X-Git-Url: https://harrygodden.com/git/?a=blobdiff_plain;f=player_skate.c;h=c6e5db6ab6c188cd3cc901301b751fa530829ecb;hb=a1056ed8198f0f5be0e0f341da8bd49aa6c47198;hp=df3d42439671373fe1c77bfd2d6c2ca0e6822200;hpb=5057afb71329100ab0cfb8cad3862c364637feb3;p=carveJwlIkooP6JGAAIwe30JlM.git

diff --git a/player_skate.c b/player_skate.c
index df3d424..c6e5db6 100644
--- a/player_skate.c
+++ b/player_skate.c
@@ -2,6 +2,7 @@
 #define PLAYER_SKATE_C
 
 #include "player.h"
+#include "audio.h"
 
 VG_STATIC void player__skate_bind( player_instance *player )
 {
@@ -35,8 +36,10 @@ VG_STATIC int skate_collide_smooth( player_instance *player,
                                     m4x3f mtx, rb_sphere *sphere,
                                     rb_ct *man )
 {
+   world_instance *world = get_active_world();
+
    int len = 0;
-   len = rb_sphere__scene( mtx, sphere, NULL, &world.rb_geo.inf.scene, man );
+   len = rb_sphere__scene( mtx, sphere, NULL, &world->rb_geo.inf.scene, man );
 
    for( int i=0; i<len; i++ )
    {
@@ -60,101 +63,18 @@ VG_STATIC int skate_collide_smooth( player_instance *player,
 
    return len;
 }
-/*
- * Gets the closest grindable edge to the player within max_dist 
- */
-VG_STATIC struct grind_edge *skate_collect_grind_edge( v3f p0, v3f p1,
-                                                       v3f c0, v3f c1, 
-                                                       float max_dist )
-{
-   bh_iter it;
-   bh_iter_init( 0, &it );
-
-   boxf region;
-
-   box_init_inf( region );
-   box_addpt( region, p0 );
-   box_addpt( region, p1 );
-   
-   float k_r = max_dist;
-   v3_add( (v3f){ k_r, k_r, k_r}, region[1], region[1] );
-   v3_add( (v3f){-k_r,-k_r,-k_r}, region[0], region[0] );
-
-   float closest = k_r*k_r;
-   struct grind_edge *closest_edge = NULL;
-   
-   int idx;
-   while( bh_next( world.grind_bh, &it, region, &idx ) )
-   {
-      struct grind_edge *edge = &world.grind_edges[ idx ];
-
-      float s,t;
-      v3f pa, pb;
-
-      float d2 = 
-         closest_segment_segment( p0, p1, edge->p0, edge->p1, &s,&t, pa, pb );
-
-      if( d2 < closest )
-      {
-         closest = d2;
-         closest_edge = edge;
-         v3_copy( pa, c0 );
-         v3_copy( pb, c1 );
-      }
-   }
-
-   return closest_edge;
-}
-
-VG_STATIC int skate_grind_collide( player_instance *player, rb_ct *contact )
-{
-   v3f p0, p1, c0, c1;
-   v3_muladds( player->rb.co, player->rb.to_world[2],  0.5f, p0 );
-   v3_muladds( player->rb.co, player->rb.to_world[2], -0.5f, p1 );
-   v3_muladds( p0, player->rb.to_world[1], 0.08f, p0 );
-   v3_muladds( p1, player->rb.to_world[1], 0.08f, p1 );
-
-   float const k_r = 0.25f;
-   struct grind_edge *closest_edge = skate_collect_grind_edge( p0, p1, 
-                                                               c0, c1, k_r );
-
-   if( closest_edge )
-   {
-      v3f delta;
-      v3_sub( c1, c0, delta );
-
-      if( v3_dot( delta, player->rb.to_world[1] ) > 0.0001f )
-      {
-         contact->p = v3_length( delta );
-         contact->type = k_contact_type_edge;
-         contact->element_id = 0;
-         v3_copy( c1, contact->co );
-         contact->rba = NULL;
-         contact->rbb = NULL;
-
-         v3f edge_dir, axis_dir;
-         v3_sub( closest_edge->p1, closest_edge->p0, edge_dir );
-         v3_normalize( edge_dir );
-         v3_cross( (v3f){0.0f,1.0f,0.0f}, edge_dir, axis_dir );
-         v3_cross( edge_dir, axis_dir, contact->n );
-
-         return 1;
-      }
-      else
-         return 0;
-   }
-
-   return 0;
-}
 
 struct grind_info
 {
    v3f co, dir, n;
 };
 
-VG_STATIC int skate_grind_scansq( v3f pos, v3f dir, float r,
+VG_STATIC int skate_grind_scansq( player_instance *player,
+                                  v3f pos, v3f dir, float r,
                                   struct grind_info *inf )
 {
+   world_instance *world = get_active_world();
+
    v4f plane;
    v3_copy( dir, plane );
    v3_normalize( plane );
@@ -182,27 +102,28 @@ VG_STATIC int skate_grind_scansq( v3f pos, v3f dir, float r,
        support_max;
 
    v3f support_axis;
-   v3_cross( plane, (v3f){0.0f,1.0f,0.0f}, support_axis );
+   v3_cross( plane, player->basis[1], support_axis );
    v3_normalize( support_axis );
    
-   while( bh_next( world.geo_bh, &it, box, &idx ) )
-   {
-      u32 *ptri = &world.scene_geo->arrindices[ idx*3 ];
+   while( bh_next( world->geo_bh, &it, box, &idx ) ){
+      u32 *ptri = &world->scene_geo->arrindices[ idx*3 ];
       v3f tri[3];
 
-      for( int j=0; j<3; j++ )
-         v3_copy( world.scene_geo->arrvertices[ptri[j]].co, tri[j] );
+      struct world_surface *surf = world_tri_index_surface(world,ptri[0]);
+      if( !(surf->info.flags & k_material_flag_skate_surface) )
+         continue;
 
       for( int j=0; j<3; j++ )
-      {
+         v3_copy( world->scene_geo->arrvertices[ptri[j]].co, tri[j] );
+
+      for( int j=0; j<3; j++ ){
          int i0 = j,
              i1 = (j+1) % 3;
          
          struct grind_sample *sample = &samples[ sample_count ];
          v3f co;
 
-         if( plane_segment( plane, tri[i0], tri[i1], co ) )
-         {
+         if( plane_segment( plane, tri[i0], tri[i1], co ) ){
             v3f d;
             v3_sub( co, pos, d );
             if( v3_length2( d ) > r*r )
@@ -214,9 +135,9 @@ VG_STATIC int skate_grind_scansq( v3f pos, v3f dir, float r,
             v3_cross( va, vb, normal );
 
             sample->normal[0] = v3_dot( support_axis, normal );
-            sample->normal[1] = normal[1];
+            sample->normal[1] = v3_dot( player->basis[1], normal );
             sample->co[0]     = v3_dot( support_axis, d );
-            sample->co[1]     = d[1];
+            sample->co[1]     = v3_dot( player->basis[1], d );
 
             v3_copy( normal, sample->normal3 ); /* normalize later
                                                    if we want to us it */
@@ -252,14 +173,12 @@ too_many_samples:
 
    int passed_samples = 0;
    
-   for( int i=0; i<sample_count-1; i++ )
-   {
+   for( int i=0; i<sample_count-1; i++ ){
       struct grind_sample *si, *sj;
 
       si = &samples[i];
 
-      for( int j=i+1; j<sample_count; j++ )
-      {
+      for( int j=i+1; j<sample_count; j++ ){
          if( i == j )
             continue;
 
@@ -293,7 +212,10 @@ too_many_samples:
          v3_muls( dir, vg_signf(v3_dot(dir,plane)), dir );
          v3_add( average_direction, dir, average_direction );
 
-         if( si->normal3[1] > sj->normal3[1] )
+         float yi = v3_dot( player->basis[1], si->normal3 ),
+               yj = v3_dot( player->basis[1], sj->normal3 );
+
+         if( yi > yj )
             v3_add( si->normal3, average_normal, average_normal );
          else
             v3_add( sj->normal3, average_normal, average_normal );
@@ -330,275 +252,79 @@ too_many_samples:
    return passed_samples;
 }
 
-#if 0
-static inline void skate_grind_coordv2i( v2f co, v2i d )
-{
-   const float k_inv_res = 1.0f/0.01f;
-   d[0] = floorf( co[0] * k_inv_res );
-   d[1] = floorf( co[1] * k_inv_res );
-}
-
-static inline u32 skate_grind_hashv2i( v2i d )
+VG_STATIC int solve_prediction_for_target( player_instance *player,
+                                           v3f target, float max_angle,
+                                           struct land_prediction *p )
 {
-   return (d[0] * 92837111) ^ (d[1] * 689287499);
-}
-
-static inline u32 skate_grind_hashv2f( v2f co )
-{
-   v2i d;
-   skate_grind_coordv2i( co, d );
-   return skate_grind_hashv2i( d );
-}
-
-VG_STATIC int skate_grind_scansq( player_instance *player, v3f pos,
-                                  v3f result_co, v3f result_dir, v3f result_n )
-{
-   v4f plane;
-   v3_copy( player->rb.v, plane );
-   v3_normalize( plane );
-   plane[3] = v3_dot( plane, pos );
-
-   boxf box;
-   float r = k_board_length;
-   v3_add( pos, (v3f){ r, r, r }, box[1] );
-   v3_sub( pos, (v3f){ r, r, r }, box[0] );
-
-   vg_line_boxf( box, VG__BLACK );
-
-   m4x3f mtx;
-   m3x3_copy( player->rb.to_world, mtx );
-   v3_copy( pos, mtx[3] );
-   
-   bh_iter it;
-   bh_iter_init( 0, &it );
-   int idx;
-
-   struct grind_sample
-   {
-      v2f co;
-      v2f normal;
-      v3f normal3,
-          centroid;
-   }
-   samples[48];
-
-   int sample_count = 0;
-
-   v2f support_min,
-       support_max;
-
-   v3f support_axis;
-   v3_cross( plane, (v3f){0.0f,1.0f,0.0f}, support_axis );
-   v3_normalize( support_axis );
-   
-   while( bh_next( world.geo_bh, &it, box, &idx ) )
-   {
-      u32 *ptri = &world.scene_geo->arrindices[ idx*3 ];
-      v3f tri[3];
-
-      for( int j=0; j<3; j++ )
-         v3_copy( world.scene_geo->arrvertices[ptri[j]].co, tri[j] );
-
-      for( int j=0; j<3; j++ )
-      {
-         int i0 = j,
-             i1 = (j+1) % 3;
-         
-         struct grind_sample *sample = &samples[ sample_count ];
-         v3f co;
-
-         if( plane_segment( plane, tri[i0], tri[i1], co ) )
-         {
-            v3f d;
-            v3_sub( co, pos, d );
-            if( v3_length2( d ) > r*r )
-               continue;
-
-            v3f va, vb, normal;
-            v3_sub( tri[1], tri[0], va );
-            v3_sub( tri[2], tri[0], vb );
-            v3_cross( va, vb, normal );
-
-            sample->normal[0] = v3_dot( support_axis, normal );
-            sample->normal[1] = normal[1];
-            sample->co[0]     = v3_dot( support_axis, d );
-            sample->co[1]     = d[1];
-
-            v3_copy( normal, sample->normal3 ); /* normalize later
-                                                   if we want to us it */
-
-            v3_muls(                      tri[0], 1.0f/3.0f, sample->centroid );
-            v3_muladds( sample->centroid, tri[1], 1.0f/3.0f, sample->centroid );
-            v3_muladds( sample->centroid, tri[2], 1.0f/3.0f, sample->centroid );
-
-            v2_normalize( sample->normal );
-            sample_count ++;
-
-            if( sample_count == vg_list_size( samples ) )
-            {
-               break;
-            }
-         }
-      }
-   }
-
-   if( sample_count < 2 )
-      return 0;
+   /* calculate the exact solution(s) to jump onto that grind spot */
 
