/*
	cl_cam.c

	camera support

	Copyright (C) 1996-1997  Id Software, Inc.

	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 2
	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, write to:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

*/
static const char rcsid[] = 
	"$Id$";

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "QF/cvar.h"
#include "QF/mathlib.h"

#include "client.h"
#include "world.h"

#include "QF/keys.h"
#include "QF/input.h"

float CL_KeyState (kbutton_t *key);

vec3_t camera_origin = {0,0,0};
vec3_t camera_angles = {0,0,0};
vec3_t player_origin = {0,0,0};
vec3_t player_angles = {0,0,0};


qboolean    SV_RecursiveHullCheck (hull_t *hull, int num, float p1f, float p2f,
								   vec3_t p1, vec3_t p2, trace_t *trace);

cvar_t     *chase_back;
cvar_t     *chase_up;
cvar_t     *chase_right;
cvar_t     *chase_active;

vec3_t      chase_angles;
vec3_t      chase_dest;
vec3_t      chase_dest_angles;
vec3_t      chase_pos;


void
Chase_Init_Cvars (void)
{
	chase_back = Cvar_Get ("chase_back", "100", CVAR_NONE, NULL, "None");
	chase_up = Cvar_Get ("chase_up", "16", CVAR_NONE, NULL, "None");
	chase_right = Cvar_Get ("chase_right", "0", CVAR_NONE, NULL, "None");
	chase_active = Cvar_Get ("chase_active", "0", CVAR_NONE, NULL, "None");
}

void
Chase_Reset (void)
{
	// for respawning and teleporting
	// start position 12 units behind head
}

void
TraceLine (vec3_t start, vec3_t end, vec3_t impact)
{
	trace_t     trace;

	memset (&trace, 0, sizeof (trace));
	SV_RecursiveHullCheck (cl.worldmodel->hulls, 0, 0, 1, start, end, &trace);

	VectorCopy (trace.endpos, impact);
}

/*
==================
Chase_Update
==================
*/
void
Chase_Update (void)
{
	vec3_t    forward, up, right, stop, dir;
	float     pitch, yaw, fwd;
	usercmd_t cmd; // movement direction
	int i;

	// lazy camera, look toward player entity

	if (chase_active->int_val == 2 || chase_active->int_val == 3)
	{
		// control camera angles with key/mouse/joy-look

		camera_angles[PITCH] += cl.viewangles[PITCH] - player_angles[PITCH];
		camera_angles[YAW]   += cl.viewangles[YAW]   - player_angles[YAW];
		camera_angles[ROLL]  += cl.viewangles[ROLL]  - player_angles[ROLL];

		if (chase_active->int_val == 2)
		{
			if (camera_angles[PITCH] < -60) camera_angles[PITCH] = -60;
			if (camera_angles[PITCH] >  60) camera_angles[PITCH] =  60;
		}

		// move camera, it's not enough to just change the angles because
		// the angles are automatically changed to look toward the player

		if (chase_active->int_val == 3)
			VectorCopy (r_refdef.vieworg, player_origin);

		AngleVectors   (camera_angles, forward, right, up);
		VectorScale    (forward, chase_back->value, forward);
		VectorSubtract (player_origin, forward, camera_origin);

		if (chase_active->int_val == 2)
		{
			VectorCopy (r_refdef.vieworg, player_origin);

			// don't let camera get too low
			if (camera_origin[2] < player_origin[2] + chase_up->value)
				camera_origin[2] = player_origin[2] + chase_up->value;
		}

		// don't let camera get too far from player

		VectorSubtract  (camera_origin, player_origin, dir);
		VectorCopy      (dir, forward);
		VectorNormalize (forward);

		if (Length (dir) > chase_back->value)
		{
			VectorScale (forward, chase_back->value, dir);
			VectorAdd   (player_origin, dir, camera_origin);
		}

