From 344f0153cf1907da87dd041db3ec517325b1c429 Mon Sep 17 00:00:00 2001
From: hgn <hgodden00@gmail.com>
Date: Sat, 23 Jul 2022 00:45:40 +0100
Subject: [PATCH] more physics shapes

---
 character.h    |   2 +-
 main.c         |   4 +-
 physics_test.h | 125 ++++++++--
 rigidbody.h    | 609 ++++++++++++++++++++++++++++++++++---------------
 4 files changed, 528 insertions(+), 212 deletions(-)

diff --git a/character.h b/character.h
index 71299e8..3421d3a 100644
--- a/character.h
+++ b/character.h
@@ -904,7 +904,7 @@ static void character_ragdoll_iter( struct character *ch )
 
    v3f rv;
 
-   float shoe_vel[2];
+   float shoe_vel[2] = {0.0f,0.0f};
    for( int i=0; i<2; i++ )
       if( ch->shoes[i] )
          shoe_vel[i] = v3_length( ch->ragdoll[i].v );
diff --git a/main.c b/main.c
index 8b2f561..f3b5b8c 100644
--- a/main.c
+++ b/main.c
@@ -38,9 +38,7 @@ static int sv_scene = 1;
 #include "shaders/standard.h"
 #include "shaders/unlit.h"
 
-#ifndef VG_RELEASE
 #include "physics_test.h"
-#endif
 
 void vg_register(void)
 {
@@ -77,7 +75,7 @@ vg_tex2d *texture_list[] =
 
 int main( int argc, char *argv[] )
 { 
-   vg_init( argc, argv, "CARBE" ); 
+   vg_init( argc, argv, "Voyager Game Engine" ); 
 }
 
 static int playermodel( int argc, char const *argv[] )
diff --git a/physics_test.h b/physics_test.h
index bd8bc07..8143c1d 100644
--- a/physics_test.h
+++ b/physics_test.h
@@ -49,29 +49,52 @@ rigidbody funnel[4] = {
 rigidbody jeff1 = { .type = k_rb_shape_capsule,
                     .inf.capsule = { .radius = 0.75f, .height = 3.0f },
                     .co = {30.0f, 4.0f, 30.0f },
-                    .q = {0.0f,0.0f,0.0f,1.0f}
+                    .q = {1.0f,0.0f,0.0f,0.0f}
 };
 
 rigidbody ball = { .type = k_rb_shape_sphere,
                    .inf.sphere = { .radius = 2.0f },
-                   .co = {0.0f,6.0f,0.0f},
+                   .co = {0.0f,20.0f,2.0f},
                    .q = {0.0f,0.0f,0.0f,1.0f}},
 
           ball1= { .type = k_rb_shape_sphere,
-                   .inf.sphere = { .radius = 1.0f },
-                   .co = {0.1f,9.0f,0.2f},
+                   .inf.sphere = { .radius = 2.0f },
+                   .co = {0.1f,25.0f,0.2f},
                    .q = {0.0f,0.0f,0.0f,1.0f}};
 
+rigidbody jeffs[16];
+
+static void reorg_jeffs(void)
+{
+   for( int i=0; i<vg_list_size(jeffs); i++ )
+   {
+      v3_copy( (v3f){ (vg_randf()-0.5f) * 10.0f,
+                      (vg_randf()-0.5f) * 10.0f + 17.0f,
+                      (vg_randf()-0.5f) * 10.0f }, jeffs[i].co );
+      v4_copy( (v4f){ vg_randf(), vg_randf(), vg_randf(), vg_randf() },
+               jeffs[i].q );
+      q_normalize( jeffs[i].q );
+      
+      jeffs[i].type = k_rb_shape_capsule;
+      jeffs[i].inf.capsule.radius = 0.75f;
+      jeffs[i].inf.capsule.height = 3.0f;
+
+      rb_init( &jeffs[i] );
+   }
+}
+
 static void physics_test_start(void)
 {
-   q_axis_angle( funnel[0].q, (v3f){1.0f,0.0f,0.0f},  0.3f );
-   q_axis_angle( funnel[1].q, (v3f){1.0f,0.0f,0.0f}, -0.3f );
-   q_axis_angle( funnel[2].q, (v3f){0.0f,0.0f,1.0f},  0.3f );
-   q_axis_angle( funnel[3].q, (v3f){0.0f,0.0f,1.0f}, -0.3f );
+   q_axis_angle( funnel[0].q, (v3f){1.0f,0.0f,0.0f},  0.6f );
+   q_axis_angle( funnel[1].q, (v3f){1.0f,0.0f,0.0f}, -0.6f );
+   q_axis_angle( funnel[2].q, (v3f){0.0f,0.0f,1.0f},  0.6f );
+   q_axis_angle( funnel[3].q, (v3f){0.0f,0.0f,1.0f}, -0.6f );
 
    for( int i=0; i<4; i++ )
       rb_init( &funnel[i] );
 
+   reorg_jeffs();
+
    rb_init( &ground );
    rb_init( &ball );
    rb_init( &ball1 );
@@ -84,6 +107,24 @@ static void physics_test_update(void)
    player_freecam();
    player_camera_update();
 
