/*
 * Copyright (C) 2005-2016 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2005 Taybin Rutkin <taybin@taybin.com>
 * Copyright (C) 2008-2011 David Robillard <d@drobilla.net>
 * Copyright (C) 2010-2011 Carl Hetherington <carl@carlh.net>
 * Copyright (C) 2014-2019 Robin Gareus <robin@gareus.org>
 * Copyright (C) 2015 Tim Mayberry <mojofunk@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <cmath>
#include <climits>
#include <string.h>

#include <cairo.h>
#include <gtkmm/menu.h>

#include "gtkmm2ext/gtk_ui.h"

#include "pbd/error.h"
#include "pbd/cartesian.h"
#include "ardour/panner.h"
#include "ardour/panner_shell.h"
#include "ardour/pannable.h"
#include "ardour/speakers.h"

#include "gtkmm2ext/colors.h"

#include "panner2d.h"
#include "keyboard.h"
#include "gui_thread.h"
#include "rgb_macros.h"
#include "utils.h"
#include "public_editor.h"
#include "ui_config.h"

#include "pbd/i18n.h"

using namespace std;
using namespace Gtk;
using namespace ARDOUR;
using namespace ARDOUR_UI_UTILS;
using namespace PBD;
using Gtkmm2ext::Keyboard;

Panner2d::ColorScheme Panner2d::colors;
bool Panner2d::have_colors = false;

static const int large_size_threshold = 100;
static const int large_border_width = 25;
static const int small_border_width = 8;

Panner2d::Target::Target (const AngularVector& a, const char *txt)
	: position (a)
	, text (txt)
	, _selected (false)
{
}

Panner2d::Target::~Target ()
{
}

void
Panner2d::Target::set_text (const char* txt)
{
	text = txt;
}

Panner2d::Panner2d (std::shared_ptr<PannerShell> p, int32_t h)
: panner_shell (p)
	, position (AngularVector (0.0, 0.0), "")
	, width (0)
	, height (h)
	, last_width (0)
	, have_elevation (false)
	, _send_mode (false)
{
	if (!have_colors) {
		set_colors ();
		have_colors = true;
	}

	UIConfiguration::instance().ColorsChanged.connect (sigc::mem_fun (*this, &Panner2d::color_handler));

	panner_shell->Changed.connect (panshell_connections, invalidator (*this), std::bind (&Panner2d::handle_state_change, this), gui_context());

	panner_shell->panner()->SignalPositionChanged.connect (panner_connections, invalidator(*this), std::bind (&Panner2d::handle_position_change, this), gui_context());

	drag_target = 0;
	set_events (Gdk::BUTTON_PRESS_MASK|Gdk::BUTTON_RELEASE_MASK|Gdk::POINTER_MOTION_MASK);

	handle_state_change ();
	handle_position_change ();
}

Panner2d::~Panner2d()
{
	for (Targets::iterator i = speakers.begin(); i != speakers.end(); ++i) {
		delete *i;
	}
	for (Targets::iterator i = signals.begin(); i != signals.end(); ++i) {
		delete *i;
	}
}

void
Panner2d::set_colors ()
{
	// TODO get all colors from theme, resolve dups
	colors.background = UIConfiguration::instance().color ("mono panner bg");
	colors.crosshairs =          0x4884a9ff; // 0.282, 0.517, 0.662, 1.0
	colors.signalcircle_border = 0x84c5e1ff; // 0.517, 0.772, 0.882, 1.0
	colors.signalcircle =        0x4884a9ff; // 0.282, 0.517, 0.662, 1.0  // also used with a = 0.9
	colors.diffusion =           0x4884a973; // 0.282, 0.517, 0.662, 0.45
	colors.diffusion_inv =       0xff6b6b73; // 1.0,   0.419, 0.419, 0.45
	colors.pos_outline =         0xffe7e7d9; // 1.0,   0.905, 0.905, 0.85
	colors.pos_fill =            0xff6b6bd9; // 1.0,   0.419, 0.419, 0.85
	colors.signal_outline =      0x84c5e1cc; // 0.517, 0.772, 0.882, 0.8
	colors.signal_fill =         0x4884a9bf; // 0.282, 0.517, 0.662, 0.75
	colors.speaker_fill =        0x4884a9ff; // 0.282, 0.517, 0.662, 1.0
	colors.text =                0x84c5e1e6; // 0.517, 0.772, 0.882, 0.9

	colors.send_bg  = UIConfiguration::instance().color ("send bg");
	colors.send_pan = UIConfiguration::instance().color ("send pan");
}

void
Panner2d::color_handler ()
{
	set_colors ();
	queue_draw ();
}

void
Panner2d::reset (uint32_t n_inputs)
{
	uint32_t nouts = panner_shell->panner()->out().n_audio();

