+++ /dev/null
-/*
- * Copyright (C) 2021-2023 Mt.ZERO Software, Harry Godden - All Rights Reserved
- */
-
-/*
- * Resources: Box2D - Erin Catto
- * qu3e - Randy Gaul
- */
-
-#include "vg/vg_console.h"
-#include "bvh.h"
-#include "scene.h"
-
-#include <math.h>
-
-#ifndef RIGIDBODY_H
-#define RIGIDBODY_H
-
-/*
- * -----------------------------------------------------------------------------
- * (K)onstants
- * -----------------------------------------------------------------------------
- */
-
-static const float
- k_rb_rate = (1.0/VG_TIMESTEP_FIXED),
- k_rb_delta = (1.0/k_rb_rate),
- k_friction = 0.4f,
- k_damp_linear = 0.1f, /* scale velocity 1/(1+x) */
- k_damp_angular = 0.1f, /* scale angular 1/(1+x) */
- k_penetration_slop = 0.01f,
- k_inertia_scale = 4.0f,
- k_phys_baumgarte = 0.2f,
- k_gravity = 9.6f,
- k_rb_density = 8.0f;
-
-static float
- k_limit_bias = 0.02f,
- k_joint_correction = 0.01f,
- k_joint_impulse = 1.0f,
- k_joint_bias = 0.08f; /* positional joints */
-
-static void rb_register_cvar(void){
- VG_VAR_F32( k_limit_bias, flags=VG_VAR_CHEAT );
- VG_VAR_F32( k_joint_bias, flags=VG_VAR_CHEAT );
- VG_VAR_F32( k_joint_correction, flags=VG_VAR_CHEAT );
- VG_VAR_F32( k_joint_impulse, flags=VG_VAR_CHEAT );
-}
-
-enum rb_shape {
- k_rb_shape_none = 0,
- k_rb_shape_box = 1,
- k_rb_shape_sphere = 2,
- k_rb_shape_capsule = 3,
-};
-
-/*
- * -----------------------------------------------------------------------------
- * structure definitions
- * -----------------------------------------------------------------------------
- */
-
-typedef struct rigidbody rigidbody;
-typedef struct contact rb_ct;
-typedef struct rb_capsule rb_capsule;
-
-struct rb_capsule{
- f32 h, r;
-};
-
-struct rigidbody{
- v3f co, v, w;
- v4f q;
-
- f32 inv_mass;
-
- m3x3f iI, iIw; /* inertia model and inverse world tensor */
- m4x3f to_world, to_local;
-};
-
-static struct contact{
- rigidbody *rba, *rbb;
- v3f co, n;
- v3f t[2];
- float p, bias, norm_impulse, tangent_impulse[2],
- normal_mass, tangent_mass[2];
-
- u32 element_id;
-
- enum contact_type type;
-}
-rb_contact_buffer[256];
-static int rb_contact_count = 0;
-
-typedef struct rb_constr_pos rb_constr_pos;
-typedef struct rb_constr_swingtwist rb_constr_swingtwist;
-
-struct rb_constr_pos{
- rigidbody *rba, *rbb;
- v3f lca, lcb;
-};
-
-struct rb_constr_swingtwist{
- rigidbody *rba, *rbb;
-
- v4f conevx, conevy; /* relative to rba */
- v3f view_offset, /* relative to rba */
- coneva, conevxb;/* relative to rbb */
-
- int tangent_violation, axis_violation;
- v3f axis, tangent_axis, tangent_target, axis_target;
-
- float conet;
- float tangent_mass, axis_mass;
-
- f32 conv_tangent, conv_axis;
-};
-
-/*
- * -----------------------------------------------------------------------------
- * Debugging
- * -----------------------------------------------------------------------------
- */
-
-static void rb_debug_contact( rb_ct *ct ){
- v3f p1;
- v3_muladds( ct->co, ct->n, 0.05f, p1 );
-
- if( ct->type == k_contact_type_default ){
- vg_line_point( ct->co, 0.0125f, 0xff0000ff );
- vg_line( ct->co, p1, 0xffffffff );
- }
- else if( ct->type == k_contact_type_edge ){
- vg_line_point( ct->co, 0.0125f, 0xff00ffc0 );
- vg_line( ct->co, p1, 0xffffffff );
- }
-}
-
-/*
- * -----------------------------------------------------------------------------
- * Integration
- * -----------------------------------------------------------------------------
- */
-
-/*
- * Update ALL matrices and tensors on rigidbody
- */
-static void rb_update_matrices( rigidbody *rb ){
- //q_normalize( rb->q );
- q_m3x3( rb->q, rb->to_world );
- v3_copy( rb->co, rb->to_world[3] );
- m4x3_invert_affine( rb->to_world, rb->to_local );
-
- /* I = R I_0 R^T */
- m3x3_mul( rb->to_world, rb->iI, rb->iIw );
- m3x3_mul( rb->iIw, rb->to_local, rb->iIw );
-}
-
-/*
- * Extrapolate rigidbody into a transform based on vg accumulator.