+   
+   for( int i=0; i<4; i++ )
+      rb_debug( &funnel[i], 0xff0060e0 );
+   rb_debug( &ground, 0xff00ff00 );
+   rb_debug( &ball, 0xffe00040 );
+   rb_debug( &ball1, 0xff00e050 );
+
+   rb_debug( &blocky, 0xffcccccc );
+   rb_debug( &jeff1, 0xff00ffff );
+
+   for( int i=0; i<vg_list_size(jeffs); i++ )
+   {
+      rb_debug( &jeffs[i], (u32[]){ 0xff0000ff, 0xff00ff00, 0xff00ffff,
+                                   0xffff0000, 0xffff00ff, 0xffffff00,
+                                   }[i%6] );
+      rb_iter( jeffs+i );
+   }
+
    {
 
    rb_iter( &ball );
@@ -94,22 +135,50 @@ static void physics_test_update(void)
 
    for( int i=0; i<4; i++ )
    {
-      rb_contact_count += rb_sphere_vs_box( &ball, &funnel[i], rb_global_ct());
-      rb_contact_count += rb_sphere_vs_box( &ball1, &funnel[i], rb_global_ct());
+      rigidbody *fn = &funnel[i];
+      rb_contact_count += rb_sphere_vs_box( &ball, fn, rb_global_ct());
+      rb_contact_count += rb_sphere_vs_box( &ball1, fn, rb_global_ct());
+      rb_contact_count += rb_capsule_vs_box( &jeff1, fn, rb_global_ct() );
+
+      for( int i=0; i<vg_list_size(jeffs); i++ )
+         rb_contact_count += rb_capsule_vs_box( jeffs+i, fn, rb_global_ct() );
    }
 
-   rb_contact_count += rb_sphere_vs_box( &ball, &ground, rb_global_ct() );
-   rb_contact_count += rb_sphere_vs_box( &ball1, &ground, rb_global_ct() );
-   rb_contact_count += rb_sphere_vs_sphere( &ball, &ball1, rb_global_ct() );
+   for( int i=0; i<vg_list_size(jeffs)-1; i++ )
+   {
+      for( int j=i+1; j<vg_list_size(jeffs); j++ )
+      {
+         rb_contact_count += rb_capsule_vs_capsule( jeffs+i, jeffs+j, 
+               rb_global_ct() );
+      }
+   }
+
+   for( int i=0; i<vg_list_size(jeffs); i++ )
+   {
+      rb_contact_count += rb_capsule_vs_box( jeffs+i, &ground, rb_global_ct() );
+      rb_contact_count += rb_capsule_vs_sphere( jeffs+i, &ball, rb_global_ct() );
+      rb_contact_count += rb_capsule_vs_sphere( jeffs+i, &ball1, rb_global_ct() );
+      rb_contact_count += rb_capsule_vs_capsule( jeffs+i, &jeff1, rb_global_ct() );
+   }
 
    rb_contact_count += rb_capsule_vs_box( &jeff1, &ground, rb_global_ct() );
    rb_contact_count += rb_capsule_vs_box( &jeff1, &blocky, rb_global_ct() );
+   rb_contact_count += rb_capsule_vs_sphere( &jeff1, &ball, rb_global_ct() );
+   rb_contact_count += rb_capsule_vs_sphere( &jeff1, &ball1, rb_global_ct() );
 
-   rb_presolve_contacts( rb_contact_buffer, rb_contact_count );
+   rb_contact_count += rb_sphere_vs_box( &ball, &ground, rb_global_ct() );
+   rb_contact_count += rb_sphere_vs_box( &ball1, &ground, rb_global_ct() );
+   rb_contact_count += rb_sphere_vs_sphere( &ball1, &ball, rb_global_ct() );
 
-   for( int i=0; i<5; i++ )
+   rb_presolve_contacts( rb_contact_buffer, rb_contact_count );
+   for( int i=0; i<8; i++ )
       rb_solve_contacts( rb_contact_buffer, rb_contact_count );
 
+   for( int i=0; i<vg_list_size(jeffs); i++ )
+   {
+      rb_update_transform(jeffs+i);
+   }
+
    rb_update_transform( &ball );
    rb_update_transform( &ball1 );
    rb_update_transform( &jeff1 );
@@ -118,19 +187,27 @@ static void physics_test_update(void)
 
    if(glfwGetKey( vg_window, GLFW_KEY_L ))
    {
-      v3_copy( player.camera_pos, jeff1.co );
+      m4x3_mulv( player.camera, (v3f){0.0f,0.0f,-5.0f}, jeff1.co );
       v3_zero( jeff1.v );
       v3_zero( jeff1.w );
    }
-   
-   for( int i=0; i<4; i++ )
-      rb_debug( &funnel[i], 0xff0060e0 );
-   rb_debug( &ground, 0xff00ff00 );
-   rb_debug( &ball, 0xffe00040 );
-   rb_debug( &ball1, 0xff00e050 );
+   if(glfwGetKey( vg_window, GLFW_KEY_K ))
+   {
+      m4x3_mulv( player.camera, (v3f){0.0f,0.0f,-5.0f}, ball.co );
+      v3_zero( ball.v );
+      v3_zero( ball.w );
+   }
+   if(glfwGetKey( vg_window, GLFW_KEY_J ))
+   {
+      m4x3_mulv( player.camera, (v3f){0.0f,0.0f,-5.0f}, ball1.co );
+      v3_zero( ball1.v );
+      v3_zero( ball1.w );
+   }
 
