#include "model.h"
+struct skeleton
+{
+ struct skeleton_bone
+ {
+ v3f co, end;
+ u32 parent;
+
+ int deform, ik;
+ int defer;
+
+ mdl_keyframe kf;
+ }
+ *bones;
+ m4x3f *final_mtx;
+
+ struct skeleton_ik
+ {
+ u32 lower, upper, target, pole;
+ m3x3f ia, ib;
+ }
+ *ik;
+
+ struct skeleton_anim
+ {
+ float rate;
+ u32 length;
+ struct mdl_keyframe *anim_data;
+ char name[32];
+ }
+ *anims;
+
+ u32 bone_count,
+ ik_count,
+ anim_count,
+ bindable_count; /* TODO: try to place IK last in the rig from export
+ so that we dont always upload transforms for
+ useless cpu IK bones. */
+};
+
+/*
+ * Lerp between two sets of keyframes and store in dest. Rotations use Nlerp.
+ */
+static void keyframe_lerp_pose( mdl_keyframe *kfa, mdl_keyframe *kfb, float t,
+ mdl_keyframe *kfd, int count )
+{
+ 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 );
+ }
+}
+
+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 );
+}
+
+/*
+ * Sample animation between 2 closest frames using time value. Output is a
+ * keyframe buffer that is allocated with an appropriate size
+ */
+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 );
+}
+
+typedef enum anim_apply
+{
+ k_anim_apply_always,
+ k_anim_apply_defer_ik,
+ k_anim_apply_deffered_only
+}
+anim_apply;
+
+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->ik && !sb->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
+ */
+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].ik = 0;
+
+ for( int 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 = &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_mtx[ sb->parent ], posemtx, skele->final_mtx[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..
+ */
+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 );
+}
+
+static void skeleton_create_inverses( struct skeleton *skele )
+{
+ /* IK: inverse 'plane-bone space' axis '(^axis,^bone,...)[base] */
+ for( int 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 void skeleton_apply_transform( struct skeleton *skele, m4x3f transform )
+{
+ /* bone space inverse matrix */
+ for( int 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] );
+ }
+}
+
+static void skeleton_apply_inverses( struct skeleton *skele )
+{
+ for( int 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)
+ */
+static void skeleton_apply_ik_pass( struct skeleton *skele )
+{
+ for( int 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] );
+ }
+}
+
+static struct skeleton_anim *skeleton_get_anim( struct skeleton *skele,
+ const char *name )
+{
+ for( int i=0; i<skele->anim_count; i++ )
+ {
+ struct skeleton_anim *anim = &skele->anims[i];
+
+ if( !strcmp( anim->name, name ) )
+ return anim;
+ }
+
+ return NULL;
+}
+
+/* Setup an animated skeleton from model */
+static int skeleton_setup( struct skeleton *skele, mdl_header *mdl )
+{
+ u32 bone_count = 1, skeleton_root = 0, ik_count = 0;
+ skele->bone_count = 0;
+ skele->bones = NULL;
+ skele->final_mtx = NULL;
+ skele->anims = NULL;
+
+ struct classtype_skeleton *inf = NULL;
+
+ for( u32 i=0; i<mdl->node_count; i++ )
+ {
+ mdl_node *pnode = mdl_node_from_id( mdl, i );
+
+ if( pnode->classtype == k_classtype_skeleton )
+ {
+ inf = mdl_get_entdata( mdl, pnode );
+ if( skele->bone_count )
+ {
+ vg_error( "Multiple skeletons in model file\n" );
+ goto error_dealloc;
+ }
+
+ skele->bone_count = inf->channels;
+ skele->ik_count = inf->ik_count;
+ skele->bones = malloc(sizeof(struct skeleton_bone)*skele->bone_count);
+ skele->ik = malloc(sizeof(struct skeleton_ik)*skele->ik_count);
+ skeleton_root = i;
+ }
+ else if( skele->bone_count )
+ {
+ int is_ik = pnode->classtype == k_classtype_ik_bone,
+ is_bone = (pnode->classtype == k_classtype_bone) || is_ik;
+
+ if( is_bone )
+ {
+ if( bone_count == skele->bone_count )
+ {
+ vg_error( "too many bones (%u/%u) @%s!\n",
+ bone_count, skele->bone_count,
+ mdl_pstr( mdl, pnode->pstr_name ));
+
+ goto error_dealloc;
+ }
+
+ 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;
+
+ if( is_ik )
+ {