+   v3f v0;
+   v3_sub( target, player->rb.co, v0 );
+   m3x3_mulv( player->invbasis, v0, v0 );
 
+   v3f ax;
+   v3_copy( v0, ax );
+   ax[1] = 0.0f;
+   v3_normalize( ax );
 
-   /* spacial hashing */
+   v3f v_local;
+   m3x3_mulv( player->invbasis, player->rb.v, v_local );
 
-   const int k_hashmap_size = 128;
-   u32 hashmap[k_hashmap_size+1];
-   u32 entries[48];
+   v2f d = { v3_dot( ax, v0 ),           v0[1] },
+       v = { v3_dot( ax, player->rb.v ), v_local[1] };
 
-   for( int i=0; i<k_hashmap_size+1; i++ )
-      hashmap[i] = 0;
+   float a = atan2f( v[1], v[0] ),
+         m = v2_length( v ),
+         root = m*m*m*m - p->gravity*(p->gravity*d[0]*d[0] + 2.0f*d[1]*m*m);
 
-   for( int i=0; i<sample_count; i++ )
+   if( root > 0.0f )
    {
-      u32 h = skate_grind_hashv2f( samples[i].co ) % k_hashmap_size;
-      hashmap[ h ] ++;
-   }
+      root = sqrtf( root );
+      float a0 = atanf( (m*m + root) / (p->gravity * d[0]) ),
+            a1 = atanf( (m*m - root) / (p->gravity * d[0]) );
 
-   /* partial sums */
-   for( int i=0; i<k_hashmap_size; i++ )
-   {
-      hashmap[i+1] += hashmap[i];
-   }
-
-   /* trash compactor */
-   for( int i=0; i<sample_count; i++ )
-   {
-      u32 h = skate_grind_hashv2f( samples[i].co ) % k_hashmap_size;
-      hashmap[ h ] --;
+      if( fabsf(a0-a) > fabsf(a1-a) )
+         a0 = a1;
 
-      entries[ hashmap[h] ] = i;
-   }
-
-
-   v3f 
-       average_direction,
-       average_normal;
-
-   v2f min_co, max_co;
-   v2_fill( min_co,  INFINITY );
-   v2_fill( max_co, -INFINITY );
+      if( fabsf(a0-a) > max_angle )
+         return 0;
 
-   v3_zero( average_direction );
-   v3_zero( average_normal );
+      /* TODO: sweep the path before chosing the smallest dist */
 
-   int passed_samples = 0;
-   
-   for( int i=0; i<sample_count; i++ )
-   {
-      struct grind_sample *si, *sj;
-      si = &samples[i];
+      p->log_length = 0;
+      p->land_dist = 0.0f;
+      v3_zero( p->apex );
+      p->type = k_prediction_grind;
 
-      v2i start;
-      skate_grind_coordv2i( si->co, start );
+      v3_muls( ax, cosf( a0 ) * m, p->v );
+      p->v[1] += sinf( a0 ) * m;
+      m3x3_mulv( player->basis, p->v, p->v );
 
-      v2i offsets[] = { {-1,-1},{ 0,-1},{ 1,-1},
-                        {-1, 0},{ 0, 0},{ 1, 0},
-                        {-1, 1},{ 0, 1},{ 1, 1} };
+      p->land_dist = d[0] / (cosf(a0)*m);
 
-      for( int j=0; j<vg_list_size(offsets); j++ )
+      /* add a trace */
+      for( int i=0; i<=20; i++ )
       {
-         v2i cell;
-         v2i_add( start, offsets[j], cell );
-         
-         u32 h = skate_grind_hashv2i( cell ) % k_hashmap_size;
-
-         int start = hashmap[ h ],
-             end   = hashmap[ h+1 ];
-
-         for( int k=start; k<end; k++ )
-         {
-            int idx = entries[ k ];
-            if( idx <= i )
-               continue;
+         float t = (float)i * (1.0f/20.0f) * p->land_dist;
 
-            sj = &samples[idx];
+         v3f p0;
+         v3_muls( p->v, t, p0 );
+         v3_muladds( p0, player->basis[1], -0.5f * p->gravity * t*t, p0 );
 
-            /* non overlapping */
-            if( v2_dist2( si->co, sj->co ) >= (0.01f*0.01f) )
-               continue;
-
-            /* not sharp angle */
-            if( v2_dot( si->normal, sj->normal ) >= 0.7f )
-               continue;
-
-            /* not convex */
-            v3f v0;
-            v3_sub( sj->centroid, si->centroid, v0 );
-            if( v3_dot( v0, si->normal3 ) >= 0.0f ||
-                v3_dot( v0, sj->normal3 ) <= 0.0f )
-               continue;
-
-            v2_minv( sj->co, min_co, min_co );
-            v2_maxv( sj->co, max_co, max_co );
-            
-            v3f n0, n1, dir;
-            v3_copy( si->normal3, n0 );
-            v3_copy( sj->normal3, n1 );
-            v3_cross( n0, n1, dir );
-            v3_normalize( dir );
-
-            /* make sure the directions all face a common hemisphere */
-            v3_muls( dir, vg_signf(v3_dot(dir,plane)), dir );
-            v3_add( average_direction, dir, average_direction );
-
-            if( si->normal3[1] > sj->normal3[1] )
-               v3_add( si->normal3, average_normal, average_normal );
-            else
-               v3_add( sj->normal3, average_normal, average_normal );
-
-            passed_samples ++;
-         }
+         v3_add( player->rb.co, p0, p->log[ p->log_length ++ ] );
       }
-   }
-
-   if( !passed_samples )
-      return 0;
 
-   if( (v3_length2( average_direction ) <= 0.001f) ||
-       (v3_length2( average_normal ) <= 0.001f ) )
+      return 1;
+   }
+   else
       return 0;
-
-   float div = 1.0f/(float)passed_samples;
-   v3_normalize( average_direction );
-   v3_normalize( average_normal );
-
-   v2f average_coord;
-   v2_add( min_co, max_co, average_coord );
-   v2_muls( average_coord, 0.5f, average_coord );
-
-
-   v3_muls( support_axis, average_coord[0], result_co );
-   result_co[1] += average_coord[1];
-   v3_add( pos, result_co, result_co );
-   
-#if 0
-   vg_line_pt3( result_co, 0.02f, VG__GREEN );
-
-   v3f p0, p1;
-   v3_muladds( result_co, average_direction,  0.35f, p0 );
-   v3_muladds( result_co, average_direction, -0.35f, p1 );
-   vg_line( p0, p1, VG__PINK );
-#endif
-
-   v3_copy( average_normal, result_n );
-   v3_copy( average_direction, result_dir );
-
-   return passed_samples;
 }
 
-#endif
-
 VG_STATIC 
 void player__approximate_best_trajectory( player_instance *player )
 {
+   world_instance *world = get_active_world();
+
    struct player_skate *s = &player->_skate;
    float k_trace_delta = k_rb_delta * 10.0f;
 
@@ -613,10 +339,14 @@ void player__approximate_best_trajectory( player_instance *player )
    v3_normalize( axis );
 
    /* at high slopes, Y component is low */
-   float angle_begin = -(1.0f-fabsf( player->rb.to_world[1][1] )),
+   float upness      = v3_dot( player->rb.to_world[1], player->basis[1] ),
+         angle_begin = -(1.0f-fabsf( upness )),
          angle_end   =   1.0f;
 
-   for( int m=0;m<=15; m++ )
+   struct grind_info grind;
+   int grind_located = 0;
+
+   for( int m=0;m<=30; m++ )
    {
       struct land_prediction *p = &s->predictions[ s->prediction_count ++ ];
 
@@ -630,12 +360,24 @@ void player__approximate_best_trajectory( player_instance *player )
       v3_copy( player->rb.v,  launch_v );
       v3_copy( launch_co, co0 );
 
-      float vt  = (float)m * (1.0f/15.0f),
+      float vt  = (float)m * (1.0f/30.0f),
             ang = vg_lerpf( angle_begin, angle_end, vt ) * 0.15f;
 
       v4f qbias;
       q_axis_angle( qbias, axis, ang );
       q_mulv( qbias, launch_v, launch_v );
+
+      float yaw_sketch = 1.0f-fabsf(upness);
+
+      float yaw_bias = ((float)(m%3) - 1.0f) * 0.08f * yaw_sketch;
+      q_axis_angle( qbias, player->rb.to_world[1], yaw_bias );
+      q_mulv( qbias, launch_v, launch_v );
+
+
+      float gravity_bias = vg_lerpf( 0.85f, 1.4f, vt ),
+            gravity      = k_gravity * gravity_bias;
+      p->gravity = gravity;
+
       v3_copy( launch_v, p->v );
 
       for( int i=1; i<=50; i++ )
@@ -643,28 +385,81 @@ void player__approximate_best_trajectory( player_instance *player )
          float t = (float)i * k_trace_delta;
 
          v3_muls( launch_v, t, co1 );
-         co1[1] += -0.5f * k_gravity * t*t;
+         v3_muladds( co1, player->basis[1], -0.5f * gravity * t*t, co1 );
          v3_add( launch_co, co1, co1 );
 
+         float launch_vy = v3_dot( launch_v,player->basis[1] );
+         if( !grind_located && (launch_vy - gravity*t < 0.0f) )
+         {
+            v3f closest;
+            if( bh_closest_point( world->geo_bh, co1, closest, 1.0f ) != -1 )
+            {
+               v3f ve;
+               v3_copy( launch_v, ve );
+               v3_muladds( ve, player->basis[1], -gravity * t, ve );
+
+               if( skate_grind_scansq( player, closest, ve, 0.5f, &grind ) )
+               {
+                  /* check alignment */
+                  v2f v0 = { v3_dot( ve, player->basis[0] ), 
+                             v3_dot( ve, player->basis[2] ) },
+                      v1 = { v3_dot( grind.dir, player->basis[0] ), 
+                             v3_dot( grind.dir, player->basis[2] ) };
+
+                  v2_normalize( v0 );
+                  v2_normalize( v1 );
+
+                  float a = v2_dot( v0, v1 );
+
+                  if( a >= cosf( VG_PIf * 0.185f ) )
+                  {
+                     grind_located = 1;
+                  }
+               }
+            }
+         }
+
          float t1;
          v3f n;
 
