2 * Copyright (C) 2021-2022 Mt.ZERO Software, Harry Godden - All Rights Reserved
36 mdl_keyframe
*anim_data
;
47 u32 lower
, upper
, target
, pole
;
58 static u32
skeleton_bone_id( struct skeleton
*skele
, const char *name
)
60 for( u32 i
=1; i
<skele
->bone_count
; i
++ ){
61 if( !strcmp( skele
->bones
[i
].name
, name
))
65 vg_error( "skeleton_bone_id( *, \"%s\" );\n", name
);
66 vg_fatal_error( "Bone does not exist\n" );
71 static void keyframe_copy_pose( mdl_keyframe
*kfa
, mdl_keyframe
*kfb
,
74 for( int i
=0; i
<num
; i
++ )
79 /* apply a rotation from the perspective of root */
80 static void keyframe_rotate_around( mdl_keyframe
*kf
,
81 v3f origin
, v3f offset
, v4f q
)
84 v3_add( kf
->co
, offset
, co
);
85 v3_sub( co
, origin
, v0
);
87 v3_add( v0
, origin
, co
);
88 v3_sub( co
, offset
, kf
->co
);
90 q_mul( q
, kf
->q
, kf
->q
);
94 static void keyframe_lerp( mdl_keyframe
*kfa
, mdl_keyframe
*kfb
, f32 t
,
96 v3_lerp( kfa
->co
, kfb
->co
, t
, kfd
->co
);
97 q_nlerp( kfa
->q
, kfb
->q
, t
, kfd
->q
);
98 v3_lerp( kfa
->s
, kfb
->s
, t
, kfd
->s
);
102 * Lerp between two sets of keyframes and store in dest. Rotations use Nlerp.
104 static void keyframe_lerp_pose( mdl_keyframe
*kfa
, mdl_keyframe
*kfb
,
105 float t
, mdl_keyframe
*kfd
, int count
){
107 keyframe_copy_pose( kfa
, kfd
, count
);
110 else if( t
>= 0.9999f
){
111 keyframe_copy_pose( kfb
, kfd
, count
);
115 for( int i
=0; i
<count
; i
++ )
116 keyframe_lerp( kfa
+i
, kfb
+i
, t
, kfd
+i
);
120 void skeleton_lerp_pose( struct skeleton
*skele
,
121 mdl_keyframe
*kfa
, mdl_keyframe
*kfb
, float t
,
124 keyframe_lerp_pose( kfa
, kfb
, t
, kfd
, skele
->bone_count
-1 );
127 static void skeleton_copy_pose( struct skeleton
*skele
,
128 mdl_keyframe
*kfa
, mdl_keyframe
*kfd
)
130 keyframe_copy_pose( kfa
, kfd
, skele
->bone_count
-1 );
134 * Sample animation between 2 closest frames using time value. Output is a
135 * keyframe buffer that is allocated with an appropriate size
137 static void skeleton_sample_anim( struct skeleton
*skele
,
138 struct skeleton_anim
*anim
,
140 mdl_keyframe
*output
)
142 f32 animtime
= fmodf( time
*anim
->rate
, anim
->length
),
143 animframe
= floorf( animtime
),
144 t
= animtime
- animframe
;
146 u32 frame
= (u32
)animframe
% anim
->length
,
147 next
= (frame
+1) % anim
->length
;
149 mdl_keyframe
*base
= anim
->anim_data
+ (skele
->bone_count
-1)*frame
,
150 *nbase
= anim
->anim_data
+ (skele
->bone_count
-1)*next
;
152 skeleton_lerp_pose( skele
, base
, nbase
, t
, output
);
155 static int skeleton_sample_anim_clamped( struct skeleton
*skele
,
156 struct skeleton_anim
*anim
,