- * Useful for rendering
- */
-static void rb_extrapolate( rigidbody *rb, v3f co, v4f q ){
- float substep = vg.time_fixed_extrapolate;
- v3_muladds( rb->co, rb->v, k_rb_delta*substep, co );
-
- 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*substep );
- q_mul( rotation, rb->q, q );
- q_normalize( q );
- }
- else{
- v4_copy( rb->q, q );
- }
-}
-
-/*
- * Inertia
- * -----------------------------------------------------------------------------
- */
-
-/*
- * Translate existing inertia tensor
- */
-static void rb_translate_inertia( m3x3f inout_inertia, f32 mass, v3f d ){
- /*
- * I = I_0 + m*[(d.d)E_3 - d(X)d]
- *
- * I: updated tensor
- * I_0: original tensor
- * m: scalar mass
- * d: translation vector
- * (X): outer product
- * E_3: identity matrix
- */
- m3x3f t, outer, scale;
- m3x3_diagonal( t, v3_dot(d,d) );
- m3x3_outer_product( outer, d, d );
- m3x3_sub( t, outer, t );
- m3x3_diagonal( scale, mass );
- m3x3_mul( scale, t, t );
- m3x3_add( inout_inertia, t, inout_inertia );
-}
-
-/*
- * Rotate existing inertia tensor
- */
-static void rb_rotate_inertia( m3x3f inout_inertia, m3x3f rotation ){
- /*
- * I = R I_0 R^T
- *
- * I: updated tensor
- * I_0: original tensor
- * R: rotation matrix
- * R^T: tranposed rotation matrix
- */
-
- m3x3f Rt;
- m3x3_transpose( rotation, Rt );
- m3x3_mul( rotation, inout_inertia, inout_inertia );
- m3x3_mul( inout_inertia, Rt, inout_inertia );
-}
-/*
- * Create inertia tensor for box
- */
-static void rb_box_inertia( boxf box, f32 mass, m3x3f out_inertia ){
- v3f e, com;
- v3_sub( box[1], box[0], e );
- v3_muladds( box[0], e, 0.5f, com );
-
- f32 ex2 = e[0]*e[0],
- ey2 = e[1]*e[1],
- ez2 = e[2]*e[2],
- ix = (ey2+ez2) * mass * (1.0f/12.0f),
- iy = (ex2+ez2) * mass * (1.0f/12.0f),
- iz = (ex2+ey2) * mass * (1.0f/12.0f);
-
- m3x3_identity( out_inertia );
- m3x3_setdiagonalv3( out_inertia, (v3f){ ix, iy, iz } );
- rb_translate_inertia( out_inertia, mass, com );
-}
-
-/*
- * Create inertia tensor for sphere
- */
-static void rb_sphere_inertia( f32 r, f32 mass, m3x3f out_inertia ){
- f32 ixyz = r*r * mass * (2.0f/5.0f);
-
- m3x3_identity( out_inertia );
- m3x3_setdiagonalv3( out_inertia, (v3f){ ixyz, ixyz, ixyz } );
-}
-
-/*
- * Create inertia tensor for capsule
- *
- * TODO: UNTESTED
- */
-static void rb_capsule_inertia( f32 r, f32 h, f32 mass, m3x3f out_inertia ){
- f32 density = mass / vg_capsule_volume( r, h ),
- ch = h-r*2.0f, /* cylinder height */
- cm = VG_PIf * ch*r*r * density, /* cylinder mass */
- hm = VG_TAUf * (1.0f/3.0f) * r*r*r * density, /* hemisphere mass */
-
- iy = r*r*cm * 0.5f,
- ixz = iy * 0.5f + cm*ch*ch*(1.0f/12.0f),
-
- aux0= (hm*2.0f*r*r)/5.0f;
-
- iy += aux0 * 2.0f;
-
- f32 aux1= ch*0.5f,
- aux2= aux0 + hm*(aux1*aux1 + 3.0f*(1.0f/8.0f)*ch*r);
-
- ixz += aux2*2.0f;
-
- m3x3_identity( out_inertia );
- m3x3_setdiagonalv3( out_inertia, (v3f){ ixz, iy, ixz } );
-}
-
-static void rb_setbody_capsule( rigidbody *rb, f32 r, f32 h,
- f32 density, f32 inertia_scale ){
- f32 vol = vg_capsule_volume( r, h ),
- mass = vol*density;
-
- rb->inv_mass = 1.0f/mass;
-
- m3x3f I;
- rb_capsule_inertia( r, h, mass * inertia_scale, I );
- m3x3_inv( I, rb->iI );
-}
-
-static void rb_setbody_box( rigidbody *rb, boxf box,
- f32 density, f32 inertia_scale ){
- f32 vol = vg_box_volume( box ),
- mass = vol*density;
-
- rb->inv_mass = 1.0f/mass;
-
- m3x3f I;
- rb_box_inertia( box, mass * inertia_scale, I );
- m3x3_inv( I, rb->iI );
-}
-
-static void rb_setbody_sphere( rigidbody *rb, f32 r,
- f32 density, f32 inertia_scale ){
- f32 vol = vg_sphere_volume( r ),
- mass = vol*density;
-
- rb->inv_mass = 1.0f/mass;
- m3x3f I;
- rb_sphere_inertia( r, mass * inertia_scale, I );
- m3x3_inv( I, rb->iI );
-}
-
-static void rb_iter( rigidbody *rb ){
- if( !vg_validf( rb->v[0] ) ||
- !vg_validf( rb->v[1] ) ||
- !vg_validf( rb->v[2] ) )
- {
- vg_fatal_error( "NaN velocity" );
- }
-
- v3f gravity = { 0.0f, -9.8f, 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->w, (v3f){0.0f,0.0f,0.0f}, 0.0025f, rb->w );
-
- /* 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 );
- q_normalize( rb->q );
- }
-}
-
-/*
- * -----------------------------------------------------------------------------
- * Boolean shape overlap functions
- * -----------------------------------------------------------------------------
- */
-
-/*
- * Project AABB, and triangle interval onto axis to check if they overlap
- */
-static int rb_box_triangle_interval( v3f extent, v3f axis, v3f tri[3] ){
- float
-
- r = extent[0] * fabsf(axis[0]) +
- extent[1] * fabsf(axis[1]) +
- extent[2] * fabsf(axis[2]),
-
- p0 = v3_dot( axis, tri[0] ),
- p1 = v3_dot( axis, tri[1] ),
- p2 = v3_dot( axis, tri[2] ),
-
- e = vg_maxf(-vg_maxf(p0,vg_maxf(p1,p2)), vg_minf(p0,vg_minf(p1,p2)));
-
- if( e > r ) return 0;
- else return 1;
-}
-
-/*
- * Seperating axis test box vs triangle
- */
-static int rb_box_triangle_sat( v3f extent, v3f center,
- m4x3f to_local, v3f tri_src[3] ){
- 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
- * -----------------------------------------------------------------------------
- */
-
-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
- */
-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 );
- }
- }
-}
-
-/*
- *
- */
-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
- */
-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
- */
-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.
- */
-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.
