walk manifold clipping

[carveJwlIkooP6JGAAIwe30JlM.git] / player.h

#ifndef PLAYER_H
#define PLAYER_H

#include "common.h"
#include "character.h"

static int freecam = 0;

static struct gplayer
{
   /* Physics */
   v3f co, v, a, v_last, m, bob;
   v4f rot;
   float vswitch, slip, slip_last,
         reverse;

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

   /* Input */
   v2f joy_l;

   v2f board_xy;
   float grab;
   float pitch;

   v3f land_target;
   v3f land_target_log[22];
   u32 land_target_colours[22];
   int land_log_count;
   m3x3f vr;

   m4x3f to_world, to_local;
   
   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;
}
player;

static void player_transform_update(void)
{
   q_normalize( player.rot );
   q_m3x3( player.rot, player.to_world );
   v3_copy( player.co, player.to_world[3] );

   m4x3_invert_affine( player.to_world, player.to_local );
}

static int reset_player( int argc, char const *argv[] )
{
   v3_zero( player.co );

   if( argc == 1 )
   {
      if( !strcmp( argv[0], "tutorial" ))
         v3_copy( world.tutorial, player.co );
   }

   v3_copy( (v3f){ 0.0f, 0.0f, -0.2f }, player.v );
   q_identity( player.rot );
   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;

   player_transform_update();
   return 0;
}

static void player_mouseview(void)
{
   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, 0.005f, view_vel );
   }
   
   v2_muls( view_vel, 0.7f, 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 = 25.0f;
   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 );
}

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

static void player_start_air(void)
{
   player.in_air = 1;

   float pstep = ktimestep*10.0f;

   float best_velocity_mod = 0.0f,
         best_velocity_delta = -9999.9f;

   v3f axis, vup;
   m3x3_mulv( player.to_world, (v3f){0.0f,1.0f,0.0f}, vup );
   v3_cross( vup, player.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.co, pco );
      v3_copy( player.v, 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, ktimestep, 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;
               best_velocity_mod = vmod;

               v3_copy( contact.pos, player.land_target );

               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;
         }
      }
   }

   //v3_rotate( player.v, best_velocity_mod, axis, player.v );
   
   return;
   v3_muls( player.v, best_velocity_mod, player.v );
}

static int sample_if_resistant( v3f pos )
{
   v3f ground;
   v3_copy( pos, ground );
   ground[1] += 4.0f;
   
   ray_hit hit;
   hit.dist = INFINITY;

   if( ray_world( ground, (v3f){0.0f,-1.0f,0.0f}, &hit ))
   {
      v3f angle;
      v3_copy( player.v, angle );
      v3_normalize( angle );
      float resistance = v3_dot( hit.normal, angle );

      if( resistance < 0.25f )
      {
         v3_copy( hit.pos, pos );
         return 1;
      }
   }

   return 0;
}

static float stable_force( float current, float diff )
{
   float new = current + diff;

   if( new * current < 0.0f )
      return 0.0f;

   return new;
}

static void player_physics_ground(void)
{
   /* 
    * Getting surface collision points,
    * the contact manifold is a triangle for simplicity.
    */
   v3f contact_front, contact_back, contact_norm, vup, vside,
       axis;
   
   float klength = 0.65f;
   m4x3_mulv( player.to_world, (v3f){ 0.15f,0.0f,-klength}, contact_norm );
   m4x3_mulv( player.to_world, (v3f){-0.15f,0.0f,-klength}, contact_front );
   m4x3_mulv( player.to_world, (v3f){ 0.00f,0.0f, klength}, contact_back );
   m3x3_mulv( player.to_world, (v3f){ 0.0f, 1.0f, 0.0f}, vup );
   m3x3_mulv( player.to_world, (v3f){ 1.0f, 0.0f, 0.0f}, vside );

   v3f cn0, cn1, cn2;
   
   int contact_count = 
      sample_if_resistant( contact_front ) +
      sample_if_resistant( contact_back ) +
      sample_if_resistant( contact_norm );
   
   if( contact_count < 3 )
   {
      player_start_air();
      return;
   }

   v3f norm;
   v3f v0, v1;
   v3_sub( contact_norm, contact_front, v0 );
   v3_sub( contact_back, contact_front, v1 );
   v3_cross( v1, v0, norm );
   v3_normalize( norm );

   vg_line( contact_norm, contact_front, 0xff00ff00 );
   vg_line( contact_back, contact_front, 0xff0000ff );

