//
// "$Id$"
//
// Color chooser for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2008 by Bill Spitzak and others.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA.
//
// Please report all bugs and problems on the following page:
//
//     http://www.fltk.org/str.php
//

#include <FL/Fl.H>
#include <FL/Fl_Color_Chooser.H>
#include <FL/fl_draw.H>
#include <FL/math.h>
#include <stdio.h>

// Besides being a useful object on it's own, the Fl_Color_Chooser was
// an attempt to make a complex composite object that could be easily
// imbedded into a user interface.  If you wish to make complex objects
// of your own, be sure to read this code.

// The function fl_color_chooser() creates a window containing a color
// chooser and a few buttons and current-color indicators.  It is an
// easier interface for simple programs that just need a color.

// The "hue box" can be a circle or rectilinear.
// You get a circle by defining this:
#define CIRCLE 1
// And the "hue box" can auto-update when the value changes
// you get this by defining this:
#define UPDATE_HUE_BOX 1

/**
  This \e static method converts HSV colors to RGB colorspace.
  \param[in] H, S, V color components
  \param[out] R, G, B color components
 */
void Fl_Color_Chooser::hsv2rgb(
	double H, double S, double V, double& R, double& G, double& B) {
  if (S < 5.0e-6) {
    R = G = B = V;
  } else {
    int i = (int)H;  
    double f = H - (float)i;
    double p1 = V*(1.0-S);
    double p2 = V*(1.0-S*f);
    double p3 = V*(1.0-S*(1.0-f));
    switch (i) {
    case 0: R = V;   G = p3;  B = p1;  break;
    case 1: R = p2;  G = V;   B = p1;  break;
    case 2: R = p1;  G = V;   B = p3;  break;
    case 3: R = p1;  G = p2;  B = V;   break;
    case 4: R = p3;  G = p1;  B = V;   break;
    case 5: R = V;   G = p1;  B = p2;  break;
    }
  }
}

/**
  This \e static method converts RGB colors to HSV colorspace.
  \param[in] R, G, B color components
  \param[out] H, S, V color components
 */
void Fl_Color_Chooser::rgb2hsv(
	double R, double G, double B, double& H, double& S, double& V) {
  double maxv = R > G ? R : G; if (B > maxv) maxv = B;
  V = maxv;
  if (maxv>0) {
    double minv = R < G ? R : G; if (B < minv) minv = B;
    S = 1.0 - double(minv)/maxv;
    if (maxv > minv) {
      if (maxv == R) {H = (G-B)/double(maxv-minv); if (H<0) H += 6.0;}
      else if (maxv == G) H = 2.0+(B-R)/double(maxv-minv);
      else H = 4.0+(R-G)/double(maxv-minv);
    }
  }
}

enum {M_RGB, M_BYTE, M_HEX, M_HSV}; // modes
static Fl_Menu_Item mode_menu[] = {
  {"rgb"},
  {"byte"},
  {"hex"},
  {"hsv"},
  {0}
};

int Flcc_Value_Input::format(char* buf) {
  Fl_Color_Chooser* c = (Fl_Color_Chooser*)parent();
  if (c->mode() == M_HEX) return sprintf(buf,"0x%02X", int(value()));
  else return Fl_Valuator::format(buf);
}

void Fl_Color_Chooser::set_valuators() {
  switch (mode()) {
  case M_RGB:
    rvalue.range(0,1); rvalue.step(1,1000); rvalue.value(r_);
    gvalue.range(0,1); gvalue.step(1,1000); gvalue.value(g_);
    bvalue.range(0,1); bvalue.step(1,1000); bvalue.value(b_);
    break;
  case M_BYTE:
  case M_HEX:
    rvalue.range(0,255); rvalue.step(1); rvalue.value(int(255*r_+.5));
    gvalue.range(0,255); gvalue.step(1); gvalue.value(int(255*g_+.5));
    bvalue.range(0,255); bvalue.step(1); bvalue.value(int(255*b_+.5));
    break;
  case M_HSV:
    rvalue.range(0,6); rvalue.step(1,1000); rvalue.value(hue_);
    gvalue.range(0,1); gvalue.step(1,1000); gvalue.value(saturation_);
    bvalue.range(0,1); bvalue.step(1,1000); bvalue.value(value_);
    break;
  }
}

