skeleton.h

   1 #ifndef SKELETON_H
   2 #define SKELETON_H
   3
   4 #include "model.h"
   5
   6 struct skeleton
   7 {
   8    struct skeleton_bone
   9    {
  10       v3f co, end;
  11       u32 children; /* maybe remove */
  12       u32 parent;
  13
  14       mdl_keyframe kf;
  15    }
  16    *bones;
  17    m4x3f *final_transforms;
  18
  19    struct skeleton_anim
  20    {
  21       float rate;
  22       u32 length;
  23       struct mdl_keyframe *anim_data;
  24       char name[32];
  25    }
  26    *anims;
  27
  28    u32 bone_count,
  29        anim_count;
  30 };
  31
  32 static void skeleton_apply_frame( m4x3f transform,
  33                                   struct skeleton *skele,
  34                                   struct skeleton_anim *anim,
  35                                   float time )
  36 {
  37    u32 frame = time*anim->rate;
  38    frame = frame % anim->length;
  39
  40    mdl_keyframe *base = anim->anim_data + (skele->bone_count-1)*frame;
  41    m4x3_copy( transform, skele->final_transforms[0] );
  42
  43    for( int i=1; i<skele->bone_count; i++ )
  44    {
  45       struct skeleton_bone *sb = &skele->bones[i];
  46
  47       /* process pose */
  48       m4x3f posemtx;
  49
  50       v3f temp_delta;
  51       v3_sub( skele->bones[i].co, skele->bones[sb->parent].co, temp_delta );
  52
  53
  54       /* pose matrix */
  55       mdl_keyframe *kf = base+i-1;
  56
  57       q_m3x3( kf->q, posemtx );
  58       v3_copy( kf->co, posemtx[3] );
  59       v3_add( temp_delta, posemtx[3], posemtx[3] );
  60
  61       /* final matrix */
  62       m4x3_mul( skele->final_transforms[ sb->parent ], posemtx,
  63                         skele->final_transforms[i] );
  64    }
  65
  66    /* armature space -> bone space matrix ( for verts ) */
  67    for( int i=1; i<skele->bone_count; i++ )
  68    {
  69       m4x3f abmtx;
  70       m3x3_identity( abmtx );
  71       v3_negate( skele->bones[i].co, abmtx[3] );
  72       m4x3_mul( skele->final_transforms[i], abmtx,
  73                 skele->final_transforms[i] );
  74    }
  75 }
  76
  77 static struct skeleton_anim *skeleton_get_anim( struct skeleton *skele,
  78                                                 const char *name )
  79 {
  80    for( int i=0; i<skele->anim_count; i++ )
  81    {
  82       struct skeleton_anim *anim = &skele->anims[i];
  83
  84       if( !strcmp( anim->name, name ) )
  85          return anim;
  86    }
  87
  88    return NULL;
  89 }
  90
  91 /* Setup an animated skeleton from model */
  92 static int skeleton_setup( struct skeleton *skele, mdl_header *mdl )
  93 {
  94    u32 bone_count = 1, skeleton_root = 0;
  95    skele->bone_count = 0;
  96    skele->bones = NULL;
  97    skele->final_transforms = NULL;
  98    skele->anims = NULL;
  99
 100    struct classtype_skeleton *inf = NULL;
 101
 102    for( u32 i=0; i<mdl->node_count; i++ )
 103    {
 104       mdl_node *pnode = mdl_node_from_id( mdl, i );
 105
 106       if( pnode->classtype == k_classtype_skeleton )
 107       {
 108          inf = mdl_get_entdata( mdl, pnode );
 109          if( skele->bone_count )
 110          {
 111             vg_error( "Multiple skeletons in model file\n" );
 112             free( skele->bones );
 113             return 0;
 114          }
 115
 116          skele->bone_count = inf->channels;
 117          skele->bones = malloc(sizeof(struct skeleton_bone)*skele->bone_count);
 118          skeleton_root = i;
 119       }
 120       else if( skele->bone_count )
 121       {
 122          if( pnode->classtype == k_classtype_bone )
 123          {
 124             struct skeleton_bone *sb = &skele->bones[bone_count ++];
 125             v3_copy( pnode->co, sb->co );
 126             v3_copy( pnode->s, sb->end );
 127             sb->parent = pnode->parent-skeleton_root;
 128          }
 129          else
 130          {
 131             break;
 132          }
 133       }
 134    }
 135
 136    if( !inf )
 137    {
 138       vg_error( "No skeleton in model\n" );
 139       return 0;
 140    }
 141
 142    if( bone_count != skele->bone_count )
 143    {
 144       vg_error( "Loaded %u bones out of %u\n", bone_count, skele->bone_count );
 145       return 0;
 146    }
 147
 148    /* fill in implicit root bone */
 149    v3_zero( skele->bones[0].co );
 150    v3_copy( (v3f){0.0f,1.0f,0.0f}, skele->bones[0].end );
 151    skele->bones[0].parent = 0xffffffff;
 152
 153    skele->final_transforms = malloc( sizeof(m4x3f) * skele->bone_count );
 154    skele->anim_count = inf->anim_count;
 155    skele->anims = malloc( sizeof(struct skeleton_anim) * inf->anim_count);
 156
 157    for( int i=0; i<inf->anim_count; i++ )
 158    {
 159       mdl_animation *anim =
 160          mdl_animation_from_id( mdl, inf->anim_start+i );
 161
 162       skele->anims[i].rate = anim->rate;
 163       skele->anims[i].length = anim->length;
 164       strncpy( skele->anims[i].name, mdl_pstr(mdl, anim->pstr_name), 32 );
 165
 166       u32 total_keyframes = (skele->bone_count-1)*anim->length;
 167       size_t block_size = sizeof(mdl_keyframe) * total_keyframes;
 168       mdl_keyframe *dst = malloc( block_size );
 169
 170       skele->anims[i].anim_data = dst;
 171       memcpy( dst, mdl_get_animdata( mdl, anim ), block_size );
 172    }
 173
 174    vg_success( "Loaded skeleton with %u bones\n", skele->bone_count );
 175    return 1;
 176 }
 177
 178 static void skeleton_debug( struct skeleton *skele )
 179 {
 180    for( int i=0; i<skele->bone_count; i ++ )
 181    {
 182       struct skeleton_bone *sb = &skele->bones[i];
 183
 184       v3f p0, p1;
 185       v3_copy( sb->co, p0 );
 186       v3_add( p0, sb->end, p1 );
 187       vg_line( p0, p1, 0xffffffff );
 188
 189       m4x3_mulv( skele->final_transforms[i], p0, p0 );
 190       m4x3_mulv( skele->final_transforms[i], p1, p1 );
 191       vg_line( p0, p1, 0xff0000ff );
 192    }
 193 }
 194
 195 #endif /* SKELETON_H */