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[voxel] add SVO defrecord, minor optimizations
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@postspectacular
postspectacular committed Mar 26, 2015
1 parent 3f4f291 commit 71a5a56
Showing 1 changed file with 54 additions and 44 deletions.
98 changes: 54 additions & 44 deletions geom-voxel/src/svo.org
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Original file line number Diff line number Diff line change
Expand Up @@ -23,9 +23,8 @@
(def used-bits
"Returns a lazy-seq of bit ids used in `x`.
Only checks 8bit range (0 - 255)."
(reduce
(fn [acc x] (conj acc (vec (filter #(pos? (bit-and x (bit-vals %))) (range 8)))))
[] (range 0x100)))
(let [xf (fn [x] (vec (eduction (filter #(pos? (bit-and x (bit-vals %)))) (range 8))))]
(into [] (map xf) (range 0x100))))
#+END_SRC

** Helper & index functions
Expand Down Expand Up @@ -84,20 +83,26 @@
** SVO implementation & operations

#+BEGIN_SRC clojure :noweb-ref impl
(defrecord SVO [data dim max-depth prec branches])

(defn voxeltree
"Creates a new voxel tree structure with the given root
node dimension and min precision."
[^double dim prec]
(let [depth (max-depth dim prec)]
{:dim dim :max-depth depth :prec (size-at-depth dim (inc depth)) :data {}
:branches (vec (cons 0 (reverse (map #(apply + (take % depth-size)) (range 1 (inc depth))))))}))
(map->SVO
{:data {}
:dim dim
:max-depth depth
:prec (size-at-depth dim (inc depth))
:branches (vec (cons 0 (reverse (map #(apply + (take % depth-size)) (range 1 (inc depth))))))})))

(defn set-at
"Marks voxel at given position as set. Updates tree at all levels."
([tree v]
(set-at tree V3 (* (:dim tree) 0.5) 0 0 (:max-depth tree) (:branches tree) v))
([tree offset dim idx depth max-depth branches v]
(let [id (node-id offset dim v)
(let [id (node-id offset dim v)
data (:data tree)
tree (assoc tree :data
(assoc data idx
Expand All @@ -121,8 +126,8 @@
([tree max-depth v]
(depth-at tree V3 (* (:dim tree) 0.5) 0 0 (min max-depth (:max-depth tree)) (:branches tree) v))
([tree offset dim idx depth max-depth branches v]
(let [id (node-id offset dim v)
n-val (get (:data tree) idx 0)
(let [id (node-id offset dim v)
n-val (get (:data tree) idx 0)
found? (and (> n-val 0) (> (bit-and n-val (bit-shift-left 1 id)) 0))]
;; (prn :d depth :o offset :o2 (g/madd (vec3 dim) 2 offset) :dim dim :idx idx :id id :val n-val :found found?)
(if found?
Expand All @@ -142,7 +147,7 @@
([tree v]
(delete-at tree V3 (* (:dim tree) 0.5) 0 0 (:max-depth tree) (:branches tree) v))
([tree offset dim idx depth max-depth branches v]
(let [id (node-id offset dim v)
(let [id (node-id offset dim v)
bmask (bit-shift-left 1 id)
n-val (get (:data tree) idx 0)]
(if (pos? (bit-and n-val bmask))
Expand All @@ -164,7 +169,7 @@
result))
(let [new-val (bit-and n-val (bit-xor 0xff bmask))]
;; (prn :d depth :o offset :o2 (g/madd (vec3 dim) 2 offset) :dim dim :idx idx :id id :val n-val)
(if (= new-val n-val)
(if (== new-val n-val)
[tree false]
[(assoc tree :data (assoc (:data tree) idx new-val)) true])))
[tree false]))))
Expand All @@ -175,10 +180,10 @@
(select (:data tree) V3 (* (:dim tree) 0.5) 0 0 (min min-depth (:max-depth tree)) (:branches tree))
(persistent!)))
([data offset dim idx depth min-depth branches acc]
(let [n-val (get data idx 0)
(let [n-val (get data idx 0)
c-depth (inc depth)
c-dim (* dim 0.5)
noff (node-offset offset dim)]
c-dim (* dim 0.5)
noff (node-offset offset dim)]
;; (prn :d depth :o offset :o2 (g/madd (vec3 dim) 2 offset) :dim dim :idx idx :val n-val)
(if (zero? n-val)
acc
Expand All @@ -196,21 +201,23 @@
acc (used-bits n-val))
;; collect voxels
(reduce
#(conj! % (g/+ (noff %2) (vec3 c-dim)))
#(conj! % (g/+ (noff %2) c-dim))
acc (used-bits n-val)))))))

