+ v3f tri[3];
+
+ for( int i=0; i<3; i++ ){
+ m4x3_mulv( to_local, tri_src[i], tri[i] );
+ v3_sub( tri[i], center, tri[i] );
+ }
+
+ v3f f0,f1,f2,n;
+ v3_sub( tri[1], tri[0], f0 );
+ v3_sub( tri[2], tri[1], f1 );
+ v3_sub( tri[0], tri[2], f2 );
+
+
+ v3f axis[9];
+ v3_cross( (v3f){1.0f,0.0f,0.0f}, f0, axis[0] );
+ v3_cross( (v3f){1.0f,0.0f,0.0f}, f1, axis[1] );
+ v3_cross( (v3f){1.0f,0.0f,0.0f}, f2, axis[2] );
+ v3_cross( (v3f){0.0f,1.0f,0.0f}, f0, axis[3] );
+ v3_cross( (v3f){0.0f,1.0f,0.0f}, f1, axis[4] );
+ v3_cross( (v3f){0.0f,1.0f,0.0f}, f2, axis[5] );
+ v3_cross( (v3f){0.0f,0.0f,1.0f}, f0, axis[6] );
+ v3_cross( (v3f){0.0f,0.0f,1.0f}, f1, axis[7] );
+ v3_cross( (v3f){0.0f,0.0f,1.0f}, f2, axis[8] );
+
+ for( int i=0; i<9; i++ )
+ if(!rb_box_triangle_interval( extent, axis[i], tri )) return 0;
+
+ /* u0, u1, u2 */
+ if(!rb_box_triangle_interval( extent, (v3f){1.0f,0.0f,0.0f}, tri )) return 0;
+ if(!rb_box_triangle_interval( extent, (v3f){0.0f,1.0f,0.0f}, tri )) return 0;
+ if(!rb_box_triangle_interval( extent, (v3f){0.0f,0.0f,1.0f}, tri )) return 0;
+
+ /* normal */
+ v3_cross( f0, f1, n );
+ if(!rb_box_triangle_interval( extent, n, tri )) return 0;
+
+ return 1;
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * Manifold
+ * -----------------------------------------------------------------------------
+ */
+
+VG_STATIC int rb_manifold_apply_filtered( rb_ct *man, int len )
+{
+ int k = 0;
+
+ for( int i=0; i<len; i++ ){
+ rb_ct *ct = &man[i];
+
+ if( ct->type == k_contact_type_disabled )
+ continue;
+
+ man[k ++] = man[i];
+ }
+
+ return k;
+}
+
+/*
+ * Merge two contacts if they are within radius(r) of eachother
+ */
+VG_STATIC void rb_manifold_contact_weld( rb_ct *ci, rb_ct *cj, float r )
+{
+ if( v3_dist2( ci->co, cj->co ) < r*r ){
+ cj->type = k_contact_type_disabled;
+ ci->p = (ci->p + cj->p) * 0.5f;
+
+ v3_add( ci->co, cj->co, ci->co );
+ v3_muls( ci->co, 0.5f, ci->co );
+
+ v3f delta;
+ v3_sub( ci->rba->co, ci->co, delta );
+
+ float c0 = v3_dot( ci->n, delta ),
+ c1 = v3_dot( cj->n, delta );
+
+ if( c0 < 0.0f || c1 < 0.0f ){
+ /* error */
+ ci->type = k_contact_type_disabled;
+ }
+ else{
+ v3f n;
+ v3_muls( ci->n, c0, n );
+ v3_muladds( n, cj->n, c1, n );
+ v3_normalize( n );
+ v3_copy( n, ci->n );
+ }
+ }
+}
+
+/*
+ *
+ */
+VG_STATIC void rb_manifold_filter_joint_edges( rb_ct *man, int len, float r )
+{
+ for( int i=0; i<len-1; i++ ){
+ rb_ct *ci = &man[i];
+ if( ci->type != k_contact_type_edge )
+ continue;
+
+ for( int j=i+1; j<len; j++ ){
+ rb_ct *cj = &man[j];
+ if( cj->type != k_contact_type_edge )
+ continue;
+
+ rb_manifold_contact_weld( ci, cj, r );
+ }
+ }
+}
+
+/*
+ * Resolve overlapping pairs
+ *
+ * TODO: Remove?
