X-Git-Url: https://harrygodden.com/git/?a=blobdiff_plain;f=player_physics.h;h=e396e0031d3771cb937a5955b73c5f13bbed2de3;hb=e591be4b2ed26bbaaea79eff64e7b6070362a6ef;hp=baaa70e919a0328ec6760fc077101c33943c9787;hpb=2ca677a0ec9d00db46a8b97bec30dbea8280a79b;p=carveJwlIkooP6JGAAIwe30JlM.git

diff --git a/player_physics.h b/player_physics.h
index baaa70e..e396e00 100644
--- a/player_physics.h
+++ b/player_physics.h
@@ -1,19 +1,14 @@
 /*
- * Copyright 2021-2022 (C) Mount0 Software, Harry Godden - All Rights Reserved
- * -----------------------------------------------------------------------------
- *
- * Player physics and control submodule
- *   contains main physics models, input, and player control.
- *
- * -----------------------------------------------------------------------------
+ * Copyright (C) 2021-2022 Mt.ZERO Software, Harry Godden - All Rights Reserved
  */
 
 #ifndef PLAYER_PHYSICS_H
 #define PLAYER_PHYSICS_H
 
 #include "player.h"
+#include "camera.h"
 
-static void apply_gravity( v3f vel, float const timestep )
+VG_STATIC void apply_gravity( v3f vel, float const timestep )
 {
    v3f gravity = { 0.0f, -9.6f, 0.0f };
    v3_muladds( vel, gravity, timestep, vel );
@@ -22,31 +17,33 @@ static void apply_gravity( v3f vel, float const timestep )
 /*
  * Called when launching into the air to predict and adjust trajectories
  */
-static void player_start_air(void)
+VG_STATIC void player_start_air(void)
 {
-   if( player.in_air )
+   struct player_phys *phys = &player.phys;
+
+   if( phys->in_air )
       return;
 
-   player.in_air = 1;
+   phys->in_air = 1;
 
-   float pstep = ktimestep*10.0f;
+   float pstep = VG_TIMESTEP_FIXED * 10.0f;
    float best_velocity_delta = -9999.9f;
    float k_bias = 0.96f;
 
    v3f axis;
-   v3_cross( player.rb.up, player.rb.v, axis );
+   v3_cross( phys->rb.up, phys->rb.v, axis );
    v3_normalize( axis );
    player.land_log_count = 0;
    
-   m3x3_identity( player.vr );
+   m3x3_identity( phys->vr );
 
    for( int m=-3;m<=12; m++ )
    {
       float vmod = ((float)m / 15.0f)*0.09f;
 
       v3f pco, pco1, pv;
-      v3_copy( player.rb.co, pco );
-      v3_muls( player.rb.v, k_bias, pv );
+      v3_copy( phys->rb.co, pco );
+      v3_muls( phys->rb.v, k_bias, pv );
 
       /* 
        * Try different 'rotations' of the velocity to find the best possible
@@ -84,7 +81,8 @@ static void player_start_air(void)
             u32 scolour = (u8)(vg_minf(-land_delta * 2.0f, 255.0f));
 
             /* Bias prediction towords ramps */
-            if( ray_hit_is_ramp( &contact ) )
+            if( ray_hit_material( &contact )->info.flags 
+                  & k_material_flag_skate_surface )
             {
                land_delta *= 0.1f;
                scolour |= 0x0000a000;
@@ -96,9 +94,9 @@ static void player_start_air(void)
 
                v3_copy( contact.pos, player.land_target );
                
-               m3x3_copy( vr, player.vr_pstep );
+               m3x3_copy( vr, phys->vr_pstep );
                q_axis_angle( vr_q, axis, vmod*0.1f );
-               q_m3x3( vr_q, player.vr );
+               q_m3x3( vr_q, phys->vr );
             }
 
             v3_copy( contact.pos, 
@@ -117,15 +115,17 @@ static void player_start_air(void)
 /*
  * Main friction interface model
  */
-static void player_physics_control(void)
+VG_STATIC void player_physics_control(void)
 {
+   struct player_phys *phys = &player.phys;
+
    /*
     * Computing localized friction forces for controlling the character
     * Friction across X is significantly more than Z
     */
 
    v3f vel;
-   m3x3_mulv( player.rb.to_local, player.rb.v, vel );
+   m3x3_mulv( phys->rb.to_local, phys->rb.v, vel );
    float slip = 0.0f;
    
    if( fabsf(vel[2]) > 0.01f )
@@ -133,75 +133,86 @@ static void player_physics_control(void)
 
    if( fabsf( slip ) > 1.2f )
       slip = vg_signf( slip ) * 1.2f;
-   player.slip = slip;
-   player.reverse = -vg_signf(vel[2]);
+   phys->slip = slip;
+   phys->reverse = -vg_signf(vel[2]);
+
+   float substep = VG_TIMESTEP_FIXED * 0.2f;
 
-   float substep = ktimestep * 0.2f;
-   float fwd_resistance = (vg_get_button( "break" )? 5.0f: 0.02f) * -substep;
+#if 0
+   float fwd_resistance = vg_get_button( "break" )? 5.0f: k_friction_resistance;
+#else
+   float fwd_resistance = k_friction_resistance;
+#endif
 
    for( int i=0; i<5; i++ )
    {
-      vel[2] = stable_force( vel[2], vg_signf( vel[2] ) * fwd_resistance );
-      vel[0] = stable_force( vel[0], 
-            vg_signf( vel[0] ) * -k_friction_lat*substep );
+      vel[2] = stable_force( vel[2],vg_signf(vel[2]) * -fwd_resistance*substep);
+      vel[0] = stable_force( vel[0],vg_signf(vel[0]) * -k_friction_lat*substep);
    }
    
-   static double start_push = 0.0;
-   if( vg_get_button_down( "push" ) )
-      start_push = vg_time;
-
-   if( vg_get_button( "jump" ) )
+   if( player.input_jump->button.value )
    {
-      player.jump += ktimestep * k_jump_charge_speed;
+      phys->jump += VG_TIMESTEP_FIXED * k_jump_charge_speed;
 