- */
-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( m4x3f mtx, rb_capsule *c,
- capsule_manifold *manifold,
- rb_ct *buf ){
- v3f p0, p1;
- v3_muladds( mtx[3], mtx[1], -c->h*0.5f+c->r, p0 );
- v3_muladds( mtx[3], mtx[1], c->h*0.5f-c->r, 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->r, 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->r, 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;
-}
-
-#if 0
-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.h,
- ra = obja->inf.capsule.r,
- rb = objb->inf.sphere.r;
-
- 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;
-}
-#endif
-
-static int rb_capsule__capsule( m4x3f mtxA, rb_capsule *ca,
- m4x3f mtxB, rb_capsule *cb, rb_ct *buf ){
- f32 ha = ca->h,
- hb = cb->h,
- ra = ca->r,
- rb = cb->r,
- 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;
- f32 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
-static int rb_sphere_box( rb_object *obja, rb_object *objb, rb_ct *buf ){
- v3f co, delta;
- rigidbody *rba = &obja->rb, *rbb = &objb->rb;
-
- closest_point_obb( rba->co, rbb->bbx, rbb->to_world, rbb->to_local, co );
- v3_sub( rba->co, co, delta );
-
- float d2 = v3_length2(delta),
- r = obja->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->to_world[0], delta ),
- ly = v3_dot( rbb->to_world[1], delta ),
- lz = v3_dot( rbb->to_world[2], 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->to_world[0], vg_signf(lx), ct->n );
- else if( py < pz )
- v3_muls( rbb->to_world[1], vg_signf(ly), ct->n );
- else
- v3_muls( rbb->to_world[2], 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;
- ct->type = k_contact_type_default;
- return 1;
- }
-
- return 0;
-}
-#endif
-
-#if 0
-static int rb_sphere_sphere( rb_object *obja, rb_object *objb, rb_ct *buf ){
- rigidbody *rba = &obja->rb, *rbb = &objb->rb;
- v3f delta;
- v3_sub( rba->co, rbb->co, delta );
-
- float d2 = v3_length2(delta),
- r = obja->inf.sphere.radius + objb->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,-obja->inf.sphere.radius, p0 );
- v3_muladds( rbb->co, ct->n, objb->inf.sphere.radius, p1 );
- v3_add( p0, p1, ct->co );
- v3_muls( ct->co, 0.5f, ct->co );
- ct->type = k_contact_type_default;
- ct->p = r-d;
- ct->rba = rba;
- ct->rbb = rbb;
- return 1;
- }
-
- return 0;
-}
-#endif
-
-static int rb_sphere__triangle( m4x3f mtxA, f32 r,
- v3f tri[3], rb_ct *buf ){
- v3f delta, co;
- enum contact_type type = closest_on_triangle_1( mtxA[3], tri, co );
- v3_sub( mtxA[3], co, delta );
- f32 d2 = v3_length2( delta );
-
- 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 );
-
- if( v3_length2( ct->n ) <= 0.00001f ){
-#ifdef RIGIDBODY_CRY_ABOUT_EVERYTHING
- vg_error( "Zero area triangle!\n" );
-#endif
- return 0;
- }
-
- v3_normalize( ct->n );
-
- float d = sqrtf(d2);
-
- v3_copy( co, ct->co );
- ct->type = type;
- ct->p = r-d;
- return 1;
- }
-
- return 0;
-}
-
-static int rb_sphere__scene( m4x3f mtxA, f32 r,
- m4x3f mtxB, bh_tree *scene_bh, rb_ct *buf,
- u16 ignore ){
- scene_context *sc = scene_bh->user;
-
- int count = 0;
-
- boxf box;
- v3_sub( mtxA[3], (v3f){ r,r,r }, box[0] );
- v3_add( mtxA[3], (v3f){ r,r,r }, box[1] );
-
- bh_iter it;
- i32 idx;
- bh_iter_init_box( 0, &it, box );
-
- while( bh_next( scene_bh, &it, &idx ) ){
- u32 *ptri = &sc->arrindices[ idx*3 ];
- v3f tri[3];
-
- if( sc->arrvertices[ptri[0]].flags & ignore ) continue;
-
- for( int j=0; j<3; j++ )
- v3_copy( sc->arrvertices[ptri[j]].co, tri[j] );
-
- buf[ count ].element_id = ptri[0];
-
- vg_line( tri[0],tri[1],0x70ff6000 );
- vg_line( tri[1],tri[2],0x70ff6000 );
- vg_line( tri[2],tri[0],0x70ff6000 );
-
- int contact = rb_sphere__triangle( mtxA, r, tri, &buf[count] );
- count += contact;
-
- if( count == 16 ){
- vg_warn( "Exceeding sphere_vs_scene capacity. Geometry too dense!\n" );
- return count;
- }
- }
-
- return count;
-}
-
-static int rb_box__scene( m4x3f mtxA, boxf bbx,
- m4x3f mtxB, bh_tree *scene_bh,
- rb_ct *buf, u16 ignore ){
- scene_context *sc = scene_bh->user;
- v3f tri[3];
-
- v3f extent, center;
- v3_sub( bbx[1], bbx[0], extent );
- v3_muls( extent, 0.5f, extent );
- v3_add( bbx[0], extent, center );
-
- float r = v3_length(extent);
- boxf world_bbx;
- v3_fill( world_bbx[0], -r );
- v3_fill( world_bbx[1], r );
- for( int i=0; i<2; i++ ){
- v3_add( center, world_bbx[i], world_bbx[i] );
- v3_add( mtxA[3], world_bbx[i], world_bbx[i] );
- }
-
- m4x3f to_local;
- m4x3_invert_affine( mtxA, to_local );
-
- bh_iter it;