/**
  Sets the current rgb color values.
  Does not do the callback. Does not clamp (but out of range values will
  produce psychedelic effects in the hue selector).
  \param[in] R, G, B color components.
 */
int Fl_Color_Chooser::rgb(double R, double G, double B) {
  if (R == r_ && G == g_ && B == b_) return 0;
  r_ = R; g_ = G; b_ = B;
  double ph = hue_;
  double ps = saturation_;
  double pv = value_;
  rgb2hsv(R,G,B,hue_,saturation_,value_);
  set_valuators();
  set_changed();
  if (value_ != pv) {
#ifdef UPDATE_HUE_BOX
    huebox.damage(FL_DAMAGE_SCROLL);
#endif
    valuebox.damage(FL_DAMAGE_EXPOSE);}
  if (hue_ != ph || saturation_ != ps) {
    huebox.damage(FL_DAMAGE_EXPOSE); 
    valuebox.damage(FL_DAMAGE_SCROLL);
  }
  return 1;
}

/**
  Set the hsv values.
  The passed values are clamped (or for hue, modulus 6 is used) to get
  legal values. Does not do the callback.
  \param[in] H, S, V color components.
 */
int Fl_Color_Chooser::hsv(double H, double S, double V) {
  H = fmod(H,6.0); if (H < 0.0) H += 6.0;
  if (S < 0.0) S = 0.0; else if (S > 1.0) S = 1.0;
  if (V < 0.0) V = 0.0; else if (V > 1.0) V = 1.0;
  if (H == hue_ && S == saturation_ && V == value_) return 0;
  double ph = hue_;
  double ps = saturation_;
  double pv = value_;
  hue_ = H; saturation_ = S; value_ = V;
  if (value_ != pv) {
#ifdef UPDATE_HUE_BOX
    huebox.damage(FL_DAMAGE_SCROLL);
#endif
    valuebox.damage(FL_DAMAGE_EXPOSE);}
  if (hue_ != ph || saturation_ != ps) {
    huebox.damage(FL_DAMAGE_EXPOSE); 
    valuebox.damage(FL_DAMAGE_SCROLL);
  }
  hsv2rgb(H,S,V,r_,g_,b_);
  set_valuators();
  set_changed();
  return 1;
}

////////////////////////////////////////////////////////////////

static void tohs(double x, double y, double& h, double& s) {
#ifdef CIRCLE
  x = 2*x-1;
  y = 1-2*y;
  s = sqrt(x*x+y*y); if (s > 1.0) s = 1.0;
  h = (3.0/M_PI)*atan2(y,x);
  if (h<0) h += 6.0;
#else
  h = fmod(6.0*x,6.0); if (h < 0.0) h += 6.0;
  s = 1.0-y; if (s < 0.0) s = 0.0; else if (s > 1.0) s = 1.0;
#endif
}

int Flcc_HueBox::handle(int e) {
  static double ih, is;
  Fl_Color_Chooser* c = (Fl_Color_Chooser*)parent();
  switch (e) {
  case FL_PUSH:
    if (Fl::visible_focus()) {
      Fl::focus(this);
      redraw();
    }
    ih = c->hue();
    is = c->saturation();
  case FL_DRAG: {
    double Xf, Yf, H, S;
    Xf = (Fl::event_x()-x()-Fl::box_dx(box()))/double(w()-Fl::box_dw(box()));
    Yf = (Fl::event_y()-y()-Fl::box_dy(box()))/double(h()-Fl::box_dh(box()));
    tohs(Xf, Yf, H, S);
    if (fabs(H-ih) < 3*6.0/w()) H = ih;
    if (fabs(S-is) < 3*1.0/h()) S = is;
    if (Fl::event_state(FL_CTRL)) H = ih;
    if (c->hsv(H, S, c->value())) c->do_callback();
    } return 1;
  case FL_FOCUS :
  case FL_UNFOCUS :
    if (Fl::visible_focus()) {
      redraw();
      return 1;
    }
    else return 1;
  case FL_KEYBOARD :
    return handle_key(Fl::event_key());
  default:
    return 0;
  }
}

static void generate_image(void* vv, int X, int Y, int W, uchar* buf) {
  Flcc_HueBox* v = (Flcc_HueBox*)vv;
  int iw = v->w()-Fl::box_dw(v->box());
  double Yf = double(Y)/(v->h()-Fl::box_dh(v->box()));
#ifdef UPDATE_HUE_BOX
  const double V = ((Fl_Color_Chooser*)(v->parent()))->value();
#else
  const double V = 1.0;
#endif
  for (int x = X; x < X+W; x++) {
    double Xf = double(x)/iw;
    double H,S; tohs(Xf,Yf,H,S);
    double r,g,b;
    Fl_Color_Chooser::hsv2rgb(H,S,V,r,g,b);
    *buf++ = uchar(255*r+.5);
    *buf++ = uchar(255*g+.5);
    *buf++ = uchar(255*b+.5);
  }
}

int Flcc_HueBox::handle_key(int key) {
  int w1 = w()-Fl::box_dw(box())-6;
  int h1 = h()-Fl::box_dh(box())-6;
  Fl_Color_Chooser* c = (Fl_Color_Chooser*)parent();