-      if( !player.jump_charge )
-         player.jump_dir = player.reverse > 0.0f? 1: 0;
+      if( !phys->jump_charge )
+         phys->jump_dir = phys->reverse > 0.0f? 1: 0;
 
-      player.jump_charge = 1;
+      phys->jump_charge = 1;
    }
 
-   if( !vg_get_button("break") && vg_get_button( "push" ) )
+   static int push_thresh_last = 0;
+   float push = player.input_push->button.value;
+   int push_thresh = push>0.15f? 1: 0;
+   
+   if( push_thresh && !push_thresh_last )
+      player.phys.start_push = vg.time;
+
+   push_thresh_last = push_thresh;
+
+   if( !player.input_jump->button.value && push_thresh )
    {
-      player.pushing = 1.0f;
-      player.push_time = vg_time-start_push;
+      player.phys.pushing = 1.0f;
+      player.phys.push_time = vg.time - player.phys.start_push;
 
-      float cycle_time = player.push_time*k_push_cycle_rate,
-            amt = k_push_accel * (sinf(cycle_time)*0.5f+0.5f)*ktimestep,
+      float cycle_time = player.phys.push_time*k_push_cycle_rate,
+            amt = k_push_accel * (sinf(cycle_time)*0.5f+0.5f)*VG_TIMESTEP_FIXED,
             current = v3_length( vel ),
             new_vel = vg_minf( current + amt, k_max_push_speed );
 
       new_vel -= vg_minf(current, k_max_push_speed);
-      vel[2] -= new_vel * player.reverse;
+      vel[2] -= new_vel * phys->reverse;
    }
 
    /* Pumping */
    static float previous = 0.0f;
-   float delta = previous - player.grab,
-          pump = delta * k_pump_force*ktimestep;
-   previous = player.grab;
+   float delta = previous - phys->grab,
+          pump = delta * k_pump_force * VG_TIMESTEP_FIXED;
+   previous = phys->grab;
 
    v3f p1;
-   v3_muladds( player.rb.co, player.rb.up, pump, p1 );
-   vg_line( player.rb.co, p1, 0xff0000ff );
+   v3_muladds( phys->rb.co, phys->rb.up, pump, p1 );
+   vg_line( phys->rb.co, p1, 0xff0000ff );
 
    vel[1] += pump;
 
+   m3x3_mulv( phys->rb.to_world, vel, phys->rb.v );
    
-   m3x3_mulv( player.rb.to_world, vel, player.rb.v );
-   
-   float steer = vg_get_axis( "horizontal" );
-   player.iY -= vg_signf(steer)*powf(steer,2.0f) * k_steer_ground * ktimestep;
-   
-   v2_lerp( player.board_xy, (v2f){ slip*0.25f, 0.0f }, 
-         ktimestep*5.0f, player.board_xy);
+   float input = player.input_js1h->axis.value,
+         grab  = player.input_grab->axis.value,
+         steer = input * (1.0f-(phys->jump+grab)*0.4f),
+         steer_scaled = vg_signf(steer) * powf(steer,2.0f) * k_steer_ground;
+
+   phys->iY -= steer_scaled * VG_TIMESTEP_FIXED;
 }
 
 /*
  * Air control, no real physics
  */
-static void player_physics_control_air(void)
+VG_STATIC void player_physics_control_air(void)
 {
-   m3x3_mulv( player.vr, player.rb.v, player.rb.v );
+   struct player_phys *phys = &player.phys;
+
+   m3x3_mulv( phys->vr, phys->rb.v, phys->rb.v );
    vg_line_cross( player.land_target, 0xff0000ff, 0.25f );
 
    ray_hit hit;
@@ -209,11 +220,11 @@ static void player_physics_control_air(void)
    /* 
     * Prediction 
     */
-   float pstep = ktimestep*10.0f;
+   float pstep = VG_TIMESTEP_FIXED * 10.0f;
 
    v3f pco, pco1, pv;
-   v3_copy( player.rb.co, pco );
-   v3_copy( player.rb.v, pv );
+   v3_copy( phys->rb.co, pco );
+   v3_copy( phys->rb.v, pv );
    
    float time_to_impact = 0.0f;
    float limiter = 1.0f;
@@ -221,7 +232,7 @@ static void player_physics_control_air(void)
    for( int i=0; i<50; i++ )
    {
       v3_copy( pco, pco1 );
-      m3x3_mulv( player.vr_pstep, pv, pv );
+      m3x3_mulv( phys->vr_pstep, pv, pv );
       apply_gravity( pv, pstep );
       v3_muladds( pco, pv, pstep, pco );
       
@@ -235,9 +246,9 @@ static void player_physics_control_air(void)
       float orig_dist = contact.dist;
       if( ray_world( pco1, vdir, &contact ))
       {
-         float angle = v3_dot( player.rb.up, contact.normal );
+         float angle = v3_dot( phys->rb.up, contact.normal );
          v3f axis; 
-         v3_cross( player.rb.up, contact.normal, axis );
+         v3_cross( phys->rb.up, contact.normal, axis );
 
          time_to_impact += (contact.dist/orig_dist)*pstep;
          limiter = vg_minf( 5.0f, time_to_impact )/5.0f;
@@ -248,8 +259,9 @@ static void player_physics_control_air(void)
          if( angle < 0.99f )
          {
             v4f correction;
-            q_axis_angle( correction, axis, acosf(angle)*0.05f*(1.0f-limiter) );
-            q_mul( correction, player.rb.q, player.rb.q );
+            q_axis_angle( correction, axis, 
+                  acosf(angle)*(1.0f-limiter)*3.0f*VG_TIMESTEP_FIXED );
+            q_mul( correction, phys->rb.q, phys->rb.q );
          }
 
          vg_line_cross( contact.pos, 0xffff0000, 0.25f );
@@ -258,142 +270,259 @@ static void player_physics_control_air(void)
       time_to_impact += pstep;
    }
 