-   rb_debug( &blocky, 0xffcccccc );
-   rb_debug( &jeff1, 0xff00ffff );
+   if(glfwGetKey( vg_window, GLFW_KEY_H ))
+   {
+      reorg_jeffs();
+   }
 }
 
 static void physics_test_render(void)
diff --git a/rigidbody.h b/rigidbody.h
index 58c70d7..b140cbb 100644
--- a/rigidbody.h
+++ b/rigidbody.h
@@ -295,14 +295,16 @@ static void closest_point_obb( v3f p, rigidbody *rb, v3f dest )
    m4x3_mulv( rb->to_world, local, dest );
 }
 
-static void closest_point_segment( v3f a, v3f b, v3f point, v3f dest )
+static float closest_point_segment( v3f a, v3f b, v3f point, v3f dest )
 {
    v3f v0, v1;
    v3_sub( b, a, v0 );
    v3_sub( point, a, v1 );
 
    float t = v3_dot( v1, v0 ) / v3_length2(v0);
-   v3_muladds( a, v0, vg_clampf(t,0.0f,1.0f), dest );
+   t = vg_clampf(t,0.0f,1.0f);
+   v3_muladds( a, v0, t, dest );
+   return t;
 }
 
 static void closest_on_triangle( v3f p, v3f tri[3], v3f dest )
@@ -412,9 +414,190 @@ static void rb_debug_contact( rb_ct *ct )
    vg_line( ct->co, p1, 0xffffffff );
 }
 