- bh_iter_init_box( 0, &it, world_bbx );
- int idx;
- int count = 0;
-
- vg_line_boxf( world_bbx, VG__RED );
-
- while( bh_next( scene_bh, &it, &idx ) ){
- u32 *ptri = &sc->arrindices[ idx*3 ];
- if( sc->arrvertices[ptri[0]].flags & ignore ) continue;
-
- for( int j=0; j<3; j++ )
- v3_copy( sc->arrvertices[ptri[j]].co, tri[j] );
-
- if( rb_box_triangle_sat( extent, center, to_local, 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 );
-
- if( v3_length2( n ) <= 0.00001f ){
-#ifdef RIGIDBODY_CRY_ABOUT_EVERYTHING
- vg_error( "Zero area triangle!\n" );
-#endif
- return 0;
- }
-
- v3_normalize( n );
-
- /* find best feature */
- float best = v3_dot( mtxA[0], n );
- int axis = 0;
-
- for( int i=1; i<3; i++ ){
- float c = v3_dot( mtxA[i], n );
-
- if( fabsf(c) > fabsf(best) ){
- best = c;
- axis = i;
- }
- }
-
- v3f manifold[4];
-
- if( axis == 0 ){
- float px = best > 0.0f? bbx[0][0]: bbx[1][0];
- manifold[0][0] = px;
- manifold[0][1] = bbx[0][1];
- manifold[0][2] = bbx[0][2];
- manifold[1][0] = px;
- manifold[1][1] = bbx[1][1];
- manifold[1][2] = bbx[0][2];
- manifold[2][0] = px;
- manifold[2][1] = bbx[1][1];
- manifold[2][2] = bbx[1][2];
- manifold[3][0] = px;
- manifold[3][1] = bbx[0][1];
- manifold[3][2] = bbx[1][2];
- }
- else if( axis == 1 ){
- float py = best > 0.0f? bbx[0][1]: bbx[1][1];
- manifold[0][0] = bbx[0][0];
- manifold[0][1] = py;
- manifold[0][2] = bbx[0][2];
- manifold[1][0] = bbx[1][0];
- manifold[1][1] = py;
- manifold[1][2] = bbx[0][2];
- manifold[2][0] = bbx[1][0];
- manifold[2][1] = py;
- manifold[2][2] = bbx[1][2];
- manifold[3][0] = bbx[0][0];
- manifold[3][1] = py;
- manifold[3][2] = bbx[1][2];
- }
- else{
- float pz = best > 0.0f? bbx[0][2]: bbx[1][2];
- manifold[0][0] = bbx[0][0];
- manifold[0][1] = bbx[0][1];
- manifold[0][2] = pz;
- manifold[1][0] = bbx[1][0];
- manifold[1][1] = bbx[0][1];
- manifold[1][2] = pz;
- manifold[2][0] = bbx[1][0];
- manifold[2][1] = bbx[1][1];
- manifold[2][2] = pz;
- manifold[3][0] = bbx[0][0];
- manifold[3][1] = bbx[1][1];
- manifold[3][2] = pz;
- }
-
- for( int j=0; j<4; j++ )
- m4x3_mulv( mtxA, manifold[j], manifold[j] );
-
- 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->type = k_contact_type_default;
- count ++;
-
- if( count >= 12 )
- return count;
- }
- }
- return count;
-}
-
-static int rb_capsule__triangle( m4x3f mtxA, rb_capsule *c,
- v3f tri[3], rb_ct *buf ){
- v3f pc, p0w, p1w;
- v3_muladds( mtxA[3], mtxA[1], -c->h*0.5f+c->r, p0w );
- v3_muladds( mtxA[3], mtxA[1], c->h*0.5f-c->r, p1w );
-
- capsule_manifold manifold;
- rb_capsule_manifold_init( &manifold );
-
- v3f v0, v1, n;
- v3_sub( tri[1], tri[0], v0 );
- v3_sub( tri[2], tri[0], v1 );
- v3_cross( v0, v1, n );
-
- if( v3_length2( n ) <= 0.00001f ){
-#ifdef RIGIDBODY_CRY_ABOUT_EVERYTHING
- vg_error( "Zero area triangle!\n" );
-#endif
- return 0;
- }
-
- v3_normalize( n );
-
-#if 1
- /* deep penetration recovery. for when we clip through the triangles. so its
- * not very 'correct' */
- f32 dist;
- if( ray_tri( tri, p0w, mtxA[1], &dist, 1 ) ){
- f32 l = c->h - c->r*2.0f;
- if( (dist >= 0.0f) && (dist < l) ){
- v3f co;
- v3_muladds( p0w, mtxA[1], dist, co );
- vg_line_point( co, 0.02f, 0xffffff00 );
-
- v3f d0, d1;
- v3_sub( p0w, co, d0 );
- v3_sub( p1w, co, d1 );
-
- f32 p = vg_minf( v3_dot( n, d0 ), v3_dot( n, d1 ) ) - c->r;
-
- rb_ct *ct = buf;
- ct->p = -p;
- ct->type = k_contact_type_default;
- v3_copy( n, ct->n );
- v3_muladds( co, n, p, ct->co );
-
- return 1;
- }
- }
-#endif
-
- v3f c0, c1;
- closest_on_triangle_1( p0w, tri, c0 );
- closest_on_triangle_1( p1w, tri, c1 );
-
- v3f d0, d1, da;
- v3_sub( c0, p0w, d0 );
- v3_sub( c1, p1w, d1 );
- v3_sub( p1w, p0w, da );
-
- v3_normalize(d0);
- v3_normalize(d1);
- v3_normalize(da);
-
- /* the two balls at the ends */
- if( v3_dot( da, d0 ) <= 0.01f )
- rb_capsule_manifold( p0w, c0, 0.0f, c->r, &manifold );
- if( v3_dot( da, d1 ) >= -0.01f )
- rb_capsule_manifold( p1w, c1, 1.0f, c->r, &manifold );
-
- /* the edges to edges */
- for( int i=0; i<3; i++ ){
- int i0 = i,
- i1 = (i+1)%3;
-
- v3f ca, cb;
- float ta, tb;
- closest_segment_segment( p0w, p1w, tri[i0], tri[i1], &ta, &tb, ca, cb );
- rb_capsule_manifold( ca, cb, ta, c->r, &manifold );
- }
-
- int count = rb_capsule__manifold_done( mtxA, c, &manifold, buf );
- for( int i=0; i<count; i++ )
- v3_copy( n, buf[i].n );
-
- return count;
-}
-
-/* mtxB is defined only for tradition; it is not used currently */
