fix(misc): improve wheel beta animation

internal/modules/misc/handlers_test.go

@@ -271,7 +271,16 @@ func TestWheelOfNamesBeta_RenderGIFTiming(t *testing.T) {
 	}
 }
 
-func TestWheelOfNamesBeta_SendsAnimationWithWinnerCaption(t *testing.T) {
+func TestWheelOfNamesBeta_CurrentOptionTracksPointer(t *testing.T) {
+	for winner := range []string{"Alice", "Bob", "Carol", "Dana"} {
+		rotation := finalWheelRotation(4, winner)
+		if got := currentWheelBetaIndex(4, rotation); got != winner {
+			t.Fatalf("currentWheelBetaIndex at final rotation = %d, want %d", got, winner)
+		}
+	}
+}
+
+func TestWheelOfNamesBeta_SendsAnimationWithoutSpoilingCaption(t *testing.T) {
 	rb, _ := installMisc(t, 999)
 	rb.Bot.ProcessUpdate(context.Background(), testutil.NewPrivateMessage(7, "/wheelofnamesbeta Alice"))
 
@@ -279,8 +288,11 @@ func TestWheelOfNamesBeta_SendsAnimationWithWinnerCaption(t *testing.T) {
 	if call.Method != "sendAnimation" {
 		t.Fatalf("method = %q, want sendAnimation", call.Method)
 	}
-	if got := call.Form["caption"]; got != "Winner: Alice" {
-		t.Fatalf("caption = %q, want Winner: Alice", got)
+	if got := call.Form["caption"]; got != "Spinning..." {
+		t.Fatalf("caption = %q, want Spinning...", got)
+	}
+	if strings.Contains(call.Form["caption"], "Alice") {
+		t.Fatalf("caption spoils winner: %q", call.Form["caption"])
 	}
 	if got := call.Form["duration"]; got != "7" {
 		t.Fatalf("duration = %q, want 7", got)

internal/modules/misc/wheelofnames_beta.go

@@ -37,6 +37,8 @@ var wheelBetaPalette = color.Palette{
 	color.RGBA{R: 235, G: 117, B: 164, A: 255},
 }
 
+var wheelBetaSliceColorIndexes = []byte{3, 4, 5, 6, 7, 8, 9}
+
 func renderWheelOfNamesBetaGIF(options []string, winner int) ([]byte, error) {
 	if len(options) == 0 {
 		return nil, fmt.Errorf("no options")
@@ -51,7 +53,8 @@ func renderWheelOfNamesBetaGIF(options []string, winner int) ([]byte, error) {
 	startRotation := finalRotation - 8*2*math.Pi
 	for i := 0; i < wheelBetaSpinFrames; i++ {
 		t := float64(i) / float64(wheelBetaSpinFrames-1)
-		progress := 1 - math.Pow(1-t, 3)
+		remaining := 1 - t
+		progress := 1 - remaining*remaining*remaining
 		rotation := startRotation + (finalRotation-startRotation)*progress
 		frames = append(frames, renderWheelBetaFrame(options, winner, rotation, false))
 		delays = append(delays, wheelBetaSpinDelay)
@@ -92,7 +95,7 @@ func renderWheelBetaFrame(options []string, winner int, rotation float64, reveal
 			}
 			theta := normalizeAngle(math.Atan2(float64(dy), float64(dx)) - rotation)
 			idx := int(theta / segment)
-			colorIndex := byte(3 + idx%7)
+			colorIndex := wheelBetaSliceColorIndexes[idx%len(wheelBetaSliceColorIndexes)]
 			img.SetColorIndex(x, y, colorIndex)
 		}
 	}
@@ -101,9 +104,13 @@ func renderWheelBetaFrame(options []string, winner int, rotation float64, reveal
 	drawCircle(img, cx, cy, 18, 1)
 	drawPointer(img, cx, cy-wheelBetaRadius-10)
 	drawCenteredText(img, "WHEELOFNAMES BETA", cy+wheelBetaRadius+34, 1)
+	label := "CURRENT"
+	value := asciiWheelText(options[currentWheelBetaIndex(len(options), rotation)], 28)
 	if reveal {
-		drawResultBand(img, asciiWheelText(options[winner], 28))
+		label = "WINNER"
+		value = asciiWheelText(options[winner], 28)
 	}
+	drawStatusBand(img, label, value)
 	return img
 }
 
@@ -112,6 +119,11 @@ func finalWheelRotation(optionCount, winner int) float64 {
 	return -math.Pi/2 - (float64(winner)+0.5)*segment
 }
 
+func currentWheelBetaIndex(optionCount int, rotation float64) int {
+	segment := 2 * math.Pi / float64(optionCount)
+	return int(normalizeAngle(-math.Pi/2-rotation) / segment)
+}
+
 func normalizeAngle(theta float64) float64 {
 	theta = math.Mod(theta, 2*math.Pi)
 	if theta < 0 {
@@ -141,14 +153,14 @@ func drawPointer(img *image.Paletted, cx, tipY int) {
 	}
 }
 
-func drawResultBand(img *image.Paletted, winner string) {
+func drawStatusBand(img *image.Paletted, label, value string) {
 	for y := 230; y < 282; y++ {
 		for x := 28; x < wheelBetaSize-28; x++ {
 			img.SetColorIndex(x, y, 2)
 		}
 	}
-	drawCenteredText(img, "WINNER", 250, 1)
-	drawCenteredText(img, winner, 270, 1)
+	drawCenteredText(img, label, 250, 1)
+	drawCenteredText(img, value, 270, 1)
 }
 
 func drawCenteredText(img *image.Paletted, text string, baselineY int, colorIndex byte) {

internal/modules/misc/wheelofnames_beta_command.go

@@ -46,7 +46,7 @@ func wheelOfNamesBetaCommand() modules.Command {
 				Duration: wheelBetaDuration,
 				Width:    wheelBetaSize,
 				Height:   wheelBetaSize,
-				Caption:  "Winner: " + options[winner],
+				Caption:  "Spinning...",
 			})
 			if err != nil {
 				log.Warn("wheelofnamesbeta send animation failed", "chat", update.Message.Chat.ID, "err", err)