   /* Surface alignment */
   float angle = v3_dot( vup, norm );
   v3_cross( vup, norm, axis );

   if( angle < 0.999f )
   {
      v4f correction;
      q_axis_angle( correction, axis, acosf(angle) );
      q_mul( correction, player.rot, player.rot );
   }

   float resistance = v3_dot( norm, player.v );
   if( resistance >= 0.0f )
   {
      player_start_air();
      return;
   }
   else
   {
      v3_muladds( player.v, norm, -resistance, player.v );
   }
   
   /* This is where velocity integration used to be */

   float slip = 0.0f;

   player.co[1] = (contact_front[1]+contact_back[1])*0.5f;

   v3f vel;
   m3x3_mulv( player.to_local, player.v, vel );

   /* Calculate local forces */
   
   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] ) * -7.0f *substep );
   }
   
   static double start_push = 0.0;
   if( vg_get_button_down( "push" ) )
      start_push = vg_time;

   if( !vg_get_button("break") && vg_get_button( "push" ) )
   {
      float const k_maxpush = 16.0f,
                  k_pushaccel = 5.0f;

      float cycle_time = vg_time-start_push,
            amt = k_pushaccel * (sinf( cycle_time * 8.0f )*0.5f+0.5f)*ktimestep,
            current = v3_length( vel ),
            new_vel = vg_minf( current + amt, k_maxpush );
      new_vel -= vg_minf(current, k_maxpush);
      vel[2] -= new_vel * player.reverse;
   }
   
   m3x3_mulv( player.to_world, vel, player.v );

   if( vg_get_button( "yawl" ) )
      player.iY +=  3.6f * ktimestep;
   if( vg_get_button( "yawr" ) )
      player.iY -=  3.6f * ktimestep;
   
   float steer = vg_get_axis( "horizontal" );
   player.iY -= vg_signf(steer)*powf(steer,2.0f) * 1.5f * ktimestep;
   
   /* Too much lean and it starts to look like a snowboard here */
   v2_lerp( player.board_xy, (v2f){ slip*0.25f, 0.0f }, 
         ktimestep*5.0f, player.board_xy);
}

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_air(void)
{
   m3x3_mulv( player.vr, player.v, player.v );
   for( int i=0; i<player.land_log_count; i++ )
      draw_cross( player.land_target_log[i], player.land_target_colours[i], 1);

   draw_cross( player.land_target, 0xff0000ff, 1 );

   v3f ground_pos;
   v3_copy( player.co, ground_pos );
   ground_pos[1] += 4.0f;
   
   ray_hit hit;
   hit.dist = INFINITY;
   if( ray_world( ground_pos, (v3f){0.0f,-1.0f,0.0f}, &hit ))
   {
      if( hit.pos[1] > player.co[1] )
      {
         player.in_air = 0;
         
         if( !ray_hit_is_ramp( &hit ) )
         {
            player.is_dead = 1;
            character_ragdoll_copypose( &player.mdl, player.v );
         }

         return;
      }
   }
   
   /* Prediction 
    *
    * TODO: Find best landing surface and guide player towords it
    */
   float pstep = ktimestep*10.0f;

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

   for( int i=0; i<50; i++ )
   {
      v3_copy( pco, pco1 );
      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 ))
      {
         v3f localup;
         m3x3_mulv( player.to_world, (v3f){0.0f,1.0f,0.0f}, localup );

         float angle = v3_dot( localup, contact.normal );
         v3f axis; 
         v3_cross( localup, 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.rot, player.rot );
         }

         draw_cross( contact.pos, 0xffff0000, 1 );
         break;
      }
      time_to_impact += pstep;
   }

   player.iY -= vg_get_axis( "horizontal" ) * 3.6f * ktimestep;
   {

      float iX = vg_get_axis( "vertical" ) * 3.6f * limiter * ktimestep;
      static float siX = 0.0f;
      siX = vg_lerpf( siX, iX, 0.3f );
      
      v4f rotate;
      v3f vside;
      
      m3x3_mulv( player.to_world, (v3f){1.0f,0.0f,0.0f}, vside );

      q_axis_angle( rotate, vside, siX );
      q_mul( rotate, player.rot, player.rot );
   }
   
