+/*
+ * Copyright (C) 2021-2022 Mt.ZERO Software, Harry Godden - All Rights Reserved
+ */
+
#ifndef SKELETON_H
#define SKELETON_H
struct skeleton_bone
{
v3f co, end;
- u32 children; /* maybe remove */
u32 parent;
-
+
+ u32 flags;
+ int defer;
+
mdl_keyframe kf;
+ mdl_bone *orig_bone;
+
+ u32 collider;
+ boxf hitbox;
+ const char *name;
}
*bones;
- m4x3f *final_transforms;
+ u32 bone_count;
struct skeleton_anim
{
- float rate;
+ const char *name;
u32 length;
- struct mdl_keyframe *anim_data;
- char name[32];
+
+ float rate;
+ mdl_keyframe *anim_data;
}
*anims;
+ u32 anim_count;
+
+ m4x3f *final_mtx;
- u32 bone_count,
- anim_count;
+ struct skeleton_ik
+ {
+ u32 lower, upper, target, pole;
+ m3x3f ia, ib;
+ }
+ *ik;
+ u32 ik_count;
+
+ u32
+ collider_count,
+ bindable_count;
};
-static void skeleton_apply_frame( m4x3f transform,
- struct skeleton *skele,
- struct skeleton_anim *anim,
- float time )
+VG_STATIC u32 skeleton_bone_id( struct skeleton *skele, const char *name )
{
- u32 frame = time*anim->rate;
- frame = frame % anim->length;
+ for( u32 i=1; i<skele->bone_count; i++ ){
+ if( !strcmp( skele->bones[i].name, name ))
+ return i;
+ }
- mdl_keyframe *base = anim->anim_data + (skele->bone_count-1)*frame;
- m4x3_copy( transform, skele->final_transforms[0] );
+ vg_error( "skeleton_bone_id( *, \"%s\" );\n", name );
+ vg_fatal_exit_loop( "Bone does not exist\n" );
- for( int i=1; i<skele->bone_count; i++ )
- {
- struct skeleton_bone *sb = &skele->bones[i];
+ return 0;
+}
+
+VG_STATIC void keyframe_copy_pose( mdl_keyframe *kfa, mdl_keyframe *kfb,
+ int num )
+{
+ for( int i=0; i<num; i++ )
+ kfb[i] = kfa[i];
+}
+
+/*
+ * Lerp between two sets of keyframes and store in dest. Rotations use Nlerp.
+ */
+VG_STATIC void keyframe_lerp_pose( mdl_keyframe *kfa, mdl_keyframe *kfb,
+ float t, mdl_keyframe *kfd, int count )
+{
+ if( t <= 0.0001f ){
+ keyframe_copy_pose( kfa, kfd, count );
+ return;
+ }
+ else if( t >= 0.9999f ){
+ keyframe_copy_pose( kfb, kfd, count );
+ return;
+ }
+
+ for( int i=0; i<count; i++ ){
+ v3_lerp( kfa[i].co, kfb[i].co, t, kfd[i].co );
+ q_nlerp( kfa[i].q, kfb[i].q, t, kfd[i].q );
+ v3_lerp( kfa[i].s, kfb[i].s, t, kfd[i].s );
+ }
+}
+
+VG_STATIC
+void skeleton_lerp_pose( struct skeleton *skele,
+ mdl_keyframe *kfa, mdl_keyframe *kfb, float t,
+ mdl_keyframe *kfd )
+{
+ keyframe_lerp_pose( kfa, kfb, t, kfd, skele->bone_count-1 );
+}
+
+VG_STATIC void skeleton_copy_pose( struct skeleton *skele,
+ mdl_keyframe *kfa, mdl_keyframe *kfd )
+{
+ keyframe_copy_pose( kfa, kfd, skele->bone_count-1 );
+}
+
+/*
+ * Sample animation between 2 closest frames using time value. Output is a
+ * keyframe buffer that is allocated with an appropriate size
+ */
+VG_STATIC void skeleton_sample_anim( struct skeleton *skele,
