- /*
- * Getting surface collision points,
- * the contact manifold is a triangle for simplicity.
- */
- v3f contact_front, contact_back, fwd, fwd1, contact_norm, vup, vside,
- axis;
-
- m3x3_mulv( player.to_world, (v3f){0.0f,0.0f,-1.0f}, fwd );
- m4x3_mulv( player.to_world, (v3f){ 0.15f,0.0f,-1.0f}, contact_norm );
- m4x3_mulv( player.to_world, (v3f){-0.15f,0.0f,-1.0f}, contact_front );
- m4x3_mulv( player.to_world, (v3f){ 0.00f,0.0f, 1.0f}, contact_back );
- m3x3_mulv( player.to_world, (v3f){0.0f,1.0f,0.0f}, vup );
- m3x3_mulv( player.to_world, (v3f){1.0f,0.0f,0.0f}, vside );
-
- int all_contacting =
- sample_scene_height( &world.geo, contact_front, NULL ) &&
- sample_scene_height( &world.geo, contact_back, NULL ) &&
- sample_scene_height( &world.geo, contact_norm, NULL );
-
- if( !all_contacting )
- {
- player.in_air = 1;
- return;
- }
-
- v3f norm;
- v3f v0, v1;
- v3_sub( contact_norm, contact_front, v0 );
- v3_sub( contact_back, contact_front, v1 );
- v3_cross( v1, v0, norm );
- v3_normalize( norm );
-
- vg_line( contact_norm, contact_front, 0xff00ff00 );
- vg_line( contact_back, contact_front, 0xff0000ff );
-
- /* Surface alignment */
- float angle = v3_dot( vup, norm );
- v3_cross( vup, norm, axis );
-
- if( angle < 0.999f )
- {
- v4f correction;
- q_axis_angle( correction, axis, acosf(angle) );
- q_mul( correction, player.rot, player.rot );
- }
-
- float resistance = v3_dot( norm, player.v );
-
- if( resistance >= 0.0f )
- {
- player.in_air = 1;
- return;
- }
- else
- {
- v3_muladds( player.v, norm, -resistance, player.v );
- }
-
- /* This is where velocity integration used to be */
-
- float slip = 0.0f;
-
- player.co[1] = (contact_front[1]+contact_back[1])*0.5f;
-
- v3f vel;
- m3x3_mulv( player.to_local, player.v, vel );
-
- /* Calculate local forces */
-
- slip = (-vel[0] / vel[2]) * player.vswitch;
- if( fabsf( slip ) > 1.2f )
- slip = vg_signf( slip ) * 1.2f;
- player.slip = slip;
-
-#if 0
- if( player.slip_last*slip < 0.0f && fabsf(slip) > 0.7f )
- {
- vg_warn( "SWITCH\n" );
- player.vswitch = -player.vswitch;
- slip = -slip;
- }
-
- player.slip_last = slip;
-#endif
-
- float substep = ktimestep * 0.2f;
-
- for( int i=0; i<5; i++ )
- {
- if( fabsf(vel[2]) >= 0.02f*substep )
- vel[2] += vg_signf( vel[2] ) * -0.02f * substep;
- if( fabsf(vel[0]) >= 7.0f*substep )
- vel[0] += vg_signf( vel[0] ) * -7.0f * substep;
- }
-
- m3x3_mulv( player.to_world, vel, player.v );
-
- if( vg_get_button( "yawl" ) )
- player.iY += 3.6f * ktimestep;
- if( vg_get_button( "yawr" ) )
- player.iY -= 3.6f * ktimestep;
-
- float steer = vg_get_axis( "horizontal" );
- player.iY -= vg_signf(steer)*powf(steer,2.0f) * 1.5f * ktimestep;