   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_do_motion(void)
{
   float horizontal = vg_get_axis("horizontal"),
         vertical = vg_get_axis("vertical");

   player.joy_l[0] = vg_signf(horizontal) * powf( horizontal, 2.0f );
   player.joy_l[1] = vg_signf(vertical) * powf( vertical, 2.0f );

   if( player.in_air )
      player_physics_air();

   if( !player.in_air )
      player_physics_ground();
   
   /* Integrate velocity */
   v3f prevco;
   v3_copy( player.co, prevco );
   
   apply_gravity( player.v, ktimestep );
   v3_muladds( player.co, player.v, ktimestep, player.co );

   /* Integrate inertia */
   v4f rotate; v3f vup = {0.0f,1.0f,0.0f};
   m3x3_mulv( player.to_world, vup, vup );

   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, vup, siY );
   q_mul( rotate, player.rot, player.rot );

   player.iY = 0.0f; /* temp */

#if 0
   /* GATE COLLISION */
   if( gate_intersect( &gate_a, player.co, prevco ) )
   {
      teleport_gate *gate = &gate_a;

      m4x3f transport;
      m4x3_mul( gate->other->to_world, gate->to_local, transport );
      m4x3_mulv( transport, player.co, player.co );
      m3x3_mulv( transport, player.v, player.v );
      m3x3_mulv( transport, player.v_last, player.v_last );
      m3x3_mulv( transport, player.m, player.m );
      m3x3_mulv( transport, player.bob, player.bob );

      v4f transport_rotation;
      m3x3_q( transport, transport_rotation );
      q_mul( transport_rotation, player.rot, player.rot );
   }
#endif

   /* Camera and character */
   player_transform_update();

   player.angles[0] = atan2f( player.v[0], -player.v[2] );
   player.angles[1] = atan2f( -player.v[1], sqrtf(player.v[0]*player.v[0]+
                                       player.v[2]*player.v[2]) ) * 0.3f;

   player.air_blend = vg_lerpf( player.air_blend, player.in_air, 0.04f );
   v3_muladds( player.camera_pos, player.v, -0.05f*player.air_blend, 
         player.camera_pos );
}

/*
 * Get a sample at this pole location, will return 1 if the sample is valid,
 * and pos will be updated to be the intersection location.
 */
static int player_walkgrid_samplepole( u32 *geo, int len, v3f pos )
{
   v3f p1;
   v3_copy( pos, p1 );
   p1[1] -= 10.0f;

   vg_line( pos, p1, 0x20ffffff );

   v3f sample_pos;
   v3_copy(pos, sample_pos);

   v3f vdir = {0.0f,-1.0f,0.0f};
   int count = 0;

   ray_hit hit;
   hit.dist = INFINITY;
   for( int i=0; i<len; i++ )
   {
      u32 *tri = &world.geo.indices[ geo[i] ];
      count += bvh_ray_tri( &world.geo, tri, sample_pos, vdir, &hit );
   }

   if( count )
   {
      v3f v0, v1;
      float *pa = world.geo.verts[hit.tri[0]].co,
            *pb = world.geo.verts[hit.tri[1]].co,
            *pc = world.geo.verts[hit.tri[2]].co;

      v3_sub( pa, pb, v0 );
      v3_sub( pc, pb, v1 );
      v3_cross( v1, v0, hit.normal );
      v3_normalize( hit.normal );
      v3_muladds( sample_pos, vdir, hit.dist, pos );

      draw_cross( pos, 0xff00ff00, 0.05f );
      return count;
   }
   else
      return 0;
}

static void player_walkgrid_clip(u32 *geo, int len, v3f pos, v3f dir, v3f clip)
{
   float max_dist = 0.0f;
   v3f tri[3];
   v3f perp;
   v3_cross( dir,(v3f){0.0f,1.0f,0.0f},perp );
   v3_copy( pos, clip );

   for( int i=0; i<len; i++ )
   {
      u32 *ptri = &world.geo.indices[ geo[i] ];
      for( int j=0; j<3; j++ )
         v3_copy( world.geo.verts[ptri[j]].co, tri[j] );

      for( int k=0; k<3; k++ )
      {
         int ia = k,
             ib = (k+1)%3;
         
