numerous

[carveJwlIkooP6JGAAIwe30JlM.git] / player.h

#ifndef PLAYER_H
#define PLAYER_H

#include "audio.h"
#include "common.h"
#include "world.h"
//#include "character.h"
#include "player_model.h"
#include "bvh.h"

/* 
 * Constants 
 */

static float 
   k_walkspeed             = 7.0f,  /* no longer used */
   k_runspeed              = 14.0f,
   k_board_radius          = 0.3f,
   k_board_length          = 0.45f,
   k_board_allowance       = 0.04f,
   k_friction_lat          = 8.8f,
   k_friction_resistance   = 0.01f,
   k_max_push_speed        = 16.0f,
   k_push_accel            = 10.0f,
   k_push_cycle_rate       = 8.0f,
   k_steer_ground          = 2.5f,
   k_steer_air             = 3.6f,
   k_steer_air_lerp        = 0.3f,
   k_pump_force            = 0.0f,
   k_downforce             = 5.0f,
   k_jump_charge_speed     = (1.0f/1.0f),
   k_jump_force            = 5.0f,
   k_pitch_limit           = 1.5f,
   k_look_speed            = 2.0f,
   k_walk_accel            = 5.0f,
   k_walk_friction         = 8.0f;

static int freecam = 0;
static int walk_grid_iterations = 1;
static float fc_speed = 10.0f;

static struct gplayer
{
   /* Physics */
   rigidbody rb, collide_front, collide_back, rb_gate_frame;

   /* TODO: eugh */
   m3x3f gate_vr_frame, gate_vr_pstep_frame;
   int on_board_frame, in_air_frame;

   v3f a, v_last, m, bob, vl;

   /* Utility */
   float vswitch, slip, slip_last,
         reverse;

   float iY;   /* Yaw inertia */
   int in_air, is_dead, on_board;

   v2f board_xy;
   float grab;
   float pitch;
   float pushing, push_time;
   float jump;
   int jump_charge, jump_dir;
   
   v3f land_target;
   v3f land_target_log[22];
   u32 land_target_colours[22];
   int land_log_count;
   m3x3f vr,vr_pstep;
   
   struct character mdl;

   v3f handl_target, handr_target,
       handl, handr;
   
   /* Camera */
   float air_blend;
   
   v3f camera_pos, smooth_localcam;
   v2f angles;
   m4x3f camera, camera_inverse;

   /* animation */
   double jump_time;
   float fslide,
         fdirz, fdirx,
         fstand,
         ffly,
         fpush,
         fairdir,
         fsetup,
         walk_timer,
         fonboard;

   v3f last_step_pos;
   int step_phase;
}
player = 
{
   .on_board = 0,

   .collide_front = { .type = k_rb_shape_sphere, .inf.sphere.radius = 0.3f },
   .collide_back  = { .type = k_rb_shape_sphere, .inf.sphere.radius = 0.3f }
};

/* 
 * Player API
 */

static float *player_get_pos(void)
{
   return player.rb.co;
}


/*
 * Free camera movement
 */

static void player_mouseview(void)
{
   if( gui_want_mouse() )
      return;

   static v2f mouse_last,
              view_vel = { 0.0f, 0.0f };

   if( vg_get_button_down( "primary" ) )
      v2_copy( vg_mouse, mouse_last );

   else if( vg_get_button( "primary" ) )
   {
      v2f delta;
      v2_sub( vg_mouse, mouse_last, delta );
      v2_copy( vg_mouse, mouse_last );

      v2_muladds( view_vel, delta, 0.001f, view_vel );
   }
   
   v2_muladds( view_vel, 
         (v2f){ vg_get_axis("h1"), vg_get_axis("v1") }, 
         0.05f, view_vel );
   v2_muls( view_vel, 0.93f, view_vel );
   v2_add( view_vel, player.angles, player.angles );
   player.angles[1] = vg_clampf( player.angles[1], -VG_PIf*0.5f, VG_PIf*0.5f );
}

static void player_freecam(void)
{
   player_mouseview();

   float movespeed = fc_speed;
   v3f lookdir = { 0.0f, 0.0f, -1.0f },
       sidedir = { 1.0f, 0.0f,  0.0f };
   
   m3x3_mulv( player.camera, lookdir, lookdir );
   m3x3_mulv( player.camera, sidedir, sidedir );
   
   static v3f move_vel = { 0.0f, 0.0f, 0.0f };
   if( vg_get_button( "forward" ) )
      v3_muladds( move_vel, lookdir, ktimestep * movespeed, move_vel );
   if( vg_get_button( "back" ) )
      v3_muladds( move_vel, lookdir, ktimestep *-movespeed, move_vel );
   if( vg_get_button( "left" ) )
      v3_muladds( move_vel, sidedir, ktimestep *-movespeed, move_vel );
   if( vg_get_button( "right" ) )
      v3_muladds( move_vel, sidedir, ktimestep * movespeed, move_vel );

   v3_muls( move_vel, 0.7f, move_vel );
   v3_add( move_vel, player.camera_pos, player.camera_pos );
}

/*
 * Player Physics Implementation
 */

static void apply_gravity( v3f vel, float const timestep )
{
   v3f gravity = { 0.0f, -9.6f, 0.0f };
   v3_muladds( vel, gravity, timestep, vel );
}

/*
 * TODO: The angle bias should become greater when launching from a steeper 
 *       angle and skewed towords more 'downwards' angles when launching from
 *       shallower trajectories
 *
 *       it should also be tweaked by the controller left stick being pushed
 *       up or down
 */
static void player_start_air(void)
{
   if( player.in_air )
      return;

   player.in_air = 1;

   float pstep = ktimestep*10.0f;
   float best_velocity_delta = -9999.9f;
   float k_bias = 0.96f;

   v3f axis;
   v3_cross( player.rb.up, player.rb.v, axis );
   v3_normalize( axis );
   player.land_log_count = 0;
   
   m3x3_identity( player.vr );

   for( int m=-3;m<=12; m++ )
   {
      float vmod = ((float)m / 15.0f)*0.09f;

      v3f pco, pco1, pv;
      v3_copy( player.rb.co, pco );
      v3_muls( player.rb.v, k_bias, pv );

