From d2091939bb09dbad145e3017b802a54b69d0fcda Mon Sep 17 00:00:00 2001
From: Paulo Feodrippe <pfeodrippe@gmail.com>
Date: Tue, 28 Jan 2025 13:33:07 -0500
Subject: [PATCH] wip

---
 src/vybe/c.clj           |  6 ++++-
 src/vybe/game/system.clj | 51 ++++++++++++++++++++++++++++++++--------
 todo.md                  | 12 +++++++---
 3 files changed, 55 insertions(+), 14 deletions(-)

diff --git a/src/vybe/c.clj b/src/vybe/c.clj
index 3ba6531..4a20f44 100644
--- a/src/vybe/c.clj
+++ b/src/vybe/c.clj
@@ -1002,7 +1002,11 @@ signal(SIGSEGV, sighandler);
                           (str/join ";\n\n"))))
 
            :if
-           (let [{:keys [then else] t :test} v]
+           (let [{:keys [then else] t :test} v
+                 ;; For supporting the `:else` from a `cond` macro.
+                 t (if (= (:form t) :else)
+                     (analyze true)
+                     t)]
              (if (:form else)
                (format "( %s ? \n   ({%s;}) : \n  ({%s;})  )"
                        (emit t)
diff --git a/src/vybe/game/system.clj b/src/vybe/game/system.clj
index c326367..77deed9 100644
--- a/src/vybe/game/system.clj
+++ b/src/vybe/game/system.clj
@@ -264,7 +264,7 @@
                              c)))
        nil))
 
-(vf/defsystem-c animation-node-player-2 _w
+(vf/defsystem-c animation-node-player-2 w
   [[_ node] [:vg.anim/target-node :*]
    ;; TODO Maybe [:vg.anim/target-component [:vf/component'?c]] ?
    _ [:vg.anim/target-component '?c]
@@ -281,18 +281,49 @@
                           (vp/arr values timeline_count vt/Translation)
                           (vp/arr values timeline_count vt/Scale))
                         (vp/as [:* :void]))
-        ;; TODO Should this create a slice? (support for `count`, `first`, `last`, `nth`, iteration)
         timeline* (vp/arr timeline timeline_count :float)
         ;; TODO OPTM We could also leverage the previous index.
         idx* (vc/bs_lower_bound timeline* timeline_count (:current_time @player))
-        idx (int (max (dec (or idx* timeline_count)) 0))
-        ;; TODO idx* won't be `nil`
-        ;; TODO We should probably use the same truthy semantics as Clojure
-        t (when idx*
-            (/ (- (:current_time @player)
-                  (nth timeline* idx))
-               (- (nth timeline* (inc idx))
-                  (nth timeline* idx))))]
+        idx (cond
+              (= idx* 0)
+              0
+
+              (>= idx* timeline_count)
+              -1
+
+              :else
+              (dec idx*))
+
+        #_ #_my-ref (-> (vf.c/ecs-ref-get-id (:w @node-ref)
+                                        (vp/& (:flecs_ref @node-ref))
+                                        (:id (:flecs_ref @node-ref)))
+                   #_(vp/p->map c))]
+    #_(tap> (long (vp/& (:flecs_ref @node-ref))))
+
+    ;; TODO We could use some `:void` metadata to indicate that
+    ;; a form does not return anything.
+    (if (>= idx 0)
+      (let [v (/ (- (:current_time @player)
+                    (nth timeline* idx))
+                 (- (nth timeline* (inc idx))
+                    (nth timeline* idx)))]
+
+        (cond
+          (= kind 0)
+          (nth (vp/arr values timeline_count vt/Translation) idx)
+
+          #_(= kind 1)
+          #_(nth (vp/arr values timeline_count vt/Scale) idx)
+
+          #_(= kind 2)
+          #_(nth (vp/arr values timeline_count vt/Rotation) idx))
+
+        #_(merge @node-ref (nth values idx)
+                 #_(if t
+                     (lerp-p (nth values idx)
+                             (nth values (inc idx))
+                             t)
+                     (nth values idx)))))
 
     #_(when (< idx* 0)
         (conj parent-e :vg.anim/stop)
diff --git a/todo.md b/todo.md
index 75d8e83..6eb0afe 100644
--- a/todo.md
+++ b/todo.md
@@ -306,16 +306,22 @@
       - [x] mapping from entity id to component type
       - [x] don't use `comp-id`
       - [-] create cond automatically from it?
-      - [-] how to represent `nil` properly?
-    - [ ] fix `idx`
-    - [ ] fix `t`
+    - [x] fix `idx`
+    - [x] fix `t`
     - [ ] lerp
+      - [ ] just idx for translation
+      - [ ] scale
+      - [ ] rotation
+      - [ ] use lerp
   - [ ] :vf/entity should return a struct?
   - [ ] consider making systems `always` by default
   - [ ] `def` to a var from C?
   - [x] show line/column error correctly for an error before calling the compiler
   - [ ] Remove variables starting with a `_` in a `let` (just do the side-effect)
   - [ ] optimization (-O3)?
+  - [ ] how to represent `nil` properly?
+    - [ ] maybe with nullable
+  - [ ] should have slices? (support for `count`, `first`, `last`, `nth`, iteration)
 - [ ] built-in models
   - [x] minimal
   - [ ] more complex