+/*
+ * Copyright (C) 2021-2022 Mt.ZERO Software, Harry Godden - All Rights Reserved
+ */
+
/*
* Resources: Box2D - Erin Catto
* qu3e - Randy Gaul
*/
-#include "vg/vg.h"
-static void rb_tangent_basis( v3f n, v3f tx, v3f ty );
+#include "common.h"
+#include "bvh.h"
+#include "scene.h"
+
+VG_STATIC void rb_tangent_basis( v3f n, v3f tx, v3f ty );
+VG_STATIC bh_system bh_system_rigidbodies;
#ifndef RIGIDBODY_H
#define RIGIDBODY_H
-#define RB_DEPR
+/*
+ * -----------------------------------------------------------------------------
+ * (K)onstants
+ * -----------------------------------------------------------------------------
+ */
-#define k_rb_delta (1.0f/60.0f)
+VG_STATIC const float
+ k_rb_rate = (1.0/VG_TIMESTEP_FIXED),
+ k_rb_delta = (1.0/k_rb_rate),
+ k_friction = 0.6f,
+ k_damp_linear = 0.05f, /* scale velocity 1/(1+x) */
+ k_damp_angular = 0.1f, /* scale angular 1/(1+x) */
+ k_limit_bias = 0.02f,
+ k_joint_bias = 0.08f, /* positional joints */
+ k_joint_correction = 0.01f,
+ k_penetration_slop = 0.01f,
+ k_inertia_scale = 4.0f;
+
+/*
+ * -----------------------------------------------------------------------------
+ * structure definitions
+ * -----------------------------------------------------------------------------
+ */
typedef struct rigidbody rigidbody;
+typedef struct contact rb_ct;
+
struct rigidbody
{
- v3f co, v, I;
+ v3f co, v, w;
v4f q;
- boxf bbx;
- float inv_mass;
- struct contact
+ enum rb_shape
{
- v3f co, n, delta;
- v3f t[2];
- float bias, norm_impulse, tangent_impulse[2];
- }
- manifold[4];
- int manifold_count;
-
- v3f delta; /* where is the origin of this in relation to a parent body */
- m4x3f to_world, to_local;
-};
+ k_rb_shape_box = 0,
+ k_rb_shape_sphere = 1,
+ k_rb_shape_capsule = 2,
+ k_rb_shape_scene = 3
+ }
+ type;
+
+ union
+ {
+ struct rb_sphere
+ {
+ float radius;
+ }
+ sphere;
-static void rb_update_transform( rigidbody *rb )
-{
- q_normalize( rb->q );
- q_m3x3( rb->q, rb->to_world );
- v3_copy( rb->co, rb->to_world[3] );
+ struct rb_capsule
+ {
+ float height, radius;
+ }
+ capsule;
- m4x3_invert_affine( rb->to_world, rb->to_local );
-}
+ struct rb_scene
+ {
+ bh_tree *bh_scene;
+ }
+ scene;
+ }
+ inf;
-static void rb_init( rigidbody *rb )
-{
- q_identity( rb->q );
- v3_zero( rb->v );
- v3_zero( rb->I );
+ v3f right, up, forward;
+
+ int is_world;
- v3f dims;
- v3_sub( rb->bbx[1], rb->bbx[0], dims );
+ boxf bbx, bbx_world;
+ float inv_mass;
- rb->inv_mass = 1.0f/(8.0f*dims[0]*dims[1]*dims[2]);
+ /* inertia model and inverse world tensor */
+ v3f I;
+ m3x3f iI, iIw;
- rb_update_transform( rb );
-}
+ m4x3f to_world, to_local;
+};
-static void rb_iter( rigidbody *rb )
+VG_STATIC struct contact
{
- v3f gravity = { 0.0f, -9.6f, 0.0f };
- v3_muladds( rb->v, gravity, k_rb_delta, rb->v );
-
- /* intergrate velocity */
- v3_muladds( rb->co, rb->v, k_rb_delta, rb->co );
-
- v3_lerp( rb->I, (v3f){0.0f,0.0f,0.0f}, 0.0025f, rb->I );
+ rigidbody *rba, *rbb;
+ v3f co, n;
+ v3f t[2];
+ float p, bias, norm_impulse, tangent_impulse[2],
+ normal_mass, tangent_mass[2];
- /* inegrate inertia */
- if( v3_length2( rb->I ) > 0.0f )
- {
- v4f rotation;
- v3f axis;
- v3_copy( rb->I, axis );
-
- float mag = v3_length( axis );
- v3_divs( axis, mag, axis );
- q_axis_angle( rotation, axis, mag*k_rb_delta );
- q_mul( rotation, rb->q, rb->q );
- }
+ u32 element_id;
}
+rb_contact_buffer[256];
+VG_STATIC int rb_contact_count = 0;
+
+/*
+ * -----------------------------------------------------------------------------
+ * Math Utils
+ * -----------------------------------------------------------------------------
+ */
-static void rb_torque( rigidbody *rb, v3f axis, float mag )
+VG_STATIC float sphere_volume( float radius )
{
- v3_muladds( rb->I, axis, mag*k_rb_delta, rb->I );
+ float r3 = radius*radius*radius;
+ return (4.0f/3.0f) * VG_PIf * r3;
}
-static void rb_tangent_basis( v3f n, v3f tx, v3f ty )
+VG_STATIC void rb_tangent_basis( v3f n, v3f tx, v3f ty )
{
/* Compute tangent basis (box2d) */
if( fabsf( n[0] ) >= 0.57735027f )
v3_cross( n, tx, ty );
}
-#include "world.h"
+/*
+ * -----------------------------------------------------------------------------
+ * Debugging
+ * -----------------------------------------------------------------------------
+ */
+
+VG_STATIC void rb_debug_contact( rb_ct *ct )
+{
+ v3f p1;
+ v3_muladds( ct->co, ct->n, 0.1f, p1 );
+ vg_line_pt3( ct->co, 0.025f, 0xff0000ff );
+ vg_line( ct->co, p1, 0xffffffff );
+}
-static void rb_build_manifold( rigidbody *rb )
+VG_STATIC void debug_sphere( m4x3f m, float radius, u32 colour )
{
- v3f *box = rb->bbx;
- v3f pts[8];
- float *p000 = pts[0], *p001 = pts[1], *p010 = pts[2], *p011 = pts[3],
- *p100 = pts[4], *p101 = pts[5], *p110 = pts[6], *p111 = pts[7];
-
- p000[0]=box[0][0];p000[1]=box[0][1];p000[2]=box[0][2];
- p001[0]=box[0][0];p001[1]=box[0][1];p001[2]=box[1][2];
- p010[0]=box[0][0];p010[1]=box[1][1];p010[2]=box[0][2];
- p011[0]=box[0][0];p011[1]=box[1][1];p011[2]=box[1][2];
+ v3f ly = { 0.0f, 0.0f, radius },
+ lx = { 0.0f, radius, 0.0f },
+ lz = { 0.0f, 0.0f, radius };
+
+ 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 py = { s*radius, 0.0f, c*radius },
+ px = { s*radius, c*radius, 0.0f },
+ pz = { 0.0f, s*radius, c*radius };
+
+ v3f p0, p1, p2, p3, p4, p5;
+ m4x3_mulv( m, py, p0 );
+ m4x3_mulv( m, ly, p1 );
+ m4x3_mulv( m, px, p2 );
+ m4x3_mulv( m, lx, p3 );
+ m4x3_mulv( m, pz, p4 );
+ m4x3_mulv( m, lz, p5 );
+
+ vg_line( p0, p1, colour == 0x00? 0xff00ff00: colour );
