-/* SHite fphysics */
+/*
+ * 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>
+
+static bh_system bh_system_rigidbodies;
#ifndef RIGIDBODY_H
#define RIGIDBODY_H
-#include "vg/vg.h"
-#include "scene.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;
+
+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 );
+}
-#define k_rb_delta (1.0f/60.0f)
+/*
+ * -----------------------------------------------------------------------------
+ * structure definitions
+ * -----------------------------------------------------------------------------
+ */
typedef struct rigidbody rigidbody;
-struct rigidbody
-{
- v3f co, v, I;
+typedef struct rb_object rb_object;
+typedef struct contact rb_ct;
+typedef struct rb_sphere rb_sphere;
+typedef struct rb_capsule rb_capsule;
+typedef struct rb_scene rb_scene;
+
+struct rb_sphere{
+ float radius;
+};
+
+struct rb_capsule{
+ float height, radius;
+};
+
+struct rb_scene{
+ bh_tree *bh_scene;
+};
+
+struct rigidbody{
+ v3f co, v, w;
v4f q;
- boxf bbx;
- struct contact
- {
- v3f co, n, delta;
- v3f t[2];
- float bias, norm_impulse, tangent_impulse[2];
- }
- manifold[4];
- int manifold_count;
+ boxf bbx, bbx_world;
+ float inv_mass;
+ /* inertia model and inverse world tensor */
+ m3x3f iI, iIw;
m4x3f to_world, to_local;
};
+/* simple objects */
+struct rb_object{
+ rigidbody rb;
+ enum rb_shape{
+ 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 sphere;
+ struct rb_capsule capsule;
+ struct rb_scene scene;
+ }
+ inf;
+};
+
+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 );
+ }
+}
+
+
+static void rb_object_debug( rb_object *obj, u32 colour ){
+ if( obj->type == k_rb_shape_box ){
+ v3f *box = obj->rb.bbx;
+ vg_line_boxf_transformed( obj->rb.to_world, obj->rb.bbx, colour );
+ }
+ else if( obj->type == k_rb_shape_sphere ){
+ vg_line_sphere( obj->rb.to_world, obj->inf.sphere.radius, colour );
+ }
+ else if( obj->type == k_rb_shape_capsule ){
+ m4x3f m0, m1;
+ float h = obj->inf.capsule.height,
+ r = obj->inf.capsule.radius;
+
+ vg_line_capsule( obj->rb.to_world, r, h, colour );
+ }
+ else if( obj->type == k_rb_shape_scene ){
+ vg_line_boxf( obj->rb.bbx, colour );
+ }
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * Integration
+ * -----------------------------------------------------------------------------
+ */
+
+/*
+ * Update world space bounding box based on local one
+ */
+static void rb_update_bounds( rigidbody *rb ){
+ box_init_inf( rb->bbx_world );
+ m4x3_expand_aabb_aabb( rb->to_world, rb->bbx_world, rb->bbx );
+}
+
+/*
+ * Commit transform to rigidbody. Updates matrices
+ */
static void rb_update_transform( rigidbody *rb )
{
q_normalize( rb->q );
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 );
+
+ rb_update_bounds( rb );
}
-static void rb_init( rigidbody *rb )
+/*
+ * Extrapolate rigidbody into a transform based on vg accumulator.
