-VG_STATIC void apply_gravity( v3f vel, float const timestep )
-{
- v3f gravity = { 0.0f, -9.6f, 0.0f };
- v3_muladds( vel, gravity, timestep, vel );
-}
-
-/*
- * Called when launching into the air to predict and adjust trajectories
- */
-VG_STATIC void player_start_air(void)
-{
- struct player_phys *phys = &player.phys;
-
- if( phys->in_air )
- return;
-
- phys->in_air = 1;
-
- float pstep = VG_TIMESTEP_FIXED * 10.0f;
- float best_velocity_delta = -9999.9f;
- float k_bias = 0.96f;
-
- v3f axis;
- v3_cross( phys->rb.up, phys->rb.v, axis );
- v3_normalize( axis );
- player.land_log_count = 0;
-
- 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( phys->rb.co, pco );
- v3_muls( phys->rb.v, k_bias, pv );
-
- /*
- * Try different 'rotations' of the velocity to find the best possible
- * landing normal. This conserves magnitude at the expense of slightly
- * unrealistic results
- */
-
- m3x3f vr;
- v4f vr_q;
-
- q_axis_angle( vr_q, axis, vmod );
- q_m3x3( vr_q, vr );
-
- m3x3_mulv( vr, pv, pv );
- v3_muladds( pco, pv, pstep, pco );
-
- for( int i=0; i<50; i++ )
- {
- v3_copy( pco, pco1 );
- apply_gravity( pv, pstep );
-
- m3x3_mulv( vr, pv, pv );
- v3_muladds( pco, pv, pstep, pco );
-
- ray_hit contact;
- v3f vdir;
-
- v3_sub( pco, pco1, vdir );
- contact.dist = v3_length( vdir );
- v3_divs( vdir, contact.dist, vdir);
-
- if( ray_world( pco1, vdir, &contact ))
- {
- float land_delta = v3_dot( pv, contact.normal );
- u32 scolour = (u8)(vg_minf(-land_delta * 2.0f, 255.0f));
-
- /* Bias prediction towords ramps */
- if( ray_hit_material( &contact )->info.flags
- & k_material_flag_skate_surface )
- {
- land_delta *= 0.1f;
- scolour |= 0x0000a000;
- }
-
- if( (land_delta < 0.0f) && (land_delta > best_velocity_delta) )
- {
- best_velocity_delta = land_delta;
-
- v3_copy( contact.pos, player.land_target );
-
- m3x3_copy( vr, phys->vr_pstep );
- q_axis_angle( vr_q, axis, vmod*0.1f );
- q_m3x3( vr_q, phys->vr );
- }
-
- v3_copy( contact.pos,
- player.land_target_log[player.land_log_count] );
- player.land_target_colours[player.land_log_count] =
- 0xff000000 | scolour;
-
- player.land_log_count ++;
-
- break;
- }
- }
- }
-}
-
-/*
- * Main friction interface model
- */
-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( phys->rb.to_local, phys->rb.v, vel );
- float slip = 0.0f;
-
- if( fabsf(vel[2]) > 0.01f )
- slip = fabsf(-vel[0] / vel[2]) * vg_signf(vel[0]);
-
- if( fabsf( slip ) > 1.2f )
- slip = vg_signf( slip ) * 1.2f;
- phys->slip = slip;
- phys->reverse = -vg_signf(vel[2]);
-
- float substep = VG_TIMESTEP_FIXED * 0.2f;
-
-#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*substep);
- vel[0] = stable_force( vel[0],vg_signf(vel[0]) * -k_friction_lat*substep);
- }
-
- if( player.input_jump->button.value )
- {
- phys->jump += VG_TIMESTEP_FIXED * k_jump_charge_speed;
-
- if( !phys->jump_charge )
- phys->jump_dir = phys->reverse > 0.0f? 1: 0;
-
- phys->jump_charge = 1;
- }
-
- 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.phys.pushing = 1.0f;
- player.phys.push_time = vg.time - player.phys.start_push;
-
- 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 * phys->reverse;
- }
-
- /* Pumping */
- static float previous = 0.0f;
- float delta = previous - phys->grab,
- pump = delta * k_pump_force * VG_TIMESTEP_FIXED;
- previous = phys->grab;
-
- v3f p1;
- 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 );
-
- 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
- */
-VG_STATIC void player_physics_control_air(void)
-{
- 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;
-
- /*
- * Prediction
- */
- float pstep = VG_TIMESTEP_FIXED * 10.0f;
-
- v3f pco, pco1, pv;
- v3_copy( phys->rb.co, pco );
- v3_copy( phys->rb.v, pv );
-
- float time_to_impact = 0.0f;
- float limiter = 1.0f;
-
- for( int i=0; i<50; i++ )
- {
- v3_copy( pco, pco1 );
- m3x3_mulv( phys->vr_pstep, pv, pv );
- apply_gravity( pv, 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);
-
- float orig_dist = contact.dist;
- if( ray_world( pco1, vdir, &contact ))
- {
- float angle = v3_dot( phys->rb.up, contact.normal );
- v3f 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;
- limiter = 1.0f-limiter;
- limiter *= limiter;
- limiter = 1.0f-limiter;
-
- if( angle < 0.99f )
- {
- v4f correction;
- 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 );
- break;
- }
- time_to_impact += pstep;
- }
-
- v2f steer = { player.input_js1h->axis.value,
- player.input_js1v->axis.value };
-
- 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("grabh"), vg_get_axis("grabv") },
- phys->grab, target );
-#endif
-}
-
-VG_STATIC void player_walk_update_collision(void)
-{
- struct player_phys *phys = &player.phys;
- float h0 = 0.3f,
- h1 = 0.9f;
-
- 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] );
- 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 );
-}
-