		// check for walls between player and camera

		VectorScale    (forward, 8, forward);
		VectorAdd      (camera_origin, forward, camera_origin);
		TraceLine      (player_origin, camera_origin, stop);
		if (Length (stop) != 0)
        		VectorSubtract (stop, forward, camera_origin);

		VectorSubtract  (camera_origin, r_refdef.vieworg, dir);
		VectorCopy      (dir, forward);
		VectorNormalize (forward);

		if (chase_active->int_val == 2)
		{
			if (dir[1] == 0 && dir[0] == 0)
			{
				// look straight up or down
			//	camera_angles[YAW] = r_refdef.viewangles[YAW];
				if (dir[2] > 0) camera_angles[PITCH] = 90;
				else            camera_angles[PITCH] = 270;
			}
			else
			{
				yaw = (atan2 (dir[1], dir[0]) * 180 / M_PI);
				if (yaw <   0) yaw += 360;
				if (yaw < 180) yaw += 180;
				else           yaw -= 180;
				camera_angles[YAW] = yaw;

				fwd = sqrt (dir[0] * dir[0] + dir[1] * dir[1]);
				pitch = (atan2 (dir[2], fwd) * 180 / M_PI);
				if (pitch < 0) pitch += 360;
				camera_angles[PITCH] = pitch;
			}
		}

		VectorCopy (camera_angles, r_refdef.viewangles); // rotate camera
		VectorCopy (camera_origin, r_refdef.vieworg);    // move camera

		// get basic movement from keyboard

		memset (&cmd, 0, sizeof (cmd));
//		VectorCopy (cl.viewangles, cmd.angles);

		if (in_strafe.state & 1) {
			cmd.sidemove += cl_sidespeed->value * CL_KeyState (&in_right);
			cmd.sidemove -= cl_sidespeed->value * CL_KeyState (&in_left);
		}
		cmd.sidemove += cl_sidespeed->value * CL_KeyState (&in_moveright);
		cmd.sidemove -= cl_sidespeed->value * CL_KeyState (&in_moveleft);

		if (!(in_klook.state & 1)) {
			cmd.forwardmove += cl_forwardspeed->value * CL_KeyState (&in_forward);
			cmd.forwardmove -= cl_backspeed->value    * CL_KeyState (&in_back);
		}
		if (in_speed.state & 1) {
			cmd.forwardmove *= cl_movespeedkey->value;
			cmd.sidemove    *= cl_movespeedkey->value;
		}

		// mouse and joystick controllers add to movement
//		IN_Move (&cmd); // problem - mouse strafe movement is weird

		dir[1] = camera_angles[1];  dir[0] = 0;  dir[2] = 0;
		AngleVectors (dir, forward, right, up);

		VectorScale (forward, cmd.forwardmove, forward);
		VectorScale (right,   cmd.sidemove,    right);
		VectorAdd   (forward, right, dir);

		if (dir[1] || dir[0])
		{
			cl.viewangles[YAW] = (atan2 (dir[1], dir[0]) * 180 / M_PI);
			if (cl.viewangles[YAW] <   0) cl.viewangles[YAW] += 360;
//			if (cl.viewangles[YAW] < 180) cl.viewangles[YAW] += 180;
//			else                          cl.viewangles[YAW] -= 180;
		}

		cl.viewangles[PITCH] = 0;

		// remember the new angle to calculate the difference next frame
		VectorCopy (cl.viewangles, player_angles);

		return;
	}

	// regular camera, faces same direction as player

	AngleVectors (cl.viewangles, forward, right, up);

	// calc exact destination
	for (i = 0; i < 3; i++)
		camera_origin[i] = r_refdef.vieworg[i]
			- forward[i] * chase_back->value - right[i] * chase_right->value;
	camera_origin[2] += chase_up->value;

	// check for walls between player and camera
	TraceLine (r_refdef.vieworg, camera_origin, stop);
	if (Length (stop) != 0)
		for (i = 0; i < 3; i++)
			camera_origin[i] = stop[i] + forward[i] * 8;

	VectorCopy (camera_origin, r_refdef.vieworg);
}