+ * Useful for rendering
+ */
+static void rb_extrapolate( rigidbody *rb, v3f co, v4f q )
{
- q_identity( rb->q );
- v3_zero( rb->v );
- v3_zero( rb->I );
+ float substep = vg.time_fixed_extrapolate;
+ v3_muladds( rb->co, rb->v, k_rb_delta*substep, co );
- rb_update_transform( rb );
+ 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 );
+ }
}
-static void rb_iter( rigidbody *rb )
-{
- v3f gravity = { 0.0f, -9.6f, 0.0f };
+/*
+ * Initialize rigidbody and calculate masses, inertia
+ */
+static void rb_init_object( rb_object *obj, f32 inertia_scale ){
+ float volume = 1.0f;
+ int inert = 0;
+
+ if( obj->type == k_rb_shape_box ){
+ v3f dims;
+ v3_sub( obj->rb.bbx[1], obj->rb.bbx[0], dims );
+ volume = dims[0]*dims[1]*dims[2];
+ }
+ else if( obj->type == k_rb_shape_sphere ){
+ volume = vg_sphere_volume( obj->inf.sphere.radius );
+ v3_fill( obj->rb.bbx[0], -obj->inf.sphere.radius );
+ v3_fill( obj->rb.bbx[1], obj->inf.sphere.radius );
+ }
+ else if( obj->type == k_rb_shape_capsule ){
+ float r = obj->inf.capsule.radius,
+ h = obj->inf.capsule.height;
+ volume = vg_sphere_volume( r ) + VG_PIf * r*r * (h - r*2.0f);
+
+ v3_fill( obj->rb.bbx[0], -r );
+ v3_fill( obj->rb.bbx[1], r );
+ obj->rb.bbx[0][1] = -h;
+ obj->rb.bbx[1][1] = h;
+ }
+ else if( obj->type == k_rb_shape_scene ){
+ inert = 1;
+ box_copy( obj->inf.scene.bh_scene->nodes[0].bbx, obj->rb.bbx );
+ }
+
+ if( inert ){
+ obj->rb.inv_mass = 0.0f;
+ m3x3_zero( obj->rb.iI );
+ }
+ else{
+ f32 mass = 8.0f*volume;
+ obj->rb.inv_mass = 1.0f/mass;
+
+ v3f extent, com;
+ v3_sub( obj->rb.bbx[1], obj->rb.bbx[0], extent );
+ v3_muladds( obj->rb.bbx[0], extent, 0.5f, com );
+
+ /* local intertia tensor */
+ f32 ex2 = extent[0]*extent[0],
+ ey2 = extent[1]*extent[1],
+ ez2 = extent[2]*extent[2];
+
+ /* compute inertia tensor */
+ v3f I;
+
+ if( obj->type == k_rb_shape_box ){
+ I[0] = inertia_scale * (ey2+ez2) * mass * (1.0f/12.0f);
+ I[1] = inertia_scale * (ex2+ez2) * mass * (1.0f/12.0f);
+ I[2] = inertia_scale * (ex2+ey2) * mass * (1.0f/12.0f);
+ }
+ else if( obj->type == k_rb_shape_sphere ){
+ f32 r = obj->inf.sphere.radius;
+ v3_fill( I, inertia_scale * r*r * mass * (2.0f/5.0f) );
+ }
+ else if( obj->type == k_rb_shape_capsule ){
+ f32 r = obj->inf.capsule.radius;
+ I[1] = inertia_scale * r*r * mass * (2.0f/5.0f);
+ I[0] = inertia_scale * (ey2+ez2) * mass * (1.0f/12.0f);
+ I[2] = inertia_scale * (ey2+ex2) * mass * (1.0f/12.0f);
+ }
+ else {
+ vg_fatal_error( "" );
+ }
+
+ m3x3f i;
+ m3x3_identity( i );
+ m3x3_setdiagonalv3( i, I );
+
+ /* compute translation */
+ m3x3f i_t, i_t_outer, i_t_scale;
+ m3x3_diagonal( i_t, v3_dot(com,com) );
+ m3x3_outer_product( i_t_outer, com, com );
+ m3x3_sub( i_t, i_t_outer, i_t );
+ m3x3_diagonal( i_t_scale, mass );
+ m3x3_mul( i_t_scale, i_t, i_t );
+
+ /* TODO: compute rotation */
+
+ /* add Ic and Ict */
+ m3x3_add( i, i_t, i );
+
+ /* store as inverted */
+ m3x3_inv( i, obj->rb.iI );
+ }
+
+ rb_update_transform( &obj->rb );
+}
+
+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->I, (v3f){0.0f,0.0f,0.0f}, 0.0025f, rb->I );
+ v3_lerp( rb->w, (v3f){0.0f,0.0f,0.0f}, 0.0025f, rb->w );
/* inegrate inertia */
- if( v3_length2( rb->I ) > 0.0f )
+ if( v3_length2( rb->w ) > 0.0f )
{
v4f rotation;
v3f axis;
- v3_copy( rb->I, 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 );
}
+
+#if 0
+ /* 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 );
+#endif
}
-static void rb_torque( rigidbody *rb, v3f axis, float mag )
-{
- v3_muladds( rb->I, axis, mag*k_rb_delta, rb->I );
+
+/*
+ * -----------------------------------------------------------------------------
+ * 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;
}
-static void rb_tangent_basis( v3f n, v3f tx, v3f ty )
-{
- /* Compute tangent basis (box2d) */
- if( fabsf( n[0] ) >= 0.57735027f )
- {
- tx[0] = n[1];
- tx[1] = -n[0];
- tx[2] = 0.0f;
+/*
+ * 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] );
}
- else
- {
- tx[0] = 0.0f;
- tx[1] = n[2];
- tx[2] = -n[1];