-static void rb_box_incident_dir( v3f p, boxf box, v3f dir )
+/* 
+ * By collecting the minimum(time) and maximum(time) pairs of points, we
+ * build a reduced and stable exact manifold. 
+ * 
+ * tx: time at point
+ * rx: minimum distance of these points
+ * dx: the delta between the two points
+ *
+ * pairs will only ammend these if they are creating a collision
+ */
+typedef struct capsule_manifold capsule_manifold;
+struct capsule_manifold
+{
+   float t0, t1;
+   float r0, r1;
+   v3f d0, d1;
+};
+
+/* 
+ * Expand a line manifold with a new pair. t value is the time along segment
+ * on the oriented object which created this pair.
+ */
+static void rb_capsule_manifold( v3f pa, v3f pb, float t, float r, 
+                                 capsule_manifold *manifold )
+{
+   v3f delta;
+   v3_sub( pa, pb, delta );
+
+   if( v3_length2(delta) < r*r )
+   {
+      if( t < manifold->t0 )
+      {
+         v3_copy( delta, manifold->d0 );
+         manifold->t0 = t;
+         manifold->r0 = r;
+      }
+
+      if( t > manifold->t1 )
+      {
+         v3_copy( delta, manifold->d1 );
+         manifold->t1 = t;
+         manifold->r1 = r;
+      }
+   }
+}
+
+static void rb_capsule_manifold_init( capsule_manifold *manifold )
+{
+   manifold->t0 =  INFINITY;
+   manifold->t1 = -INFINITY;
+}
+
+static int rb_capsule_manifold_done( rigidbody *rba, rigidbody *rbb, 
+                                     capsule_manifold *manifold, rb_ct *buf )
+{
+   float h = rba->inf.capsule.height,
+        ra = rba->inf.capsule.radius;
+
+   v3f p0, p1;
+   v3_muladds( rba->co, rba->up, -h*0.5f+ra, p0 );
+   v3_muladds( rba->co, rba->up,  h*0.5f-ra, p1 );
+
+   int count = 0;
+   if( manifold->t0 <= 1.0f )
+   {
+      rb_ct *ct = buf;
+
+      v3f pa;
+      v3_muls( p0, 1.0f-manifold->t0, pa );
+      v3_muladds( pa, p1, manifold->t0, pa );
+
+      float d = v3_length( manifold->d0 );
+      v3_muls( manifold->d0, 1.0f/d, ct->n );
+      v3_muladds( pa, ct->n, -ra, ct->co );
+
+      ct->p = manifold->r0 - d;
+      ct->rba = rba;
+      ct->rbb = rbb;
+
+      count ++;
+   }
+
+   if( (manifold->t1 >= 0.0f) && (manifold->t0 != manifold->t1) )
+   {
+      rb_ct *ct = buf+count;
+
+      v3f pa;
+      v3_muls( p0, 1.0f-manifold->t1, pa );
+      v3_muladds( pa, p1, manifold->t1, pa );
+
+      float d = v3_length( manifold->d1 );
+      v3_muls( manifold->d1, 1.0f/d, ct->n );
+      v3_muladds( pa, ct->n, -ra, ct->co );
+
+      ct->p = manifold->r1 - d;
+      ct->rba = rba;
+      ct->rbb = rbb;
+
+      count ++;
+   }
+
+   /*
+    * Debugging
+    */
+
+   if( count == 2 )
+      vg_line( buf[0].co, buf[1].co, 0xff0000ff );
+
+   return count;
+}
+
+static int rb_capsule_vs_sphere( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+   float h = rba->inf.capsule.height,
+        ra = rba->inf.capsule.radius,
+        rb = rbb->inf.sphere.radius;
+
+   v3f p0, p1;
+   v3_muladds( rba->co, rba->up, -h*0.5f+ra, p0 );
+   v3_muladds( rba->co, rba->up,  h*0.5f-ra, p1 );
+
+   v3f c, delta;
+   closest_point_segment( p0, p1, rbb->co, c );
+   v3_sub( c, rbb->co, delta );
+
+   float d2 = v3_length2(delta),
+          r = ra + rb;
+
+   if( d2 < r*r )
+   {
+      float d = sqrtf(d2);
+             
+      rb_ct *ct = buf;
+      v3_muls( delta, 1.0f/d, ct->n );
+      ct->p = r-d;
+
+      v3f p0, p1;
+      v3_muladds( c, ct->n, -ra, p0 );
+      v3_muladds( rbb->co, ct->n, rb,  p1 );
+      v3_add( p0, p1, ct->co );
+      v3_muls( ct->co, 0.5f, ct->co );
+
+      ct->rba = rba;
+      ct->rbb = rbb;
+
+      return 1;
+   }
+
+   return 0;
+}
+
+static int rb_capsule_vs_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
 {
+   float ha = rba->inf.capsule.height,
+         hb = rbb->inf.capsule.height,
+         ra = rba->inf.capsule.radius,
+         rb = rbb->inf.capsule.radius,
+          r = ra+rb;
+
+   v3f p0, p1, p2, p3;
+   v3_muladds( rba->co, rba->up, -ha*0.5f+ra, p0 );
+   v3_muladds( rba->co, rba->up,  ha*0.5f-ra, p1 );
+   v3_muladds( rbb->co, rbb->up, -hb*0.5f+rb, p2 );
+   v3_muladds( rbb->co, rbb->up,  hb*0.5f-rb, p3 );
+
+   capsule_manifold manifold;
+   rb_capsule_manifold_init( &manifold );
+
+   v3f pa, pb;
+   float ta, tb;
+   closest_segment_segment( p0, p1, p2, p3, &ta, &tb, pa, pb );
+   rb_capsule_manifold( pa, pb, ta, r, &manifold );
+
+   ta = closest_point_segment( p0, p1, p2, pa );
+   tb = closest_point_segment( p0, p1, p3, pb );
+   rb_capsule_manifold( pa, p2, ta, r, &manifold );
+   rb_capsule_manifold( pb, p3, tb, r, &manifold );
+
+   closest_point_segment( p2, p3, p0, pa );
+   closest_point_segment( p2, p3, p1, pb );
+   rb_capsule_manifold( p0, pa, 0.0f, r, &manifold );
+   rb_capsule_manifold( p1, pb, 1.0f, r, &manifold );
    
+   return rb_capsule_manifold_done( rba, rbb, &manifold, buf );
 }
 
 /*
@@ -424,56 +607,125 @@ static int rb_capsule_vs_box( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
 {
    float h = rba->inf.capsule.height,
          r = rba->inf.capsule.radius;
-   
-   v3f p0, p1;
-   v3_muladds( rba->co, rba->up,  h*0.5f-r*0.5f, p1 );
-   v3_muladds( rba->co, rba->up, -h*0.5f+r*0.5f, p0 );
 
-   m4x3_mulv( rbb->to_local, p0, p0 );
-   m4x3_mulv( rbb->to_local, p1, p1 );
+   /*
+    * Solving this in symetric local space of the cube saves us some time and a 
+    * couple branches when it comes to the quad stage.
+    */
+   v3f centroid;
+   v3_add( rbb->bbx[0], rbb->bbx[1], centroid );
+   v3_muls( centroid, 0.5f, centroid );
 
