com.rafaskoberg.gdx.typinglabel.effects.Effect Maven / Gradle / Ivy

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A libGDX Label that appears as if it was being typed in real time.
There is a newer version: 1.4.0

package com.rafaskoberg.gdx.typinglabel.effects;

import com.badlogic.gdx.graphics.g2d.BitmapFont.Glyph;
import com.badlogic.gdx.math.Interpolation;
import com.badlogic.gdx.math.MathUtils;
import com.rafaskoberg.gdx.typinglabel.TypingLabel;

/** Abstract text effect. */
public abstract class Effect {
	private static final float FADEOUT_SPLIT = 0.25f;
	protected final TypingLabel label;
	public int indexStart = -1;
	public int indexEnd = -1;
	public float duration = Float.POSITIVE_INFINITY;
	private float totalTime;

	public Effect (TypingLabel label) {
		this.label = label;
	}

	public void update (float delta) {
		totalTime += delta;
	}

	/** Applies the effect to the given glyph. */
	public final void apply (Glyph glyph, int glyphIndex) {
		int localIndex = glyphIndex - indexStart;
		onApply(glyph, localIndex);
	}

	/** Called when this effect should be applied to the given glyph. */
	protected abstract void onApply (Glyph glyph, int localIndex);

	/** Returns whether or not this effect is finished and should be removed. Note that effects are infinite by default. */
	public boolean isFinished () {
		return totalTime > duration;
	}

	/** Calculates the fadeout of this effect, if any. Only considers the second half of the duration. */
	protected float calculateFadeout () {
		if (Float.isInfinite(duration)) return 1;

		// Calculate raw progress
		float progress = MathUtils.clamp(totalTime / duration, 0, 1);

		// If progress is before the split point, return a full factor
		if (progress < FADEOUT_SPLIT) return 1;

		// Otherwise calculate from the split point
		return Interpolation.smooth.apply(1, 0, (progress - FADEOUT_SPLIT) / (1f - FADEOUT_SPLIT));
	}

	/** Calculates a linear progress dividing the total time by the given modifier. Returns a value between 0 and 1 that loops in a
	 * ping-pong mode. */
	protected float calculateProgress (float modifier) {
		return calculateProgress(modifier, 0, true);
	}

	/** Calculates a linear progress dividing the total time by the given modifier. Returns a value between 0 and 1 that loops in a
	 * ping-pong mode. */
	protected float calculateProgress (float modifier, float offset) {
		return calculateProgress(modifier, offset, true);
	}

	/** Calculates a linear progress dividing the total time by the given modifier. Returns a value between 0 and 1. */
	protected float calculateProgress (float modifier, float offset, boolean pingpong) {
		float progress = totalTime / modifier + offset;
		while (progress < 0.0f) {
			progress += 2.0f;
		}
		if (pingpong) {
			progress %= 2f;
			if (progress > 1.0f) progress = 1f - (progress - 1f);
		} else {
			progress %= 1.0f;
		}
		progress = MathUtils.clamp(progress, 0, 1);
		return progress;
	}

	/** Returns the line height of the label controlling this effect. */
	protected float getLineHeight () {
		return label.getBitmapFontCache().getFont().getLineHeight() * label.getFontScaleY();
	}

}