/*
    QGLView
	Copyright (C) 2019  Ivan Pelipenko peri4ko@yandex.ru

    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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include "gltypes.h"
#include "qglview.h"

Camera * currentCamera;
QMatrix4x4 globCameraMatrix;


Camera::Camera() {
	type_ = glCamera;
	fov_ = 60.;
	angle_limit_lower_xy = 0.;
	angle_limit_upper_xy = 360.;
	angles_.setY(270.);
	depth_start = 0.1;
	depth_end = 1000.;
	mirror_x = mirror_y = false;
}


void Camera::anglesFromPoints() {
	QVector3D dv = aim_ - pos_, tv;
	tv = QVector3D(dv.x(), dv.y(), 0.);
	angles_.setZ(atan2(tv.x(), tv.y()) * rad2deg);
	angles_.setY(piClamp<GLdouble>(atan2(tv.length(), dv.z()) * rad2deg, angle_limit_lower_xy, angle_limit_upper_xy) + 180.);
}


void Camera::apply(const GLdouble & aspect) {
	glMatrixMode(GL_PROJECTION);
	if (aspect <= 1.)
		glScaled(aspect, aspect, 1.);
	QMatrix4x4 pm = glMatrixPerspective(fov_, aspect, depth_start, depth_end);
	//pm.perspective(fov_, aspect, depth_start, depth_end);
	//qDebug() << pm;// << glMatrixPerspective(fov_, aspect, depth_start, depth_end);
	//qDebug() << pm;
	setGLMatrix(pm);
	glMatrixMode(GL_MODELVIEW);
	pm.setToIdentity();
	pm.translate(0., 0., -distance());
	pm.rotate(angles_.y(), 1., 0., 0.);
	pm.rotate(angles_.x(), 0., 1., 0.);
	pm.rotate(angles_.z(), 0., 0., 1.);
	//pm.translate(-aim_);
	if (parent_) {
		//double dist = pm(2, 3);
		QMatrix4x4 pmat = parent_->worldTransform();//.inverted();
		//offset_.setZ(offset_.z() - dist);
		offset_ = pmat.column(3).toVector3D();
		pmat(0, 3) = pmat(1, 3) = pmat(2, 3) = 0.;
		pmat.translate(aim_);
		//pm.translate(-aim_);
		pm *= pmat.inverted();
		//qDebug() << pmat;
	}
	setGLMatrix(pm);
	//qDebug() << angles_;
}


QMatrix4x4 Camera::offsetMatrix() const {
	QMatrix4x4 ret;
	ret.translate(parent_ ? -offset_ : -aim_);
	return ret;
}

/*
void Camera::localTransform(QMatrix4x4 & m) {
	return;
	if (parent_)
		m *= parent_->worldTransform();
	QMatrix4x4 ret;
	//qDebug() << "local camera";
	ret.translate(0., 0., -distance());
	ret.rotate(angles_.y(), 1., 0., 0.);
	ret.rotate(angles_.x(), 0., 1., 0.);
	ret.rotate(angles_.z(), 0., 0., 1.);
	//m *= ret.inverted();
}
*/

void Camera::assign(const Camera & c) {
	pos_ = c.pos_;
	aim_ = c.aim_;
	fov_ = c.fov_;
	angles_ = c.angles_;
	angle_limit_lower_xy = c.angle_limit_lower_xy;
	angle_limit_upper_xy = c.angle_limit_upper_xy;
	buildTransform();
}


void Camera::panZ(const double & a) {
	QVector3D dv = aim_ - pos_;
	double tl = QVector2D(dv.x(), dv.y()).length();
	angles_.setZ(angles_.z() + a);
	dv = QVector3D(sin(angles_.z() * deg2rad) * tl, cos(angles_.z() * deg2rad) * tl, dv.z());
	aim_ = pos_ + dv;
	buildTransform();
}


void Camera::panXY(const double & a) {
	QVector3D dv = aim_ - pos_;
	double tl = dv.length(), tc;
	angles_.setY(angles_.y() + a);
	angles_.setY(piClamp<GLdouble>(angles_.y(), angle_limit_lower_xy, angle_limit_upper_xy));
	tc = -sin(angles_.y() * deg2rad);
	dv = QVector3D(sin(angles_.z() * deg2rad) * tc, cos(angles_.z() * deg2rad) * tc, -cos(angles_.y() * deg2rad));
	aim_ = pos_ + dv * tl;
	buildTransform();
}


void Camera::rotateZ(const double & a) {
	QVector3D dv = aim_ - pos_;
	double tl = QVector2D(dv.x(), dv.y()).length();
	angles_.setZ(angles_.z() + a);
	dv = QVector3D(sin(angles_.z() * deg2rad) * tl, cos(angles_.z() * deg2rad) * tl, dv.z());
	aim_ = pos_ + dv;
	buildTransform();
}


void Camera::rotateXY(const double & a) {
	QVector3D dv = aim_ - pos_;
	double tl = dv.length(), tc;
	angles_.setY(angles_.y() + a);
	angles_.setY(piClamp<GLdouble>(angles_.y(), angle_limit_lower_xy, angle_limit_upper_xy));
	tc = -sin(angles_.y() * deg2rad);
	dv = QVector3D(sin(angles_.z() * deg2rad) * tc, cos(angles_.z() * deg2rad) * tc, -cos(angles_.y() * deg2rad));
	aim_ = pos_ + dv * tl;
	buildTransform();
}