-   player.iY -= vg_get_axis( "horizontal" ) * k_steer_air * ktimestep;
-   {
-      float iX = vg_get_axis( "vertical" ) * 
-         player.reverse * k_steer_air * limiter * ktimestep;
+   v2f steer = { player.input_js1h->axis.value,
+                 player.input_js1v->axis.value };
 
-      static float siX = 0.0f;
-      siX = vg_lerpf( siX, iX, k_steer_air_lerp );
-      
-      v4f rotate;
-      q_axis_angle( rotate, player.rb.right, siX );
-      q_mul( rotate, player.rb.q, player.rb.q );
-   }
+   float l2 = v2_length2( steer );
+   if( l2 > 1.0f )
+      v2_muls( steer, 1.0f/sqrtf(l2), steer );
+
+   phys->iY -= steer[0] * k_steer_air * VG_TIMESTEP_FIXED;
+
+   float iX = steer[1] * 
+              phys->reverse * k_steer_air * limiter * VG_TIMESTEP_FIXED;
+
+   static float siX = 0.0f;
+   siX = vg_lerpf( siX, iX, k_steer_air_lerp );
    
+   v4f rotate;
+   q_axis_angle( rotate, phys->rb.right, siX );
+   q_mul( rotate, phys->rb.q, phys->rb.q );
+   
+#if 0
    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 );
+   v2_muladds( target, (v2f){ vg_get_axis("grabh"), vg_get_axis("grabv") },
+               phys->grab, target );
+#endif
 }
 
-/*
- * Entire Walking physics model
- * TODO: sleep when under certain velotiy
- */
-static void player_walk_physics(void)
+VG_STATIC void player_walk_update_collision(void)
 {
-   rigidbody *rbf = &player.collide_front,
-             *rbb = &player.collide_back;
-
-   m3x3_copy( player.rb.to_world, player.collide_front.to_world );
-   m3x3_copy( player.rb.to_world, player.collide_back.to_world );
-   
+   struct player_phys *phys = &player.phys;
    float h0 = 0.3f,
          h1 = 0.9f;
 
-   m4x3_mulv( player.rb.to_world, (v3f){0.0f,h0,0.0f}, rbf->co );
+   rigidbody *rbf = &player.collide_front,
+             *rbb = &player.collide_back;
+
+   v3_add( phys->rb.co, (v3f){0.0f,h0,0.0f}, rbf->co );
+   v3_add( phys->rb.co, (v3f){0.0f,h1,0.0f}, rbb->co );
    v3_copy( rbf->co, rbf->to_world[3] );
-   m4x3_mulv( player.rb.to_world, (v3f){0.0f,h1,0.0f}, rbb->co );
    v3_copy( rbb->co, rbb->to_world[3] );
-
    m4x3_invert_affine( rbf->to_world, rbf->to_local );
    m4x3_invert_affine( rbb->to_world, rbb->to_local );
 
    rb_update_bounds( rbf );
    rb_update_bounds( rbb );
+}
+
+VG_STATIC void player_integrate(void);
+/*
+ * Entire Walking physics model
+ * TODO: sleep when under certain velotiy
+ */
+VG_STATIC void player_walk_physics(void)
+{
+   struct player_phys *phys = &player.phys;
+   rigidbody *rbf = &player.collide_front,
+             *rbb = &player.collide_back;
 
-   rb_debug( rbf, 0xff0000ff );
-   rb_debug( rbb, 0xff0000ff );
+   m3x3_identity( player.collide_front.to_world );
+   m3x3_identity( player.collide_back.to_world );
+
+   v3_zero( phys->rb.w );
+   q_axis_angle( phys->rb.q, (v3f){0.0f,1.0f,0.0f}, -player.angles[0] );
 
    rb_ct manifold[64];
-   int len = 0;
+   int len;
 
-   len += rb_sphere_scene( rbf, &world.rb_geo, manifold+len );
-   len += rb_sphere_scene( rbb, &world.rb_geo, manifold+len );
+   v3f forward_dir = { sinf(player.angles[0]),0.0f,-cosf(player.angles[0]) };
+   v3f right_dir = { -forward_dir[2], 0.0f, forward_dir[0] };
 
-   rb_presolve_contacts( manifold, len );
+   v2f walk = { player.input_walkh->axis.value,
+                player.input_walkv->axis.value };
+   
+   if( v2_length2(walk) > 0.001f )
+      v2_normalize_clamp( walk );
 
-   for( int j=0; j<5; j++ )
+   if( phys->in_air )
    {
+      player_walk_update_collision();
+      rb_debug( rbf, 0xff0000ff );
+      rb_debug( rbb, 0xff0000ff );
+
+      /* allow player to accelerate a bit */
+      v3f walk_3d;
+      v3_muls( forward_dir, walk[1], walk_3d );
+      v3_muladds( walk_3d, right_dir, walk[0], walk_3d );
+
+      float current_vel = fabsf(v3_dot( walk_3d, phys->rb.v )),
+            new_vel     = current_vel + VG_TIMESTEP_FIXED*k_air_accelerate,
+            clamped_new = vg_clampf( new_vel, 0.0f, k_walkspeed ),
+            vel_diff    = vg_maxf( 0.0f, clamped_new - current_vel );
+
+      v3_muladds( phys->rb.v, right_dir,   walk[0] * vel_diff, phys->rb.v );
+      v3_muladds( phys->rb.v, forward_dir, walk[1] * vel_diff, phys->rb.v );
+
+
+      len = 0;
+      len += rb_sphere_scene( rbf, &world.rb_geo, manifold+len );
+      len += rb_sphere_scene( rbb, &world.rb_geo, manifold+len );
+      rb_presolve_contacts( manifold, len );
+
       for( int i=0; i<len; i++ )
       {
          struct contact *ct = &manifold[i];
-         
-         /*normal */
-         float vn = -v3_dot( player.rb.v, ct->n );
-         vn += ct->bias;
+         if( v3_dot( ct->n, (v3f){0.0f,1.0f,0.0f} ) > 0.5f )
+            phys->in_air = 0;
+      }
 