-static int rb_capsule__scene( m4x3f mtxA, rb_capsule *c,
- m4x3f mtxB, bh_tree *scene_bh,
- rb_ct *buf, u16 ignore ){
- int count = 0;
-
- boxf bbx;
- v3_sub( mtxA[3], (v3f){ c->h, c->h, c->h }, bbx[0] );
- v3_add( mtxA[3], (v3f){ c->h, c->h, c->h }, bbx[1] );
-
- scene_context *sc = scene_bh->user;
-
- bh_iter it;
- bh_iter_init_box( 0, &it, bbx );
- i32 idx;
- while( bh_next( scene_bh, &it, &idx ) ){
- u32 *ptri = &sc->arrindices[ idx*3 ];
- if( sc->arrvertices[ptri[0]].flags & ignore ) continue;
-
- v3f tri[3];
- for( int j=0; j<3; j++ )
- v3_copy( sc->arrvertices[ptri[j]].co, tri[j] );
-
- buf[ count ].element_id = ptri[0];
-
- int contact = rb_capsule__triangle( mtxA, c, tri, &buf[count] );
- count += contact;
-
- if( count >= 16 ){
- vg_warn("Exceeding capsule_vs_scene capacity. Geometry too dense!\n");
- return count;
- }
- }
-
- return count;
-}
-
-static int rb_global_has_space( void ){
- if( rb_contact_count + 16 > vg_list_size(rb_contact_buffer) )
- return 0;
-
- return 1;
-}
-
-static rb_ct *rb_global_buffer( void ){
- return &rb_contact_buffer[ rb_contact_count ];
-}
-
-/*
- * -----------------------------------------------------------------------------
- * Dynamics
- * -----------------------------------------------------------------------------
- */
-
-static void rb_solver_reset(void){
- rb_contact_count = 0;
-}
-
-static rb_ct *rb_global_ct(void){
- return rb_contact_buffer + rb_contact_count;
-}
-
-static void rb_prepare_contact( rb_ct *ct, float timestep ){
- ct->bias = -k_phys_baumgarte * (timestep*3600.0f)
- * vg_minf( 0.0f, -ct->p+k_penetration_slop );
-
- v3_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;
-}
-
-/* calculate total move. manifold should belong to ONE object only */
-static void rb_depenetrate( rb_ct *manifold, int len, v3f dt ){
- v3_zero( dt );
-
- for( int j=0; j<7; j++ )
- {
- for( int i=0; i<len; i++ )
- {
- struct contact *ct = &manifold[i];
-
- float resolved_amt = v3_dot( ct->n, dt ),
- remaining = (ct->p-k_penetration_slop) - resolved_amt,
- apply = vg_maxf( remaining, 0.0f ) * 0.4f;
-
- v3_muladds( dt, ct->n, apply, dt );
- }
- }
-}
-
-/*
- * 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];
- rb_prepare_contact( ct, k_rb_delta );
-
- 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
- */
-static void rb_rcv( rigidbody *rba, rigidbody *rbb, v3f ra, v3f rb, v3f rv ){
- v3f rva, rvb;
- v3_cross( rba->w, ra, rva );
- v3_add( rba->v, rva, rva );
- v3_cross( rbb->w, rb, rvb );
- v3_add( rbb->v, rvb, rvb );
-
- v3_sub( rva, rvb, rv );
-}
-
-static void rb_contact_restitution( rb_ct *ct, float cr ){
- v3f rv, ra, rb;
- v3_sub( ct->co, ct->rba->co, ra );
- v3_sub( ct->co, ct->rbb->co, rb );
- rb_rcv( ct->rba, ct->rbb, ra, rb, rv );
-
- float v = v3_dot( rv, ct->n );
-
- if( v < -1.0f ){
- ct->bias += -cr * v;
- }
-}
-
-/*
- * Apply impulse to object
- */
-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
- */
-static void rb_solve_contacts( rb_ct *buf, int len ){
- for( int i=0; i<len; i++ ){
- struct contact *ct = &buf[i];
-
- v3f rv, ra, rb;
- v3_sub( ct->co, ct->rba->co, ra );
- v3_sub( ct->co, ct->rbb->co, rb );
- rb_rcv( ct->rba, ct->rbb, ra, rb, rv );
-
- /* 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, ra, impulse );
-
- v3_muls( ct->t[j], -lambda, impulse );
- rb_linear_impulse( ct->rbb, rb, impulse );
- }
-
- /* Normal */
- rb_rcv( ct->rba, ct->rbb, ra, rb, rv );
- 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, ra, impulse );
-
- v3_muls( ct->n, -lambda, impulse );
- rb_linear_impulse( ct->rbb, rb, impulse );
- }
-}
-
-/*
- * -----------------------------------------------------------------------------
- * Constraints
- * -----------------------------------------------------------------------------
- */
-
-static void rb_debug_position_constraints( rb_constr_pos *buffer, int len ){
- for( int i=0; i<len; i++ ){
- rb_constr_pos *constr = &buffer[i];
- rigidbody *rba = constr->rba, *rbb = constr->rbb;
-
- v3f wca, wcb;
- m3x3_mulv( rba->to_world, constr->lca, wca );
- m3x3_mulv( rbb->to_world, constr->lcb, wcb );
-
- v3f p0, p1;
- v3_add( wca, rba->co, p0 );
- v3_add( wcb, rbb->co, p1 );
- vg_line_point( p0, 0.0025f, 0xff000000 );
- vg_line_point( p1, 0.0025f, 0xffffffff );
- vg_line2( p0, p1, 0xff000000, 0xffffffff );
- }
-}
-
-static void rb_presolve_swingtwist_constraints( rb_constr_swingtwist *buf,
- int len ){
- for( int i=0; i<len; i++ ){
- rb_constr_swingtwist *st = &buf[ i ];