+ vg_line( p2, p3, colour == 0x00? 0xff0000ff: colour );
+ vg_line( p4, p5, colour == 0x00? 0xffff0000: colour );
+
+ v3_copy( py, ly );
+ v3_copy( px, lx );
+ v3_copy( pz, lz );
+ }
+}
- p100[0]=box[1][0];p100[1]=box[0][1];p100[2]=box[0][2];
- p101[0]=box[1][0];p101[1]=box[0][1];p101[2]=box[1][2];
- p110[0]=box[1][0];p110[1]=box[1][1];p110[2]=box[0][2];
- p111[0]=box[1][0];p111[1]=box[1][1];p111[2]=box[1][2];
+VG_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 );
+ }
- m4x3_mulv( rb->to_world, p000, p000 );
- m4x3_mulv( rb->to_world, p001, p001 );
- m4x3_mulv( rb->to_world, p010, p010 );
- m4x3_mulv( rb->to_world, p011, p011 );
- m4x3_mulv( rb->to_world, p100, p100 );
- m4x3_mulv( rb->to_world, p101, p101 );
- m4x3_mulv( rb->to_world, p110, p110 );
- m4x3_mulv( rb->to_world, p111, p111 );
+ vg_line( a0, a1, colour );
+ vg_line( b0, b1, colour );
- rb->manifold_count = 0;
+ s0 = s1;
+ c0 = c1;
+ }
+}
- for( int i=0; i<8; i++ )
+VG_STATIC void rb_debug( rigidbody *rb, u32 colour )
+{
+ if( rb->type == k_rb_shape_box )
{
- float *point = pts[i];
- struct contact *ct = &rb->manifold[rb->manifold_count];
-
- v3f surface;
- v3_copy( point, surface );
- surface[1] += 4.0f;
+ v3f *box = rb->bbx;
+ vg_line_boxf_transformed( rb->to_world, rb->bbx, colour );
+ }
+ else if( rb->type == k_rb_shape_sphere )
+ {
+ 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;
- ray_hit hit;
- hit.dist = INFINITY;
- if( !ray_world( surface, (v3f){0.0f,-1.0f,0.0f}, &hit ))
- continue;
+ debug_capsule( rb->to_world, r, h, colour );
+ }
+ else if( rb->type == k_rb_shape_scene )
+ {
+ vg_line_boxf( rb->bbx, colour );
+ }
+}
- v3_copy( hit.normal, ct->n );
- v3_copy( hit.pos, surface );
+/*
+ * -----------------------------------------------------------------------------
+ * Integration
+ * -----------------------------------------------------------------------------
+ */
- float p = vg_minf( surface[1] - point[1], 1.0f );
+/*
+ * Update world space bounding box based on local one
+ */
+VG_STATIC void rb_update_bounds( rigidbody *rb )
+{
+ box_copy( rb->bbx, rb->bbx_world );
+ m4x3_transform_aabb( rb->to_world, rb->bbx_world );
+}
- if( p > 0.0f )
- {
- v3_add( point, surface, ct->co );
- v3_muls( ct->co, 0.5f, ct->co );
+/*
+ * Commit transform to rigidbody. Updates matrices
+ */
+VG_STATIC void rb_update_transform( rigidbody *rb )
+{
+ q_normalize( rb->q );
+ q_m3x3( rb->q, rb->to_world );
+ v3_copy( rb->co, rb->to_world[3] );
- //vg_line_pt3( ct->co, 0.0125f, 0xff0000ff );
+ m4x3_invert_affine( rb->to_world, rb->to_local );
- v3_sub( ct->co, rb->co, ct->delta );
- 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] );
+ m3x3_mulv( rb->to_world, (v3f){1.0f,0.0f, 0.0f}, rb->right );
+ m3x3_mulv( rb->to_world, (v3f){0.0f,1.0f, 0.0f}, rb->up );
+ m3x3_mulv( rb->to_world, (v3f){0.0f,0.0f,-1.0f}, rb->forward );
- ct->norm_impulse = 0.0f;
- ct->tangent_impulse[0] = 0.0f;
- ct->tangent_impulse[1] = 0.0f;
+ m3x3_mul( rb->iI, rb->to_local, rb->iIw );
+ m3x3_mul( rb->to_world, rb->iIw, rb->iIw );
- rb->manifold_count ++;
- if( rb->manifold_count == 4 )
- break;
- }
- }
+ rb_update_bounds( rb );
}
-static void rb_constraint_manifold( rigidbody *rb )
+/*
+ * Extrapolate rigidbody into a transform based on vg accumulator.
+ * Useful for rendering
+ */
+VG_STATIC void rb_extrapolate_transform( rigidbody *rb, m4x3f transform )
{
- float k_friction = 0.1f;
+ float substep = vg_clampf( vg.accumulator / k_rb_delta, 0.0f, 1.0f );
- /* Friction Impulse */
- for( int i=0; i<rb->manifold_count; i++ )
- {
- struct contact *ct = &rb->manifold[i];
+ v3f co;
+ v4f q;
+
+ v3_muladds( rb->co, rb->v, k_rb_delta*substep, co );
- v3f dv;
- v3_cross( rb->I, ct->delta, dv );
- v3_add( rb->v, dv, dv );
+ if( v3_length2( rb->w ) > 0.0f )
+ {
+ v4f rotation;
+ v3f axis;
+ v3_copy( rb->w, axis );
- for( int j=0; j<2; j++ )
- {
- float vt = vg_clampf( -v3_dot( dv, ct->t[j] ),
- -k_friction, k_friction );
+ float mag = v3_length( axis );
+ v3_divs( axis, mag, axis );
+ q_axis_angle( rotation, axis, mag*k_rb_delta*substep );
+ q_mul( rotation, rb->q, q );
+ q_normalize( q );
+ }
+ else
+ {
+ v4_copy( rb->q, q );
+ }
- vt = -v3_dot( dv, ct->t[j] );
-
- float temp = ct->tangent_impulse[j];
- ct->tangent_impulse[j] = vg_clampf( temp+vt, -k_friction, k_friction );
- vt = ct->tangent_impulse[j] - temp;
+ q_m3x3( q, transform );
+ v3_copy( co, transform[3] );
+}
- v3f impulse;
+/*
+ * Initialize rigidbody and calculate masses, inertia
+ */
+VG_STATIC void rb_init( rigidbody *rb )
+{
+ float volume = 1.0f;
- v3_muls( ct->t[j], vt, impulse );
- v3_add( impulse, rb->v, rb->v );
- v3_cross( ct->delta, impulse, impulse );
- v3_add( impulse, rb->I, rb->I );
- }
+ if( rb->type == k_rb_shape_box )
+ {
+ v3f dims;
+ v3_sub( rb->bbx[1], rb->bbx[0], dims );
+ volume = dims[0]*dims[1]*dims[2];
+ }
+ else if( rb->type == k_rb_shape_sphere )
+ {
+ volume = sphere_volume( rb->inf.sphere.radius );
+ v3_fill( rb->bbx[0], -rb->inf.sphere.radius );
+ v3_fill( rb->bbx[1], rb->inf.sphere.radius );
+ }
+ else if( rb->type == k_rb_shape_capsule )
+ {
+ float r = rb->inf.capsule.radius,
+ h = rb->inf.capsule.height;
+ volume = sphere_volume( r ) + VG_PIf * r*r * (h - r*2.0f);
+
+ v3_fill( rb->bbx[0], -rb->inf.sphere.radius );
+ v3_fill( rb->bbx[1], rb->inf.sphere.radius );
+ rb->bbx[0][1] = -h;
+ rb->bbx[1][1] = h;
+ }
+ else if( rb->type == k_rb_shape_scene )
+ {
+ rb->is_world = 1;
