/*
	cl_cam.c

	Player camera tracking in Spectator mode

	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[] = 
	"$Id$";

/*
  ZOID - This takes over player controls for spectator automatic camera.
  Player moves as a spectator, but the camera tracks an enemy player
*/

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif

#include <math.h>

#include "QF/console.h"
#include "QF/cvar.h"
#include "QF/msg.h"

#include "cl_cam.h"
#include "cl_input.h"
#include "client.h"
#include "compat.h"
#include "pmove.h"
#include "sbar.h"

#define	PM_SPECTATORMAXSPEED 500
#define	PM_STOPSPEED 100
#define	PM_MAXSPEED 320
#define BUTTON_JUMP 2
#define BUTTON_ATTACK 1
#define MAX_ANGLE_TURN 10

#include "QF/sys.h"
#include "QF/keys.h"
#include "QF/input.h"
#include "QF/mathlib.h"
#include "world.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};


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

static vec3_t desired_position;			// where the camera wants to be
static qboolean locked = false;
static int  oldbuttons;

// track high fragger
cvar_t     *cl_hightrack;

cvar_t     *cl_chasecam;

cvar_t     *cl_camera_maxpitch;
cvar_t     *cl_camera_maxyaw;

double      cam_lastviewtime;
qboolean    cam_forceview;
vec3_t      cam_viewangles;

int         spec_track = 0;				// player# of who we are tracking
int         autocam = CAM_NONE;


static void
vectoangles (vec3_t vec, vec3_t ang)
{
	float		forward, pitch, yaw;

	if (vec[1] == 0 && vec[0] == 0) {
		yaw = 0;
		if (vec[2] > 0)
			pitch = 90;
		else
			pitch = 270;
	} else {
		yaw = (int) (atan2 (vec[1], vec[0]) * (180.0 / M_PI));
		if (yaw < 0)
			yaw += 360;

		forward = sqrt (vec[0] * vec[0] + vec[1] * vec[1]);
		pitch = (int) (atan2 (vec[2], forward) * (180.0 / M_PI));
		if (pitch < 0)
			pitch += 360;
	}

	ang[0] = pitch;
	ang[1] = yaw;
	ang[2] = 0;
}


static float
vlen (vec3_t v)
{
	return sqrt (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
}

// returns true if weapon model should be drawn in camera mode
qboolean
Cam_DrawViewModel (void)
{
	if (cl.chase && chase_active->int_val)
		return false;

	if (!cl.spectator)
		return true;

	if (autocam && locked && cl_chasecam->int_val)
		return true;
	return false;
}

// returns true if we should draw this player, we don't if we are chase camming
qboolean
Cam_DrawPlayer (int playernum)
{
	if (playernum < 0) {
		// client player
		if (cl.chase == 0 || chase_active->int_val == 0)
			return false;
		if (!cl.spectator)
			return true;
	} else {
		if (!cl_chasecam->int_val)
			return true;
		if (cl.spectator && autocam && locked && spec_track == playernum)
			return false;
		if (cl.chase == 0 || chase_active->int_val == 0)
			return true;
	}
	return false;
}

void
Cam_Unlock (void)
{
	if (autocam) {
		MSG_WriteByte (&cls.netchan.message, clc_stringcmd);
		MSG_WriteString (&cls.netchan.message, "ptrack");
		autocam = CAM_NONE;
		locked = false;
		Sbar_Changed ();
	}
}

void
Cam_Lock (int playernum)
{
	char		st[40];

	snprintf (st, sizeof (st), "ptrack %i", playernum);
	MSG_WriteByte (&cls.netchan.message, clc_stringcmd);
	MSG_WriteString (&cls.netchan.message, st);
	spec_track = playernum;
	cam_forceview = true;
	locked = false;
	Sbar_Changed ();
}

pmtrace_t
Cam_DoTrace (vec3_t vec1, vec3_t vec2)
{
#if 0
	memset (&pmove, 0, sizeof (pmove));

	pmove.numphysent = 1;
	VectorCopy (vec3_origin, pmove.physents[0].origin);
	pmove.physents[0].model = cl.worldmodel;
#endif