+
+ 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];
}
- v3_normalize( tx );
- v3_cross( n, tx, ty );
+ return k;
}
-static void rb_build_manifold( rigidbody *rb, scene *sc )
-{
- 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];
-
- 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];
-
- 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 );
-
- rb->manifold_count = 0;
-
- for( int i=0; i<8; i++ )
- {
- float *point = pts[i];
- struct contact *ct = &rb->manifold[rb->manifold_count];
+/*
+ * 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 );
- v3f surface;
+ if( v3_dot( delta, ct->n ) > -0.001f )
+ ct->type = k_contact_type_disabled;
+ }
+}
- v3_copy( point, surface );
- bvh_scene_sample( sc, surface, ct->n );
+/*
+ * 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;
- float p = vg_minf( surface[1] - point[1], 1.0f );
+ if( fabsf( d ) <= w ){
+ cj->type = k_contact_type_disabled;
+ }
+ }
+ }
+}
- if( p > 0.0f )
- {
- v3_add( point, surface, ct->co );
- v3_muls( ct->co, 0.5f, ct->co );
+/*
+ * -----------------------------------------------------------------------------
+ * 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 );
- //vg_line_pt3( ct->co, 0.0125f, 0xff0000ff );
+ 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->height*0.5f+c->radius, p0 );
+ v3_muladds( mtx[3], mtx[1], c->height*0.5f-c->radius, p1 );
+
+ int count = 0;
+ if( manifold->t0 <= 1.0f ){
+ rb_ct *ct = buf;
+
+ v3f pa;
+ v3_muls( p0, 1.0f-manifold->t0, pa );
+ v3_muladds( pa, p1, manifold->t0, pa );
+
+ float d = v3_length( manifold->d0 );
+ v3_muls( manifold->d0, 1.0f/d, ct->n );
+ v3_muladds( pa, ct->n, -c->radius, ct->co );
+
+ ct->p = manifold->r0 - d;
+ ct->type = k_contact_type_default;
+ count ++;
+ }
- 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] );
+ if( (manifold->t1 >= 0.0f) && (manifold->t0 != manifold->t1) ){
+ rb_ct *ct = buf+count;
- ct->norm_impulse = 0.0f;
- ct->tangent_impulse[0] = 0.0f;
- ct->tangent_impulse[1] = 0.0f;
+ v3f pa;
+ v3_muls( p0, 1.0f-manifold->t1, pa );
+ v3_muladds( pa, p1, manifold->t1, pa );
- rb->manifold_count ++;
- if( rb->manifold_count == 4 )
- break;
+ float d = v3_length( manifold->d1 );
+ v3_muls( manifold->d1, 1.0f/d, ct->n );
+ v3_muladds( pa, ct->n, -c->radius, ct->co );
+
+ ct->p = manifold->r1 - d;
+ ct->type = k_contact_type_default;
+
+ count ++;
+ }
+
+ /*
+ * Debugging
+ */
+
+ if( count == 2 )
+ vg_line( buf[0].co, buf[1].co, 0xff0000ff );
+
+ return count;
+}
+
+static int rb_capsule_sphere( rb_object *obja, rb_object *objb, rb_ct *buf ){
+ rigidbody *rba = &obja->rb, *rbb = &objb->rb;
+ float h = obja->inf.capsule.height,
+ ra = obja->inf.capsule.radius,
+ rb = objb->inf.sphere.radius;
+
+ v3f p0, p1;
+ v3_muladds( rba->co, rba->to_world[1], -h*0.5f+ra, p0 );
+ v3_muladds( rba->co, rba->to_world[1], h*0.5f-ra, p1 );
+
+ v3f c, delta;
+ closest_point_segment( p0, p1, rbb->co, c );
+ v3_sub( c, rbb->co, delta );
+
+ float d2 = v3_length2(delta),
+ r = ra + rb;
+
+ if( d2 < r*r ){
+ float d = sqrtf(d2);
+
+ rb_ct *ct = buf;
+ v3_muls( delta, 1.0f/d, ct->n );
+ ct->p = r-d;
+
+ v3f p0, p1;
+ v3_muladds( c, ct->n, -ra, p0 );
+ v3_muladds( rbb->co, ct->n, rb, p1 );
+ v3_add( p0, p1, ct->co );
+ v3_muls( ct->co, 0.5f, ct->co );
+
+ ct->rba = rba;
+ ct->rbb = rbb;
+ ct->type = k_contact_type_default;
+
+ return 1;
+ }
+
+ return 0;
+}
+
+static int rb_capsule__capsule( m4x3f mtxA, rb_capsule *ca,
+ m4x3f mtxB, rb_capsule *cb, rb_ct *buf ){
+ float ha = ca->height,
+ hb = cb->height,
+ ra = ca->radius,
+ rb = cb->radius,
+ r = ra+rb;
+
+ v3f p0, p1, p2, p3;
+ v3_muladds( mtxA[3], mtxA[1], -ha*0.5f+ra, p0 );
+ v3_muladds( mtxA[3], mtxA[1], ha*0.5f-ra, p1 );
+ v3_muladds( mtxB[3], mtxB[1], -hb*0.5f+rb, p2 );
+ v3_muladds( mtxB[3], mtxB[1], hb*0.5f-rb, p3 );
+
+ capsule_manifold manifold;
+ rb_capsule_manifold_init( &manifold );
+
+ v3f pa, pb;
+ float ta, tb;
+ closest_segment_segment( p0, p1, p2, p3, &ta, &tb, pa, pb );