         v3f v0, v1;
         v3_sub( tri[ia], pos, v0 );
         v3_sub( tri[ib], pos, v1 );

         if( (dir[2]*v0[0] - dir[0]*v0[2]) *
             (dir[2]*v1[0] - dir[0]*v1[2]) < 0.0f )
         {
            float da = v3_dot(v0,perp),
                  db = v3_dot(v1,perp),
                  d  = da-db,
                  qa = da/d;

            v3f p0;
            v3_muls( v1, qa, p0 );
            v3_muladds( p0, v0, 1.0f-qa, p0 );

            float h = v3_dot(p0,dir)/v3_dot(dir,dir);

            if( h >= max_dist && h <= 1.0f )
            {
               max_dist = h;
               v3_copy( p0, clip );
            }
         }
      }
   }

   v3f clippos;
   v3_add( pos, clip, clippos );
   draw_cross( clippos, 0xffffff00, 0.05f );
}

static void player_walkgrid_getsurface(void)
{
   float const k_gridscale = 0.5f;
   float const k_stepheight = 0.5f;
   float const k_walkspeed = 6.0f;
   float const k_miny = 0.6f;
   float const k_height = 1.78f;
   int const k_gridamt = 8;
   float const k_region_size = (float)k_gridamt/2.0f * k_gridscale;

   v3f cell;
   v3_muls( player.co, 1.0f/k_gridscale, cell );
   v3_floor( cell, cell );
   v3_muls( cell, k_gridscale, cell );

   u32 geo[128];

   boxf region;
   v3_muladds( cell, (v3f){-1.0f,-1.0f,-1.0f}, k_region_size, region[0] );
   v3_muladds( cell, (v3f){ 1.0f, 1.0f, 1.0f}, k_region_size, region[1] );

   int tri_count = bvh_select_triangles( &world.geo, region, geo, 128 );

   v3f tri[3];
   for( int i=0; i<tri_count; i++ )
   {
      for( int j=0; j<3; j++ )
         v3_copy( world.geo.verts[ world.geo.indices[geo[i]+j] ].co, tri[j] );

#if 0
      vg_line( tri[0], tri[1], 0xffa2ff30 );
      vg_line( tri[1], tri[2], 0xffa2ff30 );
      vg_line( tri[2], tri[0], 0xffa2ff30 );
#endif 
   }

   struct grid_sample
   {
      int valid;
      v3f clip[2];
      v3f pos;
   }
   samples[ k_gridamt ][ k_gridamt ];
   
   /* Get surface samples */
   for( int y=0; y<k_gridamt; y++ )
   {
      for( int x=0; x<k_gridamt; x++ )
      {
         struct grid_sample *s = &samples[y][x];
         v3_muladds( region[0], (v3f){ x, 0, y }, k_gridscale, s->pos );
         s->pos[1] = player.co[1] + k_height;

         s->valid = player_walkgrid_samplepole( geo, tri_count, s->pos )? 1: 0;
      }
   }
   
   /* 
    * Calculate h+v clipping distances.
    * Distances are stored in A always, so you know that if the sample is
    * invalid, this signifies the start of the manifold as opposed to the
    * extent or bounds of it.
    */
   for( int i=0; i<2; i++ )
   {
      for( int x=0; x<k_gridamt; x++ )
      {
         for( int z=0; z<k_gridamt-1; z++ )
         {
            v3f clipdir = { 0.0f, 0.0f, 0.0f };
            
            struct grid_sample *sa, *sb;
            if( i == 1 )
            {
               sa = &samples[z][x];
               sb = &samples[z+1][x];
            }
            else
            {
               sa = &samples[x][z];
               sb = &samples[x][z+1];
            }

            if( sa->valid != sb->valid )
            {
               clipdir[i*2] = (float)(sa->valid - sb->valid)*k_gridscale;
               player_walkgrid_clip( geo, tri_count, 
                     sa->valid? sa->pos: sb->pos,
                     clipdir, sa->clip[i] );
            }
            else
            {
               if( sa->valid )
               {
                  vg_line( sa->pos, sb->pos, 0xffffffff );
               }
            }
         }
      }
   }

