/* 
   client/camera.cc
   This file is part of the Osirion project and is distributed under 
   the terms and conditions of the GNU General Public License version 2 
*/

#include "math/mathlib.h"
#include "math/matrix4f.h"
#include "core/core.h"
#include "client/client.h"
#include "client/camera.h"
#include "render/render.h"

using math::degrees360f;
using math::degrees180f;

using namespace render;

namespace client
{

namespace camera 
{

// gameworld coordinates of the camera target
math::Vector3f target;
math::Vector3f eye;

// target yaw, angle in XZ plane, positive is looking left
float yaw_target;
// target pitch, angle in XZ plane, positive is looking left
float pitch_target;
// distance from the camera to the target
float distance;
// current camera mode
Mode mode;

// private variables

// current yaw, angle in XZ plane, positive is looking left
float yaw_current;
// current pitch, angle in XY, positive is looking up
float pitch_current;

// default pitch in mode::Overview
float pitch_overview;

// default pitch in mode::Track
const float pitch_track = -15.0f;

// default rotate offset increase/decrease
float rotate_offset_inc;

// default translate offset increase/decrease
const float translate_offset_inc = 0.1;

void init()
{
	rotate_offset_inc = 5.0f; 

	yaw_current = 0;
	yaw_target = 0; 

	pitch_current = pitch_track * 2; 
	pitch_target = pitch_track; 

	distance = 0.4f;

	mode = Track;
}

void shutdown() 
{
}

void set_mode(Mode newmode) {
	switch(newmode) {
	case Track:
		// switch camera to Track mode
		mode = Track;
		yaw_target = 0;
		yaw_current = yaw_target;
		pitch_target = pitch_track;
		pitch_current = pitch_target;
		distance = 0.4f;
		break;

	case Free:
		// switch camera to Free mode
		mode = Free;
		yaw_target = 0;
		yaw_current = yaw_target;
		pitch_target = pitch_track;
		pitch_current = pitch_target;
		distance = 0.4f;
		break;

	case Overview:
		// switch camera to Overview mode
		mode = Overview;

	default:
		break;
	}

}

void next_mode()
{
	
 	if (!core::localcontrol()) {
		set_mode(Overview);
		return;
	}

	switch(mode) {
	case Free:
		// switch camera to Track mode
		set_mode(Track);
		break;
	case Track:
		// switch camera to Free mode
		set_mode(Free);
		break;
	default:
		break;
	}
}

void draw(float elapsed) 
{	
	math::Matrix4f matrix;
	math::Axis axis;

	float d = 0;

	if (!core::localcontrol()) {

		if (mode != Overview) {
			set_mode(Overview);
		}
		
		target.clear();
		axis.clear();
		pitch_current = -75.0f;
		axis.change_pitch(pitch_current);

		distance = 20.0f;

	} else {

		if (mode == Overview)
			set_mode(Track);

		target.assign(core::localcontrol()->location());
		
		axis.assign(core::localcontrol()->axis());
	
		if (mode == Track) {
			// make the camera swing while turning
			yaw_target = 25 * core::localcontrol()->target_direction;
			pitch_target = pitch_track - 25 * core::localcontrol()->target_pitch;
		}

		// adjust direction
		d = degrees180f(yaw_current - yaw_target);
		yaw_current = degrees360f( yaw_current - d * elapsed);
		axis.change_direction(yaw_current);

		// adjust pitch target
		d = degrees180f(pitch_current - pitch_target);
		pitch_current = degrees360f(pitch_current - d *elapsed);
		axis.change_pitch(pitch_current);

		if (core::localcontrol()->model()) 
			distance = 1+core::localcontrol()->model()->radius();
		else
			distance = 1.5f;
	}

	// map world coordinates to opengl coordinates
	gl::rotate(90.0f, 0, 1.0, 0);
	gl::rotate(-90.0f, 1.0f , 0, 0);

	// assign transformation matrix
	matrix.assign(axis);

	// apply the transpose of the axis transformation (the axis is orhtonormal)
	gl::multmatrix(matrix.transpose());

	// match the camera with the current target
	gl::translate(-1.0f * target);
	
	// apply camera offset
	gl::translate((1.0f+distance) * axis.forward());

	// calculate eye position
	eye = target - ((1.0f+distance) * axis.forward());
}

void key_right()
{
	if (mode == Free) {
		yaw_target = degrees360f(  yaw_target + rotate_offset_inc);
	}
}

void key_left()
{
	if (mode == Free) {
		yaw_target = degrees360f(  yaw_target - rotate_offset_inc);
	}
}

void key_down()
{
	if (mode == Free) {
		pitch_target = pitch_target + rotate_offset_inc;
		if (pitch_target > 90.0f) pitch_target = 90.0f;
	}
}

void key_up()
{
	if (mode == Free) {
		pitch_target = pitch_target - rotate_offset_inc;
		if (pitch_target < -90.0f) pitch_target = -90.0f;
	}
}

} // namespace camera

} // namespace client