-   /* Clip zone +y */
+   boxf bbx;
+   v3_sub( rbb->bbx[0], centroid, bbx[0] );
+   v3_sub( rbb->bbx[1], centroid, bbx[1] );
+   
+   v3f pc, p0w, p1w, p0, p1;
+   v3_muladds( rba->co, rba->up, -h*0.5f+r, p0w );
+   v3_muladds( rba->co, rba->up,  h*0.5f-r, p1w );
+
+   m4x3_mulv( rbb->to_local, p0w, p0 );
+   m4x3_mulv( rbb->to_local, p1w, p1 );
+   v3_sub( p0, centroid, p0 );
+   v3_sub( p1, centroid, p1 );
+   v3_add( p0, p1, pc );
+   v3_muls( pc, 0.5f, pc );
+
+   /* 
+    * Finding an appropriate quad to collide lines with
+    */
+   v3f region;
+   v3_div( pc, bbx[1], region );
+   
+   v3f quad[4];
+   if( (fabsf(region[0]) > fabsf(region[1])) && 
+       (fabsf(region[0]) > fabsf(region[2])) )
+   {
+      float px = vg_signf(region[0]) * bbx[1][0];
+      v3_copy( (v3f){ px, bbx[0][1], bbx[0][2] }, quad[0] );
+      v3_copy( (v3f){ px, bbx[1][1], bbx[0][2] }, quad[1] );
+      v3_copy( (v3f){ px, bbx[1][1], bbx[1][2] }, quad[2] );
+      v3_copy( (v3f){ px, bbx[0][1], bbx[1][2] }, quad[3] );
+   }
+   else if( fabsf(region[1]) > fabsf(region[2]) )
+   {
+      float py = vg_signf(region[1]) * bbx[1][1];
+      v3_copy( (v3f){ bbx[0][0], py, bbx[0][2] }, quad[0] );
+      v3_copy( (v3f){ bbx[1][0], py, bbx[0][2] }, quad[1] );
+      v3_copy( (v3f){ bbx[1][0], py, bbx[1][2] }, quad[2] );
+      v3_copy( (v3f){ bbx[0][0], py, bbx[1][2] }, quad[3] );
+   }
+   else
+   {
+      float pz = vg_signf(region[2]) * bbx[1][2];
+      v3_copy( (v3f){ bbx[0][0], bbx[0][1], pz }, quad[0] );
+      v3_copy( (v3f){ bbx[1][0], bbx[0][1], pz }, quad[1] );
+      v3_copy( (v3f){ bbx[1][0], bbx[1][1], pz }, quad[2] );
+      v3_copy( (v3f){ bbx[0][0], bbx[1][1], pz }, quad[3] );
+   }
+
+   capsule_manifold manifold;
+   rb_capsule_manifold_init( &manifold );
    
    v3f c0, c1;
-   closest_point_aabb( p0, rbb->bbx, c0 );
-   closest_point_aabb( p1, rbb->bbx, c1 );
-
-   v3f vis0;
-   m4x3_mulv( rbb->to_world, c0, vis0 );
-   vg_line_pt3( vis0, 0.1f, 0xffff00ff );
-   m4x3_mulv( rbb->to_world, c1, vis0 );
-   vg_line_pt3( vis0, 0.1f, 0xffff00ff );
+   closest_point_aabb( p0, bbx, c0 );
+   closest_point_aabb( p1, bbx, c1 );
+
+   v3f d0, d1, da;
+   v3_sub( c0, p0, d0 );
+   v3_sub( c1, p1, d1 );
+   v3_sub( p1, p0, da );
    
-   v3f d0, d1;
-   v3_sub( p0, c0, d0 );
-   v3_sub( p1, c1, d1 );
+   /* TODO: ? */
+   v3_normalize(d0);
+   v3_normalize(d1);
+   v3_normalize(da);
 
-   float d02 = v3_length2(d0),
-         d12 = v3_length2(d1);
+   if( v3_dot( da, d0 ) <= 0.01f )
+      rb_capsule_manifold( p0, c0, 0.0f, r, &manifold );
 
-   int count = 0;
+   if( v3_dot( da, d1 ) >= -0.01f )
+      rb_capsule_manifold( p1, c1, 1.0f, r, &manifold );
 
-   if( d02 <= r*r )
+   for( int i=0; i<4; i++ )
    {
-      rb_ct *ct = buf+count;
-      float d = sqrtf(d02);
-      
-      vg_info( "d: %.4f\n", d );
+      int i0 = i,
+          i1 = (i+1)%4;
 
-      v3_muls( d0, -1.0f/d, ct->n );
-      ct->p = r-d;
-      v3_add( c0, p0, ct->co );
-      v3_muls( ct->co, 0.5f, ct->co );
-      
-      m3x3_mulv( rbb->to_world, ct->n, ct->n );
-      m4x3_mulv( rbb->to_world, ct->co, ct->co );
+      v3f ca, cb;
+      float ta, tb;
+      closest_segment_segment( p0, p1, quad[i0], quad[i1], &ta, &tb, ca, cb );
+      rb_capsule_manifold( ca, cb, ta, r, &manifold );
+   }
 
-      ct->rba = rba;
-      ct->rbb = rbb;
-      count ++;
+   /*
+    * Create final contacts based on line manifold
+    */
+   m3x3_mulv( rbb->to_world, manifold.d0, manifold.d0 );
+   m3x3_mulv( rbb->to_world, manifold.d1, manifold.d1 );
+
+   /*
+    * Debugging
+    */
+
+#if 0
+   for( int i=0; i<4; i++ )
+   {
+      v3f q0, q1;
+      int i0 = i,
+          i1 = (i+1)%4;
+
+      v3_add( quad[i0], centroid, q0 );
+      v3_add( quad[i1], centroid, q1 );
+      
+      m4x3_mulv( rbb->to_world, q0, q0 );
+      m4x3_mulv( rbb->to_world, q1, q1 );
+      
+      vg_line( q0, q1, 0xffffffff );
    }
+#endif
 