      /* 
       * Try different 'rotations' of the velocity to find the best possible
       * landing normal. This conserves magnitude at the expense of slightly
       * unrealistic results
       */

      m3x3f vr;
      v4f vr_q;

      q_axis_angle( vr_q, axis, vmod );
      q_m3x3( vr_q, vr );

      m3x3_mulv( vr, pv, pv );
      v3_muladds( pco, pv, pstep, pco );

      for( int i=0; i<50; i++ )
      {
         v3_copy( pco, pco1 );
         apply_gravity( pv, pstep );

         m3x3_mulv( vr, pv, pv );
         v3_muladds( pco, pv, pstep, pco );
         
         ray_hit contact;
         v3f vdir;

         v3_sub( pco, pco1, vdir );
         contact.dist = v3_length( vdir );
         v3_divs( vdir, contact.dist, vdir);

         if( ray_world( pco1, vdir, &contact ))
         {
            float land_delta = v3_dot( pv, contact.normal );
            u32 scolour = (u8)(vg_minf(-land_delta * 2.0f, 255.0f));

            /* Bias prediction towords ramps */
            if( ray_hit_is_ramp( &contact ) )
            {
               land_delta *= 0.1f;
               scolour |= 0x0000a000;
            }

            if( (land_delta < 0.0f) && (land_delta > best_velocity_delta) )
            {
               best_velocity_delta = land_delta;

               v3_copy( contact.pos, player.land_target );
               
               m3x3_copy( vr, player.vr_pstep );
               q_axis_angle( vr_q, axis, vmod*0.1f );
               q_m3x3( vr_q, player.vr );
            }

            v3_copy( contact.pos, 
                  player.land_target_log[player.land_log_count] );
            player.land_target_colours[player.land_log_count] = 
               0xff000000 | scolour;

            player.land_log_count ++;

            break;
         }
      }
   }
}

static void draw_cross(v3f pos,u32 colour, float scale)
{
   v3f p0, p1;
   v3_add( (v3f){ scale,0.0f,0.0f}, pos, p0 );
   v3_add( (v3f){-scale,0.0f,0.0f}, pos, p1 );
   vg_line( p0, p1, colour );
   v3_add( (v3f){0.0f, scale,0.0f}, pos, p0 );
   v3_add( (v3f){0.0f,-scale,0.0f}, pos, p1 );
   vg_line( p0, p1, colour );
   v3_add( (v3f){0.0f,0.0f, scale}, pos, p0 );
   v3_add( (v3f){0.0f,0.0f,-scale}, pos, p1 );
   vg_line( p0, p1, colour );
}

static void player_physics_control(void)
{
   /*
    * Computing localized friction forces for controlling the character
    * Friction across X is significantly more than Z
    */

   v3f vel;
   m3x3_mulv( player.rb.to_local, player.rb.v, vel );
   float slip = 0.0f;
   
   if( fabsf(vel[2]) > 0.01f )
      slip = fabsf(-vel[0] / vel[2]) * vg_signf(vel[0]);

   if( fabsf( slip ) > 1.2f )
      slip = vg_signf( slip ) * 1.2f;
   player.slip = slip;
   player.reverse = -vg_signf(vel[2]);

   float substep = ktimestep * 0.2f;
   float fwd_resistance = (vg_get_button( "break" )? 5.0f: 0.02f) * -substep;

   for( int i=0; i<5; i++ )
   {
      vel[2] = stable_force( vel[2], vg_signf( vel[2] ) * fwd_resistance );
      vel[0] = stable_force( vel[0], 
            vg_signf( vel[0] ) * -k_friction_lat*substep );
   }
   
   static double start_push = 0.0;
   if( vg_get_button_down( "push" ) )
      start_push = vg_time;

   if( vg_get_button( "jump" ) )
   {
      player.jump += ktimestep * k_jump_charge_speed;

      if( !player.jump_charge )
         player.jump_dir = player.reverse > 0.0f? 1: 0;

      player.jump_charge = 1;
   }

   if( !vg_get_button("break") && vg_get_button( "push" ) )
   {
      player.pushing = 1.0f;
      player.push_time = vg_time-start_push;

      float cycle_time = player.push_time*k_push_cycle_rate,
            amt = k_push_accel * (sinf(cycle_time)*0.5f+0.5f)*ktimestep,
            current = v3_length( vel ),
            new_vel = vg_minf( current + amt, k_max_push_speed );

      new_vel -= vg_minf(current, k_max_push_speed);
      vel[2] -= new_vel * player.reverse;
   }

   /* Pumping */
   static float previous = 0.0f;
   float delta = previous - player.grab,
          pump = delta * k_pump_force*ktimestep;
   previous = player.grab;

   v3f p1;
   v3_muladds( player.rb.co, player.rb.up, pump, p1 );
   vg_line( player.rb.co, p1, 0xff0000ff );

   vel[1] += pump;

   
   m3x3_mulv( player.rb.to_world, vel, player.rb.v );
   
   float steer = vg_get_axis( "horizontal" );
   player.iY -= vg_signf(steer)*powf(steer,2.0f) * k_steer_ground * ktimestep;
   
   v2_lerp( player.board_xy, (v2f){ slip*0.25f, 0.0f }, 
         ktimestep*5.0f, player.board_xy);
}

static void player_physics_control_air(void)
{
   m3x3_mulv( player.vr, player.rb.v, player.rb.v );
   draw_cross( player.land_target, 0xff0000ff, 0.25f );

   ray_hit hit;

   /* 
    * Prediction 
    */
   float pstep = ktimestep*10.0f;

   v3f pco, pco1, pv;
   v3_copy( player.rb.co, pco );
   v3_copy( player.rb.v, pv );
   
   float time_to_impact = 0.0f;
   float limiter = 1.0f;

   for( int i=0; i<50; i++ )
   {
      v3_copy( pco, pco1 );
      m3x3_mulv( player.vr_pstep, pv, pv );
      apply_gravity( pv, pstep );
      v3_muladds( pco, pv, pstep, pco );