-         float temp = ct->norm_impulse;
-         ct->norm_impulse = vg_maxf( temp + vn, 0.0f );
-         vn = ct->norm_impulse - temp;
+      for( int j=0; j<5; j++ )
+      {
+         for( int i=0; i<len; i++ )
+         {
+            struct contact *ct = &manifold[i];
+            
+            /*normal */
+            float vn = -v3_dot( phys->rb.v, ct->n );
+            vn += ct->bias;
 
-         v3f impulse;
-         v3_muls( ct->n, vn, impulse );
+            float temp = ct->norm_impulse;
+            ct->norm_impulse = vg_maxf( temp + vn, 0.0f );
+            vn = ct->norm_impulse - temp;
 
-         v3_add( impulse, player.rb.v, player.rb.v );
+            v3f impulse;
+            v3_muls( ct->n, vn, impulse );
 
-         /* friction */
-         for( int j=0; j<2; j++ )
-         {
-            float     f = k_friction * ct->norm_impulse,
-                     vt = v3_dot( player.rb.v, ct->t[j] ),
-                 lambda = -vt;
-            
-            float temp = ct->tangent_impulse[j];
-            ct->tangent_impulse[j] = vg_clampf( temp + lambda, -f, f );
-            lambda = ct->tangent_impulse[j] - temp;
+            v3_add( impulse, phys->rb.v, phys->rb.v );
 
-            v3_muladds( player.rb.v, ct->t[j], lambda, player.rb.v );
+            /* friction */
+            for( int j=0; j<2; j++ )
+            {
+               float     f = k_friction * ct->norm_impulse,
+                        vt = v3_dot( phys->rb.v, ct->t[j] ),
+                    lambda = -vt;
+               
+               float temp = ct->tangent_impulse[j];
+               ct->tangent_impulse[j] = vg_clampf( temp + lambda, -f, f );
+               lambda = ct->tangent_impulse[j] - temp;
+
+               v3_muladds( phys->rb.v, ct->t[j], lambda, phys->rb.v );
+            }
          }
       }
+
+      player_integrate();
    }
+   else
+   {
+      player.walk = v2_length( walk );
 
-   player.in_air = len==0?1:0;
-   
-   v3_zero( player.rb.w );
-   q_axis_angle( player.rb.q, (v3f){0.0f,1.0f,0.0f}, -player.angles[0] );
+      if( player.input_walk->button.value )
+         v2_muls( walk, 0.5f, walk );
 
-   v3f forward_dir = { sinf(player.angles[0]),0.0f,-cosf(player.angles[0]) };
+      v2_muls( walk, k_walkspeed * VG_TIMESTEP_FIXED, walk );
 
-   v3f p1;
-   v3_muladds( player.rb.co, forward_dir, 2.0f, p1 );
-   vg_line( player.rb.co, p1, 0xff0000ff );
+      v3f walk_apply;
+      v3_zero( walk_apply );
 
-   float move_dead = 0.1f,
-         move = vg_get_axis("grabr")*0.5f + 0.5f - move_dead;
+      /* Do XY translation */
+      v3_muladds( walk_apply, right_dir,   walk[0], walk_apply );
+      v3_muladds( walk_apply, forward_dir, walk[1], walk_apply );
+      v3_add( walk_apply, phys->rb.co, phys->rb.co );
+      v3_divs( walk_apply, VG_TIMESTEP_FIXED, phys->rb.v );
 
-   if( move > 0.0f )
-   {
-      float move_norm = move * (1.0f/(1.0f-move_dead)),
-            speed     = vg_lerpf( 0.1f*k_runspeed, k_runspeed, move_norm ),
-            amt       = k_walk_accel * ktimestep,
-            zvel      = v3_dot( player.rb.v, forward_dir ),
-            new_vel   = vg_minf( zvel + amt, speed ),
-            diff      = new_vel - vg_minf( zvel, speed );
+      /* Directly resolve collisions */
+      player_walk_update_collision();
+      rb_debug( rbf, 0xffffff00 );
+      rb_debug( rbb, 0xffffff00 );
 
-      v3_muladds( player.rb.v, forward_dir, diff, player.rb.v );
+      len = 0;
+      len += rb_sphere_scene( rbf, &world.rb_geo, manifold+len );
+      len += rb_sphere_scene( rbb, &world.rb_geo, manifold+len );
 
-      /* TODO move */
-      float walk_norm = 30.0f/(float)player.mdl.anim_walk->length,
-            run_norm  = 30.0f/(float)player.mdl.anim_run->length ;
+      v3f dt;
+      v3_zero( dt );
+      for( int j=0; j<3; j++ )
+      {
+         for( int i=0; i<len; i++ )
+         {
+            struct contact *ct = &manifold[i];
 
-      player.walk_timer += ktimestep * vg_lerpf( walk_norm,run_norm,move_norm );
-   }
-   else
-   {
-      player.walk_timer = 0.0f;
-   }
+            float p   = vg_maxf( 0.0f, ct->p - 0.00f ),
+                  cur = vg_clampf( v3_dot( ct->n, dt ), 0.0f, p );
+            v3_muladds( dt, ct->n, (p - cur) * 0.333333333f, dt );
+         }
+      }
+      v3_add( dt, phys->rb.co, phys->rb.co );
+
+      if( len )
+      {
+         struct world_material *surface_mat = world_contact_material(manifold);
+         player.surface_prop = surface_mat->info.surface_prop;
+      }
 