158 mdl_keyframe
*output
)
160 float end
= (float)(anim
->length
-1) / anim
->rate
;
161 skeleton_sample_anim( skele
, anim
, vg_minf( end
, time
), output
);
169 typedef enum anim_apply
172 k_anim_apply_defer_ik
,
173 k_anim_apply_deffered_only
,
174 k_anim_apply_absolute
179 int should_apply_bone( struct skeleton
*skele
, u32 id
, anim_apply type
)
181 struct skeleton_bone
*sb
= &skele
->bones
[ id
],
182 *sp
= &skele
->bones
[ sb
->parent
];
184 if( type
== k_anim_apply_defer_ik
){
185 if( ((sp
->flags
& k_bone_flag_ik
) && !(sb
->flags
& k_bone_flag_ik
))
196 else if( type
== k_anim_apply_deffered_only
){
207 * Apply block of keyframes to skeletons final pose
209 static void skeleton_apply_pose( struct skeleton
*skele
, mdl_keyframe
*pose
,
210 anim_apply passtype
, m4x3f
*final_mtx
){
211 if( passtype
== k_anim_apply_absolute
){
212 for( u32 i
=1; i
<skele
->bone_count
; i
++ ){
213 mdl_keyframe
*kf
= &pose
[i
-1];
215 v3f
*posemtx
= final_mtx
[i
];
217 q_m3x3( kf
->q
, posemtx
);
218 m3x3_scale( posemtx
, kf
->s
);
219 v3_copy( kf
->co
, posemtx
[3] );
224 m4x3_identity( final_mtx
[0] );
225 skele
->bones
[0].defer
= 0;
226 skele
->bones
[0].flags
&= ~k_bone_flag_ik
;
228 for( u32 i
=1; i
<skele
->bone_count
; i
++ ){
229 struct skeleton_bone
*sb
= &skele
->bones
[i
],
230 *sp
= &skele
->bones
[sb
->parent
];
232 if( !should_apply_bone( skele
, i
, passtype
) )
241 v3_sub( skele
->bones
[i
].co
, skele
->bones
[sb
->parent
].co
, temp_delta
);
244 mdl_keyframe
*kf
= &pose
[i
-1];
245 q_m3x3( kf
->q
, posemtx
);
246 m3x3_scale( posemtx
, kf
->s
);
247 v3_copy( kf
->co
, posemtx
[3] );
248 v3_add( temp_delta
, posemtx
[3], posemtx
[3] );
251 m4x3_mul( final_mtx
[ sb
->parent
], posemtx
, final_mtx
[i
] );
256 * Take the final matrices and decompose it into an absolute positioned anim
258 static void skeleton_decompose_mtx_absolute( struct skeleton
*skele
,
261 for( u32 i
=1; i
<skele
->bone_count
; i
++ ){
262 struct skeleton_bone
*sb
= &skele
->bones
[i
];
263 mdl_keyframe
*kf
= &anim
[i
-1];
264 m4x3_decompose( final_mtx
[i
], kf
->co
, kf
->q
, kf
->s
);
269 * creates the reference inverse matrix for an IK bone, as it has an initial
270 * intrisic rotation based on the direction that the IK is setup..
272 static void skeleton_inverse_for_ik( struct skeleton
*skele
,
274 u32 id
, m3x3f inverse
)
276 v3_copy( ivaxis
, inverse
[0] );
277 v3_copy( skele
->bones
[id
].end
, inverse
[1] );
278 v3_normalize( inverse
[1] );
279 v3_cross( inverse
[0], inverse
[1], inverse
[2] );
280 m3x3_transpose( inverse
, inverse
);
284 * Creates inverse rotation matrices which the IK system uses.