      //vg_line( pco, pco1, i&0x1?0xff000000:0xffffffff );
      
      ray_hit contact;
      v3f vdir;

      v3_sub( pco, pco1, vdir );
      contact.dist = v3_length( vdir );
      v3_divs( vdir, contact.dist, vdir);
      
      float orig_dist = contact.dist;
      if( ray_world( pco1, vdir, &contact ))
      {
         float angle = v3_dot( player.rb.up, contact.normal );
         v3f axis; 
         v3_cross( player.rb.up, contact.normal, axis );

         time_to_impact += (contact.dist/orig_dist)*pstep;
         limiter = vg_minf( 5.0f, time_to_impact )/5.0f;
         limiter = 1.0f-limiter;
         limiter *= limiter;
         limiter = 1.0f-limiter;

         if( angle < 0.99f )
         {
            v4f correction;
            q_axis_angle( correction, axis, acosf(angle)*0.05f*(1.0f-limiter) );
            q_mul( correction, player.rb.q, player.rb.q );
         }

         draw_cross( contact.pos, 0xffff0000, 0.25f );
         break;
      }
      time_to_impact += pstep;
   }

   player.iY -= vg_get_axis( "horizontal" ) * k_steer_air * ktimestep;
   {
      float iX = vg_get_axis( "vertical" ) * 
         player.reverse * k_steer_air * limiter * ktimestep;

      static float siX = 0.0f;
      siX = vg_lerpf( siX, iX, k_steer_air_lerp );
      
      v4f rotate;
      q_axis_angle( rotate, player.rb.right, siX );
      q_mul( rotate, player.rb.q, player.rb.q );
   }
   
   v2f target = {0.0f,0.0f};
   v2_muladds( target, (v2f){ vg_get_axis("h1"), vg_get_axis("v1") },
               player.grab, target );
   v2_lerp( player.board_xy, target, ktimestep*3.0f, player.board_xy );
}

static void player_init(void)
{
   rb_init( &player.collide_front );
   rb_init( &player.collide_back  );
}

static void player_walk_physics(void)
{
   rigidbody *rbf = &player.collide_front,
             *rbb = &player.collide_back;

   m3x3_copy( player.rb.to_world, player.collide_front.to_world );
   m3x3_copy( player.rb.to_world, player.collide_back.to_world );
   
   float h0 = 0.3f,
         h1 = 0.9f;

   m4x3_mulv( player.rb.to_world, (v3f){0.0f,h0,0.0f}, rbf->co );
   v3_copy( rbf->co, rbf->to_world[3] );
   m4x3_mulv( player.rb.to_world, (v3f){0.0f,h1,0.0f}, rbb->co );
   v3_copy( rbb->co, rbb->to_world[3] );

   m4x3_invert_affine( rbf->to_world, rbf->to_local );
   m4x3_invert_affine( rbb->to_world, rbb->to_local );

   rb_update_bounds( rbf );
   rb_update_bounds( rbb );

   rb_debug( rbf, 0xff0000ff );
   rb_debug( rbb, 0xff0000ff );

   rb_ct manifold[64];
   int len = 0;

   len += rb_sphere_scene( rbf, &world.rb_geo, manifold+len );
   len += rb_sphere_scene( rbb, &world.rb_geo, manifold+len );

   rb_presolve_contacts( manifold, len );

   for( int j=0; j<5; j++ )
   {
      for( int i=0; i<len; i++ )
      {
         struct contact *ct = &manifold[i];
         
         /*normal */
         float vn = -v3_dot( player.rb.v, ct->n );
         vn += ct->bias;

         float temp = ct->norm_impulse;
         ct->norm_impulse = vg_maxf( temp + vn, 0.0f );
         vn = ct->norm_impulse - temp;

         v3f impulse;
         v3_muls( ct->n, vn, impulse );

         v3_add( impulse, player.rb.v, player.rb.v );

         /* friction */
         for( int j=0; j<2; j++ )
         {
            float     f = k_friction * ct->norm_impulse,
                     vt = v3_dot( player.rb.v, ct->t[j] ),
                 lambda = -vt;
            
            float temp = ct->tangent_impulse[j];
            ct->tangent_impulse[j] = vg_clampf( temp + lambda, -f, f );
            lambda = ct->tangent_impulse[j] - temp;

            v3_muladds( player.rb.v, ct->t[j], lambda, player.rb.v );
         }
      }
   }

   player.in_air = len==0?1:0;
   
   v3_zero( player.rb.w );
   q_axis_angle( player.rb.q, (v3f){0.0f,1.0f,0.0f}, -player.angles[0] );

   v3f forward_dir = { sinf(player.angles[0]),0.0f,-cosf(player.angles[0]) };

   v3f p1;
   v3_muladds( player.rb.co, forward_dir, 2.0f, p1 );
   vg_line( player.rb.co, p1, 0xff0000ff );

   float move_dead = 0.1f,
         move = vg_get_axis("grabr")*0.5f + 0.5f - move_dead;

   if( move > 0.0f )
   {
      float move_norm = move * (1.0f/(1.0f-move_dead)),
            speed     = vg_lerpf( 0.1f*k_runspeed, k_runspeed, move_norm ),
            amt       = k_walk_accel * ktimestep,
            zvel      = v3_dot( player.rb.v, forward_dir ),
            new_vel   = vg_minf( zvel + amt, speed ),
            diff      = new_vel - vg_minf( zvel, speed );

      v3_muladds( player.rb.v, forward_dir, diff, player.rb.v );

      /* TODO move */
      float walk_norm = 30.0f/(float)player.mdl.anim_walk->length,
            run_norm  = 30.0f/(float)player.mdl.anim_run->length ;

      player.walk_timer += ktimestep * vg_lerpf( walk_norm,run_norm,move_norm );
   }
   else
   {
      player.walk_timer = 0.0f;
   }

   player.rb.v[0] *= 1.0f - (ktimestep*k_walk_friction);
   player.rb.v[2] *= 1.0f - (ktimestep*k_walk_friction);
}

static void player_physics(void)
{
   /*
    * Update collision fronts
    */
   
   rigidbody *rbf = &player.collide_front,
             *rbb = &player.collide_back;

   m3x3_copy( player.rb.to_world, player.collide_front.to_world );
   m3x3_copy( player.rb.to_world, player.collide_back.to_world );
   
   player.air_blend = vg_lerpf( player.air_blend, player.in_air, 0.1f );
   float h = player.air_blend*0.2f;

   m4x3_mulv( player.rb.to_world, (v3f){0.0f,h,-k_board_length}, rbf->co );
   v3_copy( rbf->co, rbf->to_world[3] );
   m4x3_mulv( player.rb.to_world, (v3f){0.0f,h, k_board_length}, rbb->co );
   v3_copy( rbb->co, rbb->to_world[3] );