	/* signals */

	while (signals.size() < n_inputs) {
		add_signal ("", AngularVector());
	}

	if (signals.size() > n_inputs) {
		for (uint32_t i = signals.size(); i < n_inputs; ++i) {
			delete signals[i];
		}

		signals.resize (n_inputs);
	}

	label_signals ();

	for (uint32_t i = 0; i < n_inputs; ++i) {
		signals[i]->position = panner_shell->panner()->signal_position (i);
	}

	/* add all outputs */

	while (speakers.size() < nouts) {
		add_speaker (AngularVector());
	}

	if (speakers.size() > nouts) {
		for (uint32_t i = nouts; i < speakers.size(); ++i) {
			delete speakers[i];
		}

		speakers.resize (nouts);
	}

	for (Targets::iterator x = speakers.begin(); x != speakers.end(); ++x) {
		(*x)->visible = false;
	}

	vector<Speaker>& the_speakers (panner_shell->panner()->get_speakers()->speakers());

	for (uint32_t n = 0; n < nouts; ++n) {
		char buf[16];

		snprintf (buf, sizeof (buf), "%d", n+1);
		speakers[n]->set_text (buf);
		speakers[n]->position = the_speakers[n].angles();
		speakers[n]->visible = true;
	}

	queue_draw ();
}

void
Panner2d::on_size_allocate (Gtk::Allocation& alloc)
{
	width = alloc.get_width();
	height = alloc.get_height();

	if (height > large_size_threshold) {
		border = large_border_width;
	} else {
		border = small_border_width;
	}

	radius = min (width, height);
	radius -= border;
	radius /= 2;
	radius = rint(radius) + .5;

	hoffset = max ((double) (width - height), border);
	voffset = max ((double) (height - width), border);

	hoffset = rint(hoffset / 2.0);
	voffset = rint(voffset / 2.0);

	DrawingArea::on_size_allocate (alloc);
}

int
Panner2d::add_signal (const char* text, const AngularVector& a)
{
	Target* signal = new Target (a, text);
	signals.push_back (signal);
	signal->visible = true;

	return 0;
}

int
Panner2d::add_speaker (const AngularVector& a)
{
	Target* speaker = new Target (a, "");
	speakers.push_back (speaker);
	speaker->visible = true;
	queue_draw ();

	return speakers.size() - 1;
}

void
Panner2d::handle_state_change ()
{
	panner_connections.drop_connections();
	if (!panner_shell->panner()) {
		return;
	}

	panner_shell->panner()->SignalPositionChanged.connect (panner_connections, invalidator(*this), std::bind (&Panner2d::handle_position_change, this), gui_context());

	set<Evoral::Parameter> params = panner_shell->pannable()->what_can_be_automated();
	set<Evoral::Parameter>::iterator p = params.find(PanElevationAutomation);
	bool elev = have_elevation;
	have_elevation = (p == params.end()) ? false : true;
	if (elev != have_elevation) {
		handle_position_change();
	}
	queue_draw ();
}

void
Panner2d::label_signals ()
{
	uint32_t sz = signals.size();

	switch (sz) {
		case 0:
			break;

		case 1:
			signals[0]->set_text ("");
			break;

		case 2:
			signals[0]->set_text (S_("Panner|L"));
			signals[1]->set_text (S_("Panner|R"));
			break;

		default:
			for (uint32_t i = 0; i < sz; ++i) {
				char buf[64];
				snprintf (buf, sizeof (buf), "%" PRIu32, i + 1);
				signals[i]->set_text (buf);
			}
			break;
	}
}

void
Panner2d::handle_position_change ()
{
	uint32_t n;
	double w = panner_shell->pannable()->pan_width_control->get_value();