+ struct skeleton_anim *anim,
+ float time,
+ mdl_keyframe *output )
+{
+ float animtime = time*anim->rate;
+
+ u32 frame = ((u32)animtime) % anim->length,
+ next = (frame+1) % anim->length;
+
+ float t = vg_fractf( animtime );
+
+ mdl_keyframe *base = anim->anim_data + (skele->bone_count-1)*frame,
+ *nbase = anim->anim_data + (skele->bone_count-1)*next;
+
+ skeleton_lerp_pose( skele, base, nbase, t, output );
+}
+
+VG_STATIC int skeleton_sample_anim_clamped( struct skeleton *skele,
+ struct skeleton_anim *anim,
+ float time,
+ mdl_keyframe *output )
+{
+ float end = (float)(anim->length-1) / anim->rate;
+ skeleton_sample_anim( skele, anim, vg_minf( end, time ), output );
+
+ if( time > end )
+ return 0;
+ else
+ return 1;
+}
+
+typedef enum anim_apply
+{
+ k_anim_apply_always,
+ k_anim_apply_defer_ik,
+ k_anim_apply_deffered_only
+}
+anim_apply;
+
+VG_STATIC
+int should_apply_bone( struct skeleton *skele, u32 id, anim_apply type )
+{
+ struct skeleton_bone *sb = &skele->bones[ id ],
+ *sp = &skele->bones[ sb->parent ];
+
+ if( type == k_anim_apply_defer_ik ){
+ if( ((sp->flags & k_bone_flag_ik) && !(sb->flags & k_bone_flag_ik))
+ || sp->defer )
+ {
+ sb->defer = 1;
+ return 0;
+ }
+ else{
+ sb->defer = 0;
+ return 1;
+ }
+ }
+ else if( type == k_anim_apply_deffered_only ){
+ if( sb->defer )
+ return 1;
+ else
+ return 0;
+ }
+
+ return 1;
+}
+
+/*
+ * Apply block of keyframes to skeletons final pose
+ */
+VG_STATIC void skeleton_apply_pose( struct skeleton *skele, mdl_keyframe *pose,
+ anim_apply passtype )
+{
+ m4x3_identity( skele->final_mtx[0] );
+ skele->bones[0].defer = 0;
+ skele->bones[0].flags &= ~k_bone_flag_ik;
+
+ for( u32 i=1; i<skele->bone_count; i++ ){
+ struct skeleton_bone *sb = &skele->bones[i],
+ *sp = &skele->bones[sb->parent];
+
+ if( !should_apply_bone( skele, i, passtype ) )
+ continue;
+
+ sb->defer = 0;
/* process pose */
m4x3f posemtx;
v3f temp_delta;
v3_sub( skele->bones[i].co, skele->bones[sb->parent].co, temp_delta );
-
/* pose matrix */
- mdl_keyframe *kf = base+i-1;
-
+ mdl_keyframe *kf = &pose[i-1];
q_m3x3( kf->q, posemtx );
v3_copy( kf->co, posemtx[3] );
v3_add( temp_delta, posemtx[3], posemtx[3] );
/* final matrix */
- m4x3_mul( skele->final_transforms[ sb->parent ], posemtx,
- skele->final_transforms[i] );
+ m4x3_mul( skele->final_mtx[ sb->parent ], posemtx, skele->final_mtx[i] );
}
+}
- /* armature space -> bone space matrix ( for verts ) */
- for( int i=1; i<skele->bone_count; i++ )
- {
- m4x3f abmtx;
- m3x3_identity( abmtx );
- v3_negate( skele->bones[i].co, abmtx[3] );
- m4x3_mul( skele->final_transforms[i], abmtx,
- skele->final_transforms[i] );
+/*
+ * creates the reference inverse matrix for an IK bone, as it has an initial
+ * intrisic rotation based on the direction that the IK is setup..