-
- v3f vx, vy, va, vxb, axis, center;
-
- m3x3_mulv( st->rba->to_world, st->conevx, vx );
- m3x3_mulv( st->rbb->to_world, st->conevxb, vxb );
- m3x3_mulv( st->rba->to_world, st->conevy, vy );
- m3x3_mulv( st->rbb->to_world, st->coneva, va );
- m4x3_mulv( st->rba->to_world, st->view_offset, center );
- v3_cross( vy, vx, axis );
-
- /* Constraint violated ? */
- float fx = v3_dot( vx, va ), /* projection world */
- fy = v3_dot( vy, va ),
- fn = v3_dot( va, axis ),
-
- rx = st->conevx[3], /* elipse radii */
- ry = st->conevy[3],
-
- lx = fx/rx, /* projection local (fn==lz) */
- ly = fy/ry;
-
- st->tangent_violation = ((lx*lx + ly*ly) > fn*fn) || (fn <= 0.0f);
- if( st->tangent_violation ){
- /* Calculate a good position and the axis to solve on */
- v2f closest, tangent,
- p = { fx/fabsf(fn), fy/fabsf(fn) };
-
- closest_point_elipse( p, (v2f){rx,ry}, closest );
- tangent[0] = -closest[1] / (ry*ry);
- tangent[1] = closest[0] / (rx*rx);
- v2_normalize( tangent );
-
- v3f v0, v1;
- v3_muladds( axis, vx, closest[0], v0 );
- v3_muladds( v0, vy, closest[1], v0 );
- v3_normalize( v0 );
-
- v3_muls( vx, tangent[0], v1 );
- v3_muladds( v1, vy, tangent[1], v1 );
-
- v3_copy( v0, st->tangent_target );
- v3_copy( v1, st->tangent_axis );
-
- /* calculate mass */
- v3f aIw, bIw;
- m3x3_mulv( st->rba->iIw, st->tangent_axis, aIw );
- m3x3_mulv( st->rbb->iIw, st->tangent_axis, bIw );
- st->tangent_mass = 1.0f / (v3_dot( st->tangent_axis, aIw ) +
- v3_dot( st->tangent_axis, bIw ));
-
- float angle = v3_dot( va, st->tangent_target );
- }
-
- v3f refaxis;
- v3_cross( vy, va, refaxis ); /* our default rotation */
- v3_normalize( refaxis );
-
- float angle = v3_dot( refaxis, vxb );
- st->axis_violation = fabsf(angle) < st->conet;
-
- if( st->axis_violation ){
- v3f dir_test;
- v3_cross( refaxis, vxb, dir_test );
-
- if( v3_dot(dir_test, va) < 0.0f )
- st->axis_violation = -st->axis_violation;
-
- float newang = (float)st->axis_violation * acosf(st->conet-0.0001f);
-
- v3f refaxis_up;
- v3_cross( va, refaxis, refaxis_up );
- v3_muls( refaxis_up, sinf(newang), st->axis_target );
- v3_muladds( st->axis_target, refaxis, -cosf(newang), st->axis_target );
-
- /* calculate mass */
- v3_copy( va, st->axis );
- v3f aIw, bIw;
- m3x3_mulv( st->rba->iIw, st->axis, aIw );
- m3x3_mulv( st->rbb->iIw, st->axis, bIw );
- st->axis_mass = 1.0f / (v3_dot( st->axis, aIw ) +
- v3_dot( st->axis, bIw ));
- }
- }
-}
-
-static void rb_debug_swingtwist_constraints( rb_constr_swingtwist *buf,
- int len ){
- float size = 0.12f;
-
- for( int i=0; i<len; i++ ){
- rb_constr_swingtwist *st = &buf[ i ];
-
- v3f vx, vxb, vy, va, axis, center;
-
- m3x3_mulv( st->rba->to_world, st->conevx, vx );
- m3x3_mulv( st->rbb->to_world, st->conevxb, vxb );
- m3x3_mulv( st->rba->to_world, st->conevy, vy );
- m3x3_mulv( st->rbb->to_world, st->coneva, va );
- m4x3_mulv( st->rba->to_world, st->view_offset, center );
- v3_cross( vy, vx, axis );
-
- float rx = st->conevx[3], /* elipse radii */
- ry = st->conevy[3];
-
- v3f p0, p1;
- v3_muladds( center, va, size, p1 );
- vg_line( center, p1, 0xffffffff );
- vg_line_point( p1, 0.00025f, 0xffffffff );
-
- if( st->tangent_violation ){
- v3_muladds( center, st->tangent_target, size, p0 );
-
- vg_line( center, p0, 0xff00ff00 );
- vg_line_point( p0, 0.00025f, 0xff00ff00 );
- vg_line( p1, p0, 0xff000000 );
- }
-
- for( int x=0; x<32; x++ ){
- float t0 = ((float)x * (1.0f/32.0f)) * VG_TAUf,
- t1 = (((float)x+1.0f) * (1.0f/32.0f)) * VG_TAUf,
- c0 = cosf( t0 ),
- s0 = sinf( t0 ),
- c1 = cosf( t1 ),
- s1 = sinf( t1 );
-
- v3f v0, v1;
- v3_muladds( axis, vx, c0*rx, v0 );
- v3_muladds( v0, vy, s0*ry, v0 );
- v3_muladds( axis, vx, c1*rx, v1 );
- v3_muladds( v1, vy, s1*ry, v1 );
-
- v3_normalize( v0 );
- v3_normalize( v1 );
-
- v3_muladds( center, v0, size, p0 );
- v3_muladds( center, v1, size, p1 );
-
- u32 col0r = fabsf(c0) * 255.0f,
- col0g = fabsf(s0) * 255.0f,
- col1r = fabsf(c1) * 255.0f,
- col1g = fabsf(s1) * 255.0f,
- col = st->tangent_violation? 0xff0000ff: 0xff000000,
- col0 = col | (col0r<<16) | (col0g << 8),
- col1 = col | (col1r<<16) | (col1g << 8);
-
- vg_line2( center, p0, VG__NONE, col0 );
- vg_line2( p0, p1, col0, col1 );
- }
-
- /* Draw twist */
- v3_muladds( center, va, size, p0 );
- v3_muladds( p0, vxb, size, p1 );
-
- vg_line( p0, p1, 0xff0000ff );
-
- if( st->axis_violation ){
- v3_muladds( p0, st->axis_target, size*1.25f, p1 );
- vg_line( p0, p1, 0xffffff00 );