+ box_copy( rb->inf.scene.bh_scene->nodes[0].bbx, rb->bbx );
}
- /* Normal Impulse */
- for( int i=0; i<rb->manifold_count; i++ )
+ if( rb->is_world )
+ {
+ rb->inv_mass = 0.0f;
+ v3_zero( rb->I );
+ m3x3_zero(rb->iI);
+ }
+ else
{
- struct contact *ct = &rb->manifold[i];
+ float mass = 2.0f*volume;
+ rb->inv_mass = 1.0f/mass;
+
+ v3f extent;
+ v3_sub( rb->bbx[1], rb->bbx[0], extent );
+ v3_muls( extent, 0.5f, extent );
+
+ /* local intertia tensor */
+ float scale = k_inertia_scale;
+ float ex2 = scale*extent[0]*extent[0],
+ ey2 = scale*extent[1]*extent[1],
+ ez2 = scale*extent[2]*extent[2];
+
+ rb->I[0] = ((1.0f/12.0f) * mass * (ey2+ez2));
+ rb->I[1] = ((1.0f/12.0f) * mass * (ex2+ez2));
+ rb->I[2] = ((1.0f/12.0f) * mass * (ex2+ey2));
+
+ m3x3_identity( rb->iI );
+ rb->iI[0][0] = rb->I[0];
+ rb->iI[1][1] = rb->I[1];
+ rb->iI[2][2] = rb->I[2];
+ m3x3_inv( rb->iI, rb->iI );
+ }
- v3f dv;
- v3_cross( rb->I, ct->delta, dv );
- v3_add( rb->v, dv, dv );
+ v3_zero( rb->v );
+ v3_zero( rb->w );
- float vn = -v3_dot( dv, ct->n );
- vn += ct->bias;
+ rb_update_transform( rb );
+}
- float temp = ct->norm_impulse;
- ct->norm_impulse = vg_maxf( temp + vn, 0.0f );
- vn = ct->norm_impulse - temp;
+VG_STATIC void rb_iter( rigidbody *rb )
+{
+ v3f gravity = { 0.0f, -9.8f, 0.0f };
+ v3_muladds( rb->v, gravity, k_rb_delta, rb->v );
- v3f impulse;
+ /* intergrate velocity */
+ v3_muladds( rb->co, rb->v, k_rb_delta, rb->co );
+ v3_lerp( rb->w, (v3f){0.0f,0.0f,0.0f}, 0.0025f, rb->w );
- v3_muls( ct->n, vn, impulse );
- v3_add( impulse, rb->v, rb->v );
- v3_cross( ct->delta, impulse, impulse );
- v3_add( impulse, rb->I, rb->I );
+ /* inegrate inertia */
+ if( v3_length2( rb->w ) > 0.0f )
+ {
+ v4f rotation;
+ v3f axis;
+ v3_copy( rb->w, axis );
+
+ float mag = v3_length( axis );
+ v3_divs( axis, mag, axis );
+ q_axis_angle( rotation, axis, mag*k_rb_delta );
+ q_mul( rotation, rb->q, rb->q );
}
+
+ /* damping */
+ v3_muls( rb->v, 1.0f/(1.0f+k_rb_delta*k_damp_linear), rb->v );
+ v3_muls( rb->w, 1.0f/(1.0f+k_rb_delta*k_damp_angular), rb->w );
}
-struct rb_angle_limit
-{
- rigidbody *rba, *rbb;
- v3f axis;
- float impulse, bias;
-};
+/*
+ * -----------------------------------------------------------------------------
+ * Closest point functions
+ * -----------------------------------------------------------------------------
+ */
-static int rb_angle_limit_force(
- rigidbody *rba, v3f va,
- rigidbody *rbb, v3f vb,
- float max )
+/*
+ * These closest point tests were learned from Real-Time Collision Detection by
+ * Christer Ericson
+ */
+VG_STATIC float closest_segment_segment( v3f p1, v3f q1, v3f p2, v3f q2,
+ float *s, float *t, v3f c1, v3f c2)
{
- v3f wva, wvb;
- m3x3_mulv( rba->to_world, va, wva );
- m3x3_mulv( rbb->to_world, vb, wvb );
+ v3f d1,d2,r;
+ v3_sub( q1, p1, d1 );
+ v3_sub( q2, p2, d2 );
+ v3_sub( p1, p2, r );
- float dt = v3_dot(wva,wvb)*0.999f,
- ang = fabsf(dt);
- ang = acosf( dt );
- if( ang > max )
- {
- float correction = max-ang;
+ float a = v3_length2( d1 ),
+ e = v3_length2( d2 ),
+ f = v3_dot( d2, r );
- v3f axis;
- v3_cross( wva, wvb, axis );
-
- v4f rotation;
- q_axis_angle( rotation, axis, -correction*0.25f );
- q_mul( rotation, rba->q, rba->q );
+ const float kEpsilon = 0.0001f;
- q_axis_angle( rotation, axis, correction*0.25f );
- q_mul( rotation, rbb->q, rbb->q );
+ if( a <= kEpsilon && e <= kEpsilon )
+ {
+ *s = 0.0f;
+ *t = 0.0f;
+ v3_copy( p1, c1 );
+ v3_copy( p2, c2 );
- return 1;
+ v3f v0;
+ v3_sub( c1, c2, v0 );
+
+ return v3_length2( v0 );
+ }
+
+ if( a<= kEpsilon )
+ {
+ *s = 0.0f;
+ *t = vg_clampf( f / e, 0.0f, 1.0f );
+ }
+ else
+ {
+ float c = v3_dot( d1, r );
+ if( e <= kEpsilon )
+ {
+ *t = 0.0f;
+ *s = vg_clampf( -c / a, 0.0f, 1.0f );
+ }
+ else
+ {
+ float b = v3_dot(d1,d2),
+ d = a*e-b*b;
+
+ if( d != 0.0f )
+ {
+ *s = vg_clampf((b*f - c*e)/d, 0.0f, 1.0f);
+ }
+ else
+ {
+ *s = 0.0f;
+ }
+
+ *t = (b*(*s)+f) / e;
+
+ if( *t < 0.0f )
+ {
+ *t = 0.0f;
+ *s = vg_clampf( -c / a, 0.0f, 1.0f );
+ }
+ else if( *t > 1.0f )
+ {
+ *t = 1.0f;
+ *s = vg_clampf((b-c)/a,0.0f,1.0f);
+ }
+ }
}
- return 0;
+ v3_muladds( p1, d1, *s, c1 );
+ v3_muladds( p2, d2, *t, c2 );
+
+ v3f v0;
+ v3_sub( c1, c2, v0 );
+ return v3_length2( v0 );
}
-static void rb_constraint_angle_limit( struct rb_angle_limit *limit )
+VG_STATIC void closest_point_aabb( v3f p, boxf box, v3f dest )
{
+ v3_maxv( p, box[0], dest );
+ v3_minv( dest, box[1], dest );
+}
+VG_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 );
}
+VG_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);
+ t = vg_clampf(t,0.0f,1.0f);
+ v3_muladds( a, v0, t, dest );
+ return t;
+}
-RB_DEPR
-static void rb_constraint_angle( rigidbody *rba, v3f va,
- rigidbody *rbb, v3f vb,
- float max, float spring )
+VG_STATIC void closest_on_triangle( v3f p, v3f tri[3], v3f dest )
{
- v3f wva, wvb;
- m3x3_mulv( rba->to_world, va, wva );
- m3x3_mulv( rbb->to_world, vb, wvb );
+ v3f ab, ac, ap;
+ float d1, d2;
+
+ /* Region outside A */
+ v3_sub( tri[1], tri[0], ab );
+ v3_sub( tri[2], tri[0], ac );
+ v3_sub( p, tri[0], ap );
+
+ d1 = v3_dot(ab,ap);
+ d2 = v3_dot(ac,ap);
+ if( d1 <= 0.0f && d2 <= 0.0f )
+ {
+ v3_copy( tri[0], dest );
+ v3_copy( (v3f){INFINITY,INFINITY,INFINITY}, dest );
+ return;
+ }
- float dt = v3_dot(wva,wvb)*0.999f,
- ang = fabsf(dt);
+ /* Region outside B */
+ v3f bp;
+ float d3, d4;
- v3f axis;
- v3_cross( wva, wvb, axis );
- v3_muladds( rba->I, axis, ang*spring*0.5f, rba->I );
- v3_muladds( rbb->I, axis, -ang*spring*0.5f, rbb->I );