#ifdef CIRCLE
  int X = int(.5*(cos(c->hue()*(M_PI/3.0))*c->saturation()+1) * w1);
  int Y = int(.5*(1-sin(c->hue()*(M_PI/3.0))*c->saturation()) * h1);
#else
  int X = int(c->hue()/6.0*w1);
  int Y = int((1-c->saturation())*h1);
#endif

  switch (key) {
    case FL_Up :
      Y -= 3;
      break;
    case FL_Down :
      Y += 3;
      break;
    case FL_Left :
      X -= 3;
      break;
    case FL_Right :
      X += 3;
      break;
    default :
      return 0;
  }

  double Xf, Yf, H, S;
  Xf = (double)X/(double)w1;
  Yf = (double)Y/(double)h1;
  tohs(Xf, Yf, H, S);
  if (c->hsv(H, S, c->value())) c->do_callback();

  return 1;
}

void Flcc_HueBox::draw() {
  if (damage()&FL_DAMAGE_ALL) draw_box();
  int x1 = x()+Fl::box_dx(box());
  int yy1 = y()+Fl::box_dy(box());
  int w1 = w()-Fl::box_dw(box());
  int h1 = h()-Fl::box_dh(box());
  if (damage() == FL_DAMAGE_EXPOSE) fl_clip(x1+px,yy1+py,6,6);
  fl_draw_image(generate_image, this, x1, yy1, w1, h1);
  if (damage() == FL_DAMAGE_EXPOSE) fl_pop_clip();
  Fl_Color_Chooser* c = (Fl_Color_Chooser*)parent();
#ifdef CIRCLE
  int X = int(.5*(cos(c->hue()*(M_PI/3.0))*c->saturation()+1) * (w1-6));
  int Y = int(.5*(1-sin(c->hue()*(M_PI/3.0))*c->saturation()) * (h1-6));
#else
  int X = int(c->hue()/6.0*(w1-6));
  int Y = int((1-c->saturation())*(h1-6));
#endif
  if (X < 0) X = 0; else if (X > w1-6) X = w1-6;
  if (Y < 0) Y = 0; else if (Y > h1-6) Y = h1-6;
  //  fl_color(c->value()>.75 ? FL_BLACK : FL_WHITE);
  draw_box(FL_UP_BOX,x1+X,yy1+Y,6,6,Fl::focus() == this ? FL_FOREGROUND_COLOR : FL_GRAY);
  px = X; py = Y;
}

////////////////////////////////////////////////////////////////

int Flcc_ValueBox::handle(int e) {
  static double iv;
  Fl_Color_Chooser* c = (Fl_Color_Chooser*)parent();
  switch (e) {
  case FL_PUSH:
    if (Fl::visible_focus()) {
      Fl::focus(this);
      redraw();
    }
    iv = c->value();
  case FL_DRAG: {
    double Yf;
    Yf = 1-(Fl::event_y()-y()-Fl::box_dy(box()))/double(h()-Fl::box_dh(box()));
    if (fabs(Yf-iv)<(3*1.0/h())) Yf = iv;
    if (c->hsv(c->hue(),c->saturation(),Yf)) c->do_callback();
    } return 1;
  case FL_FOCUS :
  case FL_UNFOCUS :
    if (Fl::visible_focus()) {
      redraw();
      return 1;
    }
    else return 1;
  case FL_KEYBOARD :
    return handle_key(Fl::event_key());
  default:
    return 0;
  }
}

static double tr, tg, tb;
static void generate_vimage(void* vv, int X, int Y, int W, uchar* buf) {
  Flcc_ValueBox* v = (Flcc_ValueBox*)vv;
  double Yf = 255*(1.0-double(Y)/(v->h()-Fl::box_dh(v->box())));
  uchar r = uchar(tr*Yf+.5);
  uchar g = uchar(tg*Yf+.5);
  uchar b = uchar(tb*Yf+.5);
  for (int x = X; x < X+W; x++) {
    *buf++ = r; *buf++ = g; *buf++ = b;
  }
}