-   player.rb.v[0] *= 1.0f - (ktimestep*k_walk_friction);
-   player.rb.v[2] *= 1.0f - (ktimestep*k_walk_friction);
+      /* jump */
+      if( player.input_jump->button.value )
+      {
+         phys->rb.v[1] = 5.0f;
+         phys->in_air = 1;
+         return;
+      }
+      
+      /* if we've put us in the air, step down slowly */
+      phys->in_air = 1;
+      float max_dist = 0.3f,
+            start_y = phys->rb.co[1];
+
+      for( int j=0; j<8; j++ )
+      {
+         for( int i=0; i<len; i++ )
+         {
+            struct contact *ct = &manifold[i];
+            if( v3_dot( ct->n, (v3f){0.0f,1.0f,0.0f} ) > 0.5f )
+            {
+               phys->in_air = 0;
+               if( j == 0 )
+                  return;
+
+               v3f dt;
+               v3_zero( dt );
+               for( int j=0; j<3; j++ )
+               {
+                  for( int i=0; i<len; i++ )
+                  {
+                     struct contact *ct = &manifold[i];
+
+                     float p   = vg_maxf( 0.0f, ct->p - 0.0025f ),
+                           cur = vg_clampf( v3_dot( ct->n, dt ), 0.0f, p );
+                     v3_muladds( dt, ct->n, (p - cur) * 0.333333333f, dt );
+                  }
+               }
+               v3_add( dt, phys->rb.co, phys->rb.co );
+               return;
+            }
+         }
+
+         phys->rb.co[1] -= max_dist * 0.125f;
+
+         player_walk_update_collision();
+         len = 0;
+         len += rb_sphere_scene( rbf, &world.rb_geo, manifold+len );
+         len += rb_sphere_scene( rbb, &world.rb_geo, manifold+len );
+      }
+      
+      /* Transitioning into air mode */
+      phys->rb.co[1] = start_y;
+   }
 }
 
 /*
  * Physics collision detection, and control
  */
-static void player_physics(void)
+VG_STATIC void player_physics(void)
 {
+   struct player_phys *phys = &player.phys;
    /*
     * Update collision fronts
     */
@@ -401,15 +530,15 @@ static void player_physics(void)
    rigidbody *rbf = &player.collide_front,
              *rbb = &player.collide_back;
 
-   m3x3_copy( player.rb.to_world, player.collide_front.to_world );
-   m3x3_copy( player.rb.to_world, player.collide_back.to_world );
+   m3x3_copy( phys->rb.to_world, player.collide_front.to_world );
+   m3x3_copy( phys->rb.to_world, player.collide_back.to_world );
    
-   player.air_blend = vg_lerpf( player.air_blend, player.in_air, 0.1f );
+   player.air_blend = vg_lerpf( player.air_blend, phys->in_air, 0.1f );
    float h = player.air_blend*0.2f;
 
-   m4x3_mulv( player.rb.to_world, (v3f){0.0f,h,-k_board_length}, rbf->co );
+   m4x3_mulv( phys->rb.to_world, (v3f){0.0f,h,-k_board_length}, rbf->co );
    v3_copy( rbf->co, rbf->to_world[3] );
-   m4x3_mulv( player.rb.to_world, (v3f){0.0f,h, k_board_length}, rbb->co );
+   m4x3_mulv( phys->rb.to_world, (v3f){0.0f,h, k_board_length}, rbb->co );
    v3_copy( rbb->co, rbb->to_world[3] );
 
    m4x3_invert_affine( rbf->to_world, rbf->to_local );
@@ -427,6 +556,27 @@ static void player_physics(void)
    len += rb_sphere_scene( rbf, &world.rb_geo, manifold+len );
    len += rb_sphere_scene( rbb, &world.rb_geo, manifold+len );
 
+   /* 
+    * Preprocess collision points, and create a surface picture.
+    * we want contacts that are within our 'capsule's internal line to be 
+    * clamped so that they face the line and do not oppose, to stop the
+    * player hanging up on stuff
+    */
+   for( int i=0; i<len; i++ )
+   {
+      v3f dfront, dback;
+      v3_sub( manifold[i].co, rbf->co, dfront );
+      v3_sub( manifold[i].co, rbb->co, dback );
+
+      if( (v3_dot( dfront, phys->rb.forward ) < -0.02f) &&
+          (v3_dot( dback,  phys->rb.forward ) > 0.02f))
+      {
+         float p = v3_dot( manifold[i].n, phys->rb.forward );
+         v3_muladds( manifold[i].n, phys->rb.forward, -p, manifold[i].n );
+         v3_normalize( manifold[i].n );
+      }
+   }
+
    rb_presolve_contacts( manifold, len );
    v3f surface_avg = {0.0f, 0.0f, 0.0f};
 
@@ -443,12 +593,14 @@ static void player_physics(void)
 
       v3_normalize( surface_avg );
 
-      if( v3_dot( player.rb.v, surface_avg ) > 0.5f )
+      if( v3_dot( phys->rb.v, surface_avg ) > 0.5f )
       {
          player_start_air();
       }
       else
-         player.in_air = 0;
+      {
+         phys->in_air = 0;
+      }
    }
 
    for( int j=0; j<5; j++ )
@@ -458,9 +610,9 @@ static void player_physics(void)
          struct contact *ct = &manifold[i];
          
          v3f dv, delta;
-         v3_sub( ct->co, player.rb.co, delta ); 
-         v3_cross( player.rb.w, delta, dv );
-         v3_add( player.rb.v, dv, dv );
+         v3_sub( ct->co, phys->rb.co, delta ); 
+         v3_cross( phys->rb.w, delta, dv );
+         v3_add( phys->rb.v, dv, dv );
 
          float vn = -v3_dot( dv, ct->n );
          vn += ct->bias;
@@ -472,14 +624,14 @@ static void player_physics(void)
          v3f impulse;
          v3_muls( ct->n, vn, impulse );
 
-         if( fabsf(v3_dot( impulse, player.rb.forward )) > 10.0f ||
-             fabsf(v3_dot( impulse, player.rb.up )) > 50.0f )
+         if( fabsf(v3_dot( impulse, phys->rb.forward )) > 10.0f ||
+             fabsf(v3_dot( impulse, phys->rb.up )) > 50.0f )
          {
             player_kill();
             return;
          }
 