+ v3_sub( p, tri[1], bp );
+ d3 = v3_dot( ab, bp );
+ d4 = v3_dot( ac, bp );
- return;
+ if( d3 >= 0.0f && d4 <= d3 )
+ {
+ v3_copy( tri[1], dest );
+ v3_copy( (v3f){INFINITY,INFINITY,INFINITY}, dest );
+ return;
+ }
- /* TODO: convert max into the dot product value so we dont have to always
- * evaluate acosf, only if its greater than the angle specified */
- ang = acosf( dt );
- if( ang > max )
+ /* Edge region of AB */
+ float vc = d1*d4 - d3*d2;
+ if( vc <= 0.0f && d1 >= 0.0f && d3 <= 0.0f )
{
- float correction = max-ang;
-
- v4f rotation;
- q_axis_angle( rotation, axis, -correction*0.125f );
- q_mul( rotation, rba->q, rba->q );
+ float v = d1 / (d1-d3);
+ v3_muladds( tri[0], ab, v, dest );
+ v3_copy( (v3f){INFINITY,INFINITY,INFINITY}, dest );
+ return;
+ }
- q_axis_angle( rotation, axis, correction*0.125f );
- q_mul( rotation, rbb->q, rbb->q );
+ /* Region outside C */
+ v3f cp;
+ float d5, d6;
+ v3_sub( p, tri[2], cp );
+ d5 = v3_dot(ab, cp);
+ d6 = v3_dot(ac, cp);
+
+ if( d6 >= 0.0f && d5 <= d6 )
+ {
+ v3_copy( tri[2], dest );
+ v3_copy( (v3f){INFINITY,INFINITY,INFINITY}, dest );
+ return;
}
-}
-static void rb_relative_velocity( rigidbody *ra, v3f lca,
- rigidbody *rb, v3f lcb, v3f rcv )
-{
- v3f wca, wcb;
- m3x3_mulv( ra->to_world, lca, wca );
- m3x3_mulv( rb->to_world, lcb, wcb );
+ /* Region of AC */
+ float vb = d5*d2 - d1*d6;
+ if( vb <= 0.0f && d2 >= 0.0f && d6 <= 0.0f )
+ {
+ float w = d2 / (d2-d6);
+ v3_muladds( tri[0], ac, w, dest );
+ v3_copy( (v3f){INFINITY,INFINITY,INFINITY}, dest );
+ return;
+ }
- v3_sub( ra->v, rb->v, rcv );
+ /* Region of BC */
+ float va = d3*d6 - d5*d4;
+ if( va <= 0.0f && (d4-d3) >= 0.0f && (d5-d6) >= 0.0f )
+ {
+ float w = (d4-d3) / ((d4-d3) + (d5-d6));
+ v3f bc;
+ v3_sub( tri[2], tri[1], bc );
+ v3_muladds( tri[1], bc, w, dest );
+ v3_copy( (v3f){INFINITY,INFINITY,INFINITY}, dest );
+ return;
+ }
- v3f rcv_Ra, rcv_Rb;
- v3_cross( ra->I, wca, rcv_Ra );
- v3_cross( rb->I, wcb, rcv_Rb );
- v3_add( rcv_Ra, rcv, rcv );
- v3_sub( rcv, rcv_Rb, rcv );
+ /* P inside region, Q via barycentric coordinates uvw */
+ float d = 1.0f/(va+vb+vc),
+ v = vb*d,
+ w = vc*d;
+
+ v3_muladds( tri[0], ab, v, dest );
+ v3_muladds( dest, ac, w, dest );
}
-static void rb_constraint_position( rigidbody *ra, v3f lca,
- rigidbody *rb, v3f lcb )
+VG_STATIC void closest_on_triangle_1( v3f p, v3f tri[3], v3f dest )
{
- /* C = (COa + Ra*LCa) - (COb + Rb*LCb) = 0 */
- v3f wca, wcb;
- m3x3_mulv( ra->to_world, lca, wca );
- m3x3_mulv( rb->to_world, lcb, wcb );
-
- v3f delta;
- v3_add( wcb, rb->co, delta );
- v3_sub( delta, wca, delta );
- v3_sub( delta, ra->co, delta );
-
- v3_muladds( ra->co, delta, 0.5f, ra->co );
- v3_muladds( rb->co, delta, -0.5f, rb->co );
+ v3f ab, ac, ap;
+ float d1, d2;
- v3f rcv;
- v3_sub( ra->v, rb->v, rcv );
+ /* Region outside A */
+ v3_sub( tri[1], tri[0], ab );
+ v3_sub( tri[2], tri[0], ac );
+ v3_sub( p, tri[0], ap );
+
+ d1 = v3_dot(ab,ap);
+ d2 = v3_dot(ac,ap);
+ if( d1 <= 0.0f && d2 <= 0.0f )
+ {
+ v3_copy( tri[0], dest );
+ return;
+ }
- v3f rcv_Ra, rcv_Rb;
- v3_cross( ra->I, wca, rcv_Ra );
- v3_cross( rb->I, wcb, rcv_Rb );
- v3_add( rcv_Ra, rcv, rcv );
- v3_sub( rcv, rcv_Rb, rcv );
+ /* Region outside B */
+ v3f bp;
+ float d3, d4;
- float nm = 0.5f/(rb->inv_mass + ra->inv_mass);
+ v3_sub( p, tri[1], bp );
+ d3 = v3_dot( ab, bp );
+ d4 = v3_dot( ac, bp );
- float mass_a = 1.0f/ra->inv_mass,
- mass_b = 1.0f/rb->inv_mass,
- total_mass = mass_a+mass_b;
+ if( d3 >= 0.0f && d4 <= d3 )
+ {
+ v3_copy( tri[1], dest );
+ return;
+ }
- v3f impulse;
- v3_muls( rcv, 1.0f, impulse );
- v3_muladds( rb->v, impulse, mass_b/total_mass, rb->v );
- v3_cross( wcb, impulse, impulse );
- v3_add( impulse, rb->I, rb->I );
+ /* Edge region of AB */
+ float vc = d1*d4 - d3*d2;
+ if( vc <= 0.0f && d1 >= 0.0f && d3 <= 0.0f )
+ {
+ float v = d1 / (d1-d3);
+ v3_muladds( tri[0], ab, v, dest );
+ return;
+ }
- v3_muls( rcv, -1.0f, impulse );
- v3_muladds( ra->v, impulse, mass_a/total_mass, ra->v );
- v3_cross( wca, impulse, impulse );
- v3_add( impulse, ra->I, ra->I );
+ /* Region outside C */
+ v3f cp;
+ float d5, d6;
+ v3_sub( p, tri[2], cp );
+ d5 = v3_dot(ab, cp);
+ d6 = v3_dot(ac, cp);
+
+ if( d6 >= 0.0f && d5 <= d6 )
+ {
+ v3_copy( tri[2], dest );
+ return;
+ }
-#if 0
- v3f impulse;
- v3_muls( delta, 0.5f*spring, impulse );
+ /* Region of AC */
+ float vb = d5*d2 - d1*d6;
+ if( vb <= 0.0f && d2 >= 0.0f && d6 <= 0.0f )
+ {
+ float w = d2 / (d2-d6);
+ v3_muladds( tri[0], ac, w, dest );
+ return;
+ }
- v3_add( impulse, ra->v, ra->v );
- v3_cross( wca, impulse, impulse );
- v3_add( impulse, ra->I, ra->I );
+ /* Region of BC */
+ float va = d3*d6 - d5*d4;
+ if( va <= 0.0f && (d4-d3) >= 0.0f && (d5-d6) >= 0.0f )
+ {
+ float w = (d4-d3) / ((d4-d3) + (d5-d6));
+ v3f bc;
+ v3_sub( tri[2], tri[1], bc );
+ v3_muladds( tri[1], bc, w, dest );
+ return;
+ }
- v3_muls( delta, -0.5f*spring, impulse );
+ /* P inside region, Q via barycentric coordinates uvw */
+ float d = 1.0f/(va+vb+vc),
+ v = vb*d,
+ w = vc*d;
- v3_add( impulse, rb->v, rb->v );
- v3_cross( wcb, impulse, impulse );
- v3_add( impulse, rb->I, rb->I );
-#endif
+ v3_muladds( tri[0], ab, v, dest );
+ v3_muladds( dest, ac, w, dest );
}
-static void rb_debug( rigidbody *rb, u32 colour )
-{
- v3f *box = rb->bbx;
- v3f p000, p001, p010, p011, p100, p101, p110, p111;
-
- p000[0]=box[0][0];p000[1]=box[0][1];p000[2]=box[0][2];
- p001[0]=box[0][0];p001[1]=box[0][1];p001[2]=box[1][2];
