0.715158;
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const double bY = 0.072187;
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double r, g, b, a;
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ArdourCanvas::color_to_rgba (c, r, g, b, a);
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return (gam_sRGB (rY*inv_gam_sRGB(r) + gY*inv_gam_sRGB(g) + bY*inv_gam_sRGB(b))) / 255.0;
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}
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uint32_t
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ArdourCanvas::contrasting_text_color (uint32_t c)
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{
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/* use a slightly off-white... XXX should really look this up */
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static const uint32_t white = ArdourCanvas::rgba_to_color (0.98, 0.98, 0.98, 1.0);
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static const uint32_t black = ArdourCanvas::rgba_to_color (0.0, 0.0, 0.0, 1.0);
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return (luminance (c) < 0.50) ? white : black;
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}
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HSV::HSV ()
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: h (0.0)
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, s (1.0)
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, v (1.0)
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, a (1.0)
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{
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}
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HSV::HSV (double hh, double ss, double vv, double aa)
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: h (hh)
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, s (ss)
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, v (vv)
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, a (aa)
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{
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if (h < 0.0) {
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/* normalize negative hue values into positive range */
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h = 360.0 + h;
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}
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}
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HSV::HSV (Color c)
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{
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color_to_hsva (c, h, s, v, a);
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}
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HSV::HSV (const std::string& str)
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{
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stringstream ss (str);
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ss >> h;
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ss >> s;
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ss >> v;
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ss >> a;
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}
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string
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HSV::to_string () const
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{
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PBD::LocaleGuard lg;
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stringstream ss;
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ss << PBD::to_string(h) << ' ';
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ss << PBD::to_string(s) << ' ';
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ss << PBD::to_string(v) << ' ';
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ss << PBD::to_string(a);
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return ss.str();
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}
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bool
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HSV::is_gray () const
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{
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return s == 0;
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}
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void
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HSV::clamp ()
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{
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h = fmod (h, 360.0);
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if (h < 0.0) {
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/* normalize negative hue values into positive range */
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h = 360.0 + h;
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}
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s = min (1.0, s);
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v = min (1.0, v);
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a = min (1.0, a);
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}
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HSV
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HSV::operator+ (const HSV& operand) const
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{
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HSV hsv;
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hsv.h = h + operand.h;
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hsv.s = s + operand.s;
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hsv.v = v + operand.v;
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hsv.a = a + operand.a;
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hsv.clamp ();
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return hsv;
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}
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HSV
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HSV::operator- (const HSV& operand) const
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{
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HSV hsv;
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hsv.h = h - operand.h;
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hsv.s = s - operand.s;
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hsv.v = s - operand.v;
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hsv.a = a - operand.a;
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hsv.clamp ();
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return hsv;
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}
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HSV&
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HSV::operator=(Color c)
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{
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color_to_hsva (c, h, s, v, a);
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clamp ();
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return *this;
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}
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HSV&
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HSV::operator=(const std::string& str)
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{
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uint32_t c;
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c = strtol (str.c_str(), 0, 16);
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color_to_hsva (c, h, s, v, a);
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clamp ();
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return *this;
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}
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bool
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HSV::operator== (const HSV& other)
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{
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return h == other.h &&
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s == other.s &&
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v == other.v &&
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a == other.a;
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}
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HSV
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HSV::shade (double factor) const
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{
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HSV hsv (*this);
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/* algorithm derived from a google palette website
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and analysis of their color palettes.
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basic rule: to make a color darker, increase its saturation
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until it reaches 88%, but then additionally reduce value/lightness
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by a larger amount.
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invert rule to make a color lighter.
