#define k_rb_delta (1.0f/k_rb_rate)
typedef struct rigidbody rigidbody;
+typedef struct contact rb_ct;
+
struct rigidbody
{
v3f co, v, w;
v3f right, up, forward;
+ int is_world;
+
boxf bbx, bbx_world;
float inv_mass;
m4x3f to_world, to_local;
};
+static rigidbody rb_static_null =
+{
+ .co={0.0f,0.0f,0.0f},
+ .q={0.0f,0.0f,0.0f,1.0f},
+ .v={0.0f,0.0f,0.0f},
+ .w={0.0f,0.0f,0.0f},
+ .is_world = 1,
+ .inv_mass = 0.0f
+};
+
static void rb_debug( rigidbody *rb, u32 colour );
static struct contact
{
- rigidbody *rba;
- v3f co, n, delta;
+ rigidbody *rba, *rbb;
+ v3f co, n;
v3f t[2];
- float bias, norm_impulse, tangent_impulse[2];
+ float mass_total, p, bias, norm_impulse, tangent_impulse[2];
}
rb_contact_buffer[256];
static int rb_contact_count = 0;
rb->bbx[1][1] = h;
}
- rb->inv_mass = 1.0f/(8.0f*volume);
+ if( rb->is_world )
+ {
+ rb->inv_mass = 0.0f;
+ }
+ else
+ {
+ rb->inv_mass = 1.0f/(8.0f*volume);
+ }
v3_zero( rb->v );
v3_zero( rb->w );
static void rb_solver_reset(void);
static void rb_build_manifold_terrain( rigidbody *rb );
static void rb_build_manifold_terrain_sphere( rigidbody *rb );
-static void rb_solve_contacts(void);
+static void rb_solve_contacts( rb_ct *buf, int len );
+static void rb_presolve_contacts( rb_ct *buffer, int len );
+/*
+ * These closest point tests were learned from Real-Time Collision Detection by
+ * Christer Ericson
+ */
static float closest_segment_segment( v3f p1, v3f q1, v3f p2, v3f q2,
float *s, float *t, v3f c1, v3f c2)
{
return v3_length2( v0 );
}
-static void closest_point_segment( v3f a, v3f b, v3f point, v3f dest )
+static void closest_point_aabb( v3f p, boxf box, v3f dest )
+{
+ v3_maxv( p, box[0], dest );
+ v3_minv( dest, box[1], dest );
+}
+
+static void closest_point_obb( v3f p, rigidbody *rb, v3f dest )
+{
+ v3f local;
+ m4x3_mulv( rb->to_local, p, local );
+ closest_point_aabb( local, rb->bbx, local );
+ m4x3_mulv( rb->to_world, local, 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;
}
-/* Real-Time Collision Detection */
static void closest_on_triangle( v3f p, v3f tri[3], v3f dest )
{
v3f ab, ac, ap;
v3_muladds( dest, ac, w, dest );
}
+/*
+ * 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
+ */
+
+static void rb_debug_contact( rb_ct *ct )
+{
+ v3f p1;
+ v3_muladds( ct->co, ct->n, 0.2f, p1 );
+ vg_line_pt3( ct->co, 0.1f, 0xff0000ff );
+ vg_line( ct->co, p1, 0xffffffff );
+}
+
+/*
+ * 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 );
+}
+
+/*
+ * Generates up to two contacts; optimised for the most stable manifold
+ */
+static int rb_capsule_vs_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])) )
+ {
+ 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, 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 );
+
+ /* TODO: ? */
+ v3_normalize(d0);
+ v3_normalize(d1);
+ v3_normalize(da);
+
+ if( v3_dot( da, d0 ) <= 0.01f )
+ rb_capsule_manifold( p0, c0, 0.0f, r, &manifold );
+
+ if( v3_dot( da, d1 ) >= -0.01f )
+ rb_capsule_manifold( p1, c1, 1.0f, r, &manifold );
+
+ for( int i=0; i<4; i++ )
+ {
+ int i0 = i,
+ i1 = (i+1)%4;
+
+ 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 );
+ }
+
+ /*
+ * 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 rb_capsule_manifold_done( rba, rbb, &manifold, buf );
+}
+
+static int rb_sphere_vs_box( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ v3f co, delta;
+
+ closest_point_obb( rba->co, rbb, co );
+ v3_sub( rba->co, co, delta );
+
+ float d2 = v3_length2(delta),
+ r = rba->inf.sphere.radius;
+
+ if( d2 <= r*r )
+ {
+ float d;
+
+ rb_ct *ct = buf;
+ if( d2 <= 0.0001f )
+ {
+ v3_sub( rba->co, rbb->co, delta );
+
+ /*
+ * some extra testing is required to find the best axis to push the
+ * object back outside the box. Since there isnt a clear seperating
+ * vector already, especially on really high aspect boxes.