-   return count;
+   return rb_capsule_manifold_done( rba, rbb, &manifold, buf );
 }
 
 static int rb_sphere_vs_box( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
@@ -522,8 +774,7 @@ static int rb_sphere_vs_box( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
          d = sqrtf(d2);
          v3_muls( delta, 1.0f/d, ct->n );
          ct->p = r-d;
-         v3_add( co, rba->co, ct->co );
-         v3_muls( ct->co, 0.5f, ct->co );
+         v3_copy( co, ct->co );
       }
 
       ct->rba = rba;
@@ -547,11 +798,11 @@ static int rb_sphere_vs_sphere( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
       float d = sqrtf(d2);
 
       rb_ct *ct = buf;
-      v3_muls( delta, -1.0f/d, ct->n );
+      v3_muls( delta, 1.0f/d, ct->n );
 
       v3f p0, p1;
-      v3_muladds( rba->co, ct->n, rba->inf.sphere.radius, p0 );
-      v3_muladds( rbb->co, ct->n,-rbb->inf.sphere.radius, p1 );
+      v3_muladds( rba->co, ct->n,-rba->inf.sphere.radius, p0 );
+      v3_muladds( rbb->co, ct->n, rbb->inf.sphere.radius, p1 );
       v3_add( p0, p1, ct->co );
       v3_muls( ct->co, 0.5f, ct->co );
       ct->p = r-d;
@@ -563,17 +814,43 @@ static int rb_sphere_vs_sphere( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
    return 0;
 }
 
-static int rb_box_vs_sphere( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+static int RB_MATRIX_ERROR( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
 {
-   return rb_sphere_vs_box( rbb, rba, buf );
+   vg_error( "Collision type is unimplemented between types %d and %d\n",
+             rba->type, rbb->type );
+
+   return 0;
 }
 
-static int rb_box_vs_box( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+static int rb_sphere_vs_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
 {
-   /* TODO: Generating a stable quad manifold, lots of clipping */
-   return 0;
+   return rb_capsule_vs_sphere( rbb, rba, buf );
 }
 
+static int rb_box_vs_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+   return rb_capsule_vs_box( rbb, rba, buf );
+}
+
+static int rb_box_vs_sphere( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+   return rb_sphere_vs_box( rbb, rba, buf );
+}
+
+static int (*rb_jump_table[4][4])( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+= {
+              /* box */         /* Sphere */         /* Capsule */
+/*box    */ { RB_MATRIX_ERROR,  rb_box_vs_sphere,    rb_box_vs_capsule,    RB_MATRIX_ERROR },
+/*sphere */ { rb_sphere_vs_box, rb_sphere_vs_sphere, rb_sphere_vs_capsule, RB_MATRIX_ERROR },
+/*capsule*/ { rb_capsule_vs_box,rb_capsule_vs_sphere,rb_capsule_vs_capsule,RB_MATRIX_ERROR },
+/*mesh   */ { RB_MATRIX_ERROR,  RB_MATRIX_ERROR,     RB_MATRIX_ERROR,      RB_MATRIX_ERROR }
+};
+
+
+/*
+ * Generic functions
+ */
+
 /* 
  * This function does not accept triangle as a dynamic object, it is assumed
  * to always be static.
@@ -615,10 +892,6 @@ static int rb_sphere_vs_triangle( rigidbody *rba, v3f tri[3], rb_ct *buf )
 }
 
 
-/*
- * Generic functions
- */
-
 RB_DEPR
 static int sphere_vs_triangle( v3f c, float r, v3f tri[3], 
       v3f co, v3f norm, float *p )
@@ -826,16 +1099,16 @@ static void rb_rcv( rb_ct *ct, v3f rv, v3f da, v3f db )
    rigidbody *rba = ct->rba,
              *rbb = ct->rbb;
 
-   v3_sub( rba->co, ct->co, da );
-   v3_sub( rbb->co, ct->co, db );
+   v3_sub( ct->co, rba->co, da );
+   v3_sub( ct->co, rbb->co, db );
    
    v3f rva, rvb;
    v3_cross( rba->w, da, rva );
    v3_add( rba->v, rva, rva );
-
    v3_cross( rbb->w, db, rvb );
    v3_add( rbb->v, rvb, rvb );
-   v3_add( rva, rvb, rv );
+
+   v3_sub( rva, rvb, rv );
 }
 
 /*
@@ -846,16 +1119,20 @@ static void rb_standard_impulse( rb_ct *ct, v3f da, v3f db, v3f impulse )
    rigidbody *rba = ct->rba,
              *rbb = ct->rbb;
 
+   v3f ia, ib;
+   v3_muls( impulse,  ct->mass_total*rba->inv_mass, ia );
+   v3_muls( impulse, -ct->mass_total*rbb->inv_mass, ib );
+
    /* response */
-   v3_muladds( rba->v, impulse, ct->mass_total * rba->inv_mass, rba->v );
-   v3_muladds( rbb->v, impulse, ct->mass_total * rbb->inv_mass, rbb->v );
+   v3_add( rba->v, ia, rba->v );
+   v3_add( rbb->v, ib, rbb->v );
    