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*/
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if (factor > 1.0) {
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if (s < 88) {
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hsv.v += (hsv.v * (factor * 10.0));
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}
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hsv.s *= factor;
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} else {
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if (s < 88) {
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hsv.v -= (hsv.v * (factor * 10.0));
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}
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hsv.s *= factor;
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}
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hsv.clamp();
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return hsv;
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}
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HSV
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HSV::outline () const
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{
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if (luminance (color()) < 0.50) {
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/* light color, darker outline: black with 15% opacity */
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return HSV (0.0, 0.0, 0.0, 0.15);
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} else {
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/* dark color, lighter outline: white with 15% opacity */
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return HSV (0.0, 0.0, 1.0, 0.15);
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}
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}
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HSV
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HSV::mix (const HSV& other, double amount) const
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{
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HSV hsv;
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hsv.h = h + (amount * (other.h - h));
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hsv.v = v + (amount * (other.s - s));
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hsv.s = s + (amount * (other.v - v));
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hsv.clamp();
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return hsv;
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}
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HSV
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HSV::delta (const HSV& other) const
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{
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HSV d;
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if (is_gray() && other.is_gray()) {
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d.h = 0.0;
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d.s = 0.0;
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d.v = v - other.v;
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} else {
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d.h = h - other.h;
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d.s = s - other.s;
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d.v = v - other.v;
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}
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d.a = a - other.a;
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/* do not clamp - we are returning a delta */
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return d;
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}
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double
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HSV::distance (const HSV& other) const
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{
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if (is_gray() && other.is_gray()) {
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/* human color perception of achromatics generates about 450
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distinct colors. By contrast, CIE94 could give a maximal
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perceptual distance of sqrt ((360^2) + 1 + 1) = 360. The 450
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are not evenly spread (Webers Law), so lets use 360 as an
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approximation of the number of distinct achromatics.
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So, scale up the achromatic difference to give about
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a maximal distance between v = 1.0 and v = 0.0 of 360.
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A difference of about 0.0055 will generate a return value of
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2, which is roughly the limit of human perceptual
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discrimination for chromatics.
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*/
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return fabs (360.0 * (v - other.v));
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}
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if (is_gray() != other.is_gray()) {
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/* no comparison possible */
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return DBL_MAX;
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}
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/* Use CIE94 definition for now */
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double sL, sA, sB;
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double oL, oA, oB;
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double r, g, b, alpha; // Careful, "a" is a field of this
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Color c;
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c = hsva_to_color (h, s, v, a);
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color_to_rgba (c, r, g, b, alpha);
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Rgb2Lab (&sL, &sA, &sB, r, g, b);
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c = hsva_to_color (other.h, other.s, other.v, other.a);
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color_to_rgba (c, r, g, b, alpha);
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Rgb2Lab (&oL, &oA, &oB, r, g, b);
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// Weighting factors depending on the application (1 = default)
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const double whtL = 1.0;
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const double whtC = 1.0;
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const double whtH = 1.0;
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const double xC1 = sqrt ((sA * sA) + (sB * oB));
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const double xC2 = sqrt ((oA * oA) + (oB * oB));
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double xDL = oL - sL;
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double xDC = xC2 - xC1;