286 static void skeleton_create_inverses( struct skeleton
*skele
)
288 /* IK: inverse 'plane-bone space' axis '(^axis,^bone,...)[base] */
289 for( u32 i
=0; i
<skele
->ik_count
; i
++ ){
290 struct skeleton_ik
*ik
= &skele
->ik
[i
];
293 v3f iv0
, iv1
, ivaxis
;
294 v3_sub( skele
->bones
[ik
->target
].co
, skele
->bones
[ik
->lower
].co
, iv0
);
295 v3_sub( skele
->bones
[ik
->pole
].co
, skele
->bones
[ik
->lower
].co
, iv1
);
296 v3_cross( iv0
, iv1
, ivaxis
);
297 v3_normalize( ivaxis
);
299 skeleton_inverse_for_ik( skele
, ivaxis
, ik
->lower
, ik
->ia
);
300 skeleton_inverse_for_ik( skele
, ivaxis
, ik
->upper
, ik
->ib
);
305 * Apply a model matrix to all bones, should be done last
308 void skeleton_apply_transform( struct skeleton
*skele
, m4x3f transform
,
311 for( u32 i
=0; i
<skele
->bone_count
; i
++ ){
312 struct skeleton_bone
*sb
= &skele
->bones
[i
];
313 m4x3_mul( transform
, final_mtx
[i
], final_mtx
[i
] );
318 * Apply an inverse matrix to all bones which maps vertices from bind space into
319 * bone relative positions
321 static void skeleton_apply_inverses( struct skeleton
*skele
, m4x3f
*final_mtx
){
322 for( u32 i
=0; i
<skele
->bone_count
; i
++ ){
323 struct skeleton_bone
*sb
= &skele
->bones
[i
];
325 m3x3_identity( inverse
);
326 v3_negate( sb
->co
, inverse
[3] );
328 m4x3_mul( final_mtx
[i
], inverse
, final_mtx
[i
] );
333 * Apply all IK modifiers (2 bone ik reference from blender is supported)
335 static void skeleton_apply_ik_pass( struct skeleton
*skele
, m4x3f
*final_mtx
){
336 for( u32 i
=0; i
<skele
->ik_count
; i
++ ){
337 struct skeleton_ik
*ik
= &skele
->ik
[i
];
339 v3f v0
, /* base -> target */
340 v1
, /* base -> pole */
347 v3_copy( final_mtx
[ik
->lower
][3], co_base
);
348 v3_copy( final_mtx
[ik
->target
][3], co_target
);
349 v3_copy( final_mtx
[ik
->pole
][3], co_pole
);
351 v3_sub( co_target
, co_base
, v0
);
352 v3_sub( co_pole
, co_base
, v1
);
353 v3_cross( v0
, v1
, vaxis
);
354 v3_normalize( vaxis
);
356 v3_cross( vaxis
, v0
, v1
);
358 /* localize problem into [x:v0,y:v1] 2d plane */
359 v2f base
= { v3_dot( v0
, co_base
), v3_dot( v1
, co_base
) },
360 end
= { v3_dot( v0
, co_target
), v3_dot( v1
, co_target
) },
363 /* Compute angles (basic trig)*/
365 v2_sub( end
, base
, delta
);
368 l1
= v3_length( skele
->bones
[ik
->lower
].end
),
369 l2
= v3_length( skele
->bones
[ik
->upper
].end
),
370 d
= vg_clampf( v2_length(delta
), fabsf(l1
- l2
), l1
+l2
-0.00001f
),
371 c
= acosf( (l1
*l1
+ d
*d
- l2
*l2
) / (2.0f
*l1
*d
) ),
372 rot
= atan2f( delta
[1], delta
[0] ) + c
- VG_PIf
/2.0f
;
374 knee
[0] = sinf(-rot
) * l1
;
375 knee
[1] = cosf(-rot
) * l1
;
377 m4x3_identity( final_mtx
[ik
->lower
] );
378 m4x3_identity( final_mtx
[ik
->upper
] );
380 /* create rotation matrix */
382 v3_muladds( co_base
, v0
, knee
[0], co_knee
);
383 v3_muladds( co_knee
, v1
, knee
[1], co_knee
);
384 vg_line( co_base
, co_knee
, 0xff00ff00 );