    /* Angular velocity */
    v3f wa, wb;
-   v3_cross( da, impulse, wa );
-   v3_cross( db, impulse, wb );
-   v3_muladds( rba->w, wa, ct->mass_total * rba->inv_mass, rba->w );
-   v3_muladds( rbb->w, wb, ct->mass_total * rbb->inv_mass, rbb->w );
+   v3_cross( da, ia, wa );
+   v3_cross( db, ib, wb );
+   v3_add( rba->w, wa, rba->w );
+   v3_add( rbb->w, wb, rbb->w );
 }
 
 /*
@@ -899,8 +1176,7 @@ static void rb_solve_contacts( rb_ct *buf, int len )
       v3f rv, da, db;
       rb_rcv( ct, rv, da, db );
 
-      float vn = -v3_dot( rv, ct->n );
-      vn += ct->bias;
+      float vn = -v3_dot( rv, ct->n ) + ct->bias;
 
       float temp = ct->norm_impulse;
       ct->norm_impulse = vg_maxf( temp + vn, 0.0f );
@@ -1106,6 +1382,88 @@ static void debug_sphere( m4x3f m, float radius, u32 colour )
    }
 }
 
+static void debug_capsule( m4x3f m, float radius, float h, u32 colour )
+{
+   v3f ly = { 0.0f, 0.0f, radius },
+       lx = { 0.0f, radius, 0.0f },
+       lz = { 0.0f, 0.0f, radius };
+
+   float s0 = sinf(0.0f)*radius,
+         c0 = cosf(0.0f)*radius;
+
+   v3f p0, p1, up, right, forward;
+   m3x3_mulv( m, (v3f){0.0f,1.0f,0.0f}, up );
+   m3x3_mulv( m, (v3f){1.0f,0.0f,0.0f}, right );
+   m3x3_mulv( m, (v3f){0.0f,0.0f,-1.0f}, forward );
+   v3_muladds( m[3], up, -h*0.5f+radius, p0 );
+   v3_muladds( m[3], up,  h*0.5f-radius, p1 );
+
+   v3f a0, a1, b0, b1;
+   v3_muladds( p0, right, radius, a0 );
+   v3_muladds( p1, right, radius, a1 );
+   v3_muladds( p0, forward, radius, b0 );
+   v3_muladds( p1, forward, radius, b1 );
+   vg_line( a0, a1, colour );
+   vg_line( b0, b1, colour );
+
+   v3_muladds( p0, right, -radius, a0 );
+   v3_muladds( p1, right, -radius, a1 );
+   v3_muladds( p0, forward, -radius, b0 );
+   v3_muladds( p1, forward, -radius, b1 );
+   vg_line( a0, a1, colour );
+   vg_line( b0, b1, colour );
+   
+   for( int i=0; i<16; i++ )
+   {
+      float t = ((float)(i+1) * (1.0f/16.0f)) * VG_PIf * 2.0f,
+            s1 = sinf(t)*radius,
+            c1 = cosf(t)*radius;
+
+      v3f e0 = { s0, 0.0f, c0 },
+          e1 = { s1, 0.0f, c1 },
+          e2 = { s0, c0, 0.0f },
+          e3 = { s1, c1, 0.0f },
+          e4 = { 0.0f, c0, s0 },
+          e5 = { 0.0f, c1, s1 };
+
+      m3x3_mulv( m, e0, e0 );
+      m3x3_mulv( m, e1, e1 );
+      m3x3_mulv( m, e2, e2 );
+      m3x3_mulv( m, e3, e3 );
+      m3x3_mulv( m, e4, e4 );
+      m3x3_mulv( m, e5, e5 );
+
+      v3_add( p0, e0, a0 );
+      v3_add( p0, e1, a1 );
+      v3_add( p1, e0, b0 );
+      v3_add( p1, e1, b1 );
+
+      vg_line( a0, a1, colour );
+      vg_line( b0, b1, colour );
+
+      if( c0 < 0.0f )
+      {
+         v3_add( p0, e2, a0 );
+         v3_add( p0, e3, a1 );
+         v3_add( p0, e4, b0 );
+         v3_add( p0, e5, b1 );
+      }
+      else
+      {
+         v3_add( p1, e2, a0 );
+         v3_add( p1, e3, a1 );
+         v3_add( p1, e4, b0 );
+         v3_add( p1, e5, b1 );
+      }
+
+      vg_line( a0, a1, colour );
+      vg_line( b0, b1, colour );
+
+      s0 = s1;
+      c0 = c1;
+   }
+}
+
 static void rb_debug( rigidbody *rb, u32 colour )
 {
    if( rb->type == k_rb_shape_box )
@@ -1123,15 +1481,7 @@ static void rb_debug( rigidbody *rb, u32 colour )
       float h = rb->inf.capsule.height,
             r = rb->inf.capsule.radius;
 
