/* 
   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 "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 
{

// public variables

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


// current x offset
float x_offset;
// current z offset
float z_offset;

// default pitch in mode::Track
const float pitch_track = 0.0f; // 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 = core::localcontrol()->direction();
		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 = core::localcontrol()->direction();
		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;
		x_offset = 0;
		z_offset = 0;
		distance = 20.0f;
	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) 
{	
	if (!core::localcontrol()) {
		// switch the camera to Overview of the player is not controling anything
		if (mode != Overview) {
			set_mode(Overview);

			camera::target = math::Vector3f(0,0,0);
		}
	} else {
		if (mode == Overview)
			set_mode(Track);

		camera::target = core::localcontrol()->location();
	}
	
	if (mode == Track) {
		yaw_target = core::localcontrol()->direction();
	}

	if ((mode == Free) || (mode == Track)) {
		// adjust yaw
		float d = degrees180f(yaw_current - yaw_target);
		yaw_current = degrees360f( yaw_current - d * elapsed) ;
	
		// adjust pitch target
		d = degrees180f(pitch_current - pitch_target);
		pitch_current = degrees360f( pitch_current - d *elapsed);
	}

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

	// map camera coordinates to opengl coordinates
	switch (mode) {
	case Free:
	case Track:
		if (core::localcontrol()->model()) 
			distance = core::localcontrol()->model()->radius();
		else
			distance = 0.5f;

		// draw the camera transformation
		gl::translate(0.0f, 0.0f, -3*distance/4);
		gl::translate(1.2+distance, 0.0f, 0.0f);
		gl::rotate(-pitch_current, 0.0f, 1.0f, 0.0f);
		gl::rotate(-yaw_current, 0.0f, 0.0f, 1.0f);
		gl::translate(-1*target);
		break;

	case Overview:

		eye = target;
		eye.z = eye.z + distance-1;

		gl::rotate(-75.0f, 0.0f, 1.0f, 0.0f);
		gl::translate(0.0f, 0.0f, -distance);
		//gl::translate(x_offset, 0.0f, z_offset);
		gl::translate(-1*target);
		break;
	default:
		break;
	}
}

void key_right()
{
	if (mode == Free) {
		yaw_target = degrees360f(  yaw_target + rotate_offset_inc);
	} else if (mode == Overview) {
		z_offset += translate_offset_inc;
	}
}

void key_left()
{
	if (mode == Free) {
		yaw_target = degrees360f(  yaw_target - rotate_offset_inc);
	} else if (mode == Overview) {
		z_offset -= translate_offset_inc;
	}
}

void key_up()
{
	if (mode == Free) {
		pitch_target = pitch_target + rotate_offset_inc;
		if (pitch_target > 90.0f) pitch_target = 90.0f;
	} else if (mode == Overview) {
		x_offset += translate_offset_inc;
	}
}

void key_down()
{
	if (mode == Free) {
		pitch_target = pitch_target - rotate_offset_inc;
		if (pitch_target < -90.0f) pitch_target = -90.0f;
	} else if (mode == Overview) {
		x_offset -= translate_offset_inc;
	}
}

} // namespace camera

} // namespace client