-         v3_add( impulse, player.rb.v, player.rb.v );
+         v3_add( impulse, phys->rb.v, phys->rb.v );
          v3_cross( delta, impulse, impulse );
 
          /*
@@ -490,65 +642,86 @@ static void player_physics(void)
           * components.
           */
          
-         float wy = v3_dot( player.rb.up, impulse ),
-               wx = v3_dot( player.rb.right, impulse )*1.5f;
+         float wy = v3_dot( phys->rb.up, impulse ),
+               wx = v3_dot( phys->rb.right, impulse )*1.5f;
 
-         v3_muladds( player.rb.w, player.rb.up, wy, player.rb.w );
-         v3_muladds( player.rb.w, player.rb.right, wx, player.rb.w );
+         v3_muladds( phys->rb.w, phys->rb.up, wy, phys->rb.w );
+         v3_muladds( phys->rb.w, phys->rb.right, wx, phys->rb.w );
       }
    }
 
-   float grabt = vg_get_axis( "grabr" )*0.5f+0.5f;
-   player.grab = vg_lerpf( player.grab, grabt, 0.14f );
-   player.pushing = 0.0f;
+   float grabt = player.input_grab->axis.value;
 
-   if( !player.in_air )
+   if( grabt > 0.5f )
    {
-      v3f axis;
-      float angle = v3_dot( player.rb.up, surface_avg );
-      v3_cross( player.rb.up, surface_avg, axis );
+      v2_muladds( phys->grab_mouse_delta, vg.mouse_delta, 0.02f, 
+                  phys->grab_mouse_delta );
+      v2_normalize_clamp( phys->grab_mouse_delta );
+   }
+   else
+      v2_zero( phys->grab_mouse_delta );
+
+   phys->grab = vg_lerpf( phys->grab, grabt, 0.14f );
+   player.phys.pushing = 0.0f;
+
+   if( !phys->in_air )
+   {
+      /* 20/10/22: make this only go axisways instead, may effect velocities. */
+
+      v3f projected, axis;
+
+      float d = v3_dot( phys->rb.forward, surface_avg );
+      v3_muladds( surface_avg, phys->rb.forward, -d, projected );
+      v3_normalize( projected );
+
+      float angle = v3_dot( phys->rb.up, projected );
+      v3_cross( phys->rb.up, projected, axis );
 
-      //float cz = v3_dot( player.rb.forward, axis );
-      //v3_muls( player.rb.forward, cz, axis );
+      v3f p0, p1;
+      v3_add( phys->rb.co, projected, p0 );
+      v3_add( phys->rb.co, phys->rb.up, p1 );
+      vg_line( phys->rb.co, p0, 0xff00ff00 );
+      vg_line( phys->rb.co, p1, 0xff000fff );
 
-      if( angle < 0.999f )
+      if( fabsf(angle) < 0.999f )
       {
          v4f correction;
-         q_axis_angle( correction, axis, acosf(angle)*0.3f );
-         q_mul( correction, player.rb.q, player.rb.q );
+         q_axis_angle( correction, axis, acosf(angle)*4.0f*VG_TIMESTEP_FIXED );
+         q_mul( correction, phys->rb.q, phys->rb.q );
       }
 
-      v3_muladds( player.rb.v, player.rb.up, 
-            -k_downforce*ktimestep, player.rb.v );
+      float const DOWNFORCE = -k_downforce*VG_TIMESTEP_FIXED;
+      v3_muladds( phys->rb.v, phys->rb.up, DOWNFORCE, phys->rb.v );
 
       player_physics_control();
 
-      if( !player.jump_charge && player.jump > 0.2f )
+      if( !phys->jump_charge && phys->jump > 0.2f )
       {
          v3f jumpdir;
          
          /* Launch more up if alignment is up else improve velocity */
-         float aup = fabsf(v3_dot( (v3f){0.0f,1.0f,0.0f}, player.rb.up )),
+         float aup = fabsf(v3_dot( (v3f){0.0f,1.0f,0.0f}, phys->rb.up )),
                mod = 0.5f,
                dir = mod + aup*(1.0f-mod);
 
-         v3_copy( player.rb.v, jumpdir );
+         v3_copy( phys->rb.v, jumpdir );
          v3_normalize( jumpdir );
          v3_muls( jumpdir, 1.0f-dir, jumpdir );
-         v3_muladds( jumpdir, player.rb.up, dir, jumpdir );
+         v3_muladds( jumpdir, phys->rb.up, dir, jumpdir );
          v3_normalize( jumpdir );
          
-         float force = k_jump_force*player.jump;
-         v3_muladds( player.rb.v, jumpdir, force, player.rb.v );
-         player.jump = 0.0f;
-
-         player.jump_time = vg_time;
+         float force = k_jump_force*phys->jump;
+         v3_muladds( phys->rb.v, jumpdir, force, phys->rb.v );
+         phys->jump = 0.0f;
 
+         player.jump_time = vg.time;
+         
+         /* TODO: Move to audio file */
          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_position( &audio_player_extra, phys->rb.co );
          audio_player_set_vol( &audio_player_extra, 20.0f );
-         audio_player_playclip( &audio_player_extra, &audio_jumps[rand()%4] );
+         audio_player_playclip( &audio_player_extra, &audio_jumps[rand()%2] );
          audio_unlock();
       }
    }
@@ -557,83 +730,113 @@ static void player_physics(void)
       player_physics_control_air();
    }
 
-   if( !player.jump_charge )
+   if( !phys->jump_charge )
    {
-      player.jump -= k_jump_charge_speed * ktimestep;
+      phys->jump -= k_jump_charge_speed * VG_TIMESTEP_FIXED;
    }
-   player.jump_charge = 0;
-   player.jump = vg_clampf( player.jump, 0.0f, 1.0f );
+
+   phys->jump_charge = 0;
+   phys->jump = vg_clampf( phys->jump, 0.0f, 1.0f );
+}
+
+VG_STATIC void player_save_frame(void)
+{
+   player.phys_gate_frame = player.phys;
+}
+
+VG_STATIC void player_restore_frame(void)
+{
+   player.phys = player.phys_gate_frame;
+   rb_update_transform( &player.phys.rb );
+}
+
+VG_STATIC void player_integrate(void)
+{
+   struct player_phys *phys = &player.phys;
+   apply_gravity( phys->rb.v, VG_TIMESTEP_FIXED );
+   v3_muladds( phys->rb.co, phys->rb.v, VG_TIMESTEP_FIXED, phys->rb.co );
 }
 