   /* Draw connections */
   for( int x=0; x<k_gridamt-1; x++ )
   {
      for( int z=0; z<k_gridamt-1; z++ )
      {
         static const struct conf
         {
            struct confedge
            {  
               /* i: sample index
                * d: data index
                * a: axis index
                */
               int i0, i1, 
                   d0, d1,
                   a0, a1;
            }
            edges[2];
            int edge_count;
         }
         k_configs[16] = {
            {{},0},
            {{{ 3, 3, 3, 0, 1,0 }}, 1},
            {{{ 2, 2, 1, 3, 0,1 }}, 1},
            {{{ 2, 3, 1, 0, 0,0 }}, 1},

            {{{ 1, 1, 0, 1, 1,0 }}, 1},
            {{{ 3, 3, 3, 0, 1,0 },
              { 1, 1, 0, 1, 1,0 }}, 2},
            {{{ 1, 2, 0, 3, 1,1 }}, 1},
            {{{ 1, 3, 0, 0, 1,0 }}, 1},

            {{{ 0, 0, 0, 0, 0,1 }}, 1},
            {{{ 3, 0, 3, 0, 1,1 }}, 1},
            {{{ 2, 2, 1, 3, 0,1 },
              { 0, 0, 0, 0, 0,1 }}, 2},
            {{{ 2, 0, 1, 0, 0,1 }}, 1},

            {{{ 0, 1, 0, 1, 0,0 }}, 1},
            {{{ 3, 1, 3, 1, 1,0 }}, 1},
            {{{ 0, 2, 0, 3, 0,1 }}, 1},
            {{},0},
         };
         
         struct grid_sample *corners[4] =
         {
            &samples[z][x],
            &samples[z+1][x],
            &samples[z+1][x+1],
            &samples[z][x+1]
         };

         u32 config = (corners[0]->valid<<3) | (corners[1]->valid<<2) | 
                      (corners[2]->valid<<1) | corners[3]->valid;

         const struct conf *conf = &k_configs[ config ];

         for( int i=0; i<conf->edge_count; i++ )
         {
            const struct confedge *edge = &conf->edges[i];

            v3f p0, p1;
            v3_add( corners[edge->i0]->pos, 
                    corners[edge->d0]->clip[edge->a0], p0 );
            v3_add( corners[edge->i1]->pos, 
                    corners[edge->d1]->clip[edge->a1], p1 );
            vg_line( p0, p1, 0xff0000ff );

            vg_line( corners[edge->i0]->pos, p0, 0xffffffff );
            vg_line( corners[edge->i1]->pos, p1, 0xffffffff );
         }
      }
   }
}

static void player_walkgrid(void)
{
   player_walkgrid_getsurface();

   float const k_gridscale = 0.5f;
   float const k_stepheight = 0.5f;
   float const k_walkspeed = 6.0f;
   float const k_miny = 0.6f;
   float const k_height = 1.78f;
   int const k_gridamt = 8;

#if 0
   v3f cell;
   v3_muls( player.co, 1.0f/k_gridscale, cell );
   v3_floor( cell, cell );
   v3_muls( cell, k_gridscale, cell );
   
   struct grid_sample
   {
      ray_hit hit;
      int valid;
   }
   samples[ k_gridamt ][ k_gridamt ];

   v3f grid_origin;
   v3_muladds( cell, (v3f){ -1.0f,0.0f,-1.0f }, 
         (float)(k_gridamt/2) * k_gridscale, grid_origin );

   /* 
    * Get sample 'poles'
    */
   for( int y=0; y<k_gridamt; y++ )
   {
      for( int x=0; x<k_gridamt; x++ )
      {
         v3f sample_coord;
         v3_muladds( grid_origin, (v3f){ x, 0, y }, k_gridscale, sample_coord );
         sample_coord[1] += k_height;

         struct grid_sample *sample = &samples[y][x];
         sample->valid = 0;
         sample->hit.dist = k_stepheight+k_height;

         if( ray_world( sample_coord, (v3f){0.0f,-1.0f,0.0f}, &sample->hit ))
         {
            if( sample->hit.normal[1] >= k_miny &&
                ray_hit_is_ramp( &sample->hit ))
            {
               sample->valid = 1;
               draw_cross( sample->hit.pos, 0xff00ff00, 0.1f );
            }
            else
               draw_cross( sample->hit.pos, 0xff0000ff, 0.1f );
         }
      }
   }

