/* 
   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 "client/client.h"
#include "client/camera.h"
#include "render/render.h"
#include "math/mathlib.h"

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

using namespace render;

namespace client
{

namespace camera 
{

// public variables

// camera target
math::Vector3f target;
// 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::Track
float pitch_track;
// default pitch in mode::Overview
float pitch_overview;
// default offset increment
float offset_inc;

void init()
{
	pitch_overview = -60.0f;
	pitch_track = -15.0f; 
	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 draw(float elapsed) 
{	
	// TODO camera needs to get this from selected core entity
	if (mode == Track) {
		yaw_target = game.ship.yaw();
	}

	// 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);

	switch (mode) {
	case Free:
		gl::translate(1.0f+distance, -distance/2, 0.0f);
		gl::rotate(-pitch_current, 0, 0, 1.0f);
		gl::rotate(-yaw_current, 0, 1.0f, 0);
		break;
	case Track:
		gl::translate(1.0f+distance, -distance , 0.0f);
		gl::rotate(-pitch_current, 0, 0, 1.0f);
		gl::rotate(-yaw_current, 0, 1.0f, 0);
		break;
	case Overview:		
		gl::translate(-distance/2, -distance, 0.0f);
		gl::rotate(-pitch_current, 0, 0, 1.0f);
		gl::rotate(-yaw_current, 0, 1.0f, 0);		
		break;
	default:
		break;
	}
}

void rotate_right()
{
	if (mode == Free || mode == Overview) {
		yaw_target = degrees360f(  yaw_target + offset_inc);
	}
}

void rotate_left()
{
	if (mode == Free || mode == Overview) {
		yaw_target = degrees360f(  yaw_target - offset_inc);
	}
}

void rotate_up()
{
	if (mode == Free) {
		pitch_target = pitch_target - offset_inc;
		if (pitch_target < -90.0f) pitch_target = -90.0f;
	}
}

void rotate_down()
{
	if (mode == Free) {
		pitch_target = pitch_target + offset_inc;
		if (pitch_target > 90.0f) pitch_target = 90.0f;
	}
}

void nextmode() {
	switch(mode) {
	case Overview:
		// switch camera to Track mode
		mode = Track;
		yaw_target = game.ship.yaw();
		yaw_current = yaw_target;
		pitch_target = pitch_track;
		pitch_current = pitch_target;
		distance = 0.4f;
		break;
	case Track:
		// switch camera to Free mode
		mode = Free;
		yaw_target = game.ship.yaw();
		yaw_current = yaw_target;
		pitch_target = pitch_track;
		pitch_current = pitch_target;
		distance = 0.4f;
		break;
	case Free:
		// switch camera to Overview mode
		mode = Overview;
		yaw_target = 0;
		yaw_current = 0;
		pitch_target = pitch_overview;
		pitch_current = pitch_target;
		distance = 10.0f;
	default:
		break;
	}
}

} // namespace camera

} // namespace client