- p010[0]=box[0][0];p010[1]=box[1][1];p010[2]=box[0][2];
- p011[0]=box[0][0];p011[1]=box[1][1];p011[2]=box[1][2];
+/*
+ * -----------------------------------------------------------------------------
+ * Boolean shape overlap functions
+ * -----------------------------------------------------------------------------
+ */
- p100[0]=box[1][0];p100[1]=box[0][1];p100[2]=box[0][2];
- p101[0]=box[1][0];p101[1]=box[0][1];p101[2]=box[1][2];
- p110[0]=box[1][0];p110[1]=box[1][1];p110[2]=box[0][2];
- p111[0]=box[1][0];p111[1]=box[1][1];p111[2]=box[1][2];
+/*
+ * Project AABB, and triangle interval onto axis to check if they overlap
+ */
+VG_STATIC int rb_box_triangle_interval( v3f extent, v3f axis, v3f tri[3] )
+{
+ float
- m4x3_mulv( rb->to_world, p000, p000 );
- m4x3_mulv( rb->to_world, p001, p001 );
- m4x3_mulv( rb->to_world, p010, p010 );
- m4x3_mulv( rb->to_world, p011, p011 );
- m4x3_mulv( rb->to_world, p100, p100 );
- m4x3_mulv( rb->to_world, p101, p101 );
- m4x3_mulv( rb->to_world, p110, p110 );
- m4x3_mulv( rb->to_world, p111, p111 );
-
- vg_line( p000, p001, colour );
- vg_line( p001, p011, colour );
- vg_line( p011, p010, colour );
- vg_line( p010, p000, colour );
+ r = extent[0] * fabsf(axis[0]) +
+ extent[1] * fabsf(axis[1]) +
+ extent[2] * fabsf(axis[2]),
- vg_line( p100, p101, colour );
- vg_line( p101, p111, colour );
- vg_line( p111, p110, colour );
- vg_line( p110, p100, colour );
+ p0 = v3_dot( axis, tri[0] ),
+ p1 = v3_dot( axis, tri[1] ),
+ p2 = v3_dot( axis, tri[2] ),
- vg_line( p100, p000, colour );
- vg_line( p101, p001, colour );
- vg_line( p110, p010, colour );
- vg_line( p111, p011, colour );
+ e = vg_maxf(-vg_maxf(p0,vg_maxf(p1,p2)), vg_minf(p0,vg_minf(p1,p2)));
- vg_line( p000, p110, colour );
- vg_line( p100, p010, colour );
+ if( e > r ) return 0;
+ else return 1;
}
/*
- * out penetration distance, normal
+ * Seperating axis test box vs triangle
*/
-static int rb_point_in_body( rigidbody *rb, v3f pos, float *pen, v3f normal )
+VG_STATIC int rb_box_triangle_sat( rigidbody *rba, v3f tri_src[3] )
{
- v3f local;
- m4x3_mulv( rb->to_local, pos, local );
+ v3f tri[3];
- if( local[0] > rb->bbx[0][0] && local[0] < rb->bbx[1][0] &&
- local[1] > rb->bbx[0][1] && local[1] < rb->bbx[1][1] &&
- local[2] > rb->bbx[0][2] && local[2] < rb->bbx[1][2] )
+ v3f extent, c;
+ v3_sub( rba->bbx[1], rba->bbx[0], extent );
+ v3_muls( extent, 0.5f, extent );
+ v3_add( rba->bbx[0], extent, c );
+
+ for( int i=0; i<3; i++ )
{
- v3f area, com, comrel;
- v3_add( rb->bbx[0], rb->bbx[1], com );
- v3_muls( com, 0.5f, com );
+ m4x3_mulv( rba->to_local, tri_src[i], tri[i] );
+ v3_sub( tri[i], c, tri[i] );
+ }
- v3_sub( rb->bbx[1], rb->bbx[0], area );
- v3_sub( local, com, comrel );
- v3_div( comrel, area, comrel );
+ /* 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;
+
+ v3f v0,v1,v2,n, e0,e1,e2;
+ v3_sub( tri[1], tri[0], v0 );
+ v3_sub( tri[2], tri[0], v1 );
+ v3_sub( tri[2], tri[1], v2 );
+ v3_normalize( v0 );
+ v3_normalize( v1 );
+ v3_normalize( v2 );
+ v3_cross( v0, v1, n );
+ v3_cross( v0, n, e0 );
+ v3_cross( n, v1, e1 );
+ v3_cross( v2, n, e2 );
+
+ /* normal */
+ if(!rb_box_triangle_interval( extent, n, tri )) return 0;
+
+ v3f axis[9];
+ v3_cross( e0, (v3f){1.0f,0.0f,0.0f}, axis[0] );
+ v3_cross( e0, (v3f){0.0f,1.0f,0.0f}, axis[1] );
+ v3_cross( e0, (v3f){0.0f,0.0f,1.0f}, axis[2] );
+ v3_cross( e1, (v3f){1.0f,0.0f,0.0f}, axis[3] );
+ v3_cross( e1, (v3f){0.0f,1.0f,0.0f}, axis[4] );
+ v3_cross( e1, (v3f){0.0f,0.0f,1.0f}, axis[5] );
+ v3_cross( e2, (v3f){1.0f,0.0f,0.0f}, axis[6] );
+ v3_cross( e2, (v3f){0.0f,1.0f,0.0f}, axis[7] );
+ v3_cross( e2, (v3f){0.0f,0.0f,1.0f}, axis[8] );
+
+ for( int i=0; i<9; i++ )
+ if(!rb_box_triangle_interval( extent, axis[i], tri )) return 0;
- int axis = 0;
- float max_mag = fabsf(comrel[0]);
+ return 1;
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * 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( 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;
+}
+
+VG_STATIC int rb_capsule_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;
+}
+
+VG_STATIC int rb_capsule_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
+ */
+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])) )
+ {
+ 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 );
+
+ 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 );
- if( fabsf(comrel[1]) > max_mag )
+ vg_line( q0, q1, 0xffffffff );
+ }
+#endif
+
+ return rb_capsule_manifold_done( rba, rbb, &manifold, buf );
+}
+
+VG_STATIC int rb_sphere_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;
+}
+
+VG_STATIC int rb_sphere_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;
+}
+
+VG_STATIC int rb_sphere_triangle( rigidbody *rba, rigidbody *rbb,
+ v3f tri[3], rb_ct *buf )
+{
+ v3f delta, co;
+
+ closest_on_triangle_1( rba->co, tri, co );
+ v3_sub( rba->co, co, delta );
+
+ vg_line( rba->co, co, 0xffff0000 );
+ vg_line_pt3( rba->co, 0.1f, 0xff00ffff );
+
+ float d2 = v3_length2( delta ),
+ r = rba->inf.sphere.radius;
+
+ if( d2 < r*r )
+ {
+ rb_ct *ct = buf;
+
+ v3f ab, ac, tn;
+ v3_sub( tri[2], tri[0], ab );
+ v3_sub( tri[1], tri[0], ac );
+ v3_cross( ac, ab, tn );
+ v3_copy( tn, ct->n );
+ v3_normalize( ct->n );
+
+ float d = sqrtf(d2);
+
+ v3_copy( co, ct->co );
+ ct->p = r-d;
+ ct->rba = rba;
+ ct->rbb = rbb;
+ return 1;
+ }
+
+ return 0;
+}
+
+VG_STATIC int rb_sphere_scene( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ scene *sc = rbb->inf.scene.bh_scene->user;