   m4x3_invert_affine( rbf->to_world, rbf->to_local );
   m4x3_invert_affine( rbb->to_world, rbb->to_local );

   rb_update_bounds( rbf );
   rb_update_bounds( rbb );

   rb_debug( rbf, 0xff00ffff );
   rb_debug( rbb, 0xffffff00 );

   rb_ct manifold[64];
   int len = 0;

   len += rb_sphere_scene( rbf, &world.rb_geo, manifold+len );
   len += rb_sphere_scene( rbb, &world.rb_geo, manifold+len );

   rb_presolve_contacts( manifold, len );
   v3f surface_avg = {0.0f, 0.0f, 0.0f};

   if( !len )
   {
      player_start_air();
   }
   else
   {
      for( int i=0; i<len; i++ )
      {
         v3_add( manifold[i].n, surface_avg, surface_avg );

#if 0
         if( manifold[i].element_id <= world.sm_geo_std_oob.vertex_count )
         {
            player.is_dead = 1;
            character_ragdoll_copypose( &player.mdl, player.rb.v );
            return;
         }
#endif
      }

      v3_normalize( surface_avg );

      if( v3_dot( player.rb.v, surface_avg ) > 0.5f )
      {
         player_start_air();
      }
      else
         player.in_air = 0;
   }

   for( int j=0; j<5; j++ )
   {
      for( int i=0; i<len; i++ )
      {
         struct contact *ct = &manifold[i];
         
         v3f dv, delta;
         v3_sub( ct->co, player.rb.co, delta ); 
         v3_cross( player.rb.w, delta, dv );
         v3_add( player.rb.v, dv, dv );

         float vn = -v3_dot( dv, ct->n );
         vn += ct->bias;

         float temp = ct->norm_impulse;
         ct->norm_impulse = vg_maxf( temp + vn, 0.0f );
         vn = ct->norm_impulse - temp;

         v3f impulse;
         v3_muls( ct->n, vn, impulse );

         if( fabsf(v3_dot( impulse, player.rb.forward )) > 10.0f ||
             fabsf(v3_dot( impulse, player.rb.up )) > 50.0f )
         {
            player.is_dead = 1;
            character_ragdoll_copypose( &player.mdl, player.rb.v );
            return;
         }

         v3_add( impulse, player.rb.v, player.rb.v );
         v3_cross( delta, impulse, impulse );

         /*
          * W Impulses are limited to the Y and X axises, we don't really want
          * roll angular velocities being included.
          *
          * Can also tweak the resistance of each axis here by scaling the wx,wy
          * components.
          */
         
         float wy = v3_dot( player.rb.up, impulse ),
               wx = v3_dot( player.rb.right, impulse )*1.5f;

         v3_muladds( player.rb.w, player.rb.up, wy, player.rb.w );
         v3_muladds( player.rb.w, player.rb.right, wx, player.rb.w );
      }
   }

   float grabt = vg_get_axis( "grabr" )*0.5f+0.5f;
   player.grab = vg_lerpf( player.grab, grabt, 0.14f );
   player.pushing = 0.0f;

   if( !player.in_air )
   {
      v3f axis;
      float angle = v3_dot( player.rb.up, surface_avg );
      v3_cross( player.rb.up, surface_avg, axis );

      //float cz = v3_dot( player.rb.forward, axis );
      //v3_muls( player.rb.forward, cz, axis );

      if( angle < 0.999f )
      {
         v4f correction;
         q_axis_angle( correction, axis, acosf(angle)*0.3f );
         q_mul( correction, player.rb.q, player.rb.q );
      }

      v3_muladds( player.rb.v, player.rb.up, 
            -k_downforce*ktimestep, player.rb.v );

      player_physics_control();

      if( !player.jump_charge && player.jump > 0.2f )
      {
         v3f jumpdir;
         
         /* Launch more up if alignment is up else improve velocity */
         float aup = fabsf(v3_dot( (v3f){0.0f,1.0f,0.0f}, player.rb.up )),
               mod = 0.5f,
               dir = mod + aup*(1.0f-mod);

         v3_copy( player.rb.v, jumpdir );
         v3_normalize( jumpdir );
         v3_muls( jumpdir, 1.0f-dir, jumpdir );
         v3_muladds( jumpdir, player.rb.up, dir, jumpdir );
         v3_normalize( jumpdir );
         
         float force = k_jump_force*player.jump;
         v3_muladds( player.rb.v, jumpdir, force, player.rb.v );
         player.jump = 0.0f;

         player.jump_time = vg_time;

         audio_lock();
         audio_player_set_flags( &audio_player_extra, AUDIO_FLAG_SPACIAL_3D );
         audio_player_set_position( &audio_player_extra, player.rb.co );
         audio_player_set_vol( &audio_player_extra, 20.0f );
         audio_player_playclip( &audio_player_extra, &audio_jumps[rand()%4] );
         audio_unlock();
      }
   }
   else
   {
      player_physics_control_air();
   }

   if( !player.jump_charge )
   {
      player.jump -= k_jump_charge_speed * ktimestep;
   }
   player.jump_charge = 0;
   player.jump = vg_clampf( player.jump, 0.0f, 1.0f );
}

static void player_do_motion(void)
{
   float horizontal = vg_get_axis("horizontal"),
         vertical = vg_get_axis("vertical");

   if( player.on_board )
      player_physics();
   else
      player_walk_physics();
   
   /* Integrate velocity */
   v3f prevco;
   v3_copy( player.rb.co, prevco );
   
   apply_gravity( player.rb.v, ktimestep );
   v3_muladds( player.rb.co, player.rb.v, ktimestep, player.rb.co );

   /* Real angular velocity integration */
   v3_lerp( player.rb.w, (v3f){0.0f,0.0f,0.0f}, 0.125f, player.rb.w );
   if( v3_length2( player.rb.w ) > 0.0f )
   {
      v4f rotation;
      v3f axis;
      v3_copy( player.rb.w, axis );
      
      float mag = v3_length( axis );
      v3_divs( axis, mag, axis );
      q_axis_angle( rotation, axis, mag*k_rb_delta );
      q_mul( rotation, player.rb.q, player.rb.q );
   }