	VectorCopy (vec1, pmove.origin);
	return PM_PlayerMove (pmove.origin, vec2);
}

// Returns distance or 9999 if invalid for some reason
static float
Cam_TryFlyby (player_state_t * self, player_state_t * player, vec3_t vec,
			  qboolean checkvis)
{
	float       len;
	pmtrace_t   trace;
	vec3_t      v;

	vectoangles (vec, v);
//	v[0] = -v[0];
	VectorCopy (v, pmove.angles);
	VectorNormalize (vec);
	VectorMA (player->origin, 800, vec, v);
	// v is endpos
	// fake a player move
	trace = Cam_DoTrace (player->origin, v);
	if ( /* trace.inopen || */ trace.inwater)
		return 9999;
	VectorCopy (trace.endpos, vec);
	VectorSubtract (trace.endpos, player->origin, v);
	len = sqrt (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
	if (len < 32 || len > 800)
		return 9999;
	if (checkvis) {
		VectorSubtract (trace.endpos, self->origin, v);
		len = sqrt (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);

		trace = Cam_DoTrace (self->origin, vec);
		if (trace.fraction != 1 || trace.inwater)
			return 9999;
	}
	return len;
}

// Is player visible?
static qboolean
Cam_IsVisible (player_state_t * player, vec3_t vec)
{
	float       d;
	pmtrace_t   trace;
	vec3_t      v;

	trace = Cam_DoTrace (player->origin, vec);
	if (trace.fraction != 1 || /* trace.inopen || */ trace.inwater)
		return false;
	// check distance, don't let the player get too far away or too close
	VectorSubtract (player->origin, vec, v);
	d = vlen (v);
	if (d < 16)
		return false;
	return true;
}

static qboolean
InitFlyby (player_state_t * self, player_state_t * player, int checkvis)
{
	float       f, max;
	vec3_t      forward, right, up, vec, vec2;

	VectorCopy (player->viewangles, vec);
	vec[0] = 0;
	AngleVectors (vec, forward, right, up);
//	for (i = 0; i < 3; i++)
//		forward[i] *= 3;

	max = 1000;
	VectorAdd (forward, up, vec2);
	VectorAdd (vec2, right, vec2);
	if ((f = Cam_TryFlyby (self, player, vec2, checkvis)) < max) {
		max = f;
		VectorCopy (vec2, vec);
	}
	VectorAdd (forward, up, vec2);
	VectorSubtract (vec2, right, vec2);
	if ((f = Cam_TryFlyby (self, player, vec2, checkvis)) < max) {
		max = f;
		VectorCopy (vec2, vec);
	}
	VectorAdd (forward, right, vec2);
	if ((f = Cam_TryFlyby (self, player, vec2, checkvis)) < max) {
		max = f;
		VectorCopy (vec2, vec);
	}
	VectorSubtract (forward, right, vec2);
	if ((f = Cam_TryFlyby (self, player, vec2, checkvis)) < max) {
		max = f;
		VectorCopy (vec2, vec);
	}
	VectorAdd (forward, up, vec2);
	if ((f = Cam_TryFlyby (self, player, vec2, checkvis)) < max) {
		max = f;
		VectorCopy (vec2, vec);
	}
	VectorSubtract (forward, up, vec2);
	if ((f = Cam_TryFlyby (self, player, vec2, checkvis)) < max) {
		max = f;
		VectorCopy (vec2, vec);
	}
	VectorAdd (up, right, vec2);
	VectorSubtract (vec2, forward, vec2);
	if ((f = Cam_TryFlyby (self, player, vec2, checkvis)) < max) {
		max = f;
		VectorCopy (vec2, vec);
	}
	VectorSubtract (up, right, vec2);
	VectorSubtract (vec2, forward, vec2);
	if ((f = Cam_TryFlyby (self, player, vec2, checkvis)) < max) {
		max = f;
		VectorCopy (vec2, vec);
	}
	// invert
	VectorSubtract (vec3_origin, forward, vec2);
	if ((f = Cam_TryFlyby (self, player, vec2, checkvis)) < max) {
		max = f;
		VectorCopy (vec2, vec);
	}
	VectorCopy (forward, vec2);
	if ((f = Cam_TryFlyby (self, player, vec2, checkvis)) < max) {
		max = f;
		VectorCopy (vec2, vec);
	}
	// invert
	VectorSubtract (vec3_origin, right, vec2);
	if ((f = Cam_TryFlyby (self, player, vec2, checkvis)) < max) {
		max = f;
		VectorCopy (vec2, vec);
	}
	VectorCopy (right, vec2);
	if ((f = Cam_TryFlyby (self, player, vec2, checkvis)) < max) {
		max = f;
		VectorCopy (vec2, vec);
	}
	// ack, can't find him
	if (max >= 1000) {
//		Cam_Unlock();
		return false;
	}
	locked = true;
	VectorCopy (vec, desired_position);
	return true;
}

static void
Cam_CheckHighTarget (void)
{
	int				i, j, max;
	player_info_t  *s;

	j = -1;
	for (i = 0, max = -9999; i < MAX_CLIENTS; i++) {
		s = &cl.players[i];
		if (s->name[0] && !s->spectator && s->frags > max) {
			max = s->frags;
			j = i;
		}
	}
	if (j >= 0) {
		if (!locked || cl.players[j].frags > cl.players[spec_track].frags)
			Cam_Lock (j);
	} else
		Cam_Unlock ();
}