+
+ u32 geo[128];
+ v3f tri[3];
+ int len = bh_select( rbb->inf.scene.bh_scene, rba->bbx_world, geo, 128 );
+
+ int count = 0;
+
+ for( int i=0; i<len; i++ )
+ {
+ u32 *ptri = &sc->arrindices[ geo[i]*3 ];
+
+ for( int j=0; j<3; j++ )
+ v3_copy( sc->arrvertices[ptri[j]].co, tri[j] );
+
+ vg_line(tri[0],tri[1],0xff00ff00 );
+ vg_line(tri[1],tri[2],0xff00ff00 );
+ vg_line(tri[2],tri[0],0xff00ff00 );
+
+ buf[count].element_id = ptri[0];
+ count += rb_sphere_triangle( rba, rbb, tri, buf+count );
+
+ if( count == 12 )
+ {
+ vg_warn( "Exceeding sphere_vs_scene capacity. Geometry too dense!\n" );
+ return count;
+ }
+ }
+
+ return count;
+}
+
+VG_STATIC int rb_box_scene( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ scene *sc = rbb->inf.scene.bh_scene->user;
+
+ u32 geo[128];
+ v3f tri[3];
+ int len = bh_select( rbb->inf.scene.bh_scene, rba->bbx_world, geo, 128 );
+
+ int count = 0;
+
+ for( int i=0; i<len; i++ )
+ {
+ u32 *ptri = &sc->arrindices[ geo[i]*3 ];
+
+ for( int j=0; j<3; j++ )
+ v3_copy( sc->arrvertices[ptri[j]].co, tri[j] );
+
+ if( rb_box_triangle_sat( rba, tri ) )
+ {
+ vg_line(tri[0],tri[1],0xff50ff00 );
+ vg_line(tri[1],tri[2],0xff50ff00 );
+ vg_line(tri[2],tri[0],0xff50ff00 );
+ }
+ else
+ {
+ vg_line(tri[0],tri[1],0xff0000ff );
+ vg_line(tri[1],tri[2],0xff0000ff );
+ vg_line(tri[2],tri[0],0xff0000ff );
+
+ continue;
+ }
+
+ v3f v0,v1,n;
+ v3_sub( tri[1], tri[0], v0 );
+ v3_sub( tri[2], tri[0], v1 );
+ v3_cross( v0, v1, n );
+ v3_normalize( n );
+
+ /* find best feature */
+ float best = v3_dot( rba->right, n );
+ int axis = 0;
+
+ float cy = v3_dot( rba->up, n );
+ if( fabsf(cy) > fabsf(best) )
+ {
+ best = cy;
axis = 1;
- max_mag = fabsf(comrel[1]);
}
- if( fabsf(comrel[2]) > max_mag )
+
+ float cz = -v3_dot( rba->forward, n );
+ if( fabsf(cz) > fabsf(best) )
{
+ best = cz;
axis = 2;
- max_mag = fabsf(comrel[2]);
}
-
- v3_zero( normal );
- normal[axis] = vg_signf(comrel[axis]);
- if( normal[axis] < 0.0f )
- *pen = local[axis] - rb->bbx[0][axis];
+ v3f manifold[4];
+
+ if( axis == 0 )
+ {
+ float px = best > 0.0f? rba->bbx[0][0]: rba->bbx[1][0];
+ manifold[0][0] = px;
+ manifold[0][1] = rba->bbx[0][1];
+ manifold[0][2] = rba->bbx[0][2];
+ manifold[1][0] = px;
+ manifold[1][1] = rba->bbx[1][1];
+ manifold[1][2] = rba->bbx[0][2];
+ manifold[2][0] = px;
+ manifold[2][1] = rba->bbx[1][1];
+ manifold[2][2] = rba->bbx[1][2];
+ manifold[3][0] = px;
+ manifold[3][1] = rba->bbx[0][1];
+ manifold[3][2] = rba->bbx[1][2];
+ }
+ else if( axis == 1 )
+ {
+ float py = best > 0.0f? rba->bbx[0][1]: rba->bbx[1][1];
+ manifold[0][0] = rba->bbx[0][0];
+ manifold[0][1] = py;
+ manifold[0][2] = rba->bbx[0][2];
+ manifold[1][0] = rba->bbx[1][0];
+ manifold[1][1] = py;
+ manifold[1][2] = rba->bbx[0][2];
+ manifold[2][0] = rba->bbx[1][0];
+ manifold[2][1] = py;
+ manifold[2][2] = rba->bbx[1][2];
+ manifold[3][0] = rba->bbx[0][0];
+ manifold[3][1] = py;
+ manifold[3][2] = rba->bbx[1][2];
+ }
else
- *pen = rb->bbx[1][axis] - local[axis];
+ {
+ float pz = best > 0.0f? rba->bbx[0][2]: rba->bbx[1][2];
+ manifold[0][0] = rba->bbx[0][0];
+ manifold[0][1] = rba->bbx[0][1];
+ manifold[0][2] = pz;
+ manifold[1][0] = rba->bbx[1][0];
+ manifold[1][1] = rba->bbx[0][1];
+ manifold[1][2] = pz;
+ manifold[2][0] = rba->bbx[1][0];
+ manifold[2][1] = rba->bbx[1][1];
+ manifold[2][2] = pz;
+ manifold[3][0] = rba->bbx[0][0];
+ manifold[3][1] = rba->bbx[1][1];
+ manifold[3][2] = pz;
+ }
+
+ for( int j=0; j<4; j++ )
+ m4x3_mulv( rba->to_world, manifold[j], manifold[j] );
- m3x3_mulv( rb->to_world, normal, normal );
- return 1;
+ vg_line( manifold[0], manifold[1], 0xffffffff );
+ vg_line( manifold[1], manifold[2], 0xffffffff );
+ vg_line( manifold[2], manifold[3], 0xffffffff );
+ vg_line( manifold[3], manifold[0], 0xffffffff );
+
+ for( int j=0; j<4; j++ )
+ {
+ rb_ct *ct = buf+count;
+
+ v3_copy( manifold[j], ct->co );
+ v3_copy( n, ct->n );
+
+ float l0 = v3_dot( tri[0], n ),
+ l1 = v3_dot( manifold[j], n );
+
+ ct->p = (l0-l1)*0.5f;
+ if( ct->p < 0.0f )
+ continue;
+
+ ct->rba = rba;
+ ct->rbb = rbb;
+ count ++;
+
+ if( count >= 12 )
+ return count;
+ }
}
+ return count;
+}
+
+VG_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;
}
+VG_STATIC int rb_sphere_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ return rb_capsule_sphere( rbb, rba, buf );
+}
+
+VG_STATIC int rb_box_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ return rb_capsule_box( rbb, rba, buf );
+}
+
+VG_STATIC int rb_box_sphere( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ return rb_sphere_box( rbb, rba, buf );
+}
+
+VG_STATIC int rb_scene_box( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ return rb_box_scene( rbb, rba, buf );
+}
+
+VG_STATIC int (*rb_jump_table[4][4])( rigidbody *a, rigidbody *b, rb_ct *buf ) =
+{
+ /* box */ /* Sphere */ /* Capsule */ /* Mesh */
+ { RB_MATRIX_ERROR, rb_box_sphere, rb_box_capsule, rb_box_scene },
+ { rb_sphere_box, rb_sphere_sphere, rb_sphere_capsule, rb_sphere_scene },
+ { rb_capsule_box, rb_capsule_sphere, rb_capsule_capsule, RB_MATRIX_ERROR },
+ { rb_scene_box, RB_MATRIX_ERROR, RB_MATRIX_ERROR, RB_MATRIX_ERROR }
+};
+
+VG_STATIC int rb_collide( rigidbody *rba, rigidbody *rbb )
+{
+ int (*collider_jump)(rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+ = rb_jump_table[rba->type][rbb->type];
+
+ /*
+ * 12 is the maximum manifold size we can generate, so we are forced to abort
+ * potentially checking any more.