-         int idx = spherecast_world( co0, co1, k_board_radius, &t1, n );
+         int idx = spherecast_world( world, co0, co1, k_board_radius, &t1, n );
          if( idx != -1 )
          {
+            v3f co;
+            v3_lerp( co0, co1, t1, co );
+            v3_copy( co, p->log[ p->log_length ++ ] ); 
+
             v3_copy( n, p->n );
-            v3_lerp( co0, co1, t1, p->log[ p->log_length ++ ] ); 
             p->type = k_prediction_land;
 
             v3f ve;
             v3_copy( launch_v, ve );
-            ve[1] -= k_gravity * t;
-            p->score = -v3_dot( ve, n );
+            v3_muladds( ve, player->basis[1], -gravity * t, ve );
+
+            struct grind_info replace_grind;
+            if( skate_grind_scansq( player, co, ve, 0.3f, &replace_grind ) )
+            {
+               v3_copy( replace_grind.n, p->n );
+               p->type = k_prediction_grind;
+            }
+
+            p->score = -v3_dot( ve, p->n );
             p->land_dist = t + k_trace_delta * t1;
+
+            u32 vert_index = world->scene_geo->arrindices[ idx*3 ];
+            struct world_surface *surf = 
+               world_tri_index_surface( world, vert_index );
+            
+            /* Bias prediction towords ramps */
+            if( !(surf->info.flags & k_material_flag_skate_surface) )
+               p->score *= 10.0f;
+
             break;
          }
+         
+         if( i % 3 == 0 )
+            v3_copy( co1, p->log[ p->log_length ++ ] ); 
 
-         v3_copy( co1, p->log[ p->log_length ++ ] ); 
          v3_copy( co1, co0 );
       }
 
@@ -672,13 +467,31 @@ void player__approximate_best_trajectory( player_instance *player )
          s->prediction_count --;
    }
 
+   if( grind_located ){
+      /* calculate the exact solution(s) to jump onto that grind spot */
+      struct land_prediction *p = &s->predictions[ s->prediction_count ];
+      p->gravity = k_gravity;
+
+      if( solve_prediction_for_target( player, grind.co, 0.125f*VG_PIf, p ) ){
+         v3_copy( grind.n, p->n );
+
+         /* determine score */
+         v3f ve;
+         v3_copy( p->v, ve );
+         v3_muladds( ve, player->basis[1], -p->gravity * p->land_dist, ve );
+         p->score = -v3_dot( ve, grind.n ) * 0.85f;
+
+         s->prediction_count ++;
+      }
+   }
+
+
    float score_min =  INFINITY,
          score_max = -INFINITY;
 
    struct land_prediction *best = NULL;
 
-   for( int i=0; i<s->prediction_count; i ++ )
-   {
+   for( int i=0; i<s->prediction_count; i ++ ){
       struct land_prediction *p = &s->predictions[i];
 
       if( p->score < score_min )
@@ -688,8 +501,7 @@ void player__approximate_best_trajectory( player_instance *player )
       score_max = vg_maxf( score_max, p->score );
    }
 
-   for( int i=0; i<s->prediction_count; i ++ )
-   {
+   for( int i=0; i<s->prediction_count; i ++ ){
       struct land_prediction *p = &s->predictions[i];
       float s = p->score;
 
@@ -708,8 +520,7 @@ void player__approximate_best_trajectory( player_instance *player )
       p->colour |= 0xff000000;
    }
 
-   if( best )
-   {
+   if( best ){
       v3_copy( best->n, s->land_normal );
       v3_copy( best->v, player->rb.v );
       s->land_dist = best->land_dist;
@@ -717,23 +528,21 @@ void player__approximate_best_trajectory( player_instance *player )
       v2f steer = { player->input_js1h->axis.value,
                     player->input_js1v->axis.value };
       v2_normalize_clamp( steer );
+      s->state.gravity_bias = best->gravity;
 
-      if( (fabsf(steer[1]) > 0.5f) && (s->land_dist >= 1.5f) )
-      {
+      if( (fabsf(steer[1]) > 0.5f) && (s->land_dist >= 1.5f) ){
          s->state.flip_rate = (1.0f/s->land_dist) * vg_signf(steer[1]) *
                                  s->state.reverse ;
          s->state.flip_time = 0.0f;
          v3_copy( player->rb.to_world[0], s->state.flip_axis );
       }
-      else
-      {
+      else{
          s->state.flip_rate = 0.0f;
          v3_zero( s->state.flip_axis );
       }
    }
-   else
-   {
-      v3_copy( (v3f){0.0f,1.0f,0.0f}, s->land_normal );
+   else{
+      v3_copy( player->basis[1], s->land_normal );
    }
 }
 
@@ -751,70 +560,7 @@ VG_STATIC void skate_apply_air_model( player_instance *player )
    struct player_skate *s = &player->_skate;
 
    if( s->state.activity_prev != k_skate_activity_air )
-      player__approximate_best_trajectory( player );
-
-#if 0
-   m3x3_mulv( s->state.velocity_bias, player->rb.v, player->rb.v );
-
-   ray_hit hit;
-   /* 
-    * Prediction 
-    */
-   float pstep  = VG_TIMESTEP_FIXED * 1.0f;
-   float k_bias = 0.98f;
-
-   v3f pco, pco1, pv;
-   v3_copy( player->rb.co, pco );
-   v3_muls( player->rb.v, 1.0f, pv );
-   
-   float time_to_impact = 0.0f;
-   float limiter = 1.0f;
-
-   struct grind_edge *best_grind = NULL;
-   float closest_grind = INFINITY;
-
-   v3f target_normal = { 0.0f, 1.0f, 0.0f };
-   int has_target = 0;
-
-   for( int i=0; i<250; i++ )
-   {
-      v3_copy( pco, pco1 );
-      m3x3_mulv( s->state.velocity_bias, pv, pv );
-
-      pv[1] += -k_gravity * pstep;
-      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);
-
-      v3f c0, c1;
-      struct grind_edge *ge = skate_collect_grind_edge( pco, pco1,
-                                                        c0, c1, 0.4f );
-
-      if( ge && (v3_dot((v3f){0.0f,1.0f,0.0f},vdir) < -0.2f ) ) 
-      { 
-         vg_line( ge->p0, ge->p1, 0xff0000ff ); 
-         vg_line_cross( pco, 0xff0000ff, 0.25f );
-         has_target = 1;
-         break;
-      }
-      
-      float orig_dist = contact.dist;
-      if( ray_world( pco1, vdir, &contact ) )
-      {
-         v3_copy( contact.normal, target_normal );
-         has_target = 1;
-         time_to_impact += (contact.dist/orig_dist)*pstep;
-         vg_line_cross( contact.pos, 0xffff0000, 0.25f );
-         break;
-      }
-      time_to_impact += pstep;
-   }
-#endif
+      player__approximate_best_trajectory( player );
 
    float angle = v3_dot( player->rb.to_world[1], s->land_normal );
    angle = vg_clampf( angle, -1.0f, 1.0f );
@@ -829,9 +575,6 @@ VG_STATIC void skate_apply_air_model( player_instance *player )
    v2f steer = { player->input_js1h->axis.value,
                  player->input_js1v->axis.value };
    v2_normalize_clamp( steer );
-
-   //s->land_dist = time_to_impact;
-   s->land_dist = 1.0f;
 }
 
 VG_STATIC int player_skate_trick_input( player_instance *player );
@@ -852,8 +595,7 @@ VG_STATIC void skate_apply_trick_model( player_instance *player )
    v3_muladds( s->board_trick_residuald, s->board_trick_residualv,
                k_rb_delta, s->board_trick_residuald );
 
-   if( s->state.activity == k_skate_activity_air )
-   {
+   if( s->state.activity == k_skate_activity_air ){
       if( v3_length2( s->state.trick_vel ) < 0.0001f )
          return;
 
@@ -864,8 +606,7 @@ VG_STATIC void skate_apply_trick_model( player_instance *player )
 
       float min_rate = 99999.0f;
 
-      for( int i=0; i<3; i++ )
-      {
+      for( int i=0; i<3; i++ ){
          float v = s->state.trick_vel[i];
          if( (v > 0.0f) && (v < min_rate) )
             min_rate = v;
@@ -880,8 +621,7 @@ VG_STATIC void skate_apply_trick_model( player_instance *player )
       v3_muladds( s->state.trick_euler, s->state.trick_vel, k_rb_delta,
                   s->state.trick_euler );
 
-      if( !carry_on && (s->state.trick_time + k_rb_delta >= next_end) )
-      {
+      if( !carry_on && (s->state.trick_time + k_rb_delta >= next_end) ){
          s->state.trick_time = 0.0f;
          s->state.trick_euler[0] = roundf( s->state.trick_euler[0] );
          s->state.trick_euler[1] = roundf( s->state.trick_euler[1] );
@@ -892,8 +632,7 @@ VG_STATIC void skate_apply_trick_model( player_instance *player )
 
       s->state.trick_time += k_rb_delta;
    }
-   else
-   {
+   else{
       if( (v3_length2(s->state.trick_vel) >= 0.0001f ) &&
           s->state.trick_time > 0.2f)
       {
@@ -914,8 +653,7 @@ VG_STATIC void skate_apply_grab_model( player_instance *player )
 
    float grabt = player->input_grab->axis.value;
 
-   if( grabt > 0.5f )
-   {
+   if( grabt > 0.5f ){
       v2_muladds( s->state.grab_mouse_delta, vg.mouse_delta, 0.02f, 
                   s->state.grab_mouse_delta );
 
@@ -932,52 +670,50 @@ VG_STATIC void skate_apply_steering_model( player_instance *player )
    struct player_skate *s = &player->_skate;
 
    /* Steering */
-   float input = player->input_js1h->axis.value,
-         grab  = player->input_grab->axis.value,
-         steer = input * (1.0f-(s->state.jump_charge+grab)*0.4f),
-         steer_scaled = vg_signf(steer) * powf(steer,2.0f) * k_steer_ground;
+   float steer = player->input_js1h->axis.value,
+         grab  = player->input_grab->axis.value;
+
+   steer = vg_signf( steer ) * steer*steer * k_steer_ground;
 
    v3f steer_axis;
-   v3_muls( player->rb.to_world[1], -vg_signf( steer_scaled ), steer_axis );
+   v3_muls( player->rb.to_world[1], -vg_signf( steer ), steer_axis );
 
    float rate = 26.0f,
          top  = 1.0f;
 
-   if( s->state.activity == k_skate_activity_air )
-   {
-      rate = 6.0f * fabsf(steer_scaled);
-      top  = 1.5f;
-   }
-
-   else if( s->state.manual_direction )
-   {
-      rate = 35.0f;
+   if( s->state.activity == k_skate_activity_air ){
+      rate = 6.0f * fabsf(steer);
       top  = 1.5f;
    }
+   else{
+      /* rotate slower when grabbing on ground */
+      steer *= (1.0f-(s->state.jump_charge+grab)*0.4f);
 
-   else if( s->state.activity >= k_skate_activity_grind_any )
-   {
-      rate *= fabsf(steer_scaled);
+      if( s->state.activity == k_skate_activity_grind_5050 ){
+         rate = 0.0f;
+         top  = 0.0f;
+      }
 
-      float a = 0.8f * -steer_scaled * k_rb_delta;
+      else if( s->state.activity >= k_skate_activity_grind_any ){
+         rate *= fabsf(steer);
 
-      v4f q;
-      q_axis_angle( q, player->rb.to_world[1], a );
-      q_mulv( q, s->grind_vec, s->grind_vec );
+         float a = 0.8f * -steer * k_rb_delta;
 
-#if 0
-      float tilt = player->input_js1v->axis.value;
-      tilt *= tilt * 0.8f * k_rb_delta;
+         v4f q;
+         q_axis_angle( q, player->rb.to_world[1], a );
+         q_mulv( q, s->grind_vec, s->grind_vec );
 