// ZOID
//
// Take over the user controls and track a player.
// We find a nice position to watch the player and move there
void
Cam_Track (usercmd_t *cmd)
{
	float			len;
	frame_t		   *frame;
	player_state_t *player, *self;
	vec3_t			vec;

	if (!cl.spectator)
		return;

	if (cl_hightrack->int_val && !locked)
		Cam_CheckHighTarget ();

	if (!autocam || cls.state != ca_active)
		return;

	if (locked
		&& (!cl.players[spec_track].name[0]
			|| cl.players[spec_track].spectator)) {
		locked = false;
		if (cl_hightrack->int_val)
			Cam_CheckHighTarget ();
		else
			Cam_Unlock ();
		return;
	}

	frame = &cl.frames[cls.netchan.incoming_sequence & UPDATE_MASK];
	player = frame->playerstate + spec_track;
	self = frame->playerstate + cl.playernum;

	if (!locked || !Cam_IsVisible (player, desired_position)) {
		if (!locked || realtime - cam_lastviewtime > 0.1) {
			if (!InitFlyby (self, player, true))
				InitFlyby (self, player, false);
			cam_lastviewtime = realtime;
		}
	} else
		cam_lastviewtime = realtime;

	// couldn't track for some reason
	if (!locked || !autocam)
		return;

	if (cl_chasecam->int_val) {
		cmd->forwardmove = cmd->sidemove = cmd->upmove = 0;

		VectorCopy (player->viewangles, cl.viewangles);
		VectorCopy (player->origin, desired_position);
		if (memcmp (&desired_position, &self->origin,
					sizeof (desired_position))
			!= 0) {
			MSG_WriteByte (&cls.netchan.message, clc_tmove);
			MSG_WriteCoord (&cls.netchan.message, desired_position[0]);
			MSG_WriteCoord (&cls.netchan.message, desired_position[1]);
			MSG_WriteCoord (&cls.netchan.message, desired_position[2]);
			// move there locally immediately
			VectorCopy (desired_position, self->origin);
		}
		self->weaponframe = player->weaponframe;

	} else {
		// Ok, move to our desired position and set our angles to view
		// the player
		VectorSubtract (desired_position, self->origin, vec);
		len = vlen (vec);
		cmd->forwardmove = cmd->sidemove = cmd->upmove = 0;
		if (len > 16) {					// close enough?
			MSG_WriteByte (&cls.netchan.message, clc_tmove);
			MSG_WriteCoord (&cls.netchan.message, desired_position[0]);
			MSG_WriteCoord (&cls.netchan.message, desired_position[1]);
			MSG_WriteCoord (&cls.netchan.message, desired_position[2]);
		}
		// move there locally immediately
		VectorCopy (desired_position, self->origin);

		VectorSubtract (player->origin, desired_position, vec);
		vectoangles (vec, cl.viewangles);
		cl.viewangles[0] = -cl.viewangles[0];
	}
}

#if 0
static float
adjustang (float current, float ideal, float speed)
{
	float		move;

	current = anglemod (current);
	ideal = anglemod (ideal);

	if (current == ideal)
		return current;

	move = ideal - current;
	if (ideal > current) {
		if (move >= 180)
			move = move - 360;
	} else {
		if (move <= -180)
			move = move + 360;
	}
	if (move > 0) {
		if (move > speed)
			move = speed;
	} else {
		if (move < -speed)
			move = -speed;
	}

//Con_Printf("c/i: %4.2f/%4.2f move: %4.2f\n", current, ideal, move);
	return anglemod (current + move);
}
#endif

#if 0
void
Cam_SetView (void)
{
	frame_t		   *frame;
	player_state_t *player, *self;
	vec3_t			vec, vec2;

	if (cls.state != ca_active || !cl.spectator || !autocam || !locked)
		return;

	frame = &cl.frames[cls.netchan.incoming_sequence & UPDATE_MASK];
	player = frame->playerstate + spec_track;
	self = frame->playerstate + cl.playernum;