	position.position = AngularVector (panner_shell->pannable()->pan_azimuth_control->get_value() * 360.0,
	                                   panner_shell->pannable()->pan_elevation_control->get_value() * 90.0);

	for (uint32_t i = 0; i < signals.size(); ++i) {
		signals[i]->position = panner_shell->panner()->signal_position (i);
	}

	if (w * last_width <= 0) {
		/* changed sign */
		label_signals ();
	}

	last_width = w;

	vector<Speaker>& the_speakers (panner_shell->panner()->get_speakers()->speakers());

	for (n = 0; n < speakers.size(); ++n) {
		speakers[n]->position = the_speakers[n].angles();
	}

	queue_draw ();
}

void
Panner2d::move_signal (int which, const AngularVector& a)
{
	if (which >= int (speakers.size())) {
		return;
	}

	speakers[which]->position = a;
	queue_draw ();
}

Panner2d::Target *
Panner2d::find_closest_object (gdouble x, gdouble y, bool& is_signal)
{
	Target *closest = 0;
	Target *candidate;
	float distance;
	float best_distance = FLT_MAX;
	CartesianVector c;

	/* start with the position itself */

	PBD::AngularVector dp = position.position;
	if (!have_elevation) dp.ele = 0;
	dp.azi = 270 - dp.azi;
	dp.cartesian (c);

	cart_to_gtk (c);
	best_distance = sqrt ((c.x - x) * (c.x - x) +
			(c.y - y) * (c.y - y));
	closest = &position;

#if 0 // TODO signal grab -> change width, not position
	for (Targets::const_iterator i = signals.begin(); i != signals.end(); ++i) {
		candidate = *i;

		candidate->position.cartesian (c);
		cart_to_gtk (c);

		distance = sqrt ((c.x - x) * (c.x - x) +
				(c.y - y) * (c.y - y));

		if (distance < best_distance) {
			closest = candidate;
			best_distance = distance;
		}
	}
#endif

	is_signal = true;

	if (height > large_size_threshold) {
		/* "big" */
		if (best_distance > 30) { // arbitrary
			closest = 0;
		}
	} else {
		/* "small" */
		if (best_distance > 10) { // arbitrary
			closest = 0;
		}
	}

	/* if we didn't find a signal close by, check the speakers */

	if (!closest) {
		for (Targets::const_iterator i = speakers.begin(); i != speakers.end(); ++i) {
			candidate = *i;
			PBD::AngularVector sp = candidate->position;
			sp.azi = 270 -sp.azi;
			CartesianVector c;
			sp.cartesian (c);
			cart_to_gtk (c);

			distance = sqrt ((c.x - x) * (c.x - x) +
					(c.y - y) * (c.y - y));

			if (distance < best_distance) {
				closest = candidate;
				best_distance = distance;
			}
		}

		if (height > large_size_threshold) {
			/* "big" */
			if (best_distance < 30) { // arbitrary
				is_signal = false;
			} else {
				closest = 0;
			}
		} else {
			/* "small" */
			if (best_distance < 10) { // arbitrary
				is_signal = false;
			} else {
				closest = 0;
			}
		}
	}

	return closest;
}

void
Panner2d::set_send_drawing_mode (bool onoff)
{
	if (_send_mode != onoff) {
		_send_mode = onoff;
		queue_draw ();
	}
}

bool
Panner2d::on_motion_notify_event (GdkEventMotion *ev)
{
	gint x, y;
	GdkModifierType state;

	if (ev->is_hint) {
		gdk_window_get_pointer (ev->window, &x, &y, &state);
	} else {
		x = (int) floor (ev->x);
		y = (int) floor (ev->y);
		state = (GdkModifierType) ev->state;
	}

	if (ev->state & (GDK_BUTTON1_MASK|GDK_BUTTON2_MASK)) {
		did_move = true;
	}

	return handle_motion (x, y, state);
}

#define CSSRGBA(CL) \
	cairo_set_source_rgba (cr, UINT_RGBA_R_FLT(CL), UINT_RGBA_G_FLT(CL), UINT_RGBA_B_FLT(CL), UINT_RGBA_A_FLT(CL));