+ rb_capsule_manifold( pa, pb, ta, r, &manifold );
+
+ ta = closest_point_segment( p0, p1, p2, pa );
+ tb = closest_point_segment( p0, p1, p3, pb );
+ rb_capsule_manifold( pa, p2, ta, r, &manifold );
+ rb_capsule_manifold( pb, p3, tb, r, &manifold );
+
+ closest_point_segment( p2, p3, p0, pa );
+ closest_point_segment( p2, p3, p1, pb );
+ rb_capsule_manifold( p0, pa, 0.0f, r, &manifold );
+ rb_capsule_manifold( p1, pb, 1.0f, r, &manifold );
+
+ return rb_capsule__manifold_done( mtxA, ca, &manifold, buf );
+}
+
+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;
}
-static void rb_constraint_manifold( rigidbody *rb )
-{
- float k_friction = 0.07f;
+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;
+ }
- /* Friction Impulse */
- for( int i=0; i<rb->manifold_count; i++ )
- {
- struct contact *ct = &rb->manifold[i];
+ return 0;
+}
+
+static int rb_sphere__triangle( m4x3f mtxA, rb_sphere *b,
+ 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 );
+
+ float d2 = v3_length2( delta ),
+ r = b->radius;
- v3f dv;
- v3_cross( rb->I, ct->delta, dv );
- v3_add( rb->v, dv, dv );
+ 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, rb_sphere *b,
+ m4x3f mtxB, rb_scene *s, rb_ct *buf,
+ u16 ignore ){
+ scene_context *sc = s->bh_scene->user;
+
+ int count = 0;
+
+ float r = b->radius + 0.1f;
+ 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( s->bh_scene, &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] );
- for( int j=0; j<2; j++ )
- {
- float vt = vg_clampf( -v3_dot( dv, ct->t[j] ),
- -k_friction, k_friction );
+ 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, b, 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, rb_scene *s, rb_ct *buf, u16 ignore ){
+ scene_context *sc = s->bh_scene->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( s->bh_scene, &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 );
- vt = -v3_dot( dv, ct->t[j] );
+ 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->height*0.5f+c->radius, p0w );
+ v3_muladds( mtxA[3], mtxA[1], c->height*0.5f-c->radius, 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->height - c->radius*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->radius;
- float temp = ct->tangent_impulse[j];
- ct->tangent_impulse[j] = vg_clampf( temp+vt, -k_friction, k_friction );
- vt = ct->tangent_impulse[j] - temp;
+ 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 );
- v3f impulse;
+ 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->radius, &manifold );
+ if( v3_dot( da, d1 ) >= -0.01f )
+ rb_capsule_manifold( p1w, c1, 1.0f, c->radius, &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->radius, &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;
+}
- 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 );
+/* mtxB is defined only for tradition; it is not used currently */
+static int rb_capsule__scene( m4x3f mtxA, rb_capsule *c,
+ m4x3f mtxB, rb_scene *s,
+ rb_ct *buf, u16 ignore ){
+ int count = 0;
+
+ boxf bbx;
+ v3_sub( mtxA[3], (v3f){ c->height, c->height, c->height }, bbx[0] );
+ v3_add( mtxA[3], (v3f){ c->height, c->height, c->height }, bbx[1] );
+
+ scene_context *sc = s->bh_scene->user;
+
+ bh_iter it;
+ bh_iter_init_box( 0, &it, bbx );
+ i32 idx;
+ while( bh_next( s->bh_scene, &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;
}
}
- /* Normal Impulse */
- for( int i=0; i<rb->manifold_count; i++ )
+ 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++ )
{
- struct contact *ct = &rb->manifold[i];
+ 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 );
- v3f dv;
- v3_cross( rb->I, ct->delta, dv );
- v3_add( rb->v, dv, dv );
+ 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 );
+ }
- float vn = -v3_dot( dv, ct->n );
- vn += ct->bias;
+ /* 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 + vn, 0.0f );
- vn = ct->norm_impulse - temp;
+ 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, vn, impulse );
- v3_add( impulse, rb->v, rb->v );
- v3_cross( ct->delta, impulse, impulse );
