/// <summary>
/// A coroutine that fades a <see cref="CanvasGroup"/> object's
/// opacity from <paramref name="from"/> to <paramref name="to"/>
/// over the course of <see cref="fadeTime"/> seconds, and then
/// invokes <paramref name="onComplete"/>.
/// </summary>
/// <param name="from">The opacity value to start fading from,
/// ranging from 0 to 1.</param>
/// <param name="to">The opacity value to end fading at, ranging
/// from 0 to 1.</param>
/// <param name="onComplete">A delegate to invoke after fading is
/// complete.</param>
public static IEnumerator FadeAlpha(CanvasGroup canvasGroup, float from, float to, float fadeTime, PresentationFlag presented = null, Action onComplete = null)
{
canvasGroup.alpha = from;
var timeElapsed = 0f;
while (timeElapsed < fadeTime)
{
var fraction = timeElapsed / fadeTime;
timeElapsed += Time.deltaTime;
float a = Mathf.Lerp(from, to, fraction);
canvasGroup.alpha = a;
yield return(null);
}
canvasGroup.alpha = to;
if (to == 0)
{
canvasGroup.interactable = false;
canvasGroup.blocksRaycasts = false;
}
else
{
canvasGroup.interactable = true;
canvasGroup.blocksRaycasts = true;
}
presented?.Set();
onComplete?.Invoke();
}
public static IEnumerator Typewriter(TextMeshProUGUI text, float lettersPerSecond, PresentationFlag presented, Action onCharacterTyped, Action onComplete)
{
// Start with everything invisible
text.maxVisibleCharacters = 0;
// Wait a single frame to let the text component process its
// content, otherwise text.textInfo.characterCount won't be
// accurate
yield return(null);
// How many visible characters are present in the text?
var characterCount = text.textInfo.characterCount;
// Early out if letter speed is zero or text length is zero
if (lettersPerSecond <= 0 || characterCount == 0)
{
// Show everything and invoke the completion handler
text.maxVisibleCharacters = characterCount;
onComplete?.Invoke();
yield break;
}
// Convert 'letters per second' into its inverse
float secondsPerLetter = 1.0f / lettersPerSecond;
// If lettersPerSecond is larger than the average framerate, we
// need to show more than one letter per frame, so simply
// adding 1 letter every secondsPerLetter won't be good enough
// (we'd cap out at 1 letter per frame, which could be slower
// than the user requested.)
//
// Instead, we'll accumulate time every frame, and display as
// many letters in that frame as we need to in order to achieve
// the requested speed.
var accumulator = Time.deltaTime;
while (text.maxVisibleCharacters < characterCount)
{
// We need to show as many letters as we have accumulated
// time for.
while (accumulator >= secondsPerLetter)
{
text.maxVisibleCharacters += 1;
onCharacterTyped?.Invoke();
accumulator -= secondsPerLetter;
}
accumulator += Time.deltaTime;
yield return(null);
}
// We either finished displaying everything, or were
// interrupted. Either way, display everything now.
text.maxVisibleCharacters = characterCount;
presented?.Set();
// Wrap up by invoking our completion handler.
onComplete?.Invoke();
}
public void Start()
{
canvasGroup.alpha = 0;
hasPresented = new PresentationFlag();
hasPresented.Clear();
}