387 v3_copy( vaxis
, transform
[0] );
388 v3_muls( v0
, knee
[0], transform
[1] );
389 v3_muladds( transform
[1], v1
, knee
[1], transform
[1] );
390 v3_normalize( transform
[1] );
391 v3_cross( transform
[0], transform
[1], transform
[2] );
392 v3_copy( co_base
, transform
[3] );
394 m3x3_mul( transform
, ik
->ia
, transform
);
395 m4x3_copy( transform
, final_mtx
[ik
->lower
] );
397 /* upper/knee bone */
398 v3_copy( vaxis
, transform
[0] );
399 v3_sub( co_target
, co_knee
, transform
[1] );
400 v3_normalize( transform
[1] );
401 v3_cross( transform
[0], transform
[1], transform
[2] );
402 v3_copy( co_knee
, transform
[3] );
404 m3x3_mul( transform
, ik
->ib
, transform
);
405 m4x3_copy( transform
, final_mtx
[ik
->upper
] );
410 * Applies the typical operations that you want for an IK rig:
411 * Pose, IK, Pose(deferred), Inverses, Transform
413 static void skeleton_apply_standard( struct skeleton
*skele
, mdl_keyframe
*pose
,
414 m4x3f transform
, m4x3f
*final_mtx
){
415 skeleton_apply_pose( skele
, pose
, k_anim_apply_defer_ik
, final_mtx
);
416 skeleton_apply_ik_pass( skele
, final_mtx
);
417 skeleton_apply_pose( skele
, pose
, k_anim_apply_deffered_only
, final_mtx
);
418 skeleton_apply_inverses( skele
, final_mtx
);
419 skeleton_apply_transform( skele
, transform
, final_mtx
);
423 * Get an animation by name
425 static struct skeleton_anim
*skeleton_get_anim( struct skeleton
*skele
,
427 for( u32 i
=0; i
<skele
->anim_count
; i
++ ){
428 struct skeleton_anim
*anim
= &skele
->anims
[i
];
430 if( !strcmp( anim
->name
, name
) )
434 vg_error( "skeleton_get_anim( *, \"%s\" )\n", name
);
435 vg_fatal_error( "Invalid animation name\n" );
440 static void skeleton_alloc_from( struct skeleton
*skele
,
443 mdl_armature
*armature
){
444 skele
->bone_count
= armature
->bone_count
+1;
445 skele
->anim_count
= armature
->anim_count
;
447 skele
->collider_count
= 0;
449 for( u32 i
=0; i
<armature
->bone_count
; i
++ ){
450 mdl_bone
*bone
= mdl_arritm( &mdl
->bones
, armature
->bone_start
+i
);
452 if( bone
->flags
& k_bone_flag_ik
)
456 skele
->collider_count
++;
459 u32 bone_size
= sizeof(struct skeleton_bone
) * skele
->bone_count
,
460 ik_size
= sizeof(struct skeleton_ik
) * skele
->ik_count
,
461 mtx_size
= sizeof(m4x3f
) * skele
->bone_count
,
462 anim_size
= sizeof(struct skeleton_anim
) * skele
->anim_count
;
464 skele
->bones
= vg_linear_alloc( lin_alloc
, bone_size
);
465 skele
->ik
= vg_linear_alloc( lin_alloc
, ik_size
);
466 //skele->final_mtx = vg_linear_alloc( lin_alloc, mtx_size );
467 skele
->anims
= vg_linear_alloc( lin_alloc
, anim_size
);
469 memset( skele
->bones
, 0, bone_size
);
470 memset( skele
->ik
, 0, ik_size
);
471 //memset( skele->final_mtx, 0, mtx_size );
472 memset( skele
->anims
, 0, anim_size
);
475 static void skeleton_fatal_err(void){
476 vg_fatal_error( "Skeleton setup failed" );
479 /* Setup an animated skeleton from model. mdl's metadata should stick around */