+ */
+VG_STATIC void skeleton_inverse_for_ik( struct skeleton *skele,
+ v3f ivaxis,
+ u32 id, m3x3f inverse )
+{
+ v3_copy( ivaxis, inverse[0] );
+ v3_copy( skele->bones[id].end, inverse[1] );
+ v3_normalize( inverse[1] );
+ v3_cross( inverse[0], inverse[1], inverse[2] );
+ m3x3_transpose( inverse, inverse );
+}
+
+/*
+ * Creates inverse rotation matrices which the IK system uses.
+ */
+VG_STATIC void skeleton_create_inverses( struct skeleton *skele )
+{
+ /* IK: inverse 'plane-bone space' axis '(^axis,^bone,...)[base] */
+ for( u32 i=0; i<skele->ik_count; i++ ){
+ struct skeleton_ik *ik = &skele->ik[i];
+
+ m4x3f inverse;
+ v3f iv0, iv1, ivaxis;
+ v3_sub( skele->bones[ik->target].co, skele->bones[ik->lower].co, iv0 );
+ v3_sub( skele->bones[ik->pole].co, skele->bones[ik->lower].co, iv1 );
+ v3_cross( iv0, iv1, ivaxis );
+ v3_normalize( ivaxis );
+
+ skeleton_inverse_for_ik( skele, ivaxis, ik->lower, ik->ia );
+ skeleton_inverse_for_ik( skele, ivaxis, ik->upper, ik->ib );
}
}
-static struct skeleton_anim *skeleton_get_anim( struct skeleton *skele,
- const char *name )
+/*
+ * Apply a model matrix to all bones, should be done last
+ */
+VG_STATIC
+void skeleton_apply_transform( struct skeleton *skele, m4x3f transform )
{
- for( int i=0; i<skele->anim_count; i++ )
- {
+ for( u32 i=0; i<skele->bone_count; i++ ){
+ struct skeleton_bone *sb = &skele->bones[i];
+ m4x3_mul( transform, skele->final_mtx[i], skele->final_mtx[i] );
+ }
+}
+
+/*
+ * Apply an inverse matrix to all bones which maps vertices from bind space into
+ * bone relative positions
+ */
+VG_STATIC void skeleton_apply_inverses( struct skeleton *skele )
+{
+ for( u32 i=0; i<skele->bone_count; i++ ){
+ struct skeleton_bone *sb = &skele->bones[i];
+ m4x3f inverse;
+ m3x3_identity( inverse );
+ v3_negate( sb->co, inverse[3] );
+
+ m4x3_mul( skele->final_mtx[i], inverse, skele->final_mtx[i] );
+ }
+}
+
+/*
+ * Apply all IK modifiers (2 bone ik reference from blender is supported)
+ */
+VG_STATIC void skeleton_apply_ik_pass( struct skeleton *skele )
+{
+ for( u32 i=0; i<skele->ik_count; i++ ){
+ struct skeleton_ik *ik = &skele->ik[i];
+
+ v3f v0, /* base -> target */
+ v1, /* base -> pole */
+ vaxis;
+
+ v3f co_base,
+ co_target,
+ co_pole;
+
+ v3_copy( skele->final_mtx[ik->lower][3], co_base );
+ v3_copy( skele->final_mtx[ik->target][3], co_target );
+ v3_copy( skele->final_mtx[ik->pole][3], co_pole );
+
+ v3_sub( co_target, co_base, v0 );
+ v3_sub( co_pole, co_base, v1 );
+ v3_cross( v0, v1, vaxis );
+ v3_normalize( vaxis );
+ v3_normalize( v0 );
+ v3_cross( vaxis, v0, v1 );
+
+ /* localize problem into [x:v0,y:v1] 2d plane */
+ v2f base = { v3_dot( v0, co_base ), v3_dot( v1, co_base ) },
+ end = { v3_dot( v0, co_target ), v3_dot( v1, co_target ) },
+ knee;
+
+ /* Compute angles (basic trig)*/