-static void player_do_motion(void)
+VG_STATIC void player_do_motion(void)
 {
-   float horizontal = vg_get_axis("horizontal"),
-         vertical = vg_get_axis("vertical");
+   struct player_phys *phys = &player.phys;
+
+   if( world.water.enabled )
+   {
+      if( (phys->rb.co[1] < 0.0f) && !player.is_dead )
+      {
+         audio_lock();
+         audio_player_set_flags( &audio_player_extra, AUDIO_FLAG_SPACIAL_3D );
+         audio_player_set_position( &audio_player_extra, phys->rb.co );
+         audio_player_set_vol( &audio_player_extra, 20.0f );
+         audio_player_playclip( &audio_player_extra, &audio_splash );
+         audio_unlock();
+
+         player_kill();
+      }
+   }
 
-   if( player.on_board )
+
+   v3f prevco;
+   v3_copy( phys->rb.co, prevco );
+
+   if( phys->on_board )
+   {
       player_physics();
+      player_integrate();
+   }
    else
       player_walk_physics();
    
-   /* Integrate velocity */
-   v3f prevco;
-   v3_copy( player.rb.co, prevco );
    
-   apply_gravity( player.rb.v, ktimestep );
-   v3_muladds( player.rb.co, player.rb.v, ktimestep, player.rb.co );
-
    /* Real angular velocity integration */
-   v3_lerp( player.rb.w, (v3f){0.0f,0.0f,0.0f}, 0.125f, player.rb.w );
-   if( v3_length2( player.rb.w ) > 0.0f )
+   v3_lerp( phys->rb.w, (v3f){0.0f,0.0f,0.0f}, 0.125f, phys->rb.w );
+   if( v3_length2( phys->rb.w ) > 0.0f )
    {
       v4f rotation;
       v3f axis;
-      v3_copy( player.rb.w, axis );
+      v3_copy( phys->rb.w, axis );
       
       float mag = v3_length( axis );
       v3_divs( axis, mag, axis );
       q_axis_angle( rotation, axis, mag*k_rb_delta );
-      q_mul( rotation, player.rb.q, player.rb.q );
+      q_mul( rotation, phys->rb.q, phys->rb.q );
    }
 
    /* Faux angular velocity */
    v4f rotate; 
 
-   static float siY = 0.0f;
-   float lerpq = player.in_air? 0.04f: 0.3f;
-   siY = vg_lerpf( siY, player.iY, lerpq );
+   float lerpq = phys->in_air? 0.04f: 0.3f;
+   phys->siY = vg_lerpf( phys->siY, phys->iY, lerpq );
 
-   q_axis_angle( rotate, player.rb.up, siY );
-   q_mul( rotate, player.rb.q, player.rb.q );
-   player.iY = 0.0f;
+   q_axis_angle( rotate, phys->rb.up, phys->siY );
+   q_mul( rotate, phys->rb.q, phys->rb.q );
+   phys->iY = 0.0f;
 
    /* 
     * Gate intersection, by tracing a line over the gate planes 
     */
-   for( int i=0; i<world.routes.gate_count; i++ )
+   for( int i=0; i<world.gate_count; i++ )
    {
-      struct route_gate *rg = &world.routes.gates[i];
+      struct route_gate *rg = &world.gates[i];
       teleport_gate *gate = &rg->gate;
 
-      if( gate_intersect( gate, player.rb.co, prevco ) )
+      if( gate_intersect( gate, phys->rb.co, prevco ) )
       {
-         m4x3_mulv( gate->transport, player.rb.co, player.rb.co );
-         m3x3_mulv( gate->transport, player.rb.v, player.rb.v );
-         m3x3_mulv( gate->transport, player.vl, player.vl );
-         m3x3_mulv( gate->transport, player.v_last, player.v_last );
-         m3x3_mulv( gate->transport, player.m, player.m );
-         m3x3_mulv( gate->transport, player.bob, player.bob );
+         m4x3_mulv( gate->transport, phys->rb.co, phys->rb.co );
+         m3x3_mulv( gate->transport, phys->rb.v, phys->rb.v );
+         m3x3_mulv( gate->transport, phys->vl, phys->vl );
+         m3x3_mulv( gate->transport, phys->v_last, phys->v_last );
+         m3x3_mulv( gate->transport, phys->m, phys->m );
+         m3x3_mulv( gate->transport, phys->bob, phys->bob );
 
          v4f transport_rotation;
          m3x3_q( gate->transport, transport_rotation );
-         q_mul( transport_rotation, player.rb.q, player.rb.q );
+         q_mul( transport_rotation, phys->rb.q, phys->rb.q );
          
          world_routes_activate_gate( i );
-         player.rb_gate_frame = player.rb;
-         player.in_air_frame = player.in_air;
-         player.on_board_frame = player.on_board;
 
-         if( !player.on_board )
+         if( !phys->on_board )
          {
             v3f fwd_dir = {cosf(player.angles[0]),
                            0.0f,
@@ -643,51 +846,22 @@ static void player_do_motion(void)
             player.angles[0] = atan2f( fwd_dir[2], fwd_dir[0] );
          }
          
-         m3x3_copy( player.vr, player.gate_vr_frame );
-         m3x3_copy( player.vr_pstep, player.gate_vr_pstep_frame );
+         player.rewind_length = 0;
+         player.rewind_total_length = 0.0f;
+         player.rewind_incrementer = 10000;
+         player_save_frame();
 
          audio_lock();
-         audio_play_oneshot( &audio_gate_lap, 1.0f );
+         audio_play_oneshot( &audio_gate_pass, 1.0f );
          audio_unlock();
          break;
       }
    }
    