+ */
+VG_STATIC void rb_manifold_filter_pairs( rb_ct *man, int len, float r )
+{
+ for( int i=0; i<len-1; i++ ){
+ rb_ct *ci = &man[i];
+ int similar = 0;
+
+ if( ci->type == k_contact_type_disabled ) continue;
+
+ for( int j=i+1; j<len; j++ ){
+ rb_ct *cj = &man[j];
+
+ if( cj->type == k_contact_type_disabled ) continue;
+
+ if( v3_dist2( ci->co, cj->co ) < r*r ){
+ cj->type = k_contact_type_disabled;
+ v3_add( cj->n, ci->n, ci->n );
+ ci->p += cj->p;
+ similar ++;
+ }
+ }
+
+ if( similar ){
+ float n = 1.0f/((float)similar+1.0f);
+ v3_muls( ci->n, n, ci->n );
+ ci->p *= n;
+
+ if( v3_length2(ci->n) < 0.1f*0.1f )
+ ci->type = k_contact_type_disabled;
+ else
+ v3_normalize( ci->n );
+ }
+ }
+}
+
+/*
+ * Remove contacts that are facing away from A
+ */
+VG_STATIC void rb_manifold_filter_backface( rb_ct *man, int len )
+{
+ for( int i=0; i<len; i++ ){
+ rb_ct *ct = &man[i];
+ if( ct->type == k_contact_type_disabled )
+ continue;
+
+ v3f delta;
+ v3_sub( ct->co, ct->rba->co, delta );
+
+ if( v3_dot( delta, ct->n ) > -0.001f )
+ ct->type = k_contact_type_disabled;
+ }
+}
+
+/*
+ * Filter out duplicate coplanar results. Good for spheres.
+ */
+VG_STATIC void rb_manifold_filter_coplanar( rb_ct *man, int len, float w )
+{
+ for( int i=0; i<len; i++ ){
+ rb_ct *ci = &man[i];
+ if( ci->type == k_contact_type_disabled ||
+ ci->type == k_contact_type_edge )
+ continue;
+
+ float d1 = v3_dot( ci->co, ci->n );
+
+ for( int j=0; j<len; j++ ){
+ if( j == i )
+ continue;
+
+ rb_ct *cj = &man[j];
+ if( cj->type == k_contact_type_disabled )
+ continue;
+
+ float d2 = v3_dot( cj->co, ci->n ),
+ d = d2-d1;
+
+ if( fabsf( d ) <= w ){
+ cj->type = k_contact_type_disabled;
+ }
+ }
+ }
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * Collision matrix
+ * -----------------------------------------------------------------------------
+ */
+
+/*
+ * Contact generators
+ *
+ * These do not automatically allocate contacts, an appropriately sized
+ * buffer must be supplied. The function returns the size of the manifold
+ * which was generated.
+ *
+ * The values set on the contacts are: n, co, p, rba, rbb
+ */
+
+/*
+ * 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.
+ */
+VG_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;
+ }
+ }
+}
+
+VG_STATIC void rb_capsule_manifold_init( capsule_manifold *manifold )
+{
+ manifold->t0 = INFINITY;
+ manifold->t1 = -INFINITY;
+}
+
+VG_STATIC int rb_capsule__manifold_done( m4x3f mtx, rb_capsule *c,
+ capsule_manifold *manifold,
+ rb_ct *buf )
+{
+ v3f p0, p1;
+ v3_muladds( mtx[3], mtx[1], -c->height*0.5f+c->radius, p0 );
+ v3_muladds( mtx[3], mtx[1], c->height*0.5f-c->radius, 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, -c->radius, ct->co );
+
+ ct->p = manifold->r0 - d;
+ ct->type = k_contact_type_default;
+ 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, -c->radius, ct->co );
+
+ ct->p = manifold->r1 - d;
+ ct->type = k_contact_type_default;
+
+ count ++;
+ }
+
+ /*
+ * Debugging
+ */
+
+ if( count == 2 )
+ vg_line( buf[0].co, buf[1].co, 0xff0000ff );
+
+ return count;
+}
+
+VG_STATIC int rb_capsule_sphere( rb_object *obja, rb_object *objb, rb_ct *buf )
+{
+ rigidbody *rba = &obja->rb, *rbb = &objb->rb;
+ float h = obja->inf.capsule.height,
+ ra = obja->inf.capsule.radius,
+ rb = objb->inf.sphere.radius;
+
+ v3f p0, p1;
+ v3_muladds( rba->co, rba->to_world[1], -h*0.5f+ra, p0 );
+ v3_muladds( rba->co, rba->to_world[1], 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;
+ ct->type = k_contact_type_default;
+
+ return 1;
+ }
+
+ return 0;
+}
+
+VG_STATIC int rb_capsule__capsule( m4x3f mtxA, rb_capsule *ca,
+ m4x3f mtxB, rb_capsule *cb, rb_ct *buf )
+{
+ float ha = ca->height,
+ hb = cb->height,
+ ra = ca->radius,
+ rb = cb->radius,
+ r = ra+rb;
+
+ v3f p0, p1, p2, p3;
+ v3_muladds( mtxA[3], mtxA[1], -ha*0.5f+ra, p0 );
+ v3_muladds( mtxA[3], mtxA[1], ha*0.5f-ra, p1 );
+ v3_muladds( mtxB[3], mtxB[1], -hb*0.5f+rb, p2 );
+ v3_muladds( mtxB[3], mtxB[1], 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( mtxA, ca, &manifold, buf );
+}
+
+#if 0
+/*
+ * Generates up to two contacts; optimised for the most stable manifold
+ */
+VG_STATIC int rb_capsule_box( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ float h = rba->inf.capsule.height,
+ r = rba->inf.capsule.radius;
+
+ /*
+ * 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 );
+
+ 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])) )