#define CSSRGB(CL, A) \
	cairo_set_source_rgba (cr, UINT_RGBA_R_FLT(CL), UINT_RGBA_G_FLT(CL), UINT_RGBA_B_FLT(CL), A);
bool
Panner2d::on_expose_event (GdkEventExpose *event)
{
	CartesianVector c;
	cairo_t* cr;
	bool xsmall = (height <= large_size_threshold);
	const double diameter = radius*2.0;

	cr = gdk_cairo_create (get_window()->gobj());

	/* background */

	cairo_rectangle (cr, event->area.x, event->area.y, event->area.width, event->area.height);

	uint32_t bg = _send_mode ? colors.send_bg : colors.background;

	if (!panner_shell->bypassed()) {
		CSSRGBA(bg);
	} else {
		CSSRGB(bg, 0.2);
	}
	cairo_fill_preserve (cr);
	cairo_clip (cr);

	/* offset to give us some border */

	cairo_translate (cr, hoffset, voffset);

	cairo_set_line_width (cr, 1.0);

	/* horizontal line of "crosshairs" */

	CSSRGBA(colors.crosshairs);
	cairo_move_to (cr, 0.0, radius);
	cairo_line_to (cr, diameter, radius);
	cairo_stroke (cr);

	/* vertical line of "crosshairs" */

	cairo_move_to (cr, radius, 0);
	cairo_line_to (cr, radius, diameter);
	cairo_stroke (cr);

	/* the circle on which signals live */

	cairo_set_line_width (cr, 1.5);
	CSSRGBA(colors.signalcircle_border);
	cairo_arc (cr, radius, radius, radius, 0.0, 2.0 * M_PI);
	cairo_stroke (cr);

	for (uint32_t rad = 15; rad < 90; rad += 15) {
		cairo_set_line_width (cr, .5 + (float)rad / 150.0);
		if (rad == 45) {
			CSSRGBA(colors.signalcircle);
		} else {
			CSSRGB(colors.signalcircle, 0.9);
		}
		cairo_new_path (cr);
		cairo_arc (cr, radius, radius, radius * sin(M_PI * (float) rad / 180.0), 0, 2.0 * M_PI);
		cairo_stroke (cr);
	}

	if (!panner_shell->bypassed()) {
		/* convention top == front ^= azimuth == .5 (same as stereo/mono panners) */

		if (signals.size() > 1) {
			/* arc to show "diffusion" */

			double width_angle = fabs (panner_shell->pannable()->pan_width_control->get_value()) * 2 * M_PI;
			double position_angle = panner_shell->pannable()->pan_azimuth_control->get_value() * 2 * M_PI;

			cairo_save (cr);
			cairo_translate (cr, radius, radius);
			cairo_rotate (cr, M_PI / 2.0);
			cairo_rotate (cr, position_angle - (width_angle/2.0));
			cairo_move_to (cr, 0, 0);
			cairo_arc_negative (cr, 0, 0, radius, width_angle, 0.0);
			cairo_close_path (cr);
			if (panner_shell->pannable()->pan_width_control->get_value() >= 0.0) {
				/* normal width */
				CSSRGBA(colors.diffusion);
			} else {
				/* inverse width */
				CSSRGBA(colors.diffusion_inv);
			}
			cairo_fill (cr);
			cairo_restore (cr);
		}

		double arc_radius;

		cairo_select_font_face (cr, "sans", CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);

		if (xsmall) {
			arc_radius = 4.0;
		} else {
			cairo_set_font_size (cr, 10);
			arc_radius = 12.0;
		}

		/* draw position */

		PBD::AngularVector dp = position.position;
		if (!have_elevation) dp.ele = 0;
		dp.azi = 270 - dp.azi;
		dp.cartesian (c);
		cart_to_gtk (c);

		cairo_new_path (cr);
		cairo_arc (cr, c.x, c.y, arc_radius + 1.0, 0, 2.0 * M_PI);
		CSSRGBA(colors.pos_fill);
		cairo_fill_preserve (cr);
		CSSRGBA(colors.pos_outline);
		cairo_stroke (cr);