   /*
    * Clip grid intersections with triangle edges
    */
   for( int dir=0; dir<2; dir++ )
   {
      for( int x=0; x<k_gridamt; x++ )
      {
         for( int y=0; y<k_gridamt-1; y++ )
         {
            struct grid_sample *sa, *sb;

            if( dir == 0 )
            {
               sa = &samples[y][x];
               sb = &samples[y+1][x];
            }
            else
            {
               sa = &samples[x][y];
               sb = &samples[x][y+1];
            }

            if( (sa->valid != sb->valid) && (sa->valid||sb->valid) )
            {
               int line = dir==0? 0:2,
                   axis = dir==0? 2:0;

               v3f tri[3];
               ray_world_get_tri( sa->valid? &sa->hit: &sb->hit, tri );

               v3f other = {0,0,0};
               other[axis] = sa->valid? k_gridscale: -k_gridscale;
               v3_add( sa->valid? sa->hit.pos: sb->hit.pos, other, other );
               vg_line( sa->valid? sa->hit.pos: sb->hit.pos, 
                     other, 0xffffffff );

               v3f sample;
               if( dir == 0 )
               v3_muladds( grid_origin, (v3f){ x, 0, y }, k_gridscale, sample);
               else
               v3_muladds( grid_origin, (v3f){ y, 0, x }, k_gridscale, sample);
               
               /* Clip triangles until we find an edge inside the cell */
               float offset = sample[line],
                      basis = sample[axis];

               for( int i=0; i<3; i++ )
               {
                  int ia = i,
                      ib = (i+1)%3;
                  float pa = tri[ia][line],
                        pb = tri[ib][line];

                  vg_line( tri[ia],tri[ib],0xffaaaaaa );

                  if( (pa-offset)*(pb-offset) > 0.0f )
                     continue;

                  float d = pb-pa,
                       qa = (offset-pa)/d,
                        h = qa*tri[ib][axis] + (1.0f-qa)*tri[ia][axis],
                        q = (h-basis)/k_gridscale;

                  if( q >= 0.0f && q <= 1.0f )
                  {
                     float height = qa*tri[ia][1] + (1.0f-qa)*tri[ib][1];
                     v3f intersection;
                     if( dir == 0 )
                        v3_copy( (v3f){ offset, height, h }, intersection );
                     else
                        v3_copy( (v3f){ h, height, offset }, intersection );
                     draw_cross( intersection, 0xffff0000, 0.06f );
                     break;
                  }
               }
            }
         }
      }
   }
#endif
   v3f fwd = { -sinf(-player.angles[0]), 0.0f, -cosf(-player.angles[0]) },
       side = { -fwd[2], 0.0f, fwd[0] };

   /* Temp */
   if( glfwGetKey( vg_window, GLFW_KEY_W ) )
      v3_muladds( player.co, fwd,  ktimestep*k_walkspeed, player.co );
   if( glfwGetKey( vg_window, GLFW_KEY_S ) )
      v3_muladds( player.co, fwd, -ktimestep*k_walkspeed, player.co );

   if( glfwGetKey( vg_window, GLFW_KEY_A ) )
      v3_muladds( player.co, side, -ktimestep*k_walkspeed, player.co );
   if( glfwGetKey( vg_window, GLFW_KEY_D ) )
      v3_muladds( player.co, side,  ktimestep*k_walkspeed, player.co );
   
   m4x3_mulv( player.to_world, (v3f){0.0f,1.8f,0.0f}, player.camera_pos );
   player_mouseview();
   player_transform_update();
}

static void player_animate(void)
{
   /* Camera position */
   v3_sub( player.v, player.v_last, player.a );
   v3_copy( player.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 );
   v3f target;
   
   player.m[0] = vg_clampf( player.m[0], -2.0f, 2.0f );
   player.m[1] = vg_clampf( player.m[1], -0.2f, 5.0f );
   player.m[2] = vg_clampf( player.m[2], -2.0f, 2.0f );
   v3_copy( player.m, target );
   v3_lerp( player.bob, target, 0.2f, player.bob );