void Flcc_ValueBox::draw() {
  if (damage()&FL_DAMAGE_ALL) draw_box();
  Fl_Color_Chooser* c = (Fl_Color_Chooser*)parent();
  c->hsv2rgb(c->hue(),c->saturation(),1.0,tr,tg,tb);
  int x1 = x()+Fl::box_dx(box());
  int yy1 = y()+Fl::box_dy(box());
  int w1 = w()-Fl::box_dw(box());
  int h1 = h()-Fl::box_dh(box());
  if (damage() == FL_DAMAGE_EXPOSE) fl_clip(x1,yy1+py,w1,6);
  fl_draw_image(generate_vimage, this, x1, yy1, w1, h1);
  if (damage() == FL_DAMAGE_EXPOSE) fl_pop_clip();
  int Y = int((1-c->value()) * (h1-6));
  if (Y < 0) Y = 0; else if (Y > h1-6) Y = h1-6;
  draw_box(FL_UP_BOX,x1,yy1+Y,w1,6,Fl::focus() == this ? FL_FOREGROUND_COLOR : FL_GRAY);
  py = Y;
}

int Flcc_ValueBox::handle_key(int key) {
  int h1 = h()-Fl::box_dh(box())-6;
  Fl_Color_Chooser* c = (Fl_Color_Chooser*)parent();

  int Y = int((1-c->value()) * h1);
  if (Y < 0) Y = 0; else if (Y > h1) Y = h1;

  switch (key) {
    case FL_Up :
      Y -= 3;
      break;
    case FL_Down :
      Y += 3;
      break;
    default :
      return 0;
  }

  double Yf;
  Yf = 1-((double)Y/(double)h1);
  if (c->hsv(c->hue(),c->saturation(),Yf)) c->do_callback();

  return 1;
}

////////////////////////////////////////////////////////////////

void Fl_Color_Chooser::rgb_cb(Fl_Widget* o, void*) {
  Fl_Color_Chooser* c = (Fl_Color_Chooser*)(o->parent());
  double R = c->rvalue.value();
  double G = c->gvalue.value();
  double B = c->bvalue.value();
  if (c->mode() == M_HSV) {
    if (c->hsv(R,G,B)) c->do_callback();
    return;
  }
  if (c->mode() != M_RGB) {
    R = R/255;
    G = G/255;
    B = B/255;
  }
  if (c->rgb(R,G,B)) c->do_callback();
}

void Fl_Color_Chooser::mode_cb(Fl_Widget* o, void*) {
  Fl_Color_Chooser* c = (Fl_Color_Chooser*)(o->parent());
  // force them to redraw even if value is the same:
  c->rvalue.value(-1);
  c->gvalue.value(-1);
  c->bvalue.value(-1);
  c->set_valuators();
}

////////////////////////////////////////////////////////////////

/**
  Creates a new Fl_Color_Chooser widget using the given position, size, and
  label string.
  The recommended dimensions are 200x95. The color is initialized to black.
  \param[in] X, Y, W, H position and size of the widget
  \param[in] L widget label, default is no label
 */
Fl_Color_Chooser::Fl_Color_Chooser(int X, int Y, int W, int H, const char* L)
  : Fl_Group(0,0,195,115,L),
    huebox(0,0,115,115),
    valuebox(115,0,20,115),
    choice(140,0,55,25),
    rvalue(140,30,55,25),
    gvalue(140,60,55,25),
    bvalue(140,90,55,25),
    resize_box(0,0,115,115)
{
  end();
  resizable(resize_box);
  resize(X,Y,W,H);
  r_ = g_ = b_ = 0;
  hue_ = 0.0;
  saturation_ = 0.0;
  value_ = 0.0;
  huebox.box(FL_DOWN_FRAME);
  valuebox.box(FL_DOWN_FRAME);
  choice.menu(mode_menu);
  set_valuators();
  rvalue.callback(rgb_cb);
  gvalue.callback(rgb_cb);
  bvalue.callback(rgb_cb);
  choice.callback(mode_cb);
  choice.box(FL_THIN_UP_BOX);
  choice.textfont(FL_HELVETICA_BOLD_ITALIC);
}

////////////////////////////////////////////////////////////////
// fl_color_chooser():