- vg_line_point( p1, 0.0025f, 0xffffff80 );
- }
-
- v3f refaxis;
- v3_cross( vy, va, refaxis ); /* our default rotation */
- v3_normalize( refaxis );
- v3f refaxis_up;
- v3_cross( va, refaxis, refaxis_up );
- float newang = acosf(st->conet-0.0001f);
-
- v3_muladds( p0, refaxis_up, sinf(newang)*size, p1 );
- v3_muladds( p1, refaxis, -cosf(newang)*size, p1 );
- vg_line( p0, p1, 0xff000000 );
-
- v3_muladds( p0, refaxis_up, sinf(-newang)*size, p1 );
- v3_muladds( p1, refaxis, -cosf(-newang)*size, p1 );
- vg_line( p0, p1, 0xff404040 );
- }
-}
-
-/*
- * Solve a list of positional constraints
- */
-static void rb_solve_position_constraints( rb_constr_pos *buf, int len ){
- for( int i=0; i<len; i++ ){
- rb_constr_pos *constr = &buf[i];
- rigidbody *rba = constr->rba, *rbb = constr->rbb;
-
- v3f wa, wb;
- m3x3_mulv( rba->to_world, constr->lca, wa );
- m3x3_mulv( rbb->to_world, constr->lcb, wb );
-
- m3x3f ssra, ssrat, ssrb, ssrbt;
-
- m3x3_skew_symetric( ssrat, wa );
- m3x3_skew_symetric( ssrbt, wb );
- m3x3_transpose( ssrat, ssra );
- m3x3_transpose( ssrbt, ssrb );
-
- v3f b, b_wa, b_wb, b_a, b_b;
- m3x3_mulv( ssra, rba->w, b_wa );
- m3x3_mulv( ssrb, rbb->w, b_wb );
- v3_add( rba->v, b_wa, b );
- v3_sub( b, rbb->v, b );
- v3_sub( b, b_wb, b );
- v3_muls( b, -1.0f, b );
-
- m3x3f invMa, invMb;
- m3x3_diagonal( invMa, rba->inv_mass );
- m3x3_diagonal( invMb, rbb->inv_mass );
-
- m3x3f ia, ib;
- m3x3_mul( ssra, rba->iIw, ia );
- m3x3_mul( ia, ssrat, ia );
- m3x3_mul( ssrb, rbb->iIw, ib );
- m3x3_mul( ib, ssrbt, ib );
-
- m3x3f cma, cmb;
- m3x3_add( invMa, ia, cma );
- m3x3_add( invMb, ib, cmb );
-
- m3x3f A;
- m3x3_add( cma, cmb, A );
-
- /* Solve Ax = b ( A^-1*b = x ) */
- v3f impulse;
- m3x3f invA;
- m3x3_inv( A, invA );
- m3x3_mulv( invA, b, impulse );
-
- v3f delta_va, delta_wa, delta_vb, delta_wb;
- m3x3f iwa, iwb;
- m3x3_mul( rba->iIw, ssrat, iwa );
- m3x3_mul( rbb->iIw, ssrbt, iwb );
-
- m3x3_mulv( invMa, impulse, delta_va );
- m3x3_mulv( invMb, impulse, delta_vb );
- m3x3_mulv( iwa, impulse, delta_wa );
- m3x3_mulv( iwb, impulse, delta_wb );
-
- v3_add( rba->v, delta_va, rba->v );
- v3_add( rba->w, delta_wa, rba->w );
- v3_sub( rbb->v, delta_vb, rbb->v );
- v3_sub( rbb->w, delta_wb, rbb->w );
- }
-}
-
-static void rb_solve_swingtwist_constraints( rb_constr_swingtwist *buf,
- int len ){
- for( int i=0; i<len; i++ ){
- rb_constr_swingtwist *st = &buf[ i ];
-
- if( !st->axis_violation )
- continue;
-
- float rv = v3_dot( st->axis, st->rbb->w ) -
- v3_dot( st->axis, st->rba->w );
-
- if( rv * (float)st->axis_violation > 0.0f )
- continue;
-
- v3f impulse, wa, wb;
- v3_muls( st->axis, rv*st->axis_mass, impulse );
- m3x3_mulv( st->rba->iIw, impulse, wa );
- v3_add( st->rba->w, wa, st->rba->w );
-
- v3_muls( impulse, -1.0f, impulse );
- m3x3_mulv( st->rbb->iIw, impulse, wb );
- v3_add( st->rbb->w, wb, st->rbb->w );
-
- float rv2 = v3_dot( st->axis, st->rbb->w ) -
- v3_dot( st->axis, st->rba->w );
- }
-
- for( int i=0; i<len; i++ ){
- rb_constr_swingtwist *st = &buf[ i ];
-
- if( !st->tangent_violation )
- continue;
-
- float rv = v3_dot( st->tangent_axis, st->rbb->w ) -
- v3_dot( st->tangent_axis, st->rba->w );
-
- if( rv > 0.0f )
- continue;
-
- v3f impulse, wa, wb;
- v3_muls( st->tangent_axis, rv*st->tangent_mass, impulse );
- m3x3_mulv( st->rba->iIw, impulse, wa );
- v3_add( st->rba->w, wa, st->rba->w );
-
- v3_muls( impulse, -1.0f, impulse );
- m3x3_mulv( st->rbb->iIw, impulse, wb );
- v3_add( st->rbb->w, wb, st->rbb->w );
-
- float rv2 = v3_dot( st->tangent_axis, st->rbb->w ) -
- v3_dot( st->tangent_axis, st->rba->w );
- }
-}
-
-/* debugging */
-static void rb_postsolve_swingtwist_constraints( rb_constr_swingtwist *buf,
- u32 len ){
- for( int i=0; i<len; i++ ){
- rb_constr_swingtwist *st = &buf[ i ];
-
- if( !st->axis_violation ){
- st->conv_axis = 0.0f;
- continue;
- }
-
- f32 rv = v3_dot( st->axis, st->rbb->w ) -
- v3_dot( st->axis, st->rba->w );
-
- if( rv * (f32)st->axis_violation > 0.0f )
- st->conv_axis = 0.0f;
- else
- st->conv_axis = rv;
- }
-
- for( int i=0; i<len; i++ ){
- rb_constr_swingtwist *st = &buf[ i ];
-
- if( !st->tangent_violation ){
- st->conv_tangent = 0.0f;
- continue;
- }
-
- f32 rv = v3_dot( st->tangent_axis, st->rbb->w ) -
- v3_dot( st->tangent_axis, st->rba->w );
-
- if( rv > 0.0f )
- st->conv_tangent = 0.0f;
- else
- st->conv_tangent = rv;
- }
-}
-
-static void rb_solve_constr_angle( rigidbody *rba, rigidbody *rbb,