	VectorSubtract (player->origin, cl.simorg, vec);
	if (cam_forceview) {
		cam_forceview = false;
		vectoangles (vec, cam_viewangles);
		cam_viewangles[0] = -cam_viewangles[0];
	} else {
		vectoangles (vec, vec2);
		vec2[PITCH] = -vec2[PITCH];

		cam_viewangles[PITCH] =
			adjustang (cam_viewangles[PITCH], vec2[PITCH],
					   cl_camera_maxpitch->value);
		cam_viewangles[YAW] =
			adjustang (cam_viewangles[YAW], vec2[YAW],
					   cl_camera_maxyaw->value);
	}
	VectorCopy (cam_viewangles, cl.viewangles);
	VectorCopy (cl.viewangles, cl.simangles);
}
#endif

void
Cam_FinishMove (usercmd_t *cmd)
{
	int				end, i;
	player_info_t  *s;

	if (cls.state != ca_active)
		return;

	if (!cl.spectator)					// only in spectator mode
		return;

#if 0
	if (autocam && locked) {
		frame = &cl.frames[cls.netchan.incoming_sequence & UPDATE_MASK];
		player = frame->playerstate + spec_track;
		self = frame->playerstate + cl.playernum;

		VectorSubtract (player->origin, self->origin, vec);
		if (cam_forceview) {
			cam_forceview = false;
			vectoangles (vec, cam_viewangles);
			cam_viewangles[0] = -cam_viewangles[0];
		} else {
			vectoangles (vec, vec2);
			vec2[PITCH] = -vec2[PITCH];

			cam_viewangles[PITCH] =
				adjustang (cam_viewangles[PITCH], vec2[PITCH],
						   cl_camera_maxpitch->value);
			cam_viewangles[YAW] =
				adjustang (cam_viewangles[YAW], vec2[YAW],
						   cl_camera_maxyaw->value);
		}
		VectorCopy (cam_viewangles, cl.viewangles);
	}
#endif

	if (cmd->buttons & BUTTON_ATTACK) {
		if (!(oldbuttons & BUTTON_ATTACK)) {

			oldbuttons |= BUTTON_ATTACK;
			autocam++;

			if (autocam > CAM_TRACK) {
				Cam_Unlock ();
				VectorCopy (cl.viewangles, cmd->angles);
				return;
			}
		} else
			return;
	} else {
		oldbuttons &= ~BUTTON_ATTACK;
		if (!autocam)
			return;
	}

	if (autocam && cl_hightrack->int_val) {
		Cam_CheckHighTarget ();
		return;
	}

	if (locked) {
		if ((cmd->buttons & BUTTON_JUMP) && (oldbuttons & BUTTON_JUMP))
			return;						// don't pogo stick

		if (!(cmd->buttons & BUTTON_JUMP)) {
			oldbuttons &= ~BUTTON_JUMP;
			return;
		}
		oldbuttons |= BUTTON_JUMP;		// don't jump again until released
	}
//	Con_Printf("Selecting track target...\n");

	if (locked && autocam)
		end = (spec_track + 1) % MAX_CLIENTS;
	else
		end = spec_track;
	i = end;
	do {
		s = &cl.players[i];
		if (s->name[0] && !s->spectator) {
			Cam_Lock (i);
			return;
		}
		i = (i + 1) % MAX_CLIENTS;
	} while (i != end);
	// stay on same guy?
	i = spec_track;
	s = &cl.players[i];
	if (s->name[0] && !s->spectator) {
		Cam_Lock (i);
		return;
	}
	Con_Printf ("No target found ...\n");
	autocam = locked = false;
}

void
Cam_Reset (void)
{
	autocam = CAM_NONE;
	spec_track = 0;
}

void
CL_Cam_Init_Cvars (void)
{
	cl_camera_maxpitch = Cvar_Get ("cl_camera_maxpitch", "10", CVAR_NONE, NULL,
								   "highest camera pitch in spectator mode");
	cl_camera_maxyaw = Cvar_Get ("cl_camera_maxyaw", "30", CVAR_NONE, NULL,
								 "highest camera yaw in spectator mode");
	cl_chasecam = Cvar_Get ("cl_chasecam", "0", CVAR_NONE, NULL, "get first "
							"person view of the person you are tracking in "
							"spectator mode");
	cl_hightrack = Cvar_Get ("cl_hightrack", "0", CVAR_NONE, NULL, "view the "
							 "player who has the most frags while you are in "
							 "spectator mode.");

	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
TraceLine (vec3_t start, vec3_t end, vec3_t impact)
{
	pmtrace_t     trace;

	memset (&trace, 0, sizeof (trace));
	PM_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] = r_refdef.vieworg[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);
}