+ v2f delta;
+ v2_sub( end, base, delta );
+
+ float
+ l1 = v3_length( skele->bones[ik->lower].end ),
+ l2 = v3_length( skele->bones[ik->upper].end ),
+ d = vg_clampf( v2_length(delta), fabsf(l1 - l2), l1+l2-0.00001f ),
+ c = acosf( (l1*l1 + d*d - l2*l2) / (2.0f*l1*d) ),
+ rot = atan2f( delta[1], delta[0] ) + c - VG_PIf/2.0f;
+
+ knee[0] = sinf(-rot) * l1;
+ knee[1] = cosf(-rot) * l1;
+
+ m4x3_identity( skele->final_mtx[ik->lower] );
+ m4x3_identity( skele->final_mtx[ik->upper] );
+
+ /* create rotation matrix */
+ v3f co_knee;
+ v3_muladds( co_base, v0, knee[0], co_knee );
+ v3_muladds( co_knee, v1, knee[1], co_knee );
+ vg_line( co_base, co_knee, 0xff00ff00 );
+
+ m4x3f transform;
+ v3_copy( vaxis, transform[0] );
+ v3_muls( v0, knee[0], transform[1] );
+ v3_muladds( transform[1], v1, knee[1], transform[1] );
+ v3_normalize( transform[1] );
+ v3_cross( transform[0], transform[1], transform[2] );
+ v3_copy( co_base, transform[3] );
+
+ m3x3_mul( transform, ik->ia, transform );
+ m4x3_copy( transform, skele->final_mtx[ik->lower] );
+
+ /* upper/knee bone */
+ v3_copy( vaxis, transform[0] );
+ v3_sub( co_target, co_knee, transform[1] );
+ v3_normalize( transform[1] );
+ v3_cross( transform[0], transform[1], transform[2] );
+ v3_copy( co_knee, transform[3] );
+
+ m3x3_mul( transform, ik->ib, transform );
+ m4x3_copy( transform, skele->final_mtx[ik->upper] );
+ }
+}
+
+/*
+ * Applies the typical operations that you want for an IK rig:
+ * Pose, IK, Pose(deferred), Inverses, Transform
+ */
+VG_STATIC void skeleton_apply_standard( struct skeleton *skele, mdl_keyframe *pose,
+ m4x3f transform )
+{
+ skeleton_apply_pose( skele, pose, k_anim_apply_defer_ik );
+ skeleton_apply_ik_pass( skele );
+ skeleton_apply_pose( skele, pose, k_anim_apply_deffered_only );
+ skeleton_apply_inverses( skele );
+ skeleton_apply_transform( skele, transform );
+}
+
+/*
+ * Get an animation by name
+ */
+VG_STATIC struct skeleton_anim *skeleton_get_anim( struct skeleton *skele,
+ const char *name )
+{
+ for( u32 i=0; i<skele->anim_count; i++ ){
struct skeleton_anim *anim = &skele->anims[i];
if( !strcmp( anim->name, name ) )
return anim;
}
+ vg_error( "skeleton_get_anim( *, \"%s\" )\n", name );
+ vg_fatal_exit_loop( "Invalid animation name\n" );
+
return NULL;
}
-/* Setup an animated skeleton from model */
-static int skeleton_setup( struct skeleton *skele, mdl_header *mdl )
+VG_STATIC void skeleton_alloc_from( struct skeleton *skele,
+ void *lin_alloc,
+ mdl_context *mdl,
+ mdl_armature *armature )
{
- u32 bone_count = 1, skeleton_root = 0;
+ skele->bone_count = armature->bone_count+1;
+ skele->anim_count = armature->anim_count;
+ skele->ik_count = 0;
+ skele->collider_count = 0;
+
+ for( u32 i=0; i<armature->bone_count; i++ ){