- v3f ra, v3f rb ){
- m3x3f ssra, ssrb, ssrat, ssrbt;
- m3x3f cma, cmb;
-
- m3x3_skew_symetric( ssrat, ra );
- m3x3_skew_symetric( ssrbt, rb );
- m3x3_transpose( ssrat, ssra );
- m3x3_transpose( ssrbt, ssrb );
-
- m3x3_mul( ssra, rba->iIw, cma );
- m3x3_mul( cma, ssrat, cma );
- m3x3_mul( ssrb, rbb->iIw, cmb );
- m3x3_mul( cmb, ssrbt, cmb );
-
- m3x3f A, invA;
- m3x3_add( cma, cmb, A );
- m3x3_inv( A, invA );
-
- v3f b_wa, b_wb, b;
- m3x3_mulv( ssra, rba->w, b_wa );
- m3x3_mulv( ssrb, rbb->w, b_wb );
- v3_add( b_wa, b_wb, b );
- v3_negate( b, b );
-
- v3f impulse;
- m3x3_mulv( invA, b, impulse );
-
- v3f delta_wa, delta_wb;
- m3x3f iwa, iwb;
- m3x3_mul( rba->iIw, ssrat, iwa );
- m3x3_mul( rbb->iIw, ssrbt, iwb );
- m3x3_mulv( iwa, impulse, delta_wa );
- m3x3_mulv( iwb, impulse, delta_wb );
- v3_add( rba->w, delta_wa, rba->w );
- v3_sub( rbb->w, delta_wb, rbb->w );
-}
-
-/*
- * Correct position constraint drift errors
- * [ 0.0 <= amt <= 1.0 ]: the correction amount
- */
-static void rb_correct_position_constraints( rb_constr_pos *buf, int len,
- float amt ){
- for( int i=0; i<len; i++ ){
- rb_constr_pos *constr = &buf[i];
- rigidbody *rba = constr->rba, *rbb = constr->rbb;
-
- v3f p0, p1, d;
- m3x3_mulv( rba->to_world, constr->lca, p0 );
- m3x3_mulv( rbb->to_world, constr->lcb, p1 );
- v3_add( rba->co, p0, p0 );
- v3_add( rbb->co, p1, p1 );
- v3_sub( p1, p0, d );
-
-#if 1
- v3_muladds( rbb->co, d, -1.0f * amt, rbb->co );
- rb_update_matrices( rbb );
-#else
- f32 mt = 1.0f/(rba->inv_mass+rbb->inv_mass),
- a = mt * (k_phys_baumgarte/k_rb_delta);
-
- v3_muladds( rba->v, d, a* rba->inv_mass, rba->v );
- v3_muladds( rbb->v, d, a*-rbb->inv_mass, rbb->v );
-#endif
- }
-}
-
-static void rb_correct_swingtwist_constraints( rb_constr_swingtwist *buf,
- int len, float amt ){
- for( int i=0; i<len; i++ ){
- rb_constr_swingtwist *st = &buf[i];
-
- if( !st->tangent_violation )
- continue;
-
- v3f va;
- m3x3_mulv( st->rbb->to_world, st->coneva, va );
-
- f32 angle = v3_dot( va, st->tangent_target );
-
- if( fabsf(angle) < 0.9999f ){
- v3f axis;
- v3_cross( va, st->tangent_target, axis );
-#if 1
- angle = acosf(angle) * amt;
- v4f correction;
- q_axis_angle( correction, axis, angle );
- q_mul( correction, st->rbb->q, st->rbb->q );
- q_normalize( st->rbb->q );
- rb_update_matrices( st->rbb );
-#else
- f32 mt = 1.0f/(st->rba->inv_mass+st->rbb->inv_mass),
- wa = mt * acosf(angle) * (k_phys_baumgarte/k_rb_delta);
- //v3_muladds( st->rba->w, axis, wa*-st->rba->inv_mass, st->rba->w );
- v3_muladds( st->rbb->w, axis, wa* st->rbb->inv_mass, st->rbb->w );
-#endif
- }
- }
-
- for( int i=0; i<len; i++ ){
- rb_constr_swingtwist *st = &buf[i];
-
- if( !st->axis_violation )
- continue;
-
- v3f vxb;
- m3x3_mulv( st->rbb->to_world, st->conevxb, vxb );
-
- f32 angle = v3_dot( vxb, st->axis_target );
-
- if( fabsf(angle) < 0.9999f ){
- v3f axis;
- v3_cross( vxb, st->axis_target, axis );
-
-#if 1
- angle = acosf(angle) * amt;
- v4f correction;
- q_axis_angle( correction, axis, angle );
- q_mul( correction, st->rbb->q, st->rbb->q );
- q_normalize( st->rbb->q );
- rb_update_matrices( st->rbb );
-#else
- f32 mt = 1.0f/(st->rba->inv_mass+st->rbb->inv_mass),
- wa = mt * acosf(angle) * (k_phys_baumgarte/k_rb_delta);
- //v3_muladds( st->rba->w, axis, wa*-0.5f, st->rba->w );
- v3_muladds( st->rbb->w, axis, wa* st->rbb->inv_mass, st->rbb->w );
-#endif
- }
- }
-}
-
-static void rb_correct_contact_constraints( rb_ct *buf, int len, float amt ){
- for( int i=0; i<len; i++ ){
- rb_ct *ct = &buf[i];
- rigidbody *rba = ct->rba,
- *rbb = ct->rbb;
-
- f32 mass_total = 1.0f / (rba->inv_mass + rbb->inv_mass),
- d = ct->p*mass_total*amt;
-
- v3_muladds( rba->co, ct->n, -d * rba->inv_mass, rba->co );
- v3_muladds( rbb->co, ct->n, d * rbb->inv_mass, rbb->co );
- }
-}
-
-
-/*
- * Effectors
- */
-
-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 );
-}
-
-/* apply a spring&dampener force to match ra(worldspace) on rigidbody, to
- * rt(worldspace)
- */
-static void rb_effect_spring_target_vector( rigidbody *rba, v3f ra, v3f rt,
- float spring, float dampening,
- float timestep ){
- float d = v3_dot( rt, ra );
- float a = acosf( vg_clampf( d, -1.0f, 1.0f ) );
-
- v3f axis;
- v3_cross( rt, ra, axis );
-
- float Fs = -a * spring,
- Fd = -v3_dot( rba->w, axis ) * dampening;
-
- v3_muladds( rba->w, axis, (Fs+Fd) * timestep, rba->w );
-}
-
-#endif /* RIGIDBODY_H */
projects / carveJwlIkooP6JGAAIwe30JlM.git / commitdiff