+ */
+ if( rb_contact_count + 12 > vg_list_size(rb_contact_buffer) )
+ {
+ vg_warn( "Too many contacts made in global collider buffer (%d of %d\n)",
+ rb_contact_count, vg_list_size(rb_contact_buffer) );
+ return 0;
+ }
+
+ /*
+ * FUTURE: Replace this with a more dedicated broad phase pass
+ */
+ if( box_overlap( rba->bbx_world, rbb->bbx_world ) )
+ {
+ int count = collider_jump( rba, rbb, rb_contact_buffer+rb_contact_count);
+ rb_contact_count += count;
+ return count;
+ }
+ else
+ return 0;
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * Dynamics
+ * -----------------------------------------------------------------------------
+ */
+
+VG_STATIC void rb_solver_reset(void)
+{
+ rb_contact_count = 0;
+}
+
+VG_STATIC rb_ct *rb_global_ct(void)
+{
+ return rb_contact_buffer + rb_contact_count;
+}
+
+/*
+ * Initializing things like tangent vectors
+ */
+VG_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+k_penetration_slop );
+ 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;
+
+ v3f ra, rb, raCn, rbCn, raCt, rbCt;
+ v3_sub( ct->co, ct->rba->co, ra );
+ v3_sub( ct->co, ct->rbb->co, rb );
+ v3_cross( ra, ct->n, raCn );
+ v3_cross( rb, ct->n, rbCn );
+
+ /* orient inverse inertia tensors */
+ v3f raCnI, rbCnI;
+ m3x3_mulv( ct->rba->iIw, raCn, raCnI );
+ m3x3_mulv( ct->rbb->iIw, rbCn, rbCnI );
+
+ ct->normal_mass = ct->rba->inv_mass + ct->rbb->inv_mass;
+ ct->normal_mass += v3_dot( raCn, raCnI );
+ ct->normal_mass += v3_dot( rbCn, rbCnI );
+ ct->normal_mass = 1.0f/ct->normal_mass;
+
+ for( int j=0; j<2; j++ )
+ {
+ v3f raCtI, rbCtI;
+ v3_cross( ct->t[j], ra, raCt );
+ v3_cross( ct->t[j], rb, rbCt );
+ m3x3_mulv( ct->rba->iIw, raCt, raCtI );
+ m3x3_mulv( ct->rbb->iIw, rbCt, rbCtI );
+
+ ct->tangent_mass[j] = ct->rba->inv_mass + ct->rbb->inv_mass;
+ ct->tangent_mass[j] += v3_dot( raCt, raCtI );
+ ct->tangent_mass[j] += v3_dot( rbCt, rbCtI );
+ ct->tangent_mass[j] = 1.0f/ct->tangent_mass[j];
+ }
+
+ rb_debug_contact( ct );
+ }
+}
+
+/*
+ * Creates relative contact velocity vector, and offsets between each body
+ */
+VG_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 impulse to object
+ */
+VG_STATIC void rb_linear_impulse( rigidbody *rb, v3f delta, v3f impulse )
+{
+ /* linear */
+ v3_muladds( rb->v, impulse, rb->inv_mass, rb->v );
+
+ /* Angular velocity */
+ v3f wa;
+ v3_cross( delta, impulse, wa );
+
+ m3x3_mulv( rb->iIw, wa, wa );
+ v3_add( rb->w, wa, rb->w );
+}
+
+/*
+ * One iteration to solve the contact constraint
+ */
+VG_STATIC void rb_solve_contacts( rb_ct *buf, int len )
+{
+ for( int i=0; i<len; i++ )
+ {
+ struct contact *ct = &buf[i];
+ rigidbody *rb = ct->rba;
+
+ v3f rv, da, db;
+ rb_rcv( ct, rv, da, db );
+
+ /* Friction */
+ for( int j=0; j<2; j++ )
+ {
+ float f = k_friction * ct->norm_impulse,
+ vt = v3_dot( rv, ct->t[j] ),
+ lambda = ct->tangent_mass[j] * -vt;
+
+ float temp = ct->tangent_impulse[j];
+ ct->tangent_impulse[j] = vg_clampf( temp + lambda, -f, f );
+ lambda = ct->tangent_impulse[j] - temp;
+
+ v3f impulse;
+ v3_muls( ct->t[j], lambda, impulse );
+ rb_linear_impulse( ct->rba, da, impulse );
+
+ v3_muls( ct->t[j], -lambda, impulse );
+ rb_linear_impulse( ct->rbb, db, impulse );
+ }
+
+ /* Normal */
+ rb_rcv( ct, rv, da, db );
+ float vn = v3_dot( rv, ct->n ),
+ lambda = ct->normal_mass * (-vn + ct->bias);
+
+ float temp = ct->norm_impulse;
+ ct->norm_impulse = vg_maxf( temp + lambda, 0.0f );
+ lambda = ct->norm_impulse - temp;
+
+ v3f impulse;
+ v3_muls( ct->n, lambda, impulse );
+ rb_linear_impulse( ct->rba, da, impulse );
+
+ v3_muls( ct->n, -lambda, impulse );
+ rb_linear_impulse( ct->rbb, db, impulse );
+ }
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * Constraints
+ * -----------------------------------------------------------------------------
+ */
+
+VG_STATIC void draw_angle_limit( v3f c, v3f major, v3f minor,
+ float amin, float amax, float measured,
+ u32 colour )
+{
+ float f = 0.05f;
+ v3f ay, ax;
+ v3_muls( major, f, ay );
+ v3_muls( minor, f, ax );
+
+ for( int x=0; x<16; x++ )
+ {
+ float t0 = (float)x / 16.0f,
+ t1 = (float)(x+1) / 16.0f,
+ a0 = vg_lerpf( amin, amax, t0 ),
+ a1 = vg_lerpf( amin, amax, t1 );
+
+ v3f p0, p1;
+ v3_muladds( c, ay, cosf(a0), p0 );
+ v3_muladds( p0, ax, sinf(a0), p0 );
+ v3_muladds( c, ay, cosf(a1), p1 );
+ v3_muladds( p1, ax, sinf(a1), p1 );
+
+ vg_line( p0, p1, colour );
+
+ if( x == 0 )
+ vg_line( c, p0, colour );
+ if( x == 15 )
+ vg_line( c, p1, colour );
+ }
+
+ v3f p2;
+ v3_muladds( c, ay, cosf(measured)*1.2f, p2 );
+ v3_muladds( p2, ax, sinf(measured)*1.2f, p2 );
+ vg_line( c, p2, colour );
+}
+
+VG_STATIC void rb_debug_constraint_limits( rigidbody *ra, rigidbody *rb, v3f lca,
+ v3f limits[2] )
+{
+ v3f ax, ay, az, bx, by, bz;
+ m3x3_mulv( ra->to_world, (v3f){1.0f,0.0f,0.0f}, ax );
+ m3x3_mulv( ra->to_world, (v3f){0.0f,1.0f,0.0f}, ay );
+ m3x3_mulv( ra->to_world, (v3f){0.0f,0.0f,1.0f}, az );
+ m3x3_mulv( rb->to_world, (v3f){1.0f,0.0f,0.0f}, bx );
+ m3x3_mulv( rb->to_world, (v3f){0.0f,1.0f,0.0f}, by );
+ m3x3_mulv( rb->to_world, (v3f){0.0f,0.0f,1.0f}, bz );
+
+ v2f px, py, pz;
+ px[0] = v3_dot( ay, by );
+ px[1] = v3_dot( az, by );
+
+ py[0] = v3_dot( az, bz );
+ py[1] = v3_dot( ax, bz );
+
+ pz[0] = v3_dot( ax, bx );
+ pz[1] = v3_dot( ay, bx );
+
+ float r0 = atan2f( px[1], px[0] ),
+ r1 = atan2f( py[1], py[0] ),
+ r2 = atan2f( pz[1], pz[0] );
+
+ v3f c;
+ m4x3_mulv( ra->to_world, lca, c );
+ draw_angle_limit( c, ay, az, limits[0][0], limits[1][0], r0, 0xff0000ff );
+ draw_angle_limit( c, az, ax, limits[0][1], limits[1][1], r1, 0xff00ff00 );