+ mdl_bone *bone = mdl_arritm( &mdl->bones, armature->bone_start+i );
+
+ if( bone->flags & k_bone_flag_ik )
+ skele->ik_count ++;
+
+ if( bone->collider )
+ skele->collider_count ++;
+ }
+
+ u32 bone_size = sizeof(struct skeleton_bone) * skele->bone_count,
+ ik_size = sizeof(struct skeleton_ik) * skele->ik_count,
+ mtx_size = sizeof(m4x3f) * skele->bone_count,
+ anim_size = sizeof(struct skeleton_anim) * skele->anim_count;
+
+ skele->bones = vg_linear_alloc( lin_alloc, bone_size );
+ skele->ik = vg_linear_alloc( lin_alloc, ik_size );
+ skele->final_mtx = vg_linear_alloc( lin_alloc, mtx_size );
+ skele->anims = vg_linear_alloc( lin_alloc, anim_size );
+}
+
+VG_STATIC void skeleton_fatal_err(void)
+{
+ vg_fatal_exit_loop( "Skeleton setup failed" );
+}
+
+/* Setup an animated skeleton from model. mdl's metadata should stick around */
+VG_STATIC void skeleton_setup( struct skeleton *skele,
+ void *lin_alloc, mdl_context *mdl )
+{
+ u32 ik_count = 0, collider_count = 0;
skele->bone_count = 0;
skele->bones = NULL;
- skele->final_transforms = NULL;
+ skele->final_mtx = NULL;
skele->anims = NULL;
- struct classtype_skeleton *inf = NULL;
+ if( !mdl->armatures.count ){
+ vg_error( "No skeleton in model\n" );
+ skeleton_fatal_err();
+ }
- for( u32 i=0; i<mdl->node_count; i++ )
- {
- mdl_node *pnode = mdl_node_from_id( mdl, i );
+ mdl_armature *armature = mdl_arritm( &mdl->armatures, 0 );
+ skeleton_alloc_from( skele, lin_alloc, mdl, armature );
- if( pnode->classtype == k_classtype_skeleton )
- {
- inf = mdl_get_entdata( mdl, pnode );
- if( skele->bone_count )
- {
- vg_error( "Multiple skeletons in model file\n" );
- free( skele->bones );
- return 0;
- }
+ for( u32 i=0; i<armature->bone_count; i++ ){
+ mdl_bone *bone = mdl_arritm( &mdl->bones, armature->bone_start+i );
+ struct skeleton_bone *sb = &skele->bones[i+1];
+
+ v3_copy( bone->co, sb->co );
+ v3_copy( bone->end, sb->end );
+
+ sb->parent = bone->parent;
+ sb->name = mdl_pstr( mdl, bone->pstr_name );
+ sb->flags = bone->flags;
+ sb->collider = bone->collider;
+ sb->orig_bone = bone;
+
+ if( sb->flags & k_bone_flag_ik ){
+ skele->bones[ sb->parent ].flags |= k_bone_flag_ik;
- skele->bone_count = inf->channels;
- skele->bones = malloc(sizeof(struct skeleton_bone)*skele->bone_count);
- skeleton_root = i;
- }
- else if( skele->bone_count )
- {
- if( pnode->classtype == k_classtype_bone )
- {
- struct skeleton_bone *sb = &skele->bones[bone_count ++];
- v3_copy( pnode->co, sb->co );
- v3_copy( pnode->s, sb->end );
- sb->parent = pnode->parent-skeleton_root;
- }
- else
- {
- break;
+ if( ik_count == skele->ik_count ){
+ vg_error( "Too many ik bones, corrupt model file\n" );
+ skeleton_fatal_err();
}
+
+ struct skeleton_ik *ik = &skele->ik[ ik_count ++ ];
+ ik->upper = i+1;
+ ik->lower = bone->parent;
+ ik->target = bone->ik_target;
