progress

engine/anim.go

@@ -4,25 +4,25 @@ package engine
 // together with the current state.
 type Anim struct {
 	Def   *AnimDef
-	CurrentIndex int
-	CurrentTicks int
+	Index int
+	Ticks int
 }
 
-func (a *Anim) CurrentFrame() int { return a.Def.Frames[a.CurrentIndex].Frame }
+func (a *Anim) CurrentFrame() int { return a.Def.Frames[a.Index].Frame }
 
 // Update increments the tick count and advances the frame if necessary.
 func (a *Anim) Update() error {
-	a.CurrentTicks++
-	if !a.Def.Loop && a.CurrentIndex == len(a.Def.Frames)-1 {
+	a.Ticks++
+	if !a.Def.Loop && a.Index == len(a.Def.Frames)-1 {
 		// on the last frame of a one shot so remain on final frame
 		return nil
 	}
-	if a.CurrentTicks >= a.Def.Frames[a.CurrentIndex].DurationTicks {
-		a.CurrentTicks = 0
-		a.CurrentIndex++
+	if a.Ticks >= a.Def.Frames[a.Index].Duration {
+		a.Ticks = 0
+		a.Index++
 	}
-	if a.Def.Loop && a.CurrentIndex >= len(a.Def.Frames) {
-		a.CurrentIndex = 0
+	if a.Def.Loop && a.Index >= len(a.Def.Frames) {
+		a.Index = 0
 	}
 	return nil
 }
@@ -36,5 +36,5 @@ type AnimDef struct {
 // AnimFrame describes a frame in an animation.
 type AnimFrame struct {
 	Frame    int `json:"frame"`    // show this frame
-	DurationTicks int `json:"duration"` // for this long
+	Duration int `json:"duration"` // for this long, in ticks
 }

engine/asset.go

@@ -20,6 +20,13 @@ type AnimRef struct {
 	animdef *AnimDef
 }
 
+func (r *AnimRef) Anim() *Anim {
+	// TODO
+	return &Anim{
+		Def: r.animdef,
+	}
+}
+
 // ImageRef loads images from the AssetFS into *ebiten.Image form.
 // It is your responsibility to import _ "image/..." for whatever
 // format the files are in.

main.go

@@ -50,9 +50,9 @@ func main() {
 		Anim: engine.Anim{
 			Def: &engine.AnimDef{
 				Frames: []engine.AnimFrame{
-					{Frame: 0, DurationTicks: 16},
-					{Frame: 1, DurationTicks: 16},
-					{Frame: 2, DurationTicks: 16},
+					{Frame: 0, Duration: 16},
+					{Frame: 1, Duration: 16},
+					{Frame: 2, Duration: 16},
 				},
 				Loop: true,
 			},
@@ -62,10 +62,10 @@ func main() {
 		Anim: engine.Anim{
 			Def: &engine.AnimDef{
 				Frames: []engine.AnimFrame{
-					{Frame: 3, DurationTicks: 12},
-					{Frame: 4, DurationTicks: 12},
-					{Frame: 5, DurationTicks: 12},
-					{Frame: 6, DurationTicks: 12},
+					{Frame: 3, Duration: 12},
+					{Frame: 4, Duration: 12},
+					{Frame: 5, Duration: 12},
+					{Frame: 6, Duration: 12},
 				},
 				Loop: true,
 			},