+ draw_angle_limit( c, ax, ay, limits[0][2], limits[1][2], r2, 0xffff0000 );
+}
+
+VG_STATIC void rb_limit_cure( rigidbody *ra, rigidbody *rb, v3f axis, float d )
+{
+ if( d != 0.0f )
+ {
+ float avx = v3_dot( ra->w, axis ) - v3_dot( rb->w, axis );
+ float joint_mass = rb->inv_mass + ra->inv_mass;
+ joint_mass = 1.0f/joint_mass;
+
+ float bias = (k_limit_bias * k_rb_rate) * d,
+ lambda = -(avx + bias) * joint_mass;
+
+ /* Angular velocity */
+ v3f wa, wb;
+ v3_muls( axis, lambda * ra->inv_mass, wa );
+ v3_muls( axis, -lambda * rb->inv_mass, wb );
+
+ v3_add( ra->w, wa, ra->w );
+ v3_add( rb->w, wb, rb->w );
+ }
+}
+
+VG_STATIC void rb_constraint_limits( rigidbody *ra, v3f lca,
+ rigidbody *rb, v3f lcb, v3f limits[2] )
+{
+ v3f ax, ay, az, bx, by, bz;
+ m3x3_mulv( ra->to_world, (v3f){1.0f,0.0f,0.0f}, ax );
+ m3x3_mulv( ra->to_world, (v3f){0.0f,1.0f,0.0f}, ay );
+ m3x3_mulv( ra->to_world, (v3f){0.0f,0.0f,1.0f}, az );
+ m3x3_mulv( rb->to_world, (v3f){1.0f,0.0f,0.0f}, bx );
+ m3x3_mulv( rb->to_world, (v3f){0.0f,1.0f,0.0f}, by );
+ m3x3_mulv( rb->to_world, (v3f){0.0f,0.0f,1.0f}, bz );
+
+ v2f px, py, pz;
+ px[0] = v3_dot( ay, by );
+ px[1] = v3_dot( az, by );
+
+ py[0] = v3_dot( az, bz );
+ py[1] = v3_dot( ax, bz );
+
+ pz[0] = v3_dot( ax, bx );
+ pz[1] = v3_dot( ay, bx );
+
+ float r0 = atan2f( px[1], px[0] ),
+ r1 = atan2f( py[1], py[0] ),
+ r2 = atan2f( pz[1], pz[0] );
+
+ /* calculate angle deltas */
+ float dx = 0.0f, dy = 0.0f, dz = 0.0f;
+
+ if( r0 < limits[0][0] ) dx = limits[0][0] - r0;
+ if( r0 > limits[1][0] ) dx = limits[1][0] - r0;
+ if( r1 < limits[0][1] ) dy = limits[0][1] - r1;
+ if( r1 > limits[1][1] ) dy = limits[1][1] - r1;
+ if( r2 < limits[0][2] ) dz = limits[0][2] - r2;
+ if( r2 > limits[1][2] ) dz = limits[1][2] - r2;
+
+ v3f wca, wcb;
+ m3x3_mulv( ra->to_world, lca, wca );
+ m3x3_mulv( rb->to_world, lcb, wcb );
+
+ rb_limit_cure( ra, rb, ax, dx );
+ rb_limit_cure( ra, rb, ay, dy );
+ rb_limit_cure( ra, rb, az, dz );
+}
+
+VG_STATIC void rb_debug_constraint_position( rigidbody *ra, v3f lca,
+ rigidbody *rb, v3f lcb )
+{
+ v3f wca, wcb;
+ m3x3_mulv( ra->to_world, lca, wca );
+ m3x3_mulv( rb->to_world, lcb, wcb );
+
+ v3f p0, p1;
+ v3_add( wca, ra->co, p0 );
+ v3_add( wcb, rb->co, p1 );
+ vg_line_pt3( p0, 0.005f, 0xffffff00 );
+ vg_line_pt3( p1, 0.005f, 0xffffff00 );
+ vg_line( p0, p1, 0xffffff00 );
+}
+
+VG_STATIC void rb_constraint_position( rigidbody *ra, v3f lca,
+ rigidbody *rb, v3f lcb )
+{
+ /* C = (COa + Ra*LCa) - (COb + Rb*LCb) = 0 */
+ v3f wca, wcb;
+ m3x3_mulv( ra->to_world, lca, wca );
+ m3x3_mulv( rb->to_world, lcb, wcb );
+
+ v3f rcv;
+ v3_sub( ra->v, rb->v, rcv );
+
+ v3f rcv_Ra, rcv_Rb;
+ v3_cross( ra->w, wca, rcv_Ra );
+ v3_cross( rb->w, wcb, rcv_Rb );
+ v3_add( rcv_Ra, rcv, rcv );
+ v3_sub( rcv, rcv_Rb, rcv );
+
+ v3f delta;
+ v3f p0, p1;
+ v3_add( wca, ra->co, p0 );
+ v3_add( wcb, rb->co, p1 );
+ v3_sub( p1, p0, delta );
+
+ float dist2 = v3_length2( delta );
+
+ if( dist2 > 0.00001f )
+ {
+ float dist = sqrtf(dist2);
+ v3_muls( delta, 1.0f/dist, delta );
+
+ float joint_mass = rb->inv_mass + ra->inv_mass;
+
+ v3f raCn, rbCn, raCt, rbCt;
+ v3_cross( wca, delta, raCn );
+ v3_cross( wcb, delta, rbCn );
+
+ /* orient inverse inertia tensors */
+ v3f raCnI, rbCnI;
+ m3x3_mulv( ra->iIw, raCn, raCnI );
+ m3x3_mulv( rb->iIw, rbCn, rbCnI );
+ joint_mass += v3_dot( raCn, raCnI );
+ joint_mass += v3_dot( rbCn, rbCnI );
+ joint_mass = 1.0f/joint_mass;
+
+ float vd = v3_dot( rcv, delta ),
+ bias = -(k_joint_bias * k_rb_rate) * dist,
+ lambda = -(vd + bias) * joint_mass;
+
+ v3f impulse;
+ v3_muls( delta, lambda, impulse );
+ rb_linear_impulse( ra, wca, impulse );
+ v3_muls( delta, -lambda, impulse );
+ rb_linear_impulse( rb, wcb, impulse );
+
+ /* 'fake' snap */
+ v3_muladds( ra->co, delta, dist * k_joint_correction, ra->co );
+ v3_muladds( rb->co, delta, -dist * k_joint_correction, rb->co );
+ }
+}
+
+/*
+ * Effectors
+ */
+
+VG_STATIC void rb_effect_simple_bouyency( rigidbody *ra, v4f plane,
+ float amt, float drag )
+{
+ /* float */
+ float depth = v3_dot( plane, ra->co ) - plane[3],
+ lambda = vg_clampf( -depth, 0.0f, 1.0f ) * amt;
+
+ v3_muladds( ra->v, plane, lambda * k_rb_delta, ra->v );
+
+ if( depth < 0.0f )
+ v3_muls( ra->v, 1.0f-(drag*k_rb_delta), ra->v );
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * BVH implementation, this is ONLY for VG_STATIC rigidbodies, its to slow for
+ * realtime use.
+ * -----------------------------------------------------------------------------
+ */
+
+VG_STATIC void rb_bh_expand_bound( void *user, boxf bound, u32 item_index )
+{
+ rigidbody *rb = &((rigidbody *)user)[ item_index ];
+ box_concat( bound, rb->bbx_world );
+}
+
+VG_STATIC float rb_bh_centroid( void *user, u32 item_index, int axis )
+{
+ rigidbody *rb = &((rigidbody *)user)[ item_index ];
+ return (rb->bbx_world[axis][0] + rb->bbx_world[1][axis]) * 0.5f;
+}
+
+VG_STATIC void rb_bh_swap( void *user, u32 ia, u32 ib )
+{
+ rigidbody temp, *rba, *rbb;
+ rba = &((rigidbody *)user)[ ia ];
+ rbb = &((rigidbody *)user)[ ib ];
+
+ temp = *rba;
+ *rba = *rbb;
+ *rbb = temp;
+}
+
+VG_STATIC void rb_bh_debug( void *user, u32 item_index )
+{
+ rigidbody *rb = &((rigidbody *)user)[ item_index ];
+ rb_debug( rb, 0xff00ffff );
+}
+
+VG_STATIC bh_system bh_system_rigidbodies =
+{
+ .expand_bound = rb_bh_expand_bound,
+ .item_centroid = rb_bh_centroid,
+ .item_swap = rb_bh_swap,
+ .item_debug = rb_bh_debug,
+ .cast_ray = NULL
+};
+
#endif /* RIGIDBODY_H */
projects / carveJwlIkooP6JGAAIwe30JlM.git / blobdiff