+ struct classtype_ik_bone *ik_inf = mdl_get_entdata( mdl, pnode );
+ sb->deform = ik_inf->deform;
+ sb->ik = 1; /* TODO: place into new IK array */
+ skele->bones[ sb->parent ].ik = 1;
+
+ if( ik_count == skele->ik_count )
+ {
+ vg_error( "Too many ik bones, corrupt model file\n" );
+ goto error_dealloc;
+ }
+
+ struct skeleton_ik *ik = &skele->ik[ ik_count ++ ];
+ ik->upper = bone_count;
+ ik->lower = sb->parent;
+ ik->target = ik_inf->target;
+ ik->pole = ik_inf->pole;
+ }
+ else
+ {
+ struct classtype_bone *bone_inf = mdl_get_entdata( mdl, pnode );
+ sb->deform = bone_inf->deform;
+ sb->ik = 0;
+ }
+
+ bone_count ++;
+ }
+ else
+ {
+ break;
+ }
+ }
+ }
+
+ if( !inf )
+ {
+ vg_error( "No skeleton in model\n" );
+ return 0;
+ }
+
+ if( bone_count != skele->bone_count )
+ {
+ vg_error( "Loaded %u bones out of %u\n", bone_count, skele->bone_count );
+ goto error_dealloc;
+ }
+
+ if( ik_count != skele->ik_count )
+ {
+ vg_error( "Loaded %u ik bones out of %u\n", ik_count, skele->ik_count );
+ goto error_dealloc;
+ }
+
+ /* 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->final_mtx = 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++ )
+ {
+ 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 );
+
+ 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].anim_data = dst;
+ memcpy( dst, mdl_get_animdata( mdl, anim ), block_size );
+ }
+
+ skeleton_create_inverses( skele );
+ vg_success( "Loaded skeleton with %u bones\n", skele->bone_count );
+ return 1;
+
+error_dealloc:
+ free( skele->bones );
+ free( skele->ik );
+ return 0;
+}
+
+static void skeleton_debug( struct skeleton *skele )
+{
+ for( int i=0; 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_mtx[i], p0, p0 );
+ m4x3_mulv( skele->final_mtx[i], p1, p1 );
+
+ if( sb->deform )
+ {
+ if( sb->ik )
+ {
+ vg_line( p0, p1, 0xff0000ff );
+ }
+ else
+ {
+ vg_line( p0, p1, 0xffcccccc );
+ }
+ }
+ else
+ vg_line( p0, p1, 0xff00ffff );
+ }
+}
+
+#endif /* SKELETON_H */
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+#if 0
+#ifndef SKELETON_H
+#define SKELETON_H
+
+#include "model.h"
+
struct skeleton
{
struct skeleton_bone
/* info, not real */
int deform, ik;
+ int defer;
mdl_keyframe kf;
}
useless cpu IK bones. */
};
+/*
+ * Lerp between two sets of keyframes and store in dest. Rotations use Nlerp.
+ */
+static void keyframe_lerp_pose( mdl_keyframe *kfa, mdl_keyframe *kfb, float t,
+ mdl_keyframe *kfd, int count )
+{
+ 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 );
+ }
+}
+
+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 );
+}
+
+/*
+ * Sample animation between 2 closest frames using time value. Output is a
+ * keyframe buffer that is allocated with an appropriate size
+ */
+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 );
+}
+
+typedef enum anim_apply
+{
+ k_anim_apply_always,
+ k_anim_apply_defer_ik,
+ k_anim_apply_deffered_only
+}
+anim_apply;
+
+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->ik || sp->defer )
+ {
+ sb->defer = 1;
+ return 0;
+ }
+ }
+ else if( type == k_anim_apply_deffered_only )
+ {
+ if( !sp->defer )
+ return 0;
+ }
+
+ return 1;
+}
+
+/*
+ * Apply block of keyframes to skeletons final pose
+ */
+static void skeleton_apply_pose( m4x3f transform,
+ struct skeleton *skele, mdl_keyframe *pose,
+ anim_apply passtype )
+{
+ m4x3_copy( transform, skele->final_transforms[0] );
+ skele->bones[0].defer = 0;
+ skele->bones[0].ik = 0;
+
+ for( int 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 = &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] );
+ }
+
+ /* bone space inverse matrix ( for verts ) TODO: move to seperate pass */
+ for( int i=1; i<skele->bone_count; i++ )
+ {
+ if( !should_apply_bone( skele, i, passtype ) )
+ continue;
+
+ m4x3f abmtx;
+ m3x3_identity( abmtx );
+ v3_negate( skele->bones[i].co, abmtx[3] );
+ m4x3_mul( skele->final_transforms[i], abmtx, skele->final_transforms[i] );
+ }
+}
+
static void skeleton_apply_frame( m4x3f transform,
struct skeleton *skele,
struct skeleton_anim *anim,
}
#endif /* SKELETON_H */
+#endif