480 static void skeleton_setup( struct skeleton
*skele
,
481 void *lin_alloc
, mdl_context
*mdl
){
482 u32 ik_count
= 0, collider_count
= 0;
483 skele
->bone_count
= 0;
485 //skele->final_mtx = NULL;
488 if( !mdl
->armatures
.count
){
489 vg_error( "No skeleton in model\n" );
490 skeleton_fatal_err();
493 mdl_armature
*armature
= mdl_arritm( &mdl
->armatures
, 0 );
494 skeleton_alloc_from( skele
, lin_alloc
, mdl
, armature
);
496 for( u32 i
=0; i
<armature
->bone_count
; i
++ ){
497 mdl_bone
*bone
= mdl_arritm( &mdl
->bones
, armature
->bone_start
+i
);
498 struct skeleton_bone
*sb
= &skele
->bones
[i
+1];
500 v3_copy( bone
->co
, sb
->co
);
501 v3_copy( bone
->end
, sb
->end
);
503 sb
->parent
= bone
->parent
;
504 sb
->name
= mdl_pstr( mdl
, bone
->pstr_name
);
505 sb
->flags
= bone
->flags
;
506 sb
->collider
= bone
->collider
;
507 sb
->orig_bone
= bone
;
509 if( sb
->flags
& k_bone_flag_ik
){
510 skele
->bones
[ sb
->parent
].flags
|= k_bone_flag_ik
;
512 if( ik_count
== skele
->ik_count
){
513 vg_error( "Too many ik bones, corrupt model file\n" );
514 skeleton_fatal_err();
517 struct skeleton_ik
*ik
= &skele
->ik
[ ik_count
++ ];
519 ik
->lower
= bone
->parent
;
520 ik
->target
= bone
->ik_target
;
521 ik
->pole
= bone
->ik_pole
;
524 box_copy( bone
->hitbox
, sb
->hitbox
);
526 if( bone
->collider
){
527 if( collider_count
== skele
->collider_count
){
528 vg_error( "Too many collider bones\n" );
529 skeleton_fatal_err();
536 /* fill in implicit root bone */
537 v3_zero( skele
->bones
[0].co
);
538 v3_copy( (v3f
){0.0f
,1.0f
,0.0f
}, skele
->bones
[0].end
);
539 skele
->bones
[0].parent
= 0xffffffff;
540 skele
->bones
[0].flags
= 0;
541 skele
->bones
[0].name
= "[root]";
543 /* process animation quick refs */
544 for( u32 i
=0; i
<skele
->anim_count
; i
++ ){
545 mdl_animation
*anim
=
546 mdl_arritm( &mdl
->animations
, armature
->anim_start
+i
);
548 skele
->anims
[i
].rate
= anim
->rate
;
549 skele
->anims
[i
].length
= anim
->length
;
550 skele
->anims
[i
].name
= mdl_pstr(mdl
, anim
->pstr_name
);
551 skele
->anims
[i
].anim_data
=
552 mdl_arritm( &mdl
->keyframes
, anim
->offset
);
554 vg_info( "animation[ %f, %u ] '%s'\n", anim
->rate
,
556 skele
->anims
[i
].name
);
559 skeleton_create_inverses( skele
);
560 vg_success( "Loaded skeleton with %u bones\n", skele
->bone_count
);
561 vg_success( " %u colliders\n", skele
->collider_count
);
564 static void skeleton_debug( struct skeleton
*skele
, m4x3f
*final_mtx
){
565 for( u32 i
=1; i
<skele
->bone_count
; i
++ ){
566 struct skeleton_bone
*sb
= &skele
->bones
[i
];
569 v3_copy( sb
->co
, p0
);
570 v3_add( p0
, sb
->end
, p1
);
572 m4x3_mulv( final_mtx
[i
], p0
, p0
);
573 m4x3_mulv( final_mtx
[i
], p1
, p1
);
575 if( sb
->flags
& k_bone_flag_deform
){
576 if( sb
->flags
& k_bone_flag_ik
){
577 vg_line( p0
, p1
, 0xff0000ff );
580 vg_line( p0
, p1
, 0xffcccccc );
584 vg_line( p0
, p1
, 0xff00ffff );
588 #endif /* SKELETON_H */