-      q_axis_angle( q, player->rb.to_world[0], tilt );
-      q_mulv( q, s->grind_vec, s->grind_vec );
-#endif
+         v3_normalize( s->grind_vec );
+      }
 
-      v3_normalize( s->grind_vec );
+      else if( s->state.manual_direction ){
+         rate = 35.0f;
+         top  = 1.5f;
+      }
    }
 
    float current  = v3_dot( player->rb.to_world[1], player->rb.w ),
-         addspeed = (steer_scaled * -top) - current,
+         addspeed = (steer * -top) - current,
          maxaccel = rate * k_rb_delta,
          accel    = vg_clampf( addspeed, -maxaccel, maxaccel );
 
@@ -1014,9 +750,9 @@ VG_STATIC void skate_apply_friction_model( player_instance *player )
 
    /* Pushing additive force */
 
-   if( !player->input_jump->button.value )
-   {
-      if( player->input_push->button.value )
+   if( !player->input_jump->button.value ){
+      if( player->input_push->button.value || 
+          (vg.time-s->state.start_push<0.75) )
       {
          if( (vg.time - s->state.cur_push) > 0.25 )
             s->state.start_push = vg.time;
@@ -1047,33 +783,29 @@ VG_STATIC void skate_apply_jump_model( player_instance *player )
    s->state.charging_jump = player->input_jump->button.value;
 
    /* Cannot charge this in air */
-   if( s->state.activity == k_skate_activity_air )
-   {
+   if( s->state.activity == k_skate_activity_air ){
       s->state.charging_jump = 0;
       return;
    }
 
-   if( s->state.charging_jump )
-   {
+   if( s->state.charging_jump ){
       s->state.jump_charge += k_rb_delta * k_jump_charge_speed;
 
       if( !charging_jump_prev )
          s->state.jump_dir = s->state.reverse>0.0f? 1: 0;
    }
-   else
-   {
+   else{
       s->state.jump_charge -= k_jump_charge_speed * k_rb_delta;
    }
 
    s->state.jump_charge = vg_clampf( s->state.jump_charge, 0.0f, 1.0f );
 
    /* player let go after charging past 0.2: trigger jump */
-   if( (!s->state.charging_jump) && (s->state.jump_charge > 0.2f) )
-   {
+   if( (!s->state.charging_jump) && (s->state.jump_charge > 0.2f) ){
       v3f jumpdir;
       
       /* Launch more up if alignment is up else improve velocity */
-      float aup = v3_dot( (v3f){0.0f,1.0f,0.0f}, player->rb.to_world[1] ),
+      float aup = v3_dot( player->basis[1], player->rb.to_world[1] ),
             mod = 0.5f,
             dir = mod + fabsf(aup)*(1.0f-mod);
 
@@ -1092,7 +824,7 @@ VG_STATIC void skate_apply_jump_model( player_instance *player )
       v2f steer = { player->input_js1h->axis.value,
                     player->input_js1v->axis.value };
       v2_normalize_clamp( steer );
-
+      skate_apply_air_model( player );
 
 #if 0
       float maxspin = k_steer_air * k_rb_delta * k_spin_boost;
@@ -1101,15 +833,9 @@ VG_STATIC void skate_apply_jump_model( player_instance *player )
       s->state.lift_frames ++;
 #endif
 
-      /* FIXME audio events */
-#if 0
       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()%2] );
+      audio_oneshot_3d( &audio_jumps[rand()%2], player->rb.co, 40.0f, 1.0f );
       audio_unlock();
-#endif
    }
 }
 
@@ -1117,28 +843,29 @@ VG_STATIC void skate_apply_pump_model( player_instance *player )
 {
    struct player_skate *s = &player->_skate;
 
+   if( s->state.activity != k_skate_activity_ground ){
+      v3_zero( s->state.throw_v );
+      return;
+   }
+
    /* Throw / collect routine 
     *
     * TODO: Max speed boost
     */
-   if( player->input_grab->axis.value > 0.5f )
-   {
-      if( s->state.activity == k_skate_activity_ground )
-      {
+   if( player->input_grab->axis.value > 0.5f ){
+      if( s->state.activity == k_skate_activity_ground ){
          /* Throw */
          v3_muls( player->rb.to_world[1], k_mmthrow_scale, s->state.throw_v );
       }
    }
-   else
-   {
+   else{
       /* Collect */
       float doty = v3_dot( player->rb.to_world[1], s->state.throw_v );
       
       v3f Fl, Fv;
       v3_muladds( s->state.throw_v, player->rb.to_world[1], -doty, Fl);
 
-      if( s->state.activity == k_skate_activity_ground )
-      {
+      if( s->state.activity == k_skate_activity_ground ){
          v3_muladds( player->rb.v,     Fl,  k_mmcollect_lat, player->rb.v );
          v3_muladds( s->state.throw_v, Fl, -k_mmcollect_lat, s->state.throw_v );
       }
@@ -1149,8 +876,7 @@ VG_STATIC void skate_apply_pump_model( player_instance *player )
    }
 
    /* Decay */
-   if( v3_length2( s->state.throw_v ) > 0.0001f )
-   {
+   if( v3_length2( s->state.throw_v ) > 0.0001f ){
       v3f dir;
       v3_copy( s->state.throw_v, dir );
       v3_normalize( dir );
@@ -1186,7 +912,9 @@ VG_STATIC void skate_apply_cog_model( player_instance *player )
 
    /* Apply forces & intergrate */
    v3_muladds( s->state.cog_v, F, -rb, s->state.cog_v );
-   s->state.cog_v[1] += -9.8f * k_rb_delta;
+   v3_muladds( s->state.cog_v, player->basis[1], -9.8f * k_rb_delta,
+               s->state.cog_v );
+
    v3_muladds( s->state.cog, s->state.cog_v, k_rb_delta, s->state.cog );
 }
 
@@ -1198,8 +926,7 @@ VG_STATIC void skate_integrate( player_instance *player )
    float decay_rate = 1.0f - (k_rb_delta * 3.0f),
          decay_rate_y = 1.0f;
 
-   if( s->state.activity >= k_skate_activity_grind_any )
-   {
+   if( s->state.activity >= k_skate_activity_grind_any ){
       decay_rate = 1.0f-vg_lerpf( 3.0f, 20.0f, s->grind_strength ) * k_rb_delta;
       decay_rate_y = decay_rate;
    }
@@ -1232,20 +959,19 @@ VG_STATIC void player__skate_pre_update( player_instance *player )
 {
    struct player_skate *s = &player->_skate;
 
-   if( vg_input_button_down( player->input_use ) )
-   {
+   if( vg_input_button_down( player->input_use ) ){
       player->subsystem = k_player_subsystem_walk;
 
       v3f angles;
       v3_copy( player->cam.angles, angles );
       angles[2] = 0.0f;
 
+      player->holdout_time = 0.25f;
       player__walk_transition( player, angles );
       return;
    }
 
-   if( vg_input_button_down( player->input_reset ) )
-   {
+   if( vg_input_button_down( player->input_reset ) ){
       player->rb.co[1] += 2.0f;
       s->state.cog[1] += 2.0f;
       q_axis_angle( player->rb.q, (v3f){1.0f,0.0f,0.0f}, VG_PIf * 0.25f );
@@ -1259,21 +985,17 @@ VG_STATIC void player__skate_pre_update( player_instance *player )
    if( (s->state.activity == k_skate_activity_air) && 
        (trick_id = player_skate_trick_input( player )) )
    {
-      if( (vg.time - s->state.jump_time) < 0.1f )
-      {
+      if( (vg.time - s->state.jump_time) < 0.1f ){
          v3_zero( s->state.trick_vel );
          s->state.trick_time = 0.0f;
 
-         if( trick_id == 1 )
-         {
+         if( trick_id == 1 ){
             s->state.trick_vel[0] = 3.0f;
          }
-         else if( trick_id == 2 )
-         {
+         else if( trick_id == 2 ){
             s->state.trick_vel[2] = 3.0f;
          }
-         else if( trick_id == 3 )
-         {
+         else if( trick_id == 3 ){
             s->state.trick_vel[0] = 2.0f;
             s->state.trick_vel[2] = 2.0f;
          }
@@ -1309,6 +1031,67 @@ VG_STATIC void player__skate_post_update( player_instance *player )
 #if 0
    vg_line_pt3( s->state.apex, 0.030f, 0xff0000ff );
 #endif
+
+   audio_lock();
+
+   float air   = s->state.activity == k_skate_activity_air? 1.0f: 0.0f,
+         speed = v3_length( player->rb.v ),
+         attn  = vg_minf( 1.0f, speed*0.1f ),
+         slide = vg_clampf( fabsf(s->state.slip), 0.0f, 1.0f ),
+
+         vol_main    = sqrtf( (1.0f-air)*attn*(1.0f-slide) * 0.4f ),
+         vol_air     = sqrtf(       air *attn * 0.5f ),
+         vol_slide   = sqrtf( (1.0f-air)*attn*slide * 0.25f );
+
+   const u32 flags = AUDIO_FLAG_SPACIAL_3D|AUDIO_FLAG_LOOP;
+   if( !s->aud_main )
+      s->aud_main = audio_request_channel( &audio_board[0], flags );
+
+   if( !s->aud_air )
+      s->aud_air = audio_request_channel( &audio_board[1], flags );
+
+   if( !s->aud_slide )
+      s->aud_slide = audio_request_channel( &audio_board[2], flags );
+
+
+   /* brrrrrrrrrrrt sound for tiles and stuff 
+    * --------------------------------------------------------*/
+   float sidechain_amt = 0.0f,
+         hz            = speed * 2.0f;
+
+   if( s->surface == k_surface_prop_tiles )
+      sidechain_amt = 1.0f;
+   else
+      sidechain_amt = 0.0f;
+
+   audio_set_lfo_frequency( 0, hz );
+   audio_set_lfo_wave( 0, k_lfo_polynomial_bipolar, 
+                        vg_lerpf( 250.0f, 80.0f, attn ) );
+
+   if( s->aud_main ){
+      s->aud_main->colour = 0x00103efe;
+      audio_channel_set_spacial( s->aud_main, player->rb.co, 40.0f );
+      audio_channel_slope_volume( s->aud_main, 0.05f, vol_main );
+      audio_channel_sidechain_lfo( s->aud_main, 0, sidechain_amt );
+
+      float rate = 1.0f + (attn-0.5f)*0.2f;
+      audio_channel_set_sampling_rate( s->aud_main, rate );
+   }
+
+   if( s->aud_slide ){
+      s->aud_slide->colour = 0x00103efe;
+      audio_channel_set_spacial( s->aud_slide, player->rb.co, 40.0f );
+      audio_channel_slope_volume( s->aud_slide, 0.05f, vol_slide );
+      audio_channel_sidechain_lfo( s->aud_slide, 0, sidechain_amt );
+   }
+
+   if( s->aud_air ){
+      s->aud_air->colour = 0x00103efe;
+      audio_channel_set_spacial( s->aud_air, player->rb.co, 40.0f );
+      audio_channel_slope_volume( s->aud_air, 0.05f, vol_air );
+   }
+
+   audio_unlock();
 }
 
