+#ifndef PLAYER_GLIDE_C
+#define PLAYER_GLIDE_C
+
+#include "player_glide.h"
+#include "input.h"
+
+static f32 k_glide_steer = 2.0f,
+ k_glide_cl = 0.04f,
+ k_glide_cs = 0.02f,
+ k_glide_drag = 0.0001f,
+ k_glide_slip_yaw = 0.1f,
+ k_glide_lift_pitch = 0.0f,
+ k_glide_wing_orient = -0.1f,
+ k_glide_balance = 1.0f;
+
+static i32 k_glide_pause = 0;
+
+static void player_glide_pre_update(void){
+}
+
+static void massless_accel( rigidbody *rb, v3f delta, v3f impulse ){
+ /* linear */
+ v3_muladds( rb->v, impulse, k_rb_delta, rb->v );
+
+ /* Angular velocity */
+ v3f wa;
+ v3_cross( delta, impulse, wa );
+ v3_muladds( rb->w, wa, k_rb_delta, rb->w );
+}
+
+static void calculate_lift( v3f vl, f32 aoa_bias,
+ v3f axis, v3f back, f32 power,
+ v3f out_force ){
+ v3f up;
+ v3_cross( back, axis, up );
+
+ v3f wind;
+ v3_muladds( vl, axis, -v3_dot(axis,vl), wind );
+
+ f32 windv2 = v3_length2(wind),
+ aoa = atan2f( v3_dot( up, wind ), v3_dot( back, wind ) ) + aoa_bias,
+ cl = aoa / VG_PIf, /* TODO: make it a curve */
+ L = windv2 * cl * power;
+
+ v3f lift_dir;
+ v3_normalize( wind );
+ v3_cross( wind, axis, lift_dir );
+
+ /* this is where induced drag (from the flappy things) would go */
+
+ v3_muls( lift_dir, L, out_force );
+}
+
+static void calculate_drag( v3f vl, f32 cd, v3f out_force ){
+ f32 v2 = v3_length2( vl );
+ v3f dir;
+ v3_copy( vl, dir );
+ v3_normalize( dir );
+ v3_muls( vl, -cd*v2, out_force );
+}
+
+static void player_glide_update(void){
+ rigidbody *rb = &localplayer.rb;
+ vg_line_sphere( rb->to_world, 1.0f, 0 );
+
+ v2f steer;
+ joystick_state( k_srjoystick_steer, steer );
+
+ /* lift */
+ v3f vl, wl;
+ m3x3_mulv( rb->to_local, rb->v, vl );
+ m3x3_mulv( rb->to_local, rb->w, wl );
+
+ v3f F, Flift, Fslip, Fdrag, FslipW, FliftW;
+
+ calculate_lift( vl, steer[1]*k_glide_steer,
+ (v3f){1,0,0},
+ (v3f){0,sinf(k_glide_wing_orient),cosf(k_glide_wing_orient)},
+ k_glide_cl, Flift );
+ v3_copy( Flift, player_glide.info_lift );
+ v3_cross( (v3f){0,0,0}, Flift, FliftW );
+
+ calculate_lift( vl, 0.0f,
+ (v3f){0,1,0},(v3f){0,0,1},
+ k_glide_cs, Fslip );
+ v3_copy( Fslip, player_glide.info_slip );
+ v3_cross( (v3f){0,k_glide_lift_pitch,k_glide_slip_yaw}, Fslip, FslipW );
+
+ calculate_drag( vl, k_glide_drag, Fdrag );
+ v3_copy( Fdrag, player_glide.info_drag );
+
+ v3f balance = {0.0f,-k_glide_balance,0.0f};
+ m3x3_mulv( rb->to_local, balance, balance );
+ vg_info( PRINTF_v3f( balance ) );
+
+ v3f Fw = {
+ steer[1]*k_glide_steer - balance[2],
+ 0.0f,
+ -steer[0]*k_glide_steer + balance[0],
+ };
+
+ if( player_glide.ticker ){
+ player_glide.ticker --;
+ return;
+ }
+ player_glide.ticker += k_glide_pause;
+
+ /* apply forces */
+ v3_add( Flift, Fslip, F );
+ v3_add( F, Fdrag, F );
+
+ m3x3_mulv( rb->to_world, F, F );
+ v3_muladds( rb->v, F, k_rb_delta, rb->v );
+
+ v3_add( Fw, FslipW, Fw );
+ v3_add( Fw, FliftW, Fw );
+ m3x3_mulv( rb->to_world, Fw, Fw );
+ v3_muladds( rb->w, Fw, k_rb_delta, rb->w );
+
+ rb_iter( rb );
+ rb_update_transform( rb );
+}
+
+static void player_glide_post_update(void){
+}
+
+static void player_glide_animate(void){
+ struct player_glide *g = &player_glide;
+ struct player_glide_animator *animator = &g->animator;
+ rb_extrapolate( &localplayer.rb, animator->root_co, animator->root_q );
+}
+
+static void player_glide_pose( void *_animator, player_pose *pose ){
+ struct skeleton *sk = &localplayer.skeleton;
+ struct player_glide_animator *animator = _animator;
+
+ skeleton_sample_anim( sk, player_glide.anim_temp, 0.0f, pose->keyframes );
+
+ v3_copy( animator->root_co, pose->root_co );
+ v4_copy( animator->root_q, pose->root_q );
+}
+
+static void player_glide_post_animate(void){
+ if( localplayer.cam_control.camera_mode == k_cam_firstperson )
+ localplayer.cam_velocity_influence = 0.0f;
+ else
+ localplayer.cam_velocity_influence = 0.0f;
+
+ v3f fwd;
+ v3_muls( localplayer.rb.to_world[2], -1.0f, fwd );
+ v3_angles( fwd, localplayer.angles );
+}
+
+static void player_glide_im_gui(void){
+ player__debugtext( 1, "Nothing here" );
+ player__debugtext( 1, " lift: %.2f %.2f %.2f",
+ player_glide.info_lift[0],
+ player_glide.info_lift[1],
+ player_glide.info_lift[2] );
+ player__debugtext( 1, " slip: %.2f %.2f %.2f",
+ player_glide.info_slip[0],
+ player_glide.info_slip[1],
+ player_glide.info_slip[2] );
+ player__debugtext( 1, " drag: %.2f %.2f %.2f",
+ player_glide.info_drag[0],
+ player_glide.info_drag[1],
+ player_glide.info_drag[2] );
+}
+
+static void player_glide_bind(void){
+ struct skeleton *sk = &localplayer.skeleton;
+ player_glide.anim_temp = skeleton_get_anim( sk, "idle_cycle+y" );
+
+ u32 mask = VG_VAR_CHEAT|VG_VAR_PERSISTENT;
+ VG_VAR_F32( k_glide_steer, flags=mask );
+ VG_VAR_F32( k_glide_cl, flags=mask );
+ VG_VAR_F32( k_glide_cs, flags=mask );
+ VG_VAR_F32( k_glide_drag, flags=mask );
+ VG_VAR_F32( k_glide_slip_yaw, flags=mask );
+ VG_VAR_F32( k_glide_lift_pitch, flags=mask );
+ VG_VAR_I32( k_glide_pause, flags=mask );
+ VG_VAR_F32( k_glide_balance, flags=mask );
+ VG_VAR_F32( k_glide_wing_orient, flags=mask );
+}
+
+#endif /* PLAYER_GLIDE_C */