-      m3x3_copy( rb->to_world, m0 );
-      m3x3_copy( rb->to_world, m1 );
-      
-      v3_muladds( rb->co, rb->up, -h*0.5f, m0[3] );
-      v3_muladds( rb->co, rb->up,  h*0.5f, m1[3] );
-
-      debug_sphere( m0, r, colour );
-      debug_sphere( m1, r, colour );
-      vg_line( m0[3], m1[3], colour );
+      debug_capsule( rb->to_world, r, h, colour );
    }
 }
 
@@ -1184,115 +1534,6 @@ static int rb_point_in_body( rigidbody *rb, v3f pos, float *pen, v3f normal )
    return 0;
 }
 
-#if 0
-static void rb_build_manifold_rb_static( rigidbody *ra, rigidbody *rb_static )
-{
-   v3f verts[8];
-
-   v3f a, b;
-   v3_copy( ra->bbx[0], a );
-   v3_copy( ra->bbx[1], b );
-   
-	m4x3_mulv( ra->to_world, (v3f){ a[0], a[1], a[2] }, verts[0] );
-	m4x3_mulv( ra->to_world, (v3f){ a[0], b[1], a[2] }, verts[1] );
-	m4x3_mulv( ra->to_world, (v3f){ b[0], b[1], a[2] }, verts[2] );
-	m4x3_mulv( ra->to_world, (v3f){ b[0], a[1], a[2] }, verts[3] );
-	m4x3_mulv( ra->to_world, (v3f){ a[0], a[1], b[2] }, verts[4] );
-	m4x3_mulv( ra->to_world, (v3f){ a[0], b[1], b[2] }, verts[5] );
-	m4x3_mulv( ra->to_world, (v3f){ b[0], b[1], b[2] }, verts[6] );
-	m4x3_mulv( ra->to_world, (v3f){ b[0], a[1], b[2] }, verts[7] );
-
-   vg_line_boxf_transformed( rb_static->to_world, rb_static->bbx, 0xff0000ff );
-
-   int count = 0;
-
-   for( int i=0; i<8; i++ )
-   {
-      if( ra->manifold_count == vg_list_size(ra->manifold) )
-         return;
-
-      struct contact *ct = &ra->manifold[ ra->manifold_count ];
-      
-      float p;
-      v3f normal;
-
-      if( rb_point_in_body( rb_static, verts[i], &p, normal ))
-      {
-         v3_copy( normal, ct->n );
-         v3_muladds( verts[i], ct->n, p*0.5f, ct->co );
-         v3_sub( ct->co, ra->co, ct->delta );
-
-         vg_line_pt3( ct->co, 0.0125f, 0xffff00ff );
-         
-         ct->bias = -0.2f * (1.0f/k_rb_delta) * vg_minf( 0.0f, -p+0.04f );
-         rb_tangent_basis( ct->n, ct->t[0], ct->t[1] );
-
-         ct->norm_impulse = 0.0f;
-         ct->tangent_impulse[0] = 0.0f;
-         ct->tangent_impulse[1] = 0.0f;
-
-         ra->manifold_count ++;
-         count ++;
-         if( count == 4 )
-            return;
-      }
-   }
-}
-#endif
-
-/* 
- * Capsule phyics
- */
-
-RB_DEPR
-static void debug_capsule( m4x3f m, float height, float radius, u32 colour )
-{
-   v3f last = { 0.0f, 0.0f, radius };
-   m4x3f lower, upper;
-   m3x3_copy( m, lower );
-   m3x3_copy( m, upper );
-   m4x3_mulv( m, (v3f){0.0f,-height*0.5f+radius,0.0f}, lower[3] );
-   m4x3_mulv( m, (v3f){0.0f, height*0.5f-radius,0.0f}, upper[3] );
-   
-   for( int i=0; i<16; i++ )
-   {
-      float t = ((float)(i+1) * (1.0f/16.0f)) * VG_PIf * 2.0f,
-            s = sinf(t),
-            c = cosf(t);
-
-      v3f p = { s*radius, 0.0f, c*radius };
-
-      v3f p0, p1;
-      m4x3_mulv( lower, p, p0 );
-      m4x3_mulv( lower, last, p1 );
-      vg_line( p0, p1, colour );
-
-      m4x3_mulv( upper, p, p0 );
-      m4x3_mulv( upper, last, p1 );
-      vg_line( p0, p1, colour );
-
-      v3_copy( p, last );
-   }
-
-   for( int i=0; i<4; i++ )
-   {
-      float t = ((float)(i) * (1.0f/4.0f)) * VG_PIf * 2.0f,
-            s = sinf(t),
-            c = cosf(t);
-
-      v3f p = { s*radius, 0.0f, c*radius };
-
-      v3f p0, p1;
-      m4x3_mulv( lower, p, p0 );
-      m4x3_mulv( upper, p, p1 );
-      vg_line( p0, p1, colour );
-
-      m4x3_mulv( lower, (v3f){0.0f,-radius,0.0f}, p0 );
-      m4x3_mulv( upper, (v3f){0.0f, radius,0.0f}, p1 );
-      vg_line( p0, p1, colour );
-   }
-}
-
 /*
  * BVH implementation, this is ONLY for static rigidbodies, its to slow for
  * realtime use.
-- 
2.25.1