		/* signals */

		if (signals.size() > 0) {
			for (Targets::iterator i = signals.begin(); i != signals.end(); ++i) {
				Target* signal = *i;

				if (signal->visible) {

					/* TODO check for overlap - multiple src at same position
					 * -> visualize it properly
					 */
					PBD::AngularVector sp = signal->position;
					if (!have_elevation) sp.ele = 0;
					sp.azi += 270.0;
					sp.cartesian (c);
					cart_to_gtk (c);

					cairo_new_path (cr);
					cairo_arc (cr, c.x, c.y, arc_radius, 0, 2.0 * M_PI);
					if (_send_mode && !panner_shell->is_linked_to_route()) {
						CSSRGBA(colors.send_pan);
					} else {
						CSSRGBA(colors.signal_fill);
					}
					cairo_fill_preserve (cr);
					CSSRGBA(colors.signal_outline);
					cairo_stroke (cr);

					if (!xsmall && !signal->text.empty()) {
						CSSRGBA(colors.text);
						/* the +/- adjustments are a hack to try to center the text in the circle
						 * TODO use pango get_pixel_size() -- see mono_panner.cc
						 */
						if (xsmall) {
							cairo_move_to (cr, c.x - 1, c.y + 1);
						} else {
							cairo_move_to (cr, c.x - 4, c.y + 4);
						}
						cairo_show_text (cr, signal->text.c_str());
					}
				}
			}
		}

		/* speakers */

		int n = 0;

		for (Targets::iterator i = speakers.begin(); i != speakers.end(); ++i) {
			Target *speaker = *i;
			char buf[256];
			++n;

			if (speaker->visible) {

				PBD::AngularVector sp = speaker->position;
				sp.azi += 270.0;
				CartesianVector c;
				sp.cartesian (c);
				cart_to_gtk (c);

				snprintf (buf, sizeof (buf), "%d", n);

				/* stroke out a speaker shape */

				cairo_move_to (cr, c.x, c.y);
				cairo_save (cr);
				cairo_rotate (cr, -(sp.azi/360.0) * (2.0 * M_PI));
				if (xsmall) {
					cairo_scale (cr, 0.8, 0.8);
				} else {
					cairo_scale (cr, 1.2, 1.2);
				}
				cairo_rel_line_to (cr, 4, -2);
				cairo_rel_line_to (cr, 0, -7);
				cairo_rel_line_to (cr, 5, +5);
				cairo_rel_line_to (cr, 5, 0);
				cairo_rel_line_to (cr, 0, 5);
				cairo_rel_line_to (cr, -5, 0);
				cairo_rel_line_to (cr, -5, +5);
				cairo_rel_line_to (cr, 0, -7);
				cairo_close_path (cr);
				CSSRGBA(colors.speaker_fill);
				cairo_fill (cr);
				cairo_restore (cr);

				if (!xsmall) {
					cairo_set_font_size (cr, 16);

					/* move the text in just a bit */

					AngularVector textpos (speaker->position.azi + 270.0, speaker->position.ele, 0.85);

					textpos.cartesian (c);
					cart_to_gtk (c);
					cairo_move_to (cr, c.x, c.y);
					cairo_show_text (cr, buf);
				}

			}
		}
	}

	cairo_destroy (cr);

	return true;
}

bool
Panner2d::on_button_press_event (GdkEventButton *ev)
{
	GdkModifierType state;
	int x;
	int y;
	bool is_signal;

	if (ev->type == GDK_2BUTTON_PRESS && ev->button == 1) {
		return false;
	}

	did_move = false;

	switch (ev->button) {
	case 1:
	case 2:
		x = ev->x - hoffset;
		y = ev->y - voffset;

		if ((drag_target = find_closest_object (x, y, is_signal)) != 0) {
			if (!is_signal) {
				panner_shell->panner()->set_position (drag_target->position.azi/360.0);
				drag_target = 0;
			} else {
				drag_target->set_selected (true);
			}
		}

		state = (GdkModifierType) ev->state;
		return handle_motion (ev->x, ev->y, state);
		break;

	default:
		break;
	}

	return false;
}

bool
Panner2d::on_button_release_event (GdkEventButton *ev)
{
	gint x, y;
	GdkModifierType state;
	bool ret = false;

	switch (ev->button) {
	case 1:
		x = (int) floor (ev->x);
		y = (int) floor (ev->y);
		state = (GdkModifierType) ev->state;
		ret = handle_motion (x, y, state);
		drag_target = 0;
		break;

	case 2:
		x = (int) floor (ev->x);
		y = (int) floor (ev->y);
		state = (GdkModifierType) ev->state;

		if (Keyboard::modifier_state_contains (state, Keyboard::TertiaryModifier)) {
			toggle_bypass ();
			ret = true;
		} else {
			ret = handle_motion (x, y, state);
		}

		drag_target = 0;
		break;

	case 3:
		break;

