Evil

evil.c

bool
impl_query_pose_index(PoseIndexUncompressCtx* ctx, PoseIndexReq* req
                    , PoseIndexRes* res)
{
    if (!unpack_block(ctx))
        return false;   
    
    static void* dispatch[] = { &&above, &&below, &&exit };
    enum State { AboveThreshold = 0, BelowThreshold = 1, Done = 2 };
    
    enum State state = AboveThreshold;
    double threshold_square = pow(req->radius, 2);
    size_t i = 0;
    PoseIndexComposite winner;
    double             winner_square;
    double             square;
   
next: 
    if (i == ctx->root->index_count)
        state = Done;
    else
        square = square_value(req->x, ctx->comp[i].x
                            , req->y, ctx->comp[i].y);
    
    goto *dispatch[state];

above:
   /* if within the range we are now below threshold */
   if (square <= threshold_square) {
       winner = ctx->comp[i];
       winner_square = square;
       state = BelowThreshold;
   }
   ++i;
   goto next;

below:
   /* we have gone above limit */
   if (square > threshold_square) {
       state = AboveThreshold;
       res->timestamp_size++;
       res->timestamp = (uint64_t*)realloc(res->timestamp 
                                         , res->timestamp_size * 
                                           sizeof(uint64_t));
       res->timestamp[res->timestamp_size - 1] = winner.timestamp;
   
   /* check for new winner */
   } else if (square < winner_square) {
       winner = ctx->comp[i];
   }
   ++i;
   goto next;

exit:
    return true;
}