-   rb_update_transform( &player.rb );
-}
-
-/*
- * Free camera movement
- */
-static void player_mouseview(void)
-{
-   if( gui_want_mouse() )
-      return;
-
-   static v2f mouse_last,
-              view_vel = { 0.0f, 0.0f };
-
-   if( vg_get_button_down( "primary" ) )
-      v2_copy( vg_mouse, mouse_last );
-
-   else if( vg_get_button( "primary" ) )
-   {
-      v2f delta;
-      v2_sub( vg_mouse, mouse_last, delta );
-      v2_copy( vg_mouse, mouse_last );
-
-      v2_muladds( view_vel, delta, 0.001f, view_vel );
-   }
-   
-   v2_muladds( view_vel, 
-         (v2f){ vg_get_axis("h1"), vg_get_axis("v1") }, 
-         0.05f, view_vel );
-   v2_muls( view_vel, 0.93f, view_vel );
-   v2_add( view_vel, player.angles, player.angles );
-   player.angles[1] = vg_clampf( player.angles[1], -VG_PIf*0.5f, VG_PIf*0.5f );
+   rb_update_transform( &phys->rb );
 }
 
-static void player_freecam(void)
+VG_STATIC void player_freecam(void)
 {
    player_mouseview();
 
@@ -695,39 +869,30 @@ static void player_freecam(void)
    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 );
+   m3x3_mulv( camera_mtx, lookdir, lookdir );
+   m3x3_mulv( camera_mtx, sidedir, sidedir );
    
    static v3f move_vel = { 0.0f, 0.0f, 0.0f };
+
+   /* TODO */
+#if 0
    if( vg_get_button( "forward" ) )
-      v3_muladds( move_vel, lookdir, ktimestep * movespeed, move_vel );
+      v3_muladds( move_vel, lookdir, VG_TIMESTEP_FIXED * movespeed, move_vel );
    if( vg_get_button( "back" ) )
-      v3_muladds( move_vel, lookdir, ktimestep *-movespeed, move_vel );
+      v3_muladds( move_vel, lookdir, VG_TIMESTEP_FIXED *-movespeed, move_vel );
    if( vg_get_button( "left" ) )
-      v3_muladds( move_vel, sidedir, ktimestep *-movespeed, move_vel );
+      v3_muladds( move_vel, sidedir, VG_TIMESTEP_FIXED *-movespeed, move_vel );
    if( vg_get_button( "right" ) )
-      v3_muladds( move_vel, sidedir, ktimestep * movespeed, move_vel );
+      v3_muladds( move_vel, sidedir, VG_TIMESTEP_FIXED * movespeed, move_vel );
+#endif
 
    v3_muls( move_vel, 0.7f, move_vel );
    v3_add( move_vel, player.camera_pos, player.camera_pos );
 }
 
-static void player_camera_update(void)
-{
-   /* Update camera matrices */
-   v4f qyaw, qpitch, qcam;
-   q_axis_angle( qyaw, (v3f){ 0.0f, 1.0f, 0.0f }, -player.angles[0] ); 
-   q_axis_angle( qpitch, (v3f){ 1.0f, 0.0f, 0.0f }, -player.angles[1] ); 
-
-   q_mul( qyaw, qpitch, qcam );
-   q_m3x3( qcam, player.camera );
-
-   v3_copy( player.camera_pos, player.camera[3] );
-   m4x3_invert_affine( player.camera, player.camera_inverse );
-}
-
-static int reset_player( int argc, char const *argv[] )
+VG_STATIC int reset_player( int argc, char const *argv[] )
 {
+   struct player_phys *phys = &player.phys;
    struct respawn_point *rp = NULL, *r;
 
    if( argc == 1 )
@@ -753,7 +918,7 @@ static int reset_player( int argc, char const *argv[] )
       for( int i=0; i<world.spawn_count; i++ )
       {
          r = &world.spawns[i];
-         float d = v3_dist2( r->co, player.rb.co );
+         float d = v3_dist2( r->co, phys->rb.co );
          
          vg_info( "Dist %s : %f\n", r->name, d );
          if( d < min_dist )
@@ -773,26 +938,33 @@ static int reset_player( int argc, char const *argv[] )
       rp = &world.spawns[0];
    }
 
-   v4_copy( rp->q, player.rb.q );
-   v3_copy( rp->co, player.rb.co );
-
-   player.vswitch = 1.0f;
-   player.slip_last = 0.0f;
    player.is_dead = 0;
-   player.in_air = 1;
-   m3x3_identity( player.vr );
+
+   m3x3f the_long_way;
+   q_m3x3( rp->q, the_long_way );
+
+   v3f delta = {1.0f,0.0f,0.0f};
+   m3x3_mulv( the_long_way, delta, delta );
+
+   player.angles[0] = atan2f( delta[0], -delta[2] ); 
+   player.angles[1] = -asinf( delta[1] );
+
+
+   v4_copy( rp->q, phys->rb.q );
+   v3_copy( rp->co, phys->rb.co );
+   v3_zero( phys->rb.v );
+   
+   phys->vswitch = 1.0f;
+   phys->slip_last = 0.0f;
+   phys->in_air = 1;
+   phys->on_board = 0;
+   m3x3_identity( phys->vr );
 
    player.mdl.shoes[0] = 1;
    player.mdl.shoes[1] = 1;
    
-   rb_update_transform( &player.rb );
-   m3x3_mulv( player.rb.to_world, (v3f){ 0.0f, 0.0f, -1.2f }, player.rb.v );
-   m3x3_identity( player.gate_vr_frame );
-   m3x3_identity( player.gate_vr_pstep_frame );
-
-   player.rb_gate_frame = player.rb;
-   player.on_board_frame = player.on_board;
-   player.in_air_frame = player.in_air;
+   rb_update_transform( &phys->rb );
+   player_save_frame();
    return 1;
 }