   /* Faux angular velocity */
   v4f rotate; 

   static float siY = 0.0f;
   float lerpq = player.in_air? 0.04f: 0.3f;
   siY = vg_lerpf( siY, player.iY, lerpq );

   q_axis_angle( rotate, player.rb.up, siY );
   q_mul( rotate, player.rb.q, player.rb.q );
   player.iY = 0.0f;

   /* 
    * Gate intersection, by tracing a line over the gate planes 
    */
   for( int i=0; i<world.routes.gate_count; i++ )
   {
      struct route_gate *rg = &world.routes.gates[i];
      teleport_gate *gate = &rg->gate;

      if( gate_intersect( gate, player.rb.co, prevco ) )
      {
         m4x3_mulv( gate->transport, player.rb.co, player.rb.co );
         m3x3_mulv( gate->transport, player.rb.v, player.rb.v );
         m3x3_mulv( gate->transport, player.vl, player.vl );
         m3x3_mulv( gate->transport, player.v_last, player.v_last );
         m3x3_mulv( gate->transport, player.m, player.m );
         m3x3_mulv( gate->transport, player.bob, player.bob );

         v4f transport_rotation;
         m3x3_q( gate->transport, transport_rotation );
         q_mul( transport_rotation, player.rb.q, player.rb.q );
         
         world_routes_activate_gate( i );
         player.rb_gate_frame = player.rb;
         player.in_air_frame = player.in_air;
         player.on_board_frame = player.on_board;

         if( !player.on_board )
         {
            v3f fwd_dir = {cosf(player.angles[0]),
                           0.0f,
                           sinf(player.angles[0])};
            m3x3_mulv( gate->transport, fwd_dir, fwd_dir );

            player.angles[0] = atan2f( fwd_dir[2], fwd_dir[0] );
                                    
         }

         m3x3_copy( player.vr, player.gate_vr_frame );
         m3x3_copy( player.vr_pstep, player.gate_vr_pstep_frame );

         audio_lock();
         audio_play_oneshot( &audio_gate_lap, 1.0f );
         audio_unlock();
         break;
      }
   }
   
   rb_update_transform( &player.rb );
}

/*
 * Animation
 */

static void player_animate_offboard(void)
{
   mdl_keyframe apose[32], bpose[32];
   struct skeleton *sk = &player.mdl.sk;

   float walk_norm = (float)player.mdl.anim_walk->length/30.0f,
         run_norm  = (float)player.mdl.anim_run->length/30.0f,
         t = player.walk_timer,
         l = vg_get_axis("grabr") * 0.5f + 0.5f;

   skeleton_sample_anim( sk, player.mdl.anim_walk, t*walk_norm, apose );
   skeleton_sample_anim( sk, player.mdl.anim_run,  t*run_norm, bpose );

   skeleton_lerp_pose( sk, apose, bpose, l, apose );

   float idle_walk = vg_minf( l * 10.0f, 1.0f);

   skeleton_sample_anim( sk, player.mdl.anim_idle, vg_time*0.1f, bpose );
   skeleton_lerp_pose( sk, apose, bpose, 1.0f-idle_walk, apose );

   skeleton_apply_pose( &player.mdl.sk, apose, k_anim_apply_defer_ik );
   skeleton_apply_ik_pass( &player.mdl.sk );
   skeleton_apply_pose( &player.mdl.sk, apose, k_anim_apply_deffered_only );

   v3_copy( player.mdl.sk.final_mtx[player.mdl.id_head-1][3], 
               player.mdl.cam_pos );

   skeleton_apply_inverses( &player.mdl.sk );

   m4x3f mtx;
   v4f rot;
   q_axis_angle( rot, (v3f){0.0f,1.0f,0.0f}, -player.angles[0] - VG_PIf*0.5f );
   q_m3x3( rot, mtx );
   v3_copy( player.rb.to_world[3], mtx[3] );

   skeleton_apply_transform( &player.mdl.sk, mtx );
   skeleton_debug( &player.mdl.sk );
}

static void player_animate(void)
{
   if( !player.on_board )
   {
      player_animate_offboard();
      return;
   }

   /* Camera position */
   v3_sub( player.rb.v, player.v_last, player.a );
   v3_copy( player.rb.v, player.v_last );

   v3_add( player.m, player.a, player.m );
   v3_lerp( player.m, (v3f){0.0f,0.0f,0.0f}, 0.1f, player.m );

   player.m[0] = vg_clampf( player.m[0], -2.0f, 2.0f );
   player.m[1] = vg_clampf( player.m[1], -2.0f, 2.0f );
   player.m[2] = vg_clampf( player.m[2], -2.0f, 2.0f );
   v3_lerp( player.bob, player.m, 0.2f, player.bob );

   /* Head */
   float lslip = fabsf(player.slip);

   float kheight = 2.0f,
         kleg = 0.6f;

   v3f offset;
   v3_zero( offset );
   m3x3_mulv( player.rb.to_local, player.bob, offset );

   static float speed_wobble = 0.0f, speed_wobble_2 = 0.0f;
   
   float kickspeed = vg_clampf(v3_length(player.rb.v)*(1.0f/40.0f), 0.0f, 1.0f);
   float kicks = (vg_randf()-0.5f)*2.0f*kickspeed;
   float sign = vg_signf( kicks );
   speed_wobble = vg_lerpf( speed_wobble, kicks*kicks*sign, 0.1f );
   speed_wobble_2 = vg_lerpf( speed_wobble_2, speed_wobble, 0.04f );

   offset[0] *= 0.26f;
   offset[0] += speed_wobble_2*3.0f;

   offset[1] *= -0.3f;
   offset[2] *= 0.01f;

   offset[0] = vg_clampf( offset[0], -0.8f, 0.8f );
   offset[1] = vg_clampf( offset[1], -0.5f, 0.0f );
   offset[1] = 0.0f;

   /* 
    * Animation blending
    * ===========================================
    */

   /* scalar blending information */
   float speed = v3_length( player.rb.v );
   
   /* sliding */
   {
      float desired = vg_clampf( lslip, 0.0f, 1.0f );
      player.fslide = vg_lerpf( player.fslide, desired, 0.04f );
   }
   