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const double xDE = sqrt (((sL - oL) * (sL - oL))
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+ ((sA - oA) * (sA - oA))
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+ ((sB - oB) * (sB - oB)));
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double xDH;
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if (sqrt (xDE) > (sqrt (abs (xDL)) + sqrt (abs (xDC)))) {
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xDH = sqrt ((xDE * xDE) - (xDL * xDL) - (xDC * xDC));
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} else {
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xDH = 0;
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}
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const double xSC = 1 + (0.045 * xC1);
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const double xSH = 1 + (0.015 * xC1);
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xDL /= whtL;
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xDC /= whtC * xSC;
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xDH /= whtH * xSH;
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return sqrt ((xDL * xDL) + (xDC * xDC) + (xDH * xDH));
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}
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HSV
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HSV::opposite () const
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{
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HSV hsv (*this);
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hsv.h = fmod (h + 180.0, 360.0);
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return hsv;
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}
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HSV
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HSV::bw_text () const
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{
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return HSV (contrasting_text_color (color()));
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}
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HSV
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HSV::text () const
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{
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return opposite ();
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}
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HSV
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HSV::selected () const
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{
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/* XXX hack */
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return HSV (Color (0xff0000));
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}
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void
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HSV::print (std::ostream& o) const
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{
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if (!is_gray()) {
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o << '(' << h << ',' << s << ',' << v << ',' << a << ')';
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} else {
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o << "gray(" << v << ')';
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}
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}
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std::ostream& operator<<(std::ostream& o, const ArdourCanvas::HSV& hsv) { hsv.print (o); return o; }
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HSV
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HSV::mod (SVAModifier const & svam)
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{
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return svam (*this);
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}
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SVAModifier::SVAModifier (string const &str)
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: type (Add)
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, _s (0)
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, _v (0)
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, _a (0)
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{
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from_string (str);
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}
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void
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SVAModifier::from_string (string const & str)
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{
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char op;
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stringstream ss (str);
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string mod;
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ss >> op;
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switch (op) {
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case '*':
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type = Multiply;
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/* no-op values for multiply */
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_s = 1.0;
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_v = 1.0;
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_a = 1.0;
|
|
break;
|
|
case '+':
|
|
type = Add;
|
|
/* no-op values for add */
|
|
_s = 0.0;
|
|
_v = 0.0;
|
|
_a = 0.0;
|
|
break;
|
|
case '=':
|
|
type = Assign;
|
|
/* this will avoid assignment in operator() (see below) */
|
|
_s = -1.0;
|
|
_v = -1.0;
|
|
_a = -1.0;
|
|
break;
|
|
default:
|
|
throw failed_constructor ();
|
|
}
|
|
|
|
string::size_type pos;
|
|
|
|
while (ss) {
|
|
ss >> mod;
|
|
if ((pos = mod.find ("alpha:")) != string::npos) {
|
|
_a = PBD::string_to<double>(mod.substr (pos+6));
|
|
} else if ((pos = mod.find ("saturate:")) != string::npos) {
|
|
_s = PBD::string_to<double>(mod.substr (pos+9));
|
|
} else if ((pos = mod.find ("darkness:")) != string::npos) {
|
|
_v = PBD::string_to<double>(mod.substr (pos+9));
|
|
} else {
|
|
throw failed_constructor ();
|
|
}
|
|
}
|
|
}
|
|
|
|
string
|
|
SVAModifier::to_string () const
|
|
{
|
|
PBD::LocaleGuard lg;
|
|
stringstream ss;
|
|
|
|
switch (type) {
|
|
case Add:
|
|
ss << '+';
|
|
break;
|
|
case Multiply:
|
|
ss << '*';
|
|
break;
|
|
case Assign:
|
|
ss << '=';
|
|
break;
|
|
}
|
|
|
|
if (_s >= 0.0) {
|
|
ss << " saturate:" << PBD::to_string(_s);
|
|
}
|
|
|
|
if (_v >= 0.0) {
|
|
ss << " darker:" << PBD::to_string(_v);
|
|
}
|
|
|
|
if (_a >= 0.0) {
|
|
ss << " alpha:" << PBD::to_string(_a);
|
|
}
|
|
|
|
return ss.str();
|
|
}
|
|
|
|
HSV
|
|
SVAModifier::operator () (HSV& hsv) const
|
|
{
|
|
HSV r (hsv);
|
|
|
|
switch (type) {
|
|
case Add:
|
|
r.s += _s;
|
|
r.v += _v;
|
|
r.a += _a;
|
|
break;
|
|
case Multiply:
|
|
r.s *= _s;
|
|
r.v *= _v;
|
|
r.a *= _a;
|
|
break;
|
|
case Assign:
|
|
if (_s >= 0.0) {
|
|
r.s = _s;
|
|
}
|
|
if (_v >= 0.) {
|
|
r.v = _v;
|
|
}
|
|
if (_a >= 0.0) {
|
|
r.a = _a;
|
|
}
|
|
break;
|
|
}
|
|
|
|
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 );
|
|
}
|