- v3_add( impulse, rb->I, rb->I );
+ v3_muls( ct->n, -lambda, impulse );
+ rb_linear_impulse( ct->rbb, rb, impulse );
}
}
-static void rb_constraint_angle( rigidbody *rba, v3f va,
- rigidbody *rbb, v3f vb,
- float max, float spring )
-{
- v3f wva, wvb;
- m3x3_mulv( rba->to_world, va, wva );
- m3x3_mulv( rbb->to_world, vb, wvb );
+/*
+ * -----------------------------------------------------------------------------
+ * 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 );
+ }
- float dt = v3_dot(wva,wvb)*0.999f,
- ang = fabsf(dt);
+ v3f refaxis;
+ v3_cross( vy, va, refaxis ); /* our default rotation */
+ v3_normalize( refaxis );
- 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 );
+ float angle = v3_dot( refaxis, vxb );
+ st->axis_violation = fabsf(angle) < st->conet;
- 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 )
- {
- float correction = max-ang;
+ 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 ];
- v4f rotation;
- q_axis_angle( rotation, axis, -correction*0.125f );
- q_mul( rotation, rba->q, rba->q );
+ v3f vx, vxb, vy, va, axis, center;
- q_axis_angle( rotation, axis, correction*0.125f );
- q_mul( rotation, rbb->q, rbb->q );
+ 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 );
}
}
-static void rb_constraint_position( rigidbody *ra, v3f lca,
- rigidbody *rb, v3f lcb )
-{
- /* C = (COa + Ra*LCa) - (COb + Rb*LCb) = 0 */
+/*
+ * 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 wca, wcb;
- m3x3_mulv( ra->to_world, lca, wca );
- m3x3_mulv( rb->to_world, lcb, wcb );
+ v3f wa, wb;
+ m3x3_mulv( rba->to_world, constr->lca, wa );
+ m3x3_mulv( rbb->to_world, constr->lcb, wb );
- v3f delta;
- v3_add( wcb, rb->co, delta );
- v3_sub( delta, wca, delta );
- v3_sub( delta, ra->co, delta );
+ 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 );
+ }
+}
- v3_muladds( ra->co, delta, 0.5f, ra->co );
- v3_muladds( rb->co, delta, -0.5f, rb->co );
+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 ];
- v3f rcv;
- v3_sub( ra->v, rb->v, rcv );
+ if( !st->axis_violation )
+ continue;
- 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 );
-
- v3f impulse;
- v3_muls( rcv, 0.5f, impulse );
- v3_add( impulse, rb->v, rb->v );
- v3_cross( wcb, impulse, impulse );
- v3_add( impulse, rb->I, rb->I );
+ float rv = v3_dot( st->axis, st->rbb->w ) -
+ v3_dot( st->axis, st->rba->w );
- v3_muls( rcv, -0.5f, impulse );
- v3_add( impulse, ra->v, ra->v );
- v3_cross( wca, impulse, impulse );
- v3_add( impulse, ra->I, ra->I );
+ 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 );
-#if 0
v3f impulse;
- v3_muls( delta, 0.5f*spring, 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_transform( 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
+ }
+}
- v3_add( impulse, ra->v, ra->v );
- v3_cross( wca, impulse, impulse );
- v3_add( impulse, ra->I, ra->I );
+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 );
+ rb_update_transform( 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 );
- v3_muls( delta, -0.5f*spring, impulse );
+ if( fabsf(angle) < 0.9999f ){
+ v3f axis;
+ v3_cross( vxb, st->axis_target, axis );
- v3_add( impulse, rb->v, rb->v );
- v3_cross( wcb, impulse, impulse );
- v3_add( impulse, rb->I, rb->I );
+#if 1
+ angle = acosf(angle) * amt;
+ v4f correction;
+ q_axis_angle( correction, axis, angle );
+ q_mul( correction, st->rbb->q, st->rbb->q );
+ rb_update_transform( 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_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];
-
- 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];
-
- 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 );
-
- vg_line( p100, p101, colour );
- vg_line( p101, p111, colour );
- vg_line( p111, p110, colour );
- vg_line( p110, p100, colour );
-
- vg_line( p100, p000, colour );
- vg_line( p101, p001, colour );
- vg_line( p110, p010, colour );
- vg_line( p111, p011, colour );
-
- vg_line( p000, p110, colour );
- vg_line( p100, p010, colour );
+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 / blobdiff