1 files changed, 24 insertions, 4 deletions

diff --git a/src/ui/util.h b/src/ui/util.h
index a33bf713..c342c095 100644
--- a/src/ui/util.h
+++ b/src/ui/util.h
@@ -68,15 +68,35 @@ iLocalDef iBool isOverlapping_Rangei(iRangei a, iRangei b) {
 
 iDeclareType(Anim)
 
+enum iAnimFlag {
+    indefinite_AnimFlag = iBit(1), /* does not end; must be linear */
+    easeIn_AnimFlag     = iBit(2),
+    easeOut_AnimFlag    = iBit(3),
+    easeBoth_AnimFlag = easeIn_AnimFlag | easeOut_AnimFlag,
+};
+
 struct Impl_Anim {
     float    from, to;
     uint32_t when, due;
+    int      flags;
 };
 
-void    init_Anim       (iAnim *, float value);
-void    setValue_Anim   (iAnim *, float to, uint32_t span);
-float   value_Anim      (const iAnim *);
-iBool   isFinished_Anim (const iAnim *);
+void    init_Anim           (iAnim *, float value);
+void    setValue_Anim       (iAnim *, float to, uint32_t span);
+void    setValueLinear_Anim (iAnim *, float to, uint32_t span);
+void    setValueEased_Anim  (iAnim *, float to, uint32_t span);
+void    setFlags_Anim       (iAnim *, int flags, iBool set);
+void    stop_Anim           (iAnim *);
+
+iBool   isFinished_Anim     (const iAnim *);
+float   value_Anim          (const iAnim *);
+
+iLocalDef float targetValue_Anim(const iAnim *d) {
+    return d->to;
+}
+iLocalDef iBool isLinear_Anim(const iAnim *d) {
+    return (d->flags & (easeIn_AnimFlag | easeOut_AnimFlag)) == 0;
+}
 
 /*-----------------------------------------------------------------------------------------------*/