 /*
@@ -1325,37 +1108,49 @@ int skate_compute_surface_alignment( player_instance *player,
                                      v3f surface_normal, v3f axel_dir )
 {
    struct player_skate *s = &player->_skate;
+   world_instance *world = get_active_world();
 
    v3f truck, left, right;
    m4x3_mulv( player->rb.to_world, ra, truck );
+
    v3_muladds( truck, player->rb.to_world[0], -k_board_width, left  );
    v3_muladds( truck, player->rb.to_world[0],  k_board_width, right );
-   
    vg_line( left, right, colour );
 
-   v3_muladds( left,  player->rb.to_world[1], 0.1f, left  );
-   v3_muladds( right, player->rb.to_world[1], 0.1f, right );
-
    float k_max_truck_flex = VG_PIf * 0.25f;
    
    ray_hit ray_l, ray_r;
-   ray_l.dist = 0.2f;
-   ray_r.dist = 0.2f;
 
    v3f dir;
    v3_muls( player->rb.to_world[1], -1.0f, dir );
 
-   int res_l = ray_world( left, dir, &ray_l ),
-       res_r = ray_world( right, dir, &ray_r );
+   int res_l = 0, res_r = 0;
+
+   for( int i=0; i<8; i++ )
+   {
+      float t = 1.0f - (float)i * (1.0f/8.0f);
+      v3_muladds( truck, player->rb.to_world[0], -k_board_radius*t, left );
+      v3_muladds( left,  player->rb.to_world[1],  k_board_radius,   left );
+      ray_l.dist = 2.1f * k_board_radius;
+
+      res_l = ray_world( world, left, dir, &ray_l );
+
+      if( res_l )
+         break;
+   }
+
+   for( int i=0; i<8; i++ )
+   {
+      float t = 1.0f - (float)i * (1.0f/8.0f);
+      v3_muladds( truck, player->rb.to_world[0],  k_board_radius*t, right );
+      v3_muladds( right, player->rb.to_world[1],  k_board_radius,   right );
+      ray_r.dist = 2.1f * k_board_radius;
 
-   /* ignore bad normals */
-   if( res_l )
-      if( v3_dot( ray_l.normal, player->rb.to_world[1] ) < 0.7071f )
-         res_l = 0;
+      res_r = ray_world( world, right, dir, &ray_r );
 
-   if( res_r )
-      if( v3_dot( ray_r.normal, player->rb.to_world[1] ) < 0.7071f )
-         res_r = 0;
+      if( res_r )
+         break;
+   }
 
    v3f v0;
    v3f midpoint;
@@ -1389,15 +1184,15 @@ int skate_compute_surface_alignment( player_instance *player,
    {
       /* fallback: use the closes point to the trucks */
       v3f closest;
-      int idx = bh_closest_point( world.geo_bh, midpoint, closest, 0.1f );
+      int idx = bh_closest_point( world->geo_bh, midpoint, closest, 0.1f );
 
       if( idx != -1 )
       {
-         u32 *tri = &world.scene_geo->arrindices[ idx * 3 ];
+         u32 *tri = &world->scene_geo->arrindices[ idx * 3 ];
          v3f verts[3];
 
          for( int j=0; j<3; j++ )
-            v3_copy( world.scene_geo->arrvertices[ tri[j] ].co, verts[j] );
+            v3_copy( world->scene_geo->arrvertices[ tri[j] ].co, verts[j] );
 
          v3f vert0, vert1, n;
          v3_sub( verts[1], verts[0], vert0 );
@@ -1457,9 +1252,6 @@ VG_STATIC void skate_weight_distribute( player_instance *player )
       {
          if( reverse_dir != s->state.manual_direction )
          {
-#if 0
-            player__dead_transition( player );
-#endif
             return;
          }
       }
@@ -1474,7 +1266,6 @@ VG_STATIC void skate_weight_distribute( player_instance *player )
 
    /* TODO: Fall back on land normal */
    /* TODO: Lerp weight distribution */
-   /* TODO: Can start manual only if not charge jump */
    if( s->state.manual_direction )
    {
       v3f plane_z;
@@ -1525,10 +1316,7 @@ VG_STATIC void skate_adjust_up_direction( player_instance *player )
    }
    else
    {
-      /* FIXME UNDEFINED! */
-      vg_warn( "Undefined up target!\n" );
-
-      v3_lerp( s->state.up_dir, (v3f){0.0f,1.0f,0.0f},
+      v3_lerp( s->state.up_dir, player->basis[1],
                12.0f * s->substep_delta, s->state.up_dir );
    }
 }
@@ -1543,7 +1331,7 @@ VG_STATIC int skate_point_visible( v3f origin, v3f target )
    v3_muls( dir, 1.0f/ray.dist, dir );
    ray.dist -= 0.025f;
 
-   if( ray_world( origin, dir, &ray ) )
+   if( ray_world( get_active_world(), origin, dir, &ray ) )
       return 0;
 
    return 1;
@@ -1587,13 +1375,21 @@ VG_STATIC void skate_grind_decay( player_instance *player,
 }
 
 VG_STATIC void skate_grind_truck_apply( player_instance *player,
-                                        v3f grind_co, struct grind_info *inf,
+                                        float sign, struct grind_info *inf,
                                         float strength )
 {
    struct player_skate *s = &player->_skate;
 
+   /* TODO: Trash compactor this */
+   v3f ra = { 0.0f, -k_board_radius, sign * k_board_length };
+   v3f raw, wsp;
+   m3x3_mulv( player->rb.to_world, ra, raw );
+   v3_add( player->rb.co, raw, wsp );
+
+   v3_copy( ra, s->weight_distribution );
+
    v3f delta;
-   v3_sub( inf->co, grind_co, delta );
+   v3_sub( inf->co, wsp, delta );
 
    /* spring force */
    v3_muladds( player->rb.v, delta, k_spring_force*strength*k_rb_delta, 
@@ -1603,10 +1399,9 @@ VG_STATIC void skate_grind_truck_apply( player_instance *player,
    skate_grind_friction( player, inf, strength );
 
    /* yeah yeah yeah yeah */
-   v3f raw, axis;
-   v3_sub( grind_co, player->rb.co, raw );
-   v3_muladds( raw, inf->n, -v3_dot( inf->n, raw ), raw );
-   v3_cross( raw, inf->n, axis );
+   v3f raw_nplane, axis;
+   v3_muladds( raw, inf->n, -v3_dot( inf->n, raw ), raw_nplane );
+   v3_cross( raw_nplane, inf->n, axis );
    v3_normalize( axis );
 
    /* orientation */
@@ -1614,7 +1409,7 @@ VG_STATIC void skate_grind_truck_apply( player_instance *player,
    skate_grind_orient( inf, mtx );
    v3f target_fwd, fwd, up, target_up;
    m3x3_mulv( mtx, s->grind_vec, target_fwd );
-   v3_copy( raw, fwd );
+   v3_copy( raw_nplane, fwd );
    v3_copy( player->rb.to_world[1], up );
    v3_copy( inf->n, target_up );
 
@@ -1624,9 +1419,10 @@ VG_STATIC void skate_grind_truck_apply( player_instance *player,
    v3_normalize( target_fwd );
    v3_normalize( fwd );
 
+
    float way = player->input_js1v->axis.value *
-                  vg_signf( v3_dot( raw, player->rb.v ) );
-               
+                  vg_signf( v3_dot( raw_nplane, player->rb.v ) );
+
    v4f q;
    q_axis_angle( q, axis, VG_PIf*0.125f * way );
    q_mulv( q, target_up,  target_up );
@@ -1650,15 +1446,94 @@ VG_STATIC void skate_grind_truck_apply( player_instance *player,
 
    /* Fake contact */
    struct grind_limit *limit = &s->limits[ s->limit_count ++ ];
-   m4x3_mulv( player->rb.to_local, grind_co, limit->ra );
+   m4x3_mulv( player->rb.to_local, wsp, limit->ra );
    m3x3_mulv( player->rb.to_local, inf->n, limit->n );
    limit->p = 0.0f;
+
+   v3_copy( inf->dir, s->grind_dir );
+}
+
+VG_STATIC void skate_5050_apply( player_instance *player, 
+                                 struct grind_info *inf_front,
+                                 struct grind_info *inf_back )
+{
+   struct player_skate *s = &player->_skate;
+   struct grind_info inf_avg;
+
+   v3_sub( inf_front->co, inf_back->co, inf_avg.dir );
+   v3_muladds( inf_back->co, inf_avg.dir, 0.5f, inf_avg.co );
+   v3_normalize( inf_avg.dir );
+
+   v3f axis_front, axis_back, axis;
+   v3_cross( inf_front->dir, inf_front->n, axis_front );
+   v3_cross( inf_back->dir,  inf_back->n,  axis_back  );
+   v3_add( axis_front, axis_back, axis );
+   v3_normalize( axis );
+
+   v3_cross( axis, inf_avg.dir, inf_avg.n );
+   
+   skate_grind_decay( player, &inf_avg, 1.0f );
+
+
+   float way = player->input_js1v->axis.value *
+                  vg_signf( v3_dot( player->rb.to_world[2], player->rb.v ) );
+   v4f q;
+   v3f up, target_up;
+   v3_copy( player->rb.to_world[1], up );
+   v3_copy( inf_avg.n, target_up );
+   q_axis_angle( q, player->rb.to_world[0], VG_PIf*0.25f * -way );
+   q_mulv( q, target_up,  target_up );
+
+   v3_zero( s->weight_distribution );
+   s->weight_distribution[2] = k_board_length * -way;
+
+   rb_effect_spring_target_vector( &player->rb, up, target_up,
+                                    k_grind_spring, 
+                                    k_grind_dampener,
+                                    k_rb_delta );
+
+   v3f fwd_nplane, dir_nplane;
+   v3_muladds( player->rb.to_world[2], inf_avg.n,
+               -v3_dot( player->rb.to_world[2], inf_avg.n ), fwd_nplane );
+
+   v3f dir;
+   v3_muls( inf_avg.dir, v3_dot( fwd_nplane, inf_avg.dir ), dir );
+   v3_muladds( dir, inf_avg.n, -v3_dot( dir, inf_avg.n ), dir_nplane );
+
+   v3_normalize( fwd_nplane );
+   v3_normalize( dir_nplane );
+
+   rb_effect_spring_target_vector( &player->rb, fwd_nplane, dir_nplane,
+                                    1000.0f,
+                                    k_grind_dampener,
+                                    k_rb_delta );
+
+   v3f pos_front = { 0.0f, -k_board_radius, -1.0f * k_board_length },
+       pos_back  = { 0.0f, -k_board_radius,  1.0f * k_board_length },
+       delta_front, delta_back, delta_total;
+
+   m4x3_mulv( player->rb.to_world, pos_front, pos_front );
+   m4x3_mulv( player->rb.to_world, pos_back,  pos_back  );
+
+   v3_sub( inf_front->co, pos_front, delta_front );
+   v3_sub( inf_back->co,  pos_back, delta_back );
+   v3_add( delta_front, delta_back, delta_total );
+
+   v3_muladds( player->rb.v, delta_total, 50.0f * k_rb_delta, player->rb.v );
+
+   /* Fake contact */
+   struct grind_limit *limit = &s->limits[ s->limit_count ++ ];
+   v3_zero( limit->ra );
+   m3x3_mulv( player->rb.to_local, inf_avg.n, limit->n );
+   limit->p = 0.0f;
+
+   v3_copy( inf_avg.dir, s->grind_dir );
 }
 