void Camera::orbitZ(const double & a) {
	QVector3D dv = aim_ - pos_;
	double tl = QVector2D(dv.x(), dv.y()).length();
	angles_.setZ(angles_.z() + a);
	dv = QVector3D(sin(angles_.z() * deg2rad) * tl, cos(angles_.z() * deg2rad) * tl, dv.z());
	pos_ = aim_ - dv;
	buildTransform();
}


void Camera::orbitXY(const double & a) {
	QVector3D dv = aim_ - pos_;
	double tl = dv.length(), tc;
	angles_.setY(angles_.y() + a);
	angles_.setY(piClamp<GLdouble>(angles_.y(), angle_limit_lower_xy, angle_limit_upper_xy));
	tc = -sin(angles_.y() * deg2rad);
	dv = QVector3D(sin(angles_.z() * deg2rad) * tc, cos(angles_.z() * deg2rad) * tc, -cos(angles_.y() * deg2rad));
	pos_ = aim_ - dv * tl;
	buildTransform();
}


void Camera::setAngleZ(const double & a) {
	QVector3D dv = aim_ - pos_;
	double tl = QVector2D(dv.x(), dv.y()).length();
	angles_.setZ(a);
	dv = QVector3D(sin(angles_.z() * deg2rad) * tl, cos(angles_.z() * deg2rad) * tl, dv.z());
	aim_ = pos_ + dv;
	buildTransform();
}


void Camera::setAngleXY(const double & a) {
	QVector3D dv = aim_ - pos_;
	double tl = dv.length(), tc;
	angles_.setY(a);
	tc = -sin(angles_.y() * deg2rad);
	dv = QVector3D(sin(angles_.z() * deg2rad) * tc, cos(angles_.z() * deg2rad) * tc, -cos(angles_.y() * deg2rad));
	//pos_ = aim_ - dv;
	aim_ = pos_ + dv * tl;
	buildTransform();
	//anglesFromPoints();
}


void Camera::moveForward(const double & x, bool withZ) {
	QVector3D dv;// = aim_ - pos_;
	double tc = -sin(angles_.y() * deg2rad);
	dv = QVector3D(sin(angles_.z() * deg2rad) * tc, cos(angles_.z() * deg2rad) * tc, 0.);
	if (withZ) dv.setZ(-cos(angles_.y() * deg2rad));
	dv.normalize();
	dv *= x;
	pos_ += dv;
	aim_ += dv;
	buildTransform();
}


void Camera::moveLeft(const double & x, bool withZ) {
	QVector3D dv;// = aim_ - pos_;
	double tc = -sin(angles_.y() * deg2rad);
	dv = QVector3D(sin(angles_.z() * deg2rad - M_PI_2) * tc, cos(angles_.z() * deg2rad - M_PI_2) * tc, 0.);
	if (withZ) dv.setZ(-sin(angles_.x() * deg2rad));
	dv.normalize();
	dv *= x;
	pos_ += dv;
	aim_ += dv;
	buildTransform();
}


void Camera::moveUp(const double & x, bool onlyZ) {
	QVector3D dv;
	if (onlyZ)
		dv = QVector3D(0., 0., x);
	else {
		double tc = cos(angles_.y() * deg2rad);
		dv = QVector3D(sin(angles_.z() * deg2rad) * tc, cos(angles_.z() * deg2rad) * tc, -sin(angles_.y() * deg2rad));
		dv.normalize();
		dv *= x;
	}
	pos_ += dv;
	aim_ += dv;
	buildTransform();
}


void Camera::flyCloser(const double & s) {
	QVector3D dv = aim_ - pos_;
	double tl = dv.length() / (1. + s), tc = -sin(angles_.y() * deg2rad);
	dv = QVector3D(sin(angles_.z() * deg2rad) * tc, cos(angles_.z() * deg2rad) * tc, -cos(angles_.y() * deg2rad));
	pos_ = aim_ - dv * tl;
	buildTransform();
}


void Camera::flyFarer(const double & s) {
	QVector3D dv = aim_ - pos_;
	double tl = dv.length() * (1. + s), tc = -sin(angles_.y() * deg2rad);
	dv = QVector3D(sin(angles_.z() * deg2rad) * tc, cos(angles_.z() * deg2rad) * tc, -cos(angles_.y() * deg2rad));
	pos_ = aim_ - dv * tl;
	buildTransform();
}


void Camera::flyToDistance(const double & d) {
	QVector3D dv = aim_ - pos_;
	double tc = -sin(angles_.y() * deg2rad);
	dv = QVector3D(sin(angles_.z() * deg2rad) * tc, cos(angles_.z() * deg2rad) * tc, -cos(angles_.y() * deg2rad));
	pos_ = aim_ - dv * d;
	buildTransform();
}

/*
QVector3D Camera::pointFromViewport(int x_, int y_, double z_) {
	GLsizei mx = x_, my = viewport[3] - y_, mz = z_;
	GLdouble x,y,z;
	gluUnProject(mx, my, mz, modelview, projection, viewport, &x, &y, &z);
	return QVector3D(x,y,z);
}
*/