#include <FL/Fl_Window.H>
#include <FL/Fl_Box.H>
#include <FL/Fl_Return_Button.H>

class ColorChip : public Fl_Widget {
  void draw();
public:
  uchar r,g,b;
  ColorChip(int X, int Y, int W, int H) : Fl_Widget(X,Y,W,H) {
    box(FL_ENGRAVED_FRAME);}
};

void ColorChip::draw() {
  if (damage()&FL_DAMAGE_ALL) draw_box();
  fl_rectf(x()+Fl::box_dx(box()),
	   y()+Fl::box_dy(box()),
	   w()-Fl::box_dw(box()),
	   h()-Fl::box_dh(box()),r,g,b);
}

static void chooser_cb(Fl_Object* o, void* vv) {
  Fl_Color_Chooser* c = (Fl_Color_Chooser*)o;
  ColorChip* v = (ColorChip*)vv;
  v->r = uchar(255*c->r()+.5);
  v->g = uchar(255*c->g()+.5);
  v->b = uchar(255*c->b()+.5);
  v->damage(FL_DAMAGE_EXPOSE);
}

extern const char* fl_ok;
extern const char* fl_cancel;

/**
  \defgroup fl_color_chooser_group fl_color_chooser()

  \code #include <FL/Fl_Color_Chooser.H> \endcode

  The double version takes RGB values in the range 0.0 to 1.0.
  The uchar version takes RGB values in the range 0 to 255.
  The \p name argument specifies the label (title) for the window.

  \image html fl_color_chooser.jpg

  fl_color_chooser() pops up a window to let the user pick an arbitrary RGB
  color. They can pick the hue and saturation in the "hue box" on the left
  (hold down CTRL to just change the saturation), and the brighness using
  the vertical slider. Or they can type the 8-bit numbers into the RGB
  Fl_Value_Input fields, or drag the mouse across them to adjust them.
  The pull-down menu lets the user set the input fields to show RGB, HSV,
  or 8-bit RGB (0 to 255).

  This returns non-zero if the user picks ok, and updates the RGB values.
  If the user picks cancel or closes the window this returns zero and leaves
  RGB unchanged.

  If you use the color chooser on an 8-bit screen, it will allocate all the
  available colors, leaving you no space to exactly represent the color the
  user picks! You can however use fl_rectf() to fill a region with a simulated
  color using dithering.
 */

/** \relatesalso Fl_Color_Chooser
  \ingroup fl_color_chooser_group
  \fn int fl_color_chooser(const char* name, double& r, double& g, double& b)
  \brief Pops up a window to let the user pick an arbitrary RGB color.
  
  \param[in] name title label for the window
  \param[in] r, g, b color components in the range 0.0 to 1.0.
 */
int fl_color_chooser(const char* name, double& r, double& g, double& b) {
  Fl_Window window(215,200,name);
  Fl_Color_Chooser chooser(10, 10, 195, 115);
  ColorChip ok_color(10, 130, 95, 25);
  Fl_Return_Button ok_button(10, 165, 95, 25, fl_ok);
  ColorChip cancel_color(110, 130, 95, 25);
  cancel_color.r = uchar(255*r+.5); ok_color.r = cancel_color.r;
  ok_color.g = cancel_color.g = uchar(255*g+.5);
  ok_color.b = cancel_color.b = uchar(255*b+.5);
  Fl_Button cancel_button(110, 165, 95, 25, fl_cancel);
  window.resizable(chooser);
  chooser.rgb(r,g,b);
  chooser.callback(chooser_cb, &ok_color);
  window.end();
  window.set_modal();
  window.hotspot(window);
  window.show();
  while (window.shown()) {
    Fl::wait();
    for (;;) {
      Fl_Widget* o = Fl::readqueue();
      if (!o) break;
      if (o == &ok_button) {
	r = chooser.r();
	g = chooser.g();
	b = chooser.b();
	return 1;
      }
      if (o == &window || o == &cancel_button) return 0;
    }
  }
  return 0;
}

/** \relatesalso Fl_Color_Chooser
  \ingroup fl_color_chooser_group
  \fn int fl_color_chooser(const char* name, uchar& r, uchar& g, uchar& b)
  \brief Pops up a window to let the user pick an arbitrary RGB color.
  
  \param[in] name title label for the window
  \param[in] r, g, b color components in the range 0 to 255.
 */
int fl_color_chooser(const char* name, uchar& r, uchar& g, uchar& b) {
  double dr = r/255.0;
  double dg = g/255.0;
  double db = b/255.0;
  if (fl_color_chooser(name,dr,dg,db)) {
    r = uchar(255*dr+.5);
    g = uchar(255*dg+.5);
    b = uchar(255*db+.5);
    return 1;
  }
  return 0;
}

//
// End of "$Id$".
//