/*****************************************************************************************
 *                                                                                       *
 * OpenSpace                                                                             *
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 * Copyright (c) 2014                                                                    *
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#include <openspace/interaction/mousecontroller.h>

namespace openspace {
namespace interaction {

MouseController::MouseController()
	: _lastTrackballPos(0.f)
	, _isMouseBeingPressedAndHeld(false)
{}

glm::vec3 MouseController::mapToTrackball(glm::vec2 mousePos) {
	const float RADIUS = 0.5; // Sphere radius
	glm::vec3 out = glm::vec3(mousePos.x - 0.5, -1.0*(mousePos.y - 0.5), 0);

	// Mapping according to Holroyds trackball
	// Piece-wise sphere + hyperbolic sheet
	if (out.x*out.x + out.y*out.y <= RADIUS*RADIUS / 2.0) {
		//Spherical Region
		out.z = RADIUS*RADIUS - (out.x*out.x + out.y*out.y);
		out.z = out.z > 0.0 ? sqrtf(out.z) : 0.0;
	}
	else { //Hyperbolic Region - for smooth z values
		out.z = (RADIUS*RADIUS) / (2.0*sqrt(out.x*out.x + out.y*out.y));
	}

	return glm::normalize(out);
}

glm::vec3 MouseController::mapToCamera(glm::vec3 trackballPos) {
	//	return glm::vec3((sgct::Engine::instance()->getActiveViewMatrix() * glm::vec4(trackballPos,0)));

	//Get x,y,z axis vectors of current camera view
	glm::vec3 currentViewYaxis = glm::normalize(camera()->lookUpVector());
	psc viewDir = camera()->position() - focusNode()->worldPosition();
	glm::vec3 currentViewZaxis = glm::normalize(viewDir.vec3());
	glm::vec3 currentViewXaxis = glm::normalize(glm::cross(currentViewYaxis, currentViewZaxis));

	//mapping to camera co-ordinate
	currentViewXaxis *= trackballPos.x;
	currentViewYaxis *= trackballPos.y;
	currentViewZaxis *= trackballPos.z;
	return (currentViewXaxis + currentViewYaxis + currentViewZaxis);
}

void MouseController::trackballRotate(int x, int y) {
	// Normalize mouse coordinates to [0,1]
	float width = sgct::Engine::instance()->getActiveXResolution();
	float height = sgct::Engine::instance()->getActiveYResolution();
	glm::vec2 mousePos = glm::vec2((float)x / width, (float)y / height);

	mousePos = glm::clamp(mousePos, -0.5, 1.5); // Ugly fix #1: Camera position becomes NaN on mouse values outside [-0.5, 1.5]
	//mousePos[1] = 0.5; 							// Ugly fix #2: Tempoarily only allow rotation around y

	glm::vec3 curTrackballPos = mapToTrackball(mousePos);
	//	LDEBUG(mousePos.x << ", " << mousePos.y << " = " << curTrackballPos.x << ", " << curTrackballPos.y << ", " << curTrackballPos.z);

	// Disable movement on the first click for extra smoothness
	if (!_isMouseBeingPressedAndHeld) {
		_lastTrackballPos = curTrackballPos;
		_isMouseBeingPressedAndHeld = true;
	}

	if (curTrackballPos != _lastTrackballPos) {
		// calculate rotation angle (in radians)
		float rotationAngle = glm::angle(curTrackballPos, _lastTrackballPos);
		rotationAngle *= deltaTime() * 100.0f;

		// Map trackballpos to camera
		//		glm::vec3 trackballMappedToCamera = mapToCamera(_lastTrackballPos - curTrackballPos);
		//		psc currentCamPos = camera_->getPosition();
		//		glm::vec3 nextCamPos = currentCamPos.getVec3f() + trackballMappedToCamera;
		//		glm::vec3 rotationAxis = glm::cross(currentCamPos.getVec3f(), nextCamPos);

		glm::vec3 rotationAxis = glm::cross(_lastTrackballPos, curTrackballPos);
		rotationAxis = glm::normalize(rotationAxis);
		glm::quat quaternion = glm::angleAxis(rotationAngle, rotationAxis);

		// Apply quaternion to camera
		orbitDelta(quaternion);

		_lastTrackballPos = curTrackballPos;
	}
}


TrackballMouseController::TrackballMouseController()
	: MouseController()
	, _leftMouseButtonDown(false)
{}

void TrackballMouseController::button(MouseAction action, MouseButton button) {
	if (button == MouseButton::Left && action == MouseAction::Press)
			_leftMouseButtonDown = true;
	else if (button == MouseButton::Left && action == MouseAction::Release) {
		_leftMouseButtonDown = false;
		_isMouseBeingPressedAndHeld = false;
	}
}

void TrackballMouseController::move(float x, float y) {
	if (_leftMouseButtonDown)
			trackballRotate(x, y);
}

void TrackballMouseController::scrollWheel(int pos) {
	const double speed = 4.75;
	const double dt = deltaTime();
	if (pos < 0) {
		PowerScaledScalar dist(speed * dt, 0.0);
		distanceDelta(dist);
	}
	else if (pos > 0) {
		PowerScaledScalar dist(-speed * dt, 0.0);
		distanceDelta(dist);
	}
}

} // namespace interaction
} // namespace openspace