(defn voxel-config-at-depth
"Returns a map of configuration settings for the given `tree` and
`depth`. Depth will be clamped at tree's max-depth."
[{:keys [dim max-depth] :as tree} min-depth]
(let [depth (max (min min-depth max-depth) 0)
s (size-at-depth dim (inc depth))
s2 (* s 0.5)
(let [depth (max (min min-depth max-depth) 0)
s (size-at-depth dim (inc depth))
s2 (* s 0.5)
stride (int (/ dim s))]
{:depth depth
:size s :inv-size (/ 1.0 s)
:offset [s2 s2 s2]
:stride stride :stride-z (* stride stride)}))
{:depth depth
:size s
:inv-size (/ 1.0 s)
:offset (vec3 s2 s2 s2)
:stride stride
:stride-z (* stride stride)}))

(defn voxel-cell
"Returns the cell coordinate for the given `index` and tree
Expand Down Expand Up @@ -244,30 +251,33 @@
(voxel-config-at-depth tree min-depth) (:branches tree))
(persistent!)))
([data offset dim idx depth config branches acc]
(let [n-val (get data idx 0)
(let [n-val (get data idx 0)
c-depth (inc depth)
c-dim (* dim 0.5)
noff (node-offset offset dim)]
c-dim (* dim 0.5)
noff (node-offset offset dim)]
;; (prn :d depth :o offset :o2 (g/madd (vec3 dim) 2 offset) :dim dim :idx idx :val n-val)
(if (zero? n-val) acc
(if (< depth (:depth config))
(if (zero? n-val)
acc
(if (< depth (:depth config))
(reduce
(fn [acc id]
(select-cells data
(noff id)
c-dim
(node-index idx id c-depth branches)
c-depth
config branches
acc))
acc (used-bits n-val))
;; collect voxels
(let [{:keys [inv-size stride stride-z]} config]
(reduce
(fn [acc id]
(select-cells data
(noff id)
c-dim
(node-index idx id c-depth branches)
c-depth
config branches
acc))
acc (used-bits n-val))
;; collect voxels
(let [{:keys [inv-size stride stride-z]} config]
(reduce
(fn [acc c]
(let [[x y z] (g/* (noff c) inv-size)]
(conj! acc (+ (+ (int x) (* (int y) stride)) (* (int z) stride-z)))))
acc (used-bits n-val))))))))
(fn [acc c]
(let [[x y z] (noff c)]
(conj! acc (+ (+ (int (* x inv-size))
(* (int (* y inv-size)) stride))
(* (int (* z inv-size)) stride-z)))))
acc (used-bits n-val))))))))

(defn apply-voxels
[f tree coll] (reduce f tree coll))
Expand All @@ -276,8 +286,8 @@
(defn as-array
[tree min-depth]
(let [{:keys [stride stride-z]} (voxel-config-at-depth tree min-depth)
buf (byte-array (* stride stride-z))
v (byte 127)]
^bytes buf (byte-array (* stride stride-z))
v (byte 127)]
(doseq [c (select-cells tree min-depth)]
(aset-byte buf (int c) v))
buf))
Expand Down

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