	}

	return ret;
}

gint
Panner2d::handle_motion (gint evx, gint evy, GdkModifierType state)
{
	if (drag_target == 0) {
		return false;
	}

	if ((state & (GDK_BUTTON1_MASK|GDK_BUTTON2_MASK)) == 0) {
		return false;
	}

	evx -= hoffset;
	evy -= voffset;

	if (state & GDK_BUTTON1_MASK && !(state & GDK_BUTTON2_MASK)) {
		CartesianVector c;
		bool need_move = false;

		drag_target->position.cartesian (c);
		cart_to_gtk (c);

		if ((evx != c.x) || (evy != c.y)) {
			need_move = true;
		}

		if (need_move) {
			CartesianVector cp (evx, evy, 0.0);
			AngularVector av;
			gtk_to_cart (cp);

			if (!have_elevation) {
				clamp_to_circle (cp.x, cp.y);
				cp.angular (av);
				av.azi = fmod(270 - av.azi, 360);
				if (drag_target == &position) {
					double degree_fract = av.azi / 360.0;
					panner_shell->panner()->set_position (degree_fract);
				}
			} else {
				/* sphere projection */
				sphere_project (cp.x, cp.y, cp.z);

				double r2d = 180.0 / M_PI;
				av.azi = r2d * atan2(cp.y, cp.x);
				av.ele = r2d * asin(cp.z);
				av.azi = fmod(270 - av.azi, 360);

				if (drag_target == &position) {
					double azi_fract = av.azi / 360.0;
					double ele_fract = av.ele / 90.0;
					panner_shell->panner()->set_position (azi_fract);
					panner_shell->panner()->set_elevation (ele_fract);
				}
			}
		}
	}

	return true;
}

bool
Panner2d::on_scroll_event (GdkEventScroll* ev)
{
	switch (ev->direction) {
	case GDK_SCROLL_UP:
	case GDK_SCROLL_RIGHT:
		panner_shell->panner()->set_position (panner_shell->pannable()->pan_azimuth_control->get_value() - 1.0/360.0);
		break;

	case GDK_SCROLL_DOWN:
	case GDK_SCROLL_LEFT:
		panner_shell->panner()->set_position (panner_shell->pannable()->pan_azimuth_control->get_value() + 1.0/360.0);
		break;
	}
	return true;
}

void
Panner2d::cart_to_gtk (CartesianVector& c) const
{
	/* cartesian coordinate space:
	 *  center = 0.0
	 *  dimension = 2.0 * 2.0
	 *  increasing y moves up
	 * so max values along each axis are -1..+1
	 *
	 * GTK uses a coordinate space that is:
	 *  top left = 0.0
	 *  dimension = (radius*2.0) * (radius*2.0)
	 * increasing y moves down
	*/
	const double diameter = radius*2.0;

	c.x = diameter * ((c.x + 1.0) / 2.0);
	/* extra subtraction inverts the y-axis to match "increasing y moves down" */
	c.y = diameter - (diameter * ((c.y + 1.0) / 2.0));
}

void
Panner2d::gtk_to_cart (CartesianVector& c) const
{
	const double diameter = radius*2.0;
	c.x = ((c.x / diameter) * 2.0) - 1.0;
	c.y = (((diameter - c.y) / diameter) * 2.0) - 1.0;
}

void
Panner2d::sphere_project (double& x, double& y, double& z)
{
	double r, r2;
	r2 = x * x + y * y;
	if (r2 < 1.0) {
		z = sqrt (1.0 - r2);
	} else {
		r = sqrt (r2);
		x = x / r;
		y = y / r;
		z = 0.0;
	}
}

void
Panner2d::clamp_to_circle (double& x, double& y)
{
	double azi, ele;
	double z = 0.0;
	double l;
	PBD::cartesian_to_spherical (x, y, z, azi, ele, l);
	PBD::spherical_to_cartesian (azi, ele, 1.0, x, y, z);
}

void
Panner2d::toggle_bypass ()
{
	panner_shell->set_bypassed (!panner_shell->bypassed());
}