-VG_STATIC int skate_grind_truck_singular( player_instance *player, float sign )
+VG_STATIC int skate_grind_truck_renew( player_instance *player, float sign,
+                                       struct grind_info *inf )
 {
    struct player_skate *s = &player->_skate;
-   struct grind_info inf;
 
    v3f wheel_co = { 0.0f, 0.0f,            sign * k_board_length },
        grind_co = { 0.0f, -k_board_radius, sign * k_board_length };
@@ -1667,34 +1542,31 @@ VG_STATIC int skate_grind_truck_singular( player_instance *player, float sign )
    m4x3_mulv( player->rb.to_world, grind_co, grind_co );
 
    /* Exit condition: lost grind tracking */
-   if( !skate_grind_scansq( grind_co, player->rb.v, 0.3f, &inf ) )
+   if( !skate_grind_scansq( player, grind_co, player->rb.v, 0.3f, inf ) )
       return 0;
 
    /* Exit condition: cant see grind target directly */
-   if( !skate_point_visible( wheel_co, inf.co ) )
+   if( !skate_point_visible( wheel_co, inf->co ) )
       return 0;
 
    /* Exit condition: minimum velocity not reached, but allow a bit of error */
-   float dv   = fabsf(v3_dot( player->rb.v, inf.dir )),
+   float dv   = fabsf(v3_dot( player->rb.v, inf->dir )),
          minv = k_grind_axel_min_vel*0.8f;
 
    if( dv < minv )
       return 0;
 
-   if( fabsf(v3_dot( inf.dir, s->grind_dir )) < k_grind_max_edge_angle )
+   if( fabsf(v3_dot( inf->dir, s->grind_dir )) < k_grind_max_edge_angle )
       return 0;
 
-   v3_copy( inf.dir, s->grind_dir );
-
-   float t = vg_clampf( (dv-minv)/(k_grind_axel_min_vel-minv), 0.0f, 1.0f );
-   skate_grind_truck_apply( player, grind_co, &inf, t );
+   v3_copy( inf->dir, s->grind_dir );
    return 1;
 }
 
-VG_STATIC int skate_truck_entry_condition( player_instance *player, float sign )
+VG_STATIC int skate_grind_truck_entry( player_instance *player, float sign,
+                                       struct grind_info *inf )
 {
    struct player_skate *s = &player->_skate;
-   struct grind_info inf;
 
    /* TODO: Trash compactor this */
    v3f ra = { 0.0f, -k_board_radius, sign * k_board_length };
@@ -1703,33 +1575,36 @@ VG_STATIC int skate_truck_entry_condition( player_instance *player, float sign )
    m3x3_mulv( player->rb.to_world, ra, raw );
    v3_add( player->rb.co, raw, wsp );
 
-   if( skate_grind_scansq( wsp, player->rb.v, 0.3, &inf ) )
+   if( skate_grind_scansq( player, wsp, player->rb.v, 0.3, inf ) )
    {
-      if( fabsf(v3_dot( player->rb.v, inf.dir )) < k_grind_axel_min_vel )
+      if( fabsf(v3_dot( player->rb.v, inf->dir )) < k_grind_axel_min_vel )
          return 0;
 
       /* velocity should be at least 60% aligned */
       v3f pv, axis;
-      v3_cross( inf.n, inf.dir, axis );
-      v3_muladds( player->rb.v, inf.n, -v3_dot( player->rb.v, inf.n ), pv );
+      v3_cross( inf->n, inf->dir, axis );
+      v3_muladds( player->rb.v, inf->n, -v3_dot( player->rb.v, inf->n ), pv );
       
       if( v3_length2( pv ) < 0.0001f )
          return 0;
       v3_normalize( pv );
 
-      if( fabsf(v3_dot( pv, inf.dir )) < k_grind_axel_max_angle )
+      if( fabsf(v3_dot( pv, inf->dir )) < k_grind_axel_max_angle )
+         return 0;
+
+      if( v3_dot( player->rb.v, inf->n ) > 0.5f )
          return 0;
 
+#if 0
       /* check for vertical alignment */
-      if( v3_dot( player->rb.to_world[1], inf.n ) < k_grind_axel_max_vangle )
+      if( v3_dot( player->rb.to_world[1], inf->n ) < k_grind_axel_max_vangle )
          return 0;
-      
-      /* TODO: new condition, opposite wheel MUST be in-air or close to it */
+#endif
       
       v3f local_co, local_dir, local_n;
-      m4x3_mulv( player->rb.to_local, inf.co,  local_co );
-      m3x3_mulv( player->rb.to_local, inf.dir, local_dir );
-      m3x3_mulv( player->rb.to_local, inf.n,   local_n );
+      m4x3_mulv( player->rb.to_local, inf->co,  local_co );
+      m3x3_mulv( player->rb.to_local, inf->dir, local_dir );
+      m3x3_mulv( player->rb.to_local, inf->n,   local_n );
 
       v2f delta = { local_co[0], local_co[2] - k_board_length*sign };
 
@@ -1740,17 +1615,8 @@ VG_STATIC int skate_truck_entry_condition( player_instance *player, float sign )
       v3_add( player->rb.v, rv, rv );
 
       if( (local_co[1] >= truck_height) &&
-          (v2_length2( delta ) <= k_board_radius*k_board_radius) &&
-          (v3_dot( rv, inf.n ) < 0.1f) )
+          (v2_length2( delta ) <= k_board_radius*k_board_radius) )
       {
-         m3x3f mtx;
-         skate_grind_orient( &inf, mtx );
-         m3x3_transpose( mtx, mtx );
-         m3x3_mulv( mtx, raw, s->grind_vec );
-         v3_normalize( s->grind_vec );
-         v3_copy( inf.dir, s->grind_dir );
-
-         skate_grind_truck_apply( player, wsp, &inf, 1.0f );
          return 1;
       }
    }
@@ -1797,31 +1663,30 @@ VG_STATIC void skate_boardslide_apply( player_instance *player,
 
    vg_line_arrow( player->rb.co, dir, 0.5f, VG__GREEN );
    vg_line_arrow( player->rb.co, perp, 0.5f, VG__BLUE );
+
+   v3_copy( inf->dir, s->grind_dir );
 }
 
-VG_STATIC int skate_boardslide_entry_condition( player_instance *player )
+VG_STATIC int skate_boardslide_entry( player_instance *player,
+                                      struct grind_info *inf )
 {
    struct player_skate *s = &player->_skate;
 
-   struct grind_info inf;
-   if( skate_grind_scansq( player->rb.co, 
+   if( skate_grind_scansq( player, player->rb.co, 
                            player->rb.to_world[0], k_board_length,
-                           &inf ) )
+                           inf ) )
    {
       v3f local_co, local_dir;
-      m4x3_mulv( player->rb.to_local, inf.co, local_co );
-      m3x3_mulv( player->rb.to_local, inf.dir, local_dir );
+      m4x3_mulv( player->rb.to_local, inf->co, local_co );
+      m3x3_mulv( player->rb.to_local, inf->dir, local_dir );
 
       if( (fabsf(local_co[2]) <= k_board_length) &&   /* within wood area */
           (local_co[1] >= 0.0f) &&                    /* at deck level */
           (fabsf(local_dir[0]) >= 0.5f) )             /* perpendicular to us */
       {
-         if( fabsf(v3_dot( player->rb.v, inf.dir )) < k_grind_axel_min_vel )
+         if( fabsf(v3_dot( player->rb.v, inf->dir )) < k_grind_axel_min_vel )
             return 0;
 
-         v3_copy( inf.dir, s->grind_dir );
-
-         skate_boardslide_apply( player, &inf );
          return 1;
       }
    }
@@ -1829,118 +1694,155 @@ VG_STATIC int skate_boardslide_entry_condition( player_instance *player )
    return 0;
 }
 
-VG_STATIC int skate_boardslide_singular( player_instance *player )
+VG_STATIC int skate_boardslide_renew( player_instance *player,
+                                      struct grind_info *inf )
 {
    struct player_skate *s = &player->_skate;
 
-   struct grind_info inf;
-   if( !skate_grind_scansq( player->rb.co, 
+   if( !skate_grind_scansq( player, player->rb.co, 
                             player->rb.to_world[0], k_board_length,
-                            &inf ) )
+                            inf ) )
       return 0;
 
    /* Exit condition: cant see grind target directly */
    v3f vis;
    v3_muladds( player->rb.co, player->rb.to_world[1], 0.2f, vis );
-   if( !skate_point_visible( vis, inf.co ) )
+   if( !skate_point_visible( vis, inf->co ) )
       return 0;
 
    /* Exit condition: minimum velocity not reached, but allow a bit of error 
     * TODO: trash compactor */
-   float dv   = fabsf(v3_dot( player->rb.v, inf.dir )),
+   float dv   = fabsf(v3_dot( player->rb.v, inf->dir )),
          minv = k_grind_axel_min_vel*0.8f;
 
    if( dv < minv )
       return 0;
 
-   if( fabsf(v3_dot( inf.dir, s->grind_dir )) < k_grind_max_edge_angle )
+   if( fabsf(v3_dot( inf->dir, s->grind_dir )) < k_grind_max_edge_angle )
       return 0;
-   v3_copy( inf.dir, s->grind_dir );
 
-   float t = vg_clampf( (dv-minv)/(k_grind_axel_min_vel-minv), 0.0f, 1.0f );
-
-   skate_boardslide_apply( player, &inf );
    return 1;
 }
 
+VG_STATIC void skate_store_grind_vec( player_instance *player,
+                                      struct grind_info *inf )
+{
+   struct player_skate *s = &player->_skate;
+
+   m3x3f mtx;
+   skate_grind_orient( inf, mtx );
+   m3x3_transpose( mtx, mtx );
+
+   v3f raw;
+   v3_sub( inf->co, player->rb.co, raw );
+
+   m3x3_mulv( mtx, raw, s->grind_vec );
+   v3_normalize( s->grind_vec );
+   v3_copy( inf->dir, s->grind_dir );
+}
+
 VG_STATIC enum skate_activity skate_availible_grind( player_instance *player )
 {
    struct player_skate *s = &player->_skate;
 
-   if( s->state.activity == k_skate_activity_grind_boardslide )
+   /* debounces this state manager a little bit */
+   if( s->frames_since_activity_change < 10 )
    {
-      int result = skate_boardslide_singular( player );
+      s->frames_since_activity_change ++;
+      return k_skate_activity_undefined;
+   }
 
-      const enum skate_activity table[] =
-      {
-         k_skate_activity_undefined,
-         k_skate_activity_grind_boardslide
-      };
+   struct grind_info inf_back50,
+                     inf_front50,
+                     inf_slide;
+
+   int res_back50  = 0,
+       res_front50 = 0,
+       res_slide   = 0;
 