   /* movement information */
   {
      float dirz = player.reverse > 0.0f? 0.0f: 1.0f,
            dirx = player.slip < 0.0f?    0.0f: 1.0f,
            fly  = player.in_air?         1.0f: 0.0f;

      player.fdirz = vg_lerpf( player.fdirz, dirz, 0.04f );
      player.fdirx = vg_lerpf( player.fdirx, dirx, 0.01f );
      player.ffly  = vg_lerpf( player.ffly, fly, 0.04f );
   }
   
   struct skeleton *sk = &player.mdl.sk;

   mdl_keyframe apose[32], bpose[32];
   mdl_keyframe ground_pose[32];
   {
      /* when the player is moving fast he will crouch down a little bit */
      float stand = 1.0f - vg_clampf( speed * 0.03f, 0.0f, 1.0f );
      player.fstand = vg_lerpf( player.fstand, stand, 0.1f );

      /* stand/crouch */
      float dir_frame   = player.fdirz * (15.0f/30.0f),
            stand_blend = offset[1]*-2.0f;
      
      skeleton_sample_anim( sk, player.mdl.anim_stand, dir_frame, apose );
      skeleton_sample_anim( sk, player.mdl.anim_highg, dir_frame, bpose );
      skeleton_lerp_pose( sk, apose, bpose, stand_blend, apose );

      /* sliding */
      float slide_frame = player.fdirx * (15.0f/30.0f);
      skeleton_sample_anim( sk, player.mdl.anim_slide, slide_frame, bpose );
      skeleton_lerp_pose( sk, apose, bpose, player.fslide, apose );

      /* pushing */
      player.fpush = vg_lerpf( player.fpush, player.pushing, 0.1f );

      float pt = player.push_time;
      if( player.reverse > 0.0f )
         skeleton_sample_anim( sk, player.mdl.anim_push, pt, bpose );
      else
         skeleton_sample_anim( sk, player.mdl.anim_push_reverse, pt, bpose );

      skeleton_lerp_pose( sk, apose, bpose, player.fpush, apose );

      /* trick setup */
      float jump_start_frame = 14.0f/30.0f;
      float setup_frame = player.jump * jump_start_frame,
            setup_blend = vg_minf( player.jump*5.0f, 1.0f );
      
      float jump_frame = (vg_time - player.jump_time) + jump_start_frame;
      if( jump_frame >= jump_start_frame && jump_frame <= (40.0f/30.0f) )
         setup_frame = jump_frame;

      struct skeleton_anim *jump_anim = player.jump_dir?
                                        player.mdl.anim_ollie:
                                        player.mdl.anim_ollie_reverse;

      skeleton_sample_anim_clamped( sk, jump_anim, setup_frame, bpose );
      skeleton_lerp_pose( sk, apose, bpose, setup_blend, ground_pose );
   }
   
   mdl_keyframe air_pose[32];
   {
      float target = -vg_get_axis("horizontal");
      player.fairdir = vg_lerpf( player.fairdir, target, 0.04f );
      
      float air_frame = (player.fairdir*0.5f+0.5f) * (15.0f/30.0f);
      
      skeleton_sample_anim( sk, player.mdl.anim_air, air_frame, apose );

      static v2f grab_choice;
      v2_lerp( grab_choice, (v2f){ vg_get_axis("h1"), vg_get_axis("v1") },
                            0.04f, grab_choice );

      float ang = atan2f( grab_choice[0], grab_choice[1] ),
            ang_unit = (ang+VG_PIf) * (1.0f/VG_TAUf),
            grab_frame = ang_unit * (15.0f/30.0f);

      skeleton_sample_anim( sk, player.mdl.anim_grabs, grab_frame, bpose );
      skeleton_lerp_pose( sk, apose, bpose, player.grab, air_pose );
   }

   skeleton_lerp_pose( sk, ground_pose, air_pose, player.ffly, apose );

   float add_grab_mod = player.ffly * player.grab;

   /* additive effects */
   apose[player.mdl.id_hip-1].co[0] += offset[0]*add_grab_mod;
   apose[player.mdl.id_hip-1].co[2] += offset[2]*add_grab_mod;
   apose[player.mdl.id_ik_hand_l-1].co[0] += offset[0]*add_grab_mod;
   apose[player.mdl.id_ik_hand_l-1].co[2] += offset[2]*add_grab_mod;
   apose[player.mdl.id_ik_hand_r-1].co[0] += offset[0]*add_grab_mod;
   apose[player.mdl.id_ik_hand_r-1].co[2] += offset[2]*add_grab_mod;
   apose[player.mdl.id_ik_elbow_l-1].co[0] += offset[0]*add_grab_mod;
   apose[player.mdl.id_ik_elbow_l-1].co[2] += offset[2]*add_grab_mod;
   apose[player.mdl.id_ik_elbow_r-1].co[0] += offset[0]*add_grab_mod;
   apose[player.mdl.id_ik_elbow_r-1].co[2] += offset[2]*add_grab_mod;

   skeleton_apply_pose( &player.mdl.sk, apose, k_anim_apply_defer_ik );
   skeleton_apply_ik_pass( &player.mdl.sk );
   skeleton_apply_pose( &player.mdl.sk, apose, k_anim_apply_deffered_only );

   v3_copy( player.mdl.sk.final_mtx[player.mdl.id_head-1][3], 
               player.mdl.cam_pos );
   skeleton_apply_inverses( &player.mdl.sk );
   skeleton_apply_transform( &player.mdl.sk, player.rb.to_world );

   skeleton_debug( &player.mdl.sk );
}

static void player_camera_update(void)
{
   /* Update camera matrices */
   m4x3_identity( player.camera );
   m4x3_rotate_y( player.camera, -player.angles[0] );
   m4x3_rotate_x( player.camera, -player.angles[1] );
   v3_copy( player.camera_pos, player.camera[3] );
   m4x3_invert_affine( player.camera, player.camera_inverse );
}

static void player_animate_death_cam(void)
{
   v3f delta;
   v3f head_pos;
   v3_copy( player.mdl.ragdoll[0].rb.co, head_pos );

   v3_sub( head_pos, player.camera_pos, delta );
   v3_normalize( delta );

   v3f follow_pos;
   v3_muladds( head_pos, delta, -2.5f, follow_pos );
   v3_lerp( player.camera_pos, follow_pos, 0.1f, player.camera_pos );