+ */
+ float lx = v3_dot( rbb->right, delta ),
+ ly = v3_dot( rbb->up, delta ),
+ lz = v3_dot( rbb->forward, delta ),
+ px = rbb->bbx[1][0] - fabsf(lx),
+ py = rbb->bbx[1][1] - fabsf(ly),
+ pz = rbb->bbx[1][2] - fabsf(lz);
+
+ if( px < py && px < pz )
+ v3_muls( rbb->right, vg_signf(lx), ct->n );
+ else if( py < pz )
+ v3_muls( rbb->up, vg_signf(ly), ct->n );
+ else
+ v3_muls( rbb->forward, vg_signf(lz), ct->n );
+
+ v3_muladds( rba->co, ct->n, -r, ct->co );
+ ct->p = r;
+ }
+ else
+ {
+ d = sqrtf(d2);
+ v3_muls( delta, 1.0f/d, ct->n );
+ ct->p = r-d;
+ v3_copy( co, ct->co );
+ }
+
+ ct->rba = rba;
+ ct->rbb = rbb;
+ return 1;
+ }
+
+ return 0;
+}
+
+static int rb_sphere_vs_sphere( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ v3f delta;
+ v3_sub( rba->co, rbb->co, delta );
+
+ float d2 = v3_length2(delta),
+ r = rba->inf.sphere.radius + rbb->inf.sphere.radius;
+
+ if( d2 < r*r )
+ {
+ float d = sqrtf(d2);
+
+ rb_ct *ct = buf;
+ 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_add( p0, p1, ct->co );
+ v3_muls( ct->co, 0.5f, ct->co );
+ ct->p = r-d;
+ ct->rba = rba;
+ ct->rbb = rbb;
+ return 1;
+ }
+
+ return 0;
+}
+
+static int RB_MATRIX_ERROR( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ vg_error( "Collision type is unimplemented between types %d and %d\n",
+ rba->type, rbb->type );
+
+ return 0;
+}
+
+static int rb_sphere_vs_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ 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.
+ *
+ * The triangle is also assumed to be one sided for better detection
+ */
+static int rb_sphere_vs_triangle( rigidbody *rba, v3f tri[3], rb_ct *buf )
+{
+ v3f delta, co;
+
+ closest_on_triangle( rba->co, tri, co );
+ v3_sub( rba->co, co, delta );
+
+ float d2 = v3_length2( delta ),
+ r = rba->inf.sphere.radius;
+
+ if( d2 < r*r )
+ {
+ v3f ab, ac, tn;
+ v3_sub( tri[1], tri[0], ab );
+ v3_sub( tri[2], tri[0], ac );
+ v3_cross( ac, ab, tn );
+
+ if( v3_dot( delta, tn ) > 0.0f )
+ v3_muls( delta, -1.0f, delta );
+
+ float d = sqrtf(d2);
+
+ rb_ct *ct = buf;
+ v3_muls( delta, 1.0f/d, ct->n );
+ v3_copy( co, ct->co );
+ ct->p = r-d;
+ ct->rba = rba;
+ ct->rbb = &rb_static_null;
+ return 1;
+ }
+
+ return 0;
+}
+
+
+RB_DEPR
static int sphere_vs_triangle( v3f c, float r, v3f tri[3],
v3f co, v3f norm, float *p )
{
rb_contact_count = 0;
}
+static rb_ct *rb_global_ct(void)
+{
+ return rb_contact_buffer + rb_contact_count;
+}
+
static struct contact *rb_start_contact(void)
{
if( rb_contact_count == vg_list_size(rb_contact_buffer) )
ct->rba = rb;
v3_copy( co, ct->co );
v3_copy( norm, ct->n );
-
- v3_sub( co, rb->co, ct->delta );
rb_commit_contact( ct, p );
}
}
v3_copy( hit.normal, ct->n );
v3_add( point, surface, ct->co );
v3_muls( ct->co, 0.5f, ct->co );
- v3_sub( ct->co, rb->co, ct->delta );
rb_commit_contact( ct, p );
count ++;
}
}
-static void rb_solve_contacts(void)
+/*
+ * Initializing things like tangent vectors
+ */
+
+static void rb_presolve_contacts( rb_ct *buffer, int len )
+{
+ for( int i=0; i<len; i++ )
+ {
+ rb_ct *ct = &buffer[i];
+ ct->bias = -0.2f * k_rb_rate * vg_minf(0.0f,-ct->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;