-      return table[ result ];
+   if( s->state.activity == k_skate_activity_grind_boardslide )
+   {
+      res_slide = skate_boardslide_renew( player, &inf_slide );
    }
-   if( s->state.activity == k_skate_activity_grind_back50 )
+   else if( s->state.activity == k_skate_activity_grind_back50 )
    {
-      int result = skate_grind_truck_singular( player,   1.0f ),
-          front  = 0;//skate_truck_entry_condition( player, -1.0f );
-
-      const enum skate_activity table[] =
-      {                                   /* result  | front */
-         k_skate_activity_undefined,      /* 0         0     */
-         k_skate_activity_grind_front50,  /* 0         1     */
-         k_skate_activity_grind_back50,   /* 1         0     */
-         k_skate_activity_grind_5050      /* 1         1     */
-      };
-
-      return table[ result<<1 | front ];
+      res_back50  = skate_grind_truck_renew( player,  1.0f, &inf_back50 );
+      res_front50 = skate_grind_truck_entry( player, -1.0f, &inf_front50 );
    }
    else if( s->state.activity == k_skate_activity_grind_front50 )
    {
-      int result = skate_grind_truck_singular( player,   -1.0f ),
-          back   = 0;//skate_truck_entry_condition( player,   1.0f );
-
-      const enum skate_activity table[] =
-      {                                   /* result  | back  */
-         k_skate_activity_undefined,      /* 0         0     */
-         k_skate_activity_grind_back50,   /* 0         1     */
-         k_skate_activity_grind_front50,  /* 1         0     */
-         k_skate_activity_grind_5050      /* 1         1     */
-      };
-
-      return table[ result<<1 | back ];
+      res_front50 = skate_grind_truck_renew( player, -1.0f, &inf_front50 );
+      res_back50  = skate_grind_truck_entry( player,  1.0f, &inf_back50 );
    }
    else if( s->state.activity == k_skate_activity_grind_5050 )
    {
-      /* FIXME */
-      return k_skate_activity_grind_back50;
+      res_front50 = skate_grind_truck_renew( player, -1.0f, &inf_front50 );
+      res_back50  = skate_grind_truck_entry( player,  1.0f, &inf_back50 );
    }
    else
    {
-      int slide = skate_boardslide_entry_condition( player );
+      res_slide   = skate_boardslide_entry( player, &inf_slide );
+      res_back50  = skate_grind_truck_entry( player,  1.0f, &inf_back50 );
+      res_front50 = skate_grind_truck_entry( player, -1.0f, &inf_front50 );
 
-      if( slide )
-         return k_skate_activity_grind_boardslide;
+      if( res_back50 != res_front50 )
+      {
+         int wants_to_do_that = fabsf(player->input_js1v->axis.value) >= 0.25f;
 
-      int front = skate_truck_entry_condition( player,  -1.0f ),
-          back  = skate_truck_entry_condition( player,   1.0f );
+         res_back50  &= wants_to_do_that;
+         res_front50 &= wants_to_do_that;
+      }
+   }
 
-      const enum skate_activity table[] =
-      {                                   /* front   | back  */
-         k_skate_activity_undefined,      /* 0         0     */
-         k_skate_activity_grind_back50,   /* 0         1     */
-         k_skate_activity_grind_front50,  /* 1         0     */
-         k_skate_activity_grind_5050      /* 1         1     */
-      };
+   const enum skate_activity table[] =
+   {                                      /* slide | back | front */
+      k_skate_activity_undefined,         /* 0       0      0     */
+      k_skate_activity_grind_front50,     /* 0       0      1     */
+      k_skate_activity_grind_back50,      /* 0       1      0     */
+      k_skate_activity_grind_5050,        /* 0       1      1     */
 
-      return table[ front<<1 | back ];
+      /* slide has priority always */
+      k_skate_activity_grind_boardslide,  /* 1       0      0     */
+      k_skate_activity_grind_boardslide,  /* 1       0      1     */
+      k_skate_activity_grind_boardslide,  /* 1       1      0     */
+      k_skate_activity_grind_boardslide,  /* 1       1      1     */
    }
+   , new_activity = table[ res_slide << 2 | res_back50 << 1 | res_front50 ];
 
-   return 0;
+   if(      new_activity == k_skate_activity_undefined )
+   {
+      if( s->state.activity >= k_skate_activity_grind_any )
+         s->frames_since_activity_change = 0;
+   }
+   else if( new_activity == k_skate_activity_grind_boardslide )
+   {
+      skate_boardslide_apply( player, &inf_slide );
+   }
+   else if( new_activity == k_skate_activity_grind_back50 )
+   {
+      if( s->state.activity != k_skate_activity_grind_back50 )
+         skate_store_grind_vec( player, &inf_back50 );
+
+      skate_grind_truck_apply( player,  1.0f, &inf_back50, 1.0f );
+   }
+   else if( new_activity == k_skate_activity_grind_front50 )
+   {
+      if( s->state.activity != k_skate_activity_grind_front50 )
+         skate_store_grind_vec( player, &inf_front50 );
+
+      skate_grind_truck_apply( player, -1.0f, &inf_front50, 1.0f );
+   }
+   else if( new_activity == k_skate_activity_grind_5050 )
+      skate_5050_apply( player, &inf_front50, &inf_back50 );
+
+   return new_activity;
 }
 
 VG_STATIC void player__skate_update( player_instance *player )
 {
    struct player_skate *s = &player->_skate;
+   world_instance *world = get_active_world();
+
    v3_copy( player->rb.co, s->state.prev_pos );
    s->state.activity_prev = s->state.activity;
 
@@ -1949,7 +1851,6 @@ VG_STATIC void player__skate_update( player_instance *player )
       v3f   pos;
       float radius;
 
-      int   apply_angular;
       u32   colour;
 
       enum  board_collider_state
@@ -1965,27 +1866,13 @@ VG_STATIC void player__skate_update( player_instance *player )
       { 
          { 0.0f, 0.0f,    -k_board_length }, 
          .radius = k_board_radius,
-         .apply_angular = 1,
          .colour = VG__RED
       },
       { 
          { 0.0f, 0.0f,     k_board_length }, 
          .radius = k_board_radius,
-         .apply_angular = 1,
          .colour = VG__GREEN
-      },
-      { 
-         { 0.0f, 0.2f,    -k_board_length - k_board_end_radius }, 
-         .radius = k_board_end_radius,
-         .apply_angular = 0,
-         .colour = VG__YELOW
-      },
-      {  
-         { 0.0f, 0.2f,     k_board_length + k_board_end_radius },
-         .radius = k_board_end_radius,
-         .apply_angular = 0,
-         .colour = VG__YELOW
-      },
+      }
    };
 
    const int k_wheel_count = 2;
@@ -2013,31 +1900,36 @@ VG_STATIC void player__skate_update( player_instance *player )
    for( int i=0; i<2; i++ )
    {
       v3f normal, axel;
+      v3_copy( player->rb.to_world[0], axel );
+
       if( skate_compute_surface_alignment( player, wheels[i].pos, 
                                            wheels[i].colour, normal, axel ) )
       {
          rb_effect_spring_target_vector( &player->rb, player->rb.to_world[0],
                                           axel,
-                                          k_board_spring, k_board_dampener,
+                                          k_surface_spring, k_surface_dampener,
                                           s->substep_delta );
 
          v3_add( normal, s->surface_picture, s->surface_picture );
          contact_count ++;
       }
+
+      m3x3_mulv( player->rb.to_local, axel, s->truckv0[i] );
    }
 
    if( contact_count )
    {
       s->state.activity = k_skate_activity_ground;
+      s->state.gravity_bias = k_gravity;
       v3_normalize( s->surface_picture );
 
       skate_apply_friction_model( player );
       skate_weight_distribute( player );
-      skate_apply_pump_model( player );
    }
    else
    {
       s->state.activity = k_skate_activity_air;
+      v3_zero( s->weight_distribution );
       skate_apply_air_model( player );
    }
 
@@ -2060,7 +1952,7 @@ grinding:;
    skate_apply_jump_model( player );
    skate_apply_grab_model( player );
    skate_apply_trick_model( player );
-
+   skate_apply_pump_model( player );
 
 begin_collision:;
 
@@ -2090,6 +1982,13 @@ begin_collision:;
       q_mul( rotation, player->rb.q, future_q );
       q_normalize( future_q );
    }
+   else
+      v4_copy( player->rb.q, future_q );
+
+   v3f future_cg, current_cg, cg_offset;
+   q_mulv( player->rb.q, s->weight_distribution, current_cg );
+   q_mulv( future_q, s->weight_distribution, future_cg );
+   v3_sub( future_cg, current_cg, cg_offset );
 
    /* calculate the minimum time we can move */
    float max_time = s->substep;
@@ -2099,9 +1998,11 @@ begin_collision:;
       if( wheels[i].state == k_collider_state_disabled )
          continue;
 
-      v3f current, future;
+      v3f current, future, r_cg;
+      
       q_mulv( future_q, wheels[i].pos, future );
       v3_add( future, future_co, future );
+      v3_add( cg_offset, future, future );
 
       q_mulv( player->rb.q, wheels[i].pos, current );
       v3_add( current, player->rb.co, current );
@@ -2110,7 +2011,7 @@ begin_collision:;
       v3f n;
 
       float cast_radius = wheels[i].radius - k_penetration_slop * 2.0f;
-      if( spherecast_world( current, future, cast_radius, &t, n ) != -1)
+      if( spherecast_world( world, current, future, cast_radius, &t, n ) != -1)
          max_time = vg_minf( max_time, t * s->substep );
    }
 
@@ -2134,10 +2035,16 @@ begin_collision:;
       v3_divs( axis, mag, axis );
       q_axis_angle( rotation, axis, mag*s->substep_delta );
       q_mul( rotation, player->rb.q, player->rb.q );
+      q_normalize( player->rb.q );
+
+      q_mulv( player->rb.q, s->weight_distribution, future_cg );
+      v3_sub( current_cg, future_cg, cg_offset );
+      v3_add( player->rb.co, cg_offset, player->rb.co );
    }
 
    rb_update_transform( &player->rb );
-   player->rb.v[1] += -k_gravity * s->substep_delta;
+   v3_muladds( player->rb.v, player->basis[1],
+               -s->state.gravity_bias * s->substep_delta, player->rb.v );
 
    s->substep -= s->substep_delta;
 
@@ -2153,7 +2060,7 @@ begin_collision:;
    float t;
    v3f n;
    if( (v3_dist2( head_wp0, head_wp1 ) > 0.001f) &&
-       (spherecast_world( head_wp0, head_wp1, 0.2f, &t, n ) != -1) )
+       (spherecast_world( world, head_wp0, head_wp1, 0.2f, &t, n ) != -1) )
    {
       v3_lerp( start_co, player->rb.co, t, player->rb.co );
       rb_update_transform( &player->rb );
@@ -2164,9 +2071,6 @@ begin_collision:;
 
    /*
     * Phase 1: Regular collision detection
-    *          TODO: Me might want to automatically add contacts from CCD, 
-    *                since at high angular velocities, theres a small change
-    *                that discreet detection will miss.
     * --------------------------------------------------------------------------
     */
 
@@ -2187,20 +2091,6 @@ begin_collision:;
       if( l )
          wheels[i].state = k_collider_state_colliding;
 
-      /* for non-angular contacts we just want Y. contact positions are
-       * snapped to the local xz plane */
-      if( !wheels[i].apply_angular )
-      {
-         for( int j=0; j<l; j++ )
-         {
-            v3f ra;
-            v3_sub( man[j].co, player->rb.co, ra );
-
-            float dy = v3_dot( player->rb.to_world[1], ra );
-            v3_muladds( man[j].co, player->rb.to_world[1], -dy, man[j].co );
-         }
-      }
-
       manifold_len += l;
    }
 
@@ -2216,7 +2106,7 @@ begin_collision:;
 
    rb_ct *cman = &manifold[manifold_len];
 