   /* 
    * Make sure the camera stays above the ground
    */
   v3f min_height = {0.0f,1.0f,0.0f};

   v3f sample;
   v3_add( player.camera_pos, min_height, sample );
   ray_hit hit;
   hit.dist = min_height[1]*2.0f;

   if( ray_world( sample, (v3f){0.0f,-1.0f,0.0f}, &hit ))
      v3_add( hit.pos, min_height, player.camera_pos );

   player.camera_pos[1] = 
      vg_maxf( wrender.height + 2.0f, player.camera_pos[1] );

   player.angles[0] = atan2f( delta[0], -delta[2] ); 
   player.angles[1] = -asinf( delta[1] );
}

static void player_animate_camera(void)
{
   static v3f lerp_cam = {0.0f,0.0f,0.0f};
   v3f cam_pos;

   player.fonboard = vg_lerpf(player.fonboard, player.on_board, ktimestep*1.0f);

   if( player.on_board )
   {
      v3f offs = { -0.4f, 0.15f, 0.0f };
      v3_lerp( lerp_cam, player.mdl.cam_pos, 0.8f, lerp_cam );
      v3_add( lerp_cam, offs, cam_pos );

      /* Look angles */
      v3_lerp( player.vl, player.rb.v, 0.05f, player.vl );

      float yaw = atan2f(  player.vl[0], -player.vl[2] ),
          pitch = atan2f( -player.vl[1], 
                sqrtf(
                  player.vl[0]*player.vl[0] + player.vl[2]*player.vl[2]
                )) * 0.7f;

      player.angles[0] = yaw;
      player.angles[1] = vg_lerpf( player.angles[1], pitch + 0.30f, 
                                                         player.fonboard );

      /* Camera shake */
      static v2f shake_damp = {0.0f,0.0f};
      v2f shake = { vg_randf()-0.5f, vg_randf()-0.5f };
      v2_muls( shake, v3_length(player.rb.v)*0.3f 
                           * (1.0f+fabsf(player.slip)), shake);

      v2_lerp( shake_damp, shake, 0.01f, shake_damp );
      shake_damp[0] *= 0.2f;

      v2_muladds( player.angles, shake_damp, 0.1f, player.angles );
      m4x3_mulv( player.rb.to_world, cam_pos, player.camera_pos );
   }
   else
   {
      float speed = ktimestep * k_look_speed;
      player.angles[0] += vg_get_axis( "horizontal" ) * speed;
      player.angles[1] += vg_get_axis( "vertical" ) * speed;
      
      player.angles[1] = vg_clampf( player.angles[1], 
                                       -k_pitch_limit, k_pitch_limit );
      
      float s =  sinf(player.angles[0]) * 0.2f,
            c = -cosf(player.angles[0]) * 0.2f;
      v3f forward_dir = { s,0.15f,c };

      
      m4x3f mtx;
      v4f rot;
      q_axis_angle( rot, (v3f){0.0f,1.0f,0.0f}, 
                              -player.angles[0] -VG_PIf*0.5f );
      q_m3x3( rot, mtx );
      v3_copy( player.rb.to_world[3], mtx[3] );

      m4x3_mulv( mtx, player.mdl.cam_pos, cam_pos );
      v3_add( cam_pos, forward_dir, player.camera_pos );
      v3_lerp( player.vl, player.rb.v, 0.3f, player.vl );
   }
}

/* 
 * Audio
 */
static void player_audio(void)
{
   static int _ding = 0;
   
   int last = _ding;
   _ding = glfwGetKey(vg_window, GLFW_KEY_C);

   int trigger_ding = 0;
   if( _ding && !last )
      trigger_ding = 1;

   static int _air = 0;

   int l2 = _air;
   _air = player.in_air;

   static double last_revert = -2000.0;




   audio_lock();
   
   double revert_delta = vg_time - last_revert;
   if( player.on_board && (!_air && l2) && (fabsf(player.slip) > 0.5f) && 
         (revert_delta > 0.7) )
   {
      audio_player_set_position( &audio_player_extra, player.rb.co );
      audio_player_set_flags( &audio_player_extra, AUDIO_FLAG_SPACIAL_3D );
      audio_player_set_vol( &audio_player_extra, 2.0f );
      audio_player_playclip( &audio_player_extra, &audio_lands[rand()%5] );

      last_revert = vg_time;
   }

   static float air = 0.0f;
   air = vg_lerpf(air, player.in_air? 1.0f: 0.0f, 5.0f*ktimestep);

   /* Spacial info */
   v3f ears = { 1.0f,0.0f,0.0f };
   v3f delta;

   float *cam = player.camera[3],
         *pos = player.rb.co;
   
   if( trigger_ding )
      audio_player_playclip( &audio_player_extra, &audio_ding );

   audio_player_set_position( &audio_player0, player.rb.co );
   audio_player_set_position( &audio_player1, player.rb.co );
   audio_player_set_position( &audio_player2, player.rb.co );
   audio_player_set_position( &audio_player_gate, world.render_gate_pos );

   v3_sub( player.rb.co, player.camera[3], delta );
   v3_normalize( delta );
   m3x3_mulv( player.camera, ears, ears );

   /* TODO, Make function */
   v3_copy( ears, vg_audio.listener_ears );
   v3_copy( player.camera[3], vg_audio.listener_pos );

   /* Tunnel / occlusion */
   audio_sample_occlusion( player.camera[3] );

   int sprite_avail = -1;
   for( int i=0; i<vg_list_size(ambient_sprites); i++ )
   {
      if( !audio_player_is_playing( &ambient_sprites[i] ) )
      {
         sprite_avail = i;
         break;
      }
   }
   
   if( sprite_avail != -1 )
   {
      v3f waterpos;
      enum audio_sprite_type sprite_type = 
         audio_sample_sprite_random( player.rb.co, waterpos );

      if( sprite_type != k_audio_sprite_type_none )
      {
         audio_player *avail = &ambient_sprites[ sprite_avail ];

         audio_player_set_vol( avail, 20.0f );
         audio_player_set_flags( avail, AUDIO_FLAG_SPACIAL_3D );
         audio_player_set_position( avail, waterpos );