+ ik->pole = bone->ik_pole;
}
- }
- if( !inf )
- {
- vg_error( "No skeleton in model\n" );
- return 0;
- }
+ box_copy( bone->hitbox, sb->hitbox );
- if( bone_count != skele->bone_count )
- {
- vg_error( "Loaded %u bones out of %u\n", bone_count, skele->bone_count );
- return 0;
+ if( bone->collider ){
+ if( collider_count == skele->collider_count ){
+ vg_error( "Too many collider bones\n" );
+ skeleton_fatal_err();
+ }
+
+ collider_count ++;
+ }
}
/* fill in implicit root bone */
v3_zero( skele->bones[0].co );
v3_copy( (v3f){0.0f,1.0f,0.0f}, skele->bones[0].end );
skele->bones[0].parent = 0xffffffff;
+ skele->bones[0].flags = 0;
+ skele->bones[0].name = "[root]";
- skele->final_transforms = malloc( sizeof(m4x3f) * skele->bone_count );
- skele->anim_count = inf->anim_count;
- skele->anims = malloc( sizeof(struct skeleton_anim) * inf->anim_count);
-
- for( int i=0; i<inf->anim_count; i++ )
- {
+ /* process animation quick refs */
+ for( u32 i=0; i<skele->anim_count; i++ ){
mdl_animation *anim =
- mdl_animation_from_id( mdl, inf->anim_start+i );
-
- skele->anims[i].rate = anim->rate;
- skele->anims[i].length = anim->length;
- strncpy( skele->anims[i].name, mdl_pstr(mdl, anim->pstr_name), 32 );
+ mdl_arritm( &mdl->animations, armature->anim_start+i );
- u32 total_keyframes = (skele->bone_count-1)*anim->length;
- size_t block_size = sizeof(mdl_keyframe) * total_keyframes;
- mdl_keyframe *dst = malloc( block_size );
+ skele->anims[i].rate = anim->rate;
+ skele->anims[i].length = anim->length;
+ skele->anims[i].name = mdl_pstr(mdl, anim->pstr_name);
+ skele->anims[i].anim_data =
+ mdl_arritm( &mdl->keyframes, anim->offset );
- skele->anims[i].anim_data = dst;
- memcpy( dst, mdl_get_animdata( mdl, anim ), block_size );
+ vg_info( "animation[ %f, %u ] '%s'\n", anim->rate,
+ anim->length,
+ skele->anims[i].name );
}
+ skeleton_create_inverses( skele );
vg_success( "Loaded skeleton with %u bones\n", skele->bone_count );
- return 1;
+ vg_success( " %u colliders\n", skele->collider_count );
}
-static void skeleton_debug( struct skeleton *skele )
+VG_STATIC void skeleton_debug( struct skeleton *skele )
{
- for( int i=0; i<skele->bone_count; i ++ )
- {
+ for( u32 i=1; i<skele->bone_count; i ++ ){
struct skeleton_bone *sb = &skele->bones[i];
v3f p0, p1;
v3_copy( sb->co, p0 );
v3_add( p0, sb->end, p1 );
- vg_line( p0, p1, 0xffffffff );
- m4x3_mulv( skele->final_transforms[i], p0, p0 );
- m4x3_mulv( skele->final_transforms[i], p1, p1 );
- vg_line( p0, p1, 0xff0000ff );
+ m4x3_mulv( skele->final_mtx[i], p0, p0 );
+ m4x3_mulv( skele->final_mtx[i], p1, p1 );
+
+ if( sb->flags & k_bone_flag_deform ){
+ if( sb->flags & k_bone_flag_ik ){
+ vg_line( p0, p1, 0xff0000ff );
+ }
+ else{
+ vg_line( p0, p1, 0xffcccccc );
+ }
+ }
+ else
+ vg_line( p0, p1, 0xff00ffff );
}
}