-   int l = rb_capsule__scene( mtx, &capsule, NULL, &world.rb_geo.inf.scene,
+   int l = rb_capsule__scene( mtx, &capsule, NULL, &world->rb_geo.inf.scene,
                               cman );
 
    /* weld joints */
@@ -2245,6 +2135,11 @@ begin_collision:;
     * --------------------------------------------------------------------------
     */
 
+
+   v3f world_cog;
+   m4x3_mulv( player->rb.to_world, s->weight_distribution, world_cog );
+   vg_line_pt3( world_cog, 0.02f, VG__BLACK );
+
    for( int i=0; i<manifold_len; i ++ )
    {
       rb_prepare_contact( &manifold[i], s->substep_delta );
@@ -2276,10 +2171,6 @@ begin_collision:;
    m3x3_mul( iI, player->rb.to_local, iIw );
    m3x3_mul( player->rb.to_world, iIw, iIw );
 
-   v3f world_cog;
-   m4x3_mulv( player->rb.to_world, s->weight_distribution, world_cog );
-   vg_line_pt3( world_cog, 0.02f, VG__BLACK );
-
    for( int j=0; j<10; j++ )
    {
       for( int i=0; i<manifold_len; i++ )
@@ -2338,8 +2229,17 @@ begin_collision:;
     * --------------------------------------------------------------------------
     */
 
-   for( int i=0; i<k_wheel_count; i++ )
-   {
+   s->surface = k_surface_prop_concrete;
+
+   for( int i=0; i<manifold_len; i++ ){
+      rb_ct *ct = &manifold[i];
+      struct world_surface *surf = world_contact_surface( world, ct );
+
+      if( surf->info.surface_prop != k_surface_prop_concrete )
+         s->surface = surf->info.surface_prop;
+   }
+
+   for( int i=0; i<k_wheel_count; i++ ){
       m4x3f mtx;
       m3x3_copy( player->rb.to_world, mtx );
       m4x3_mulv( player->rb.to_world, wheels[i].pos, mtx[3] );
@@ -2349,11 +2249,12 @@ begin_collision:;
    }
 
    skate_integrate( player );
-   vg_line_pt3( s->state.cog, 0.02f,  VG__WHITE );
+   vg_line_pt3( s->state.cog, 0.02f, VG__WHITE );
 
-   teleport_gate *gate;
-   if( (gate = world_intersect_gates( player->rb.co, s->state.prev_pos )) )
-   {
+   ent_gate *gate = 
+      world_intersect_gates(world, player->rb.co, s->state.prev_pos );
+
+   if( gate ){
       m4x3_mulv( gate->transport, player->rb.co, player->rb.co );
       m3x3_mulv( gate->transport, player->rb.v,  player->rb.v );
       m4x3_mulv( gate->transport, s->state.cog,   s->state.cog );
@@ -2361,6 +2262,7 @@ begin_collision:;
       m3x3_mulv( gate->transport, s->state.throw_v, s->state.throw_v );
       m3x3_mulv( gate->transport, s->state.head_position,
                                   s->state.head_position );
+      m3x3_mulv( gate->transport, s->state.up_dir, s->state.up_dir );
 
       v4f transport_rotation;
       m3x3_q( gate->transport, transport_rotation );
@@ -2370,13 +2272,36 @@ begin_collision:;
       s->state_gate_storage = s->state;
       player__pass_gate( player, gate );
    }
+
+   /* FIXME: Rate limit */
+   static int stick_frames = 0;
+
+   if( s->state.activity == k_skate_activity_ground )
+      stick_frames ++;
+   else
+      stick_frames = 0;
+
+
+   if( stick_frames == 4 )
+   {
+      audio_lock();
+      if( (fabsf(s->state.slip) > 0.75f) )
+      {
+         audio_oneshot_3d( &audio_lands[rand()%2+3], player->rb.co, 
+                           40.0f, 1.0f );
+      }
+      else
+      {
+         audio_oneshot_3d( &audio_lands[rand()%3], player->rb.co, 
+                           40.0f, 1.0f );
+      }
+      audio_unlock();
+   }
 }
 
 VG_STATIC void player__skate_im_gui( player_instance *player )
 {
    struct player_skate *s = &player->_skate;
-
-   /* FIXME: Compression */
    player__debugtext( 1, "V:  %5.2f %5.2f %5.2f",player->rb.v[0],
                                                 player->rb.v[1],
                                                 player->rb.v[2] );
@@ -2480,11 +2405,13 @@ VG_STATIC void player__skate_animate( player_instance *player,
 
       float dirz = s->state.reverse > 0.0f? 0.0f: 1.0f,
             dirx = s->state.slip < 0.0f?    0.0f: 1.0f,
-            fly  = iair?                    1.0f: 0.0f;
+            fly  = iair?                    1.0f: 0.0f,
+            wdist= s->weight_distribution[2] / k_board_length;
 
-      s->blend_z    = vg_lerpf( s->blend_z,   dirz, 2.4f*vg.time_delta );
-      s->blend_x    = vg_lerpf( s->blend_x,   dirx, 0.6f*vg.time_delta );
-      s->blend_fly  = vg_lerpf( s->blend_fly, fly,  2.4f*vg.time_delta );
+      s->blend_z     = vg_lerpf( s->blend_z,      dirz,  2.4f*vg.time_delta );
+      s->blend_x     = vg_lerpf( s->blend_x,      dirx,  0.6f*vg.time_delta );
+      s->blend_fly   = vg_lerpf( s->blend_fly,    fly,   2.4f*vg.time_delta );
+      s->blend_weight= vg_lerpf( s->blend_weight, wdist, 9.0f*vg.time_delta );
    }
 
    mdl_keyframe apose[32], bpose[32];
@@ -2593,8 +2520,6 @@ VG_STATIC void player__skate_animate( player_instance *player,
       }
 
 
-
-
       /* angle correction */
       if( v3_length2( s->state.up_dir ) > 0.001f )
       {
@@ -2638,15 +2563,15 @@ VG_STATIC void player__skate_animate( player_instance *player,
 
 
 
-      mdl_keyframe *kf_board  = &dest->pose[av->id_board-1],
-                   *kf_foot_l = &dest->pose[av->id_ik_foot_l-1],
-                   *kf_foot_r = &dest->pose[av->id_ik_foot_r-1];
-
+      mdl_keyframe *kf_board    = &dest->pose[av->id_board-1],
+                   *kf_foot_l   = &dest->pose[av->id_ik_foot_l-1],
+                   *kf_foot_r   = &dest->pose[av->id_ik_foot_r-1],
+                   *kf_wheels[] = { &dest->pose[av->id_wheel_r-1],
+                                    &dest->pose[av->id_wheel_l-1] };
 
       v4f qtotal;
       v4f qtrickr, qyawr, qpitchr, qrollr;
       v3f eulerr;
-      
 
       v3_muls( s->board_trick_residuald, VG_TAUf, eulerr );
 
@@ -2674,6 +2599,30 @@ VG_STATIC void player__skate_animate( player_instance *player,
       q_mul( qyaw, qtrick, qtrick );
       q_mul( kf_board->q, qtrick, kf_board->q );
       q_normalize( kf_board->q );
+
+      /* foot weight distribution */
+      if( s->blend_weight > 0.0f )
+      {
+         kf_foot_l->co[2] += s->blend_weight * 0.2f;
+         kf_foot_r->co[2] += s->blend_weight * 0.1f;
+      }
+      else
+      {
+         kf_foot_r->co[2] += s->blend_weight * 0.3f;
+         kf_foot_l->co[2] += s->blend_weight * 0.1f;
+      }
+
+      /* truck rotation */
+      for( int i=0; i<2; i++ )
+      {
+         float a = vg_minf( s->truckv0[i][0], 1.0f );
+         a = -acosf( a ) * vg_signf( s->truckv0[i][1] );
+
+         v4f q;
+         q_axis_angle( q, (v3f){0.0f,0.0f,1.0f}, a );
+         q_mul( q, kf_wheels[i]->q, kf_wheels[i]->q );
+         q_normalize( kf_wheels[i]->q );
+      }
    }
 
    /* transform */
@@ -2681,24 +2630,18 @@ VG_STATIC void player__skate_animate( player_instance *player,
    v3_muladds( dest->root_co, player->rb.to_world[1], -0.1f, dest->root_co );
 
    float substep = vg_clampf( vg.accumulator / VG_TIMESTEP_FIXED, 0.0f, 1.0f );
-#if 0
-   v4f qresy, qresx, qresidual;
-   m3x3f mtx_residual;
-   q_axis_angle( qresy, player->rb.to_world[1], s->state.steery_s*substep );
-   q_axis_angle( qresx, player->rb.to_world[0], s->state.steerx_s*substep );
-
-   q_mul( qresy, qresx, qresidual );
-   q_normalize( qresidual );
-   q_mul( dest->root_q, qresidual, dest->root_q );
-   q_normalize( dest->root_q );
-#endif
 
    v4f qflip;
    if( (s->state.activity == k_skate_activity_air) &&
        (fabsf(s->state.flip_rate) > 0.01f) )
    {
-      float t = s->state.flip_time + s->state.flip_rate*substep*k_rb_delta,
-            angle = vg_clampf( t, -1.0f, 1.0f ) * VG_TAUf,
+      float t     = s->state.flip_time;
+            sign  = vg_signf( t );
+
+      t  = 1.0f - vg_minf( 1.0f, fabsf( t * 1.1f ) );
+      t  = sign * (1.0f-t*t);
+
+      float angle = vg_clampf( t, -1.0f, 1.0f ) * VG_TAUf,
             distm = s->land_dist * fabsf(s->state.flip_rate) * 3.0f,
             blend = vg_clampf( 1.0f-distm, 0.0f, 1.0f );
 
@@ -2715,6 +2658,8 @@ VG_STATIC void player__skate_animate( player_instance *player,
       q_mulv( qflip, rco, rco );
       v3_add( rco, rotation_point, dest->root_co );
    }
+
+   skeleton_copy_pose( sk, dest->pose, player->holdout_pose );
 }
 
 VG_STATIC void player__skate_post_animate( player_instance *player )
@@ -2724,7 +2669,7 @@ VG_STATIC void player__skate_post_animate( player_instance *player )
 
    player->cam_velocity_influence = 1.0f;
 
-   v3f head = { 0.0f, 1.8f, 0.0f }; /* FIXME: Viewpoint entity */
+   v3f head = { 0.0f, 1.8f, 0.0f };
    m4x3_mulv( av->sk.final_mtx[ av->id_head ], head, s->state.head_position );
    m4x3_mulv( player->rb.to_local, s->state.head_position, 
                                    s->state.head_position );
@@ -2775,13 +2720,13 @@ VG_STATIC void player__skate_clear_mechanics( player_instance *player )
 }
 
 VG_STATIC void player__skate_reset( player_instance *player,
-                                    struct respawn_point *rp )
+                                    ent_spawn *rp )
 {
    struct player_skate *s = &player->_skate;
    v3_muladds( player->rb.co, player->rb.to_world[1], 1.0f, s->state.cog );
    v3_zero( player->rb.v );
    v3_zero( s->state.cog_v );
-   v4_copy( rp->q, player->rb.q );
+   v4_copy( rp->transform.q, player->rb.q );
 
    s->state.activity = k_skate_activity_air;
    s->state.activity_prev = k_skate_activity_air;