         if( sprite_type == k_audio_sprite_type_grass )
         {
            audio_player_playclip( avail, &audio_grass[rand()%4] );
         }
         else if( sprite_type == k_audio_sprite_type_water )
         {
            audio_player_playclip( avail, &audio_water[rand()%6] );
         }
      }
   }
   
   if( freecam || player.is_dead || !player.on_board )
   {
      audio_player_set_vol( &audio_player0, 0.0f );
      audio_player_set_vol( &audio_player1, 0.0f );
      audio_player_set_vol( &audio_player2, 0.0f );

      int walk_phase = 0;
      if( vg_fractf(player.walk_timer) > 0.5f )
         walk_phase = 1;
      else
         walk_phase = 0;

      if( (player.step_phase != walk_phase) && !player.in_air )
      {
         v3_copy( player.rb.co, player.last_step_pos );

         audio_player_set_flags( &audio_player_extra, AUDIO_FLAG_SPACIAL_3D );
         audio_player_set_position( &audio_player_extra, player.rb.co );
         audio_player_set_vol( &audio_player_extra, 6.0f );
         audio_player_playclip( &audio_player_extra, 
                                          &audio_footsteps[rand()%4] );
      }

      player.step_phase = walk_phase;
   }
   else
   {
      /* Composite */
      float speed = vg_minf(v3_length( player.rb.v )*0.1f,1.0f),
            attn  = speed,
            slide = vg_clampf( fabsf(player.slip), 0.0f, 1.0f ),
            vol0  = (1.0f-air)*attn*(1.0f-slide),
            vol1  =       air *attn,
            vol2  = (1.0f-air)*attn*slide;
      
      audio_player_set_vol( &audio_player0, vol0 );
      audio_player_set_vol( &audio_player1, vol1 );
      audio_player_set_vol( &audio_player2, vol2 );

      float reverb_amt = vol0 * audio_occlusion_current * 0.5f;
      audio_player_set_pan( &audio_player3, 0.0f );
      audio_player_set_vol( &audio_player3, reverb_amt );
   }
   
#if 0
   world_audio_update( cam, ears );
#endif
   audio_unlock();
}

/*
 * Public Endpoints
 */
static float *player_cam_pos(void)
{
   return player.camera_pos;
}

static int reset_player( int argc, char const *argv[] )
{
   struct respawn_point *rp = NULL, *r;

   if( argc == 1 )
   {
      for( int i=0; i<world.spawn_count; i++ )
      {
         r = &world.spawns[i];
         if( !strcmp( r->name, argv[0] ) )
         {
            rp = r;
            break;
         }
      }

      if( !rp )
         vg_warn( "No spawn named '%s'\n", argv[0] );
   }

   if( !rp )
   {
      float min_dist = INFINITY;

      for( int i=0; i<world.spawn_count; i++ )
      {
         r = &world.spawns[i];
         float d = v3_dist2( r->co, player.rb.co );
         
         vg_info( "Dist %s : %f\n", r->name, d );
         if( d < min_dist )
         {
            min_dist = d;
            rp = r;
         }
      }
   }

   if( !rp )
   {
      vg_error( "No spawn found\n" );
      if( !world.spawn_count )
         return 0;

      rp = &world.spawns[0];
   }

   v4_copy( rp->q, player.rb.q );
   v3_copy( rp->co, player.rb.co );

   player.vswitch = 1.0f;
   player.slip_last = 0.0f;
   player.is_dead = 0;
   player.in_air = 1;
   m3x3_identity( player.vr );

   player.mdl.shoes[0] = 1;
   player.mdl.shoes[1] = 1;
   
   rb_update_transform( &player.rb );
   m3x3_mulv( player.rb.to_world, (v3f){ 0.0f, 0.0f, -1.2f }, player.rb.v );
   m3x3_identity( player.gate_vr_frame );
   m3x3_identity( player.gate_vr_pstep_frame );

   player.rb_gate_frame = player.rb;
   player.on_board_frame = player.on_board;
   player.in_air_frame = player.in_air;
   return 1;
}

static void player_update(void)
{
   for( int i=0; i<player.land_log_count; i++ )
      draw_cross( player.land_target_log[i], 
            player.land_target_colours[i], 0.25f);

   if( vg_get_axis("grabl")>0.0f)
   {
      player.rb = player.rb_gate_frame;
      player.on_board = player.on_board_frame;
      player.in_air = player.in_air_frame;
      m3x3_copy( player.gate_vr_frame, player.vr );
      m3x3_copy( player.gate_vr_pstep_frame, player.vr_pstep );
      player.is_dead = 0;
      player.in_air = 1;


      if( !player.on_board )
      {
         player.angles[0] = atan2f( -player.rb.forward[2], 
                                    -player.rb.forward[0] );
      }

      m3x3_identity( player.vr );

      player.mdl.shoes[0] = 1;
      player.mdl.shoes[1] = 1;

      world_routes_notify_reset();
   }

   if( vg_get_button_down( "switchmode" ) )
   {
      player.on_board ^= 0x1;
   }

   if( (glfwGetKey( vg_window, GLFW_KEY_O ) || (player.rb.co[1] < 0.0f)) &&
       !player.is_dead)
   {
      character_ragdoll_copypose( &player.mdl, player.rb.v );
      player.is_dead = 1;
   }

   if( player.is_dead )
   {
      character_ragdoll_iter( &player.mdl );
      character_debug_ragdoll( &player.mdl );

      if( !freecam )
         player_animate_death_cam();
   }
   else
   {
      player_do_motion();
      player_animate();

      if( !freecam )
         player_animate_camera();
   }

   if( freecam )
      player_freecam();

   player_camera_update();
   player_audio();
}

static void draw_player(void)
{
   if( player.is_dead )
      character_mimic_ragdoll( &player.mdl );

   shader_viewchar_use();
   vg_tex2d_bind( &tex_characters, 0 );
   shader_viewchar_uTexMain( 0 );
   shader_viewchar_uCamera( player.camera[3] );
   shader_viewchar_uPv( vg_pv );
   shader_link_standard_ub( _shader_viewchar.id, 2 );
   glUniformMatrix4x3fv( _uniform_viewchar_uTransforms, 
                         player.mdl.sk.bone_count,
                         0,
                         (float *)player.mdl.sk.final_mtx );
   
   mesh_bind( &player.mdl.mesh );
   mesh_draw( &player.mdl.mesh );
}

#endif /* PLAYER_H */