   /* Head */
   float lslip = fabsf(player.slip); //vg_minf( 0.4f, slip );
                              
   float grabt = vg_get_axis( "grabr" )*0.5f+0.5f;
   player.grab = vg_lerpf( player.grab, grabt, 0.04f );

   float kheight = 2.0f,
         kleg = 0.6f;

   v3f head;
   head[0] = 0.0f;
   head[1] = (0.3f+cosf(lslip)*0.5f*(1.0f-player.grab*0.7f)) * kheight;
   head[2] = 0.0f;

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

   offset[0] *= 0.3333f;
   offset[1] *= -0.25f;
   offset[2] *= 0.7f;
   v3_muladds( head, offset, 0.7f, head );
   head[1] = vg_clampf( head[1], 0.3f, kheight );

#if 0
   if( !freecam )
   {
      v3_copy( head, player.view );
      v3f camoffs = {-0.2f,-0.6f,0.00f};
      v3_add( player.view, camoffs, player.view );
   }
#endif

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

   static float fslide = 0.0f;
   static float fdirz = 0.0f;
   static float fdirx = 0.0f;
   static float fstand = 0.0f;
   static float ffly = 0.0f;

   float speed = v3_length( player.v );
   
   fstand = vg_lerpf(fstand, 1.0f-vg_clampf(speed*0.03f,0.0f,1.0f),0.1f);
   fslide = vg_lerpf(fslide, vg_clampf(lslip+fabsf(offset[0])*0.2f,
            0.0f,1.0f), 0.04f);
   fdirz = vg_lerpf(fdirz, player.reverse > 0.0f? 1.0f: 0.0f, 0.04f );
   fdirx = vg_lerpf(fdirx, player.slip < 0.0f?    1.0f: 0.0f, 0.04f );
   ffly = vg_lerpf(ffly, player.in_air?           1.0f: 0.0f, 0.04f );

   character_pose_reset( &player.mdl );

   float amt_air = ffly*ffly,
         amt_ground = 1.0f-amt_air,
         amt_std = (1.0f-fslide) * amt_ground,
         amt_stand = amt_std * fstand,
         amt_aero = amt_std * (1.0f-fstand),
         amt_slide = amt_ground * fslide;

   character_final_pose( &player.mdl, offset, &pose_stand, amt_stand );
   character_final_pose( &player.mdl, offset, &pose_aero, amt_aero*fdirz );
   character_final_pose( &player.mdl, offset, 
         &pose_aero_reverse, amt_aero * (1.0f-fdirz) );
   character_final_pose( &player.mdl, offset, &pose_slide, amt_slide*fdirx );
   character_final_pose( &player.mdl, offset, 
         &pose_slide1, amt_slide*(1.0f-fdirx) );

   character_final_pose( &player.mdl, (v3f){0.0f,0.0f,0.0f}, 
         &pose_fly, amt_air );

   /* Camera position */
   v3_lerp( player.smooth_localcam, player.mdl.cam_pos, 0.08f, 
            player.smooth_localcam );
   v3_muladds( player.smooth_localcam, offset, 0.7f, player.camera_pos );
   player.camera_pos[1] = vg_clampf( player.camera_pos[1], 0.3f, kheight );
   m4x3_mulv( player.to_world, player.camera_pos, player.camera_pos );

   /* 
    * Additive effects
    * ==========================
    */
   struct ik_basic *arm_l = &player.mdl.ik_arm_l,
                   *arm_r = &player.mdl.ik_arm_r;

   v3f localv;
   m3x3_mulv( player.to_local, player.v, localv );
   v3_muladds( arm_l->end, localv, -0.01f, arm_l->end );
   v3_muladds( arm_r->end, localv, -0.01f, arm_r->end );

   /* New board transformation */
   v4f board_rotation; v3f board_location;

   v4f rz, rx;
   q_axis_angle( rz, (v3f){ 0.0f, 0.0f, 1.0f }, player.board_xy[0] );
   q_axis_angle( rx, (v3f){ 1.0f, 0.0f, 0.0f }, player.board_xy[1] );
   q_mul( rx, rz, board_rotation );
   
   v3f *mboard = player.mdl.matrices[k_chpart_board];// player.mboard;
   q_m3x3( board_rotation, mboard );
   m3x3_mulv( mboard, (v3f){ 0.0f, -0.5f, 0.0f }, board_location );
   v3_add( (v3f){0.0f,0.5f,0.0f}, board_location, board_location );
   v3_copy( board_location, mboard[3] );