Panner2dWindow::Panner2dWindow (std::shared_ptr<PannerShell> p, int32_t h, uint32_t inputs)
	: ArdourWindow (_("Panner (2D)"))
	, widget (p, h)
	, bypass_button (_("Bypass"))
	, width_adjustment (0, -100, 100, 1, 5, 0)
	, width_spinner (width_adjustment)
{
	widget.set_name ("MixerPanZone");

	set_title (_("Panner"));
	widget.set_size_request (h, h);

	bypass_button.signal_toggled().connect (sigc::mem_fun (*this, &Panner2dWindow::bypass_toggled));
	width_spinner.signal_changed().connect (sigc::mem_fun (*this, &Panner2dWindow::width_changed));

	p->Changed.connect (panshell_connections, invalidator (*this), std::bind (&Panner2dWindow::set_bypassed, this), gui_context());
	/* needed for the width-spinbox in the main window */
	p->PannableChanged.connect (panshell_connections, invalidator (*this), std::bind (&Panner2dWindow::pannable_handler, this), gui_context());
	p->pannable()->pan_width_control->Changed.connect (panvalue_connections, invalidator(*this), std::bind (&Panner2dWindow::set_width, this), gui_context());


	button_box.set_spacing (6);
	button_box.pack_start (bypass_button, false, false);

	left_side.set_spacing (6);

	left_side.pack_start (button_box, false, false);

	Gtk::Label* l = manage (new Label (
				p->pannable()->describe_parameter(PanWidthAutomation),
				Gtk::ALIGN_START, Gtk::ALIGN_CENTER, false));
	spinner_box.pack_start (*l, false, false);
	spinner_box.pack_start (width_spinner, false, false);
	left_side.pack_start (spinner_box, false, false);

	l->show ();
	bypass_button.show ();
	button_box.show ();
	width_spinner.show ();
	spinner_box.show ();
	left_side.show ();

	hpacker.set_spacing (6);
	hpacker.set_border_width (12);
	hpacker.pack_start (widget, false, false);
	hpacker.pack_start (left_side, false, false);
	hpacker.show ();

	add (hpacker);
	reset (inputs);
	set_width();
	set_bypassed();
	widget.show ();
}

void
Panner2dWindow::reset (uint32_t n_inputs)
{
	widget.reset (n_inputs);
}

void
Panner2dWindow::bypass_toggled ()
{
	bool view = bypass_button.get_active ();
	bool model = widget.get_panner_shell()->bypassed ();

	if (model != view) {
		widget.get_panner_shell()->set_bypassed (view);
	}
}
void
Panner2dWindow::width_changed ()
{
	float model = widget.get_panner_shell()->pannable()->pan_width_control->get_value();
	float view  = width_spinner.get_value() / 100.0;
	if (model != view) {
		widget.get_panner_shell()->panner()->set_width (view);
	}
}

void
Panner2dWindow::pannable_handler ()
{
	panvalue_connections.drop_connections();
	widget.get_panner_shell()->pannable()->pan_width_control->Changed.connect (panvalue_connections, invalidator(*this), std::bind (&Panner2dWindow::set_width, this), gui_context());
	set_width();
}

void
Panner2dWindow::set_bypassed ()
{
	bool view = bypass_button.get_active ();
	bool model = widget.get_panner_shell()->bypassed ();
	if (model != view) {
		bypass_button.set_active(model);
	}

	set<Evoral::Parameter> params = widget.get_panner_shell()->pannable()->what_can_be_automated();
	set<Evoral::Parameter>::iterator p = params.find(PanWidthAutomation);
	if (p == params.end()) {
		spinner_box.set_sensitive(false);
	} else {
		spinner_box.set_sensitive(true);
	}
}

void
Panner2dWindow::set_width ()
{
	// rounding of spinbox is different from slider -- TODO use slider
	float model = (widget.get_panner_shell()->pannable()->pan_width_control->get_value() * 100.0);
	float view  = (width_spinner.get_value());
	if (model != view) {
		width_spinner.set_value (model);
	}
}

bool
Panner2dWindow::on_key_press_event (GdkEventKey* event)
{
	return relay_key_press (event, this);
}

bool
Panner2dWindow::on_key_release_event (GdkEventKey*)
{
	return true;
}