+ ct->mass_total = 1.0f/(ct->rba->inv_mass + ct->rbb->inv_mass);
+
+ rb_debug_contact( ct );
+ }
+}
+
+/*
+ * Creates relative contact velocity vector, and offsets between each body
+ */
+static void rb_rcv( rb_ct *ct, v3f rv, v3f da, v3f db )
+{
+ rigidbody *rba = ct->rba,
+ *rbb = ct->rbb;
+
+ 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_sub( rva, rvb, rv );
+}
+
+/*
+ * Apply regular and angular velocity impulses to objects involved in contact
+ */
+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_add( rba->v, ia, rba->v );
+ v3_add( rbb->v, ib, rbb->v );
+
+ /* Angular velocity */
+ v3f wa, wb;
+ v3_cross( da, ia, wa );
+ v3_cross( db, ib, wb );
+ v3_add( rba->w, wa, rba->w );
+ v3_add( rbb->w, wb, rbb->w );
+}
+
+/*
+ * One iteration to solve the contact constraint
+ */
+static void rb_solve_contacts( rb_ct *buf, int len )
{
float k_friction = 0.1f;
/* Friction Impulse */
- for( int i=0; i<rb_contact_count; i++ )
+ for( int i=0; i<len; i++ )
{
- struct contact *ct = &rb_contact_buffer[i];
+ struct contact *ct = &buf[i];
rigidbody *rb = ct->rba;
- v3f dv;
- v3_cross( rb->w, ct->delta, dv );
- v3_add( rb->v, dv, dv );
+ v3f rv, da, db;
+ rb_rcv( ct, rv, da, db );
for( int j=0; j<2; j++ )
{
- float vt = vg_clampf( -v3_dot( dv, ct->t[j] ),
- -k_friction, k_friction );
-
- vt = -v3_dot( dv, ct->t[j] );
+ float f = k_friction * ct->norm_impulse,
+ vt = -v3_dot( rv, ct->t[j] );
float temp = ct->tangent_impulse[j];
- ct->tangent_impulse[j] = vg_clampf( temp+vt, -k_friction, k_friction );
+ ct->tangent_impulse[j] = vg_clampf( temp+vt, -f, f );
vt = ct->tangent_impulse[j] - temp;
v3f impulse;
-
v3_muls( ct->t[j], vt, impulse );
- v3_add( impulse, rb->v, rb->v );
- v3_cross( ct->delta, impulse, impulse );
- v3_add( impulse, rb->w, rb->w );
+ rb_standard_impulse( ct, da, db, impulse );
}
}
/* Normal Impulse */
- for( int i=0; i<rb_contact_count; i++ )
+ for( int i=0; i<len; i++ )
{
- struct contact *ct = &rb_contact_buffer[i];
- rigidbody *rb = ct->rba;
+ struct contact *ct = &buf[i];
+ rigidbody *rba = ct->rba,
+ *rbb = ct->rbb;
- v3f dv;
- v3_cross( rb->w, ct->delta, dv );
- v3_add( rb->v, dv, dv );
+ v3f rv, da, db;
+ rb_rcv( ct, rv, da, db );
- float vn = -v3_dot( dv, 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 );
vn = ct->norm_impulse - temp;
v3f impulse;
-
v3_muls( ct->n, vn, impulse );
- v3_add( impulse, rb->v, rb->v );
- v3_cross( ct->delta, impulse, impulse );
- v3_add( impulse, rb->w, rb->w );
+ rb_standard_impulse( ct, da, db, impulse );
}
}
+/*
+ * The following ventures into not really very sophisticated at all maths
+ */
+
struct rb_angle_limit
{
rigidbody *rba, *rbb;
}
}
+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 )
{
debug_sphere( rb->to_world, rb->inf.sphere.radius, colour );
}
+ else if( rb->type == k_rb_shape_capsule )
+ {
+ m4x3f m0, m1;
+ float h = rb->inf.capsule.height,
+ r = rb->inf.capsule.radius;
+
+ debug_capsule( rb->to_world, r, h, colour );
+ }
}
/*
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
- */
-
-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.