   float wheel_r = offset[0]*-0.4f;
   v4f qwheel;
   q_axis_angle( qwheel, (v3f){0.0f,1.0f,0.0f}, wheel_r );
   
   q_m3x3( qwheel, player.mdl.matrices[k_chpart_wb] );

   m3x3_transpose( player.mdl.matrices[k_chpart_wb],
                   player.mdl.matrices[k_chpart_wf] );
   v3_copy( player.mdl.offsets[k_chpart_wb], 
         player.mdl.matrices[k_chpart_wb][3] );
   v3_copy( player.mdl.offsets[k_chpart_wf], 
         player.mdl.matrices[k_chpart_wf][3] );
   
   m4x3_mul( mboard, player.mdl.matrices[k_chpart_wb],
                     player.mdl.matrices[k_chpart_wb] );
   m4x3_mul( mboard, player.mdl.matrices[k_chpart_wf],
                     player.mdl.matrices[k_chpart_wf] );

   m4x3_mulv( mboard, player.mdl.ik_leg_l.end, player.mdl.ik_leg_l.end );
   m4x3_mulv( mboard, player.mdl.ik_leg_r.end, player.mdl.ik_leg_r.end );


   v3_copy( player.mdl.ik_arm_l.end, player.handl_target );
   v3_copy( player.mdl.ik_arm_r.end, player.handr_target );

   if( 1||player.in_air )
   {
      float tuck = player.board_xy[1],
            tuck_amt = fabsf( tuck ) * (1.0f-fabsf(player.board_xy[0]));
      
      float crouch = player.grab*0.3f;
      v3_muladds( player.mdl.ik_body.base, (v3f){0.0f,-1.0f,0.0f}, 
            crouch, player.mdl.ik_body.base );
      v3_muladds( player.mdl.ik_body.end, (v3f){0.0f,-1.0f,0.0f}, 
            crouch*1.2f, player.mdl.ik_body.end );

      if( tuck < 0.0f )
      {
         //foot_l *= 1.0f-tuck_amt*1.5f;

         if( player.grab > 0.1f )
         {
            m4x3_mulv( mboard, (v3f){0.1f,0.14f,0.6f}, 
                  player.handl_target );
         }
      }
      else
      {
         //foot_r *= 1.0f-tuck_amt*1.4f;

         if( player.grab > 0.1f )
         {
            m4x3_mulv( mboard, (v3f){0.1f,0.14f,-0.6f}, 
                  player.handr_target );
         }
      }
   }

   v3_lerp( player.handl, player.handl_target, 0.1f, player.handl );
   v3_lerp( player.handr, player.handr_target, 0.1f, player.handr );

   v3_copy( player.handl, player.mdl.ik_arm_l.end );
   v3_copy( player.handr, player.mdl.ik_arm_r.end );

   /* Head rotation */

   static float rhead = 0.0f;
   rhead = vg_lerpf( rhead,
         vg_clampf(atan2f( localv[2], -localv[0] ),-1.0f,1.0f), 0.04f );
   player.mdl.rhead = rhead;
}

static void player_update(void)
{
   if( vg_get_axis("grabl")>0.0f)
      reset_player(0,NULL);

   if( freecam )
   {
      player_freecam();
   }
   else
   {
      if( player.is_dead )
      {
         character_ragdoll_iter( &player.mdl );
         character_debug_ragdoll( &player.mdl );
      }
      else
      {
         if( player.on_board )
         {
            player_do_motion();
            player_animate();
         }
         else
         {
            player_walkgrid();
         }
      }
   }

   /* Update camera matrices */
   m4x3_identity( player.camera );
   m4x3_rotate_y( player.camera, -player.angles[0] );
   m4x3_rotate_x( player.camera, -0.33f -player.angles[1] );
   v3_copy( player.camera_pos, player.camera[3] );
   m4x3_invert_affine( player.camera, player.camera_inverse );
}

static void draw_player(void)
{
   /* Draw */
   m4x3_copy( player.to_world, player.mdl.mroot );

   if( player.is_dead )
      character_mimic_ragdoll( &player.mdl );
   else
      character_eval( &player.mdl );

   character_draw( &player.mdl, (player.is_dead|player.in_air)? 0.0f: 1.0f );
}

#endif /* PLAYER_H */