Snaking sliders initial implementation.

src/itdelatrisu/opsu/GameData.java

@@ -907,7 +907,7 @@ else if (Options.isHitLightingEnabled() && !hitResult.hideResult && hitResult.re
 						float oldColorAlpha = hitResult.color.a;
 						Colors.WHITE_FADE.a = alpha;
 						hitResult.color.a = alpha;
-						hitResult.curve.draw(hitResult.color);
+						hitResult.curve.draw(hitResult.color,1.0f);
 						Colors.WHITE_FADE.a = oldWhiteAlpha;
 						hitResult.color.a = oldColorAlpha;
 					}

src/itdelatrisu/opsu/Options.java

@@ -417,6 +417,7 @@ public void drag(GameContainer container, int d) {
 		BACKGROUND_DIM ("Background Dim", "DimLevel", "Percentage to dim the background image during gameplay.", 50, 0, 100),
 		FORCE_DEFAULT_PLAYFIELD ("Force Default Playfield", "ForceDefaultPlayfield", "Override the song background with the default playfield background.", false),
 		IGNORE_BEATMAP_SKINS ("Ignore All Beatmap Skins", "IgnoreBeatmapSkins", "Never use skin element overrides provided by beatmaps.", false),
+		SNAKING_SLIDERS ("Snaking sliders", "SnakingSliders", "Sliders gradually snake out from their starting point.", true),
 		SHOW_HIT_LIGHTING ("Show Hit Lighting", "HitLighting", "Adds an effect behind hit explosions.", true),
 		SHOW_COMBO_BURSTS ("Show Combo Bursts", "ComboBurst", "A character image is displayed at combo milestones.", true),
 		SHOW_PERFECT_HIT ("Show Perfect Hits", "PerfectHit", "Whether to show perfect hit result bursts (300s, slider ticks).", true),
@@ -941,6 +942,12 @@ public static void setDisplayMode(Container app) {
 	 */
 	public static boolean isBeatmapSkinIgnored() { return GameOption.IGNORE_BEATMAP_SKINS.getBooleanValue(); }
 
+	/**
+	 * Returns whether or not sliders should snake in or just appear fully at once.
+	 * @return true if sliders should snake in
+	 */
+	public static boolean isSliderSnaking() { return GameOption.SNAKING_SLIDERS.getBooleanValue(); }
+
 	/**
 	 * Returns the fixed circle size override, if any.
 	 * @return the CS value (0, 10], 0f if disabled

src/itdelatrisu/opsu/objects/Slider.java

@@ -30,6 +30,7 @@
 import itdelatrisu.opsu.objects.curves.Vec2f;
 import itdelatrisu.opsu.states.Game;
 import itdelatrisu.opsu.ui.Colors;
+import itdelatrisu.opsu.ui.animations.AnimationEquation;
 
 import org.newdawn.slick.Color;
 import org.newdawn.slick.GameContainer;
@@ -179,20 +180,27 @@ public void draw(Graphics g, int trackPosition) {
 		float approachScale = 1 + scale * 3;
 		float fadeinScale = (timeDiff - approachTime + fadeInTime) / (float) fadeInTime;
 		float alpha = Utils.clamp(1 - fadeinScale, 0, 1);
+		float decorationsAlpha = Utils.clamp(-2.0f * fadeinScale, 0, 1);
 		boolean overlayAboveNumber = Options.getSkin().isHitCircleOverlayAboveNumber();
-
 		float oldAlpha = Colors.WHITE_FADE.a;
 		Colors.WHITE_FADE.a = color.a = alpha;
 		Image hitCircleOverlay = GameImage.HITCIRCLE_OVERLAY.getImage();
 		Image hitCircle = GameImage.HITCIRCLE.getImage();
 		Vec2f endPos = curve.pointAt(1);
 
-		curve.draw(color);
+		float curveInterval;
+		if(Options.isSliderSnaking()){
+			curveInterval = alpha;
+		} else {
+			curveInterval = 1.0f;
+		}
+		curve.draw(color,curveInterval);
 		color.a = alpha;
 
 		// end circle
-		hitCircle.drawCentered(endPos.x, endPos.y, color);
-		hitCircleOverlay.drawCentered(endPos.x, endPos.y, Colors.WHITE_FADE);
+		Vec2f endCircPos = curve.pointAt(curveInterval);
+		hitCircle.drawCentered(endCircPos.x, endCircPos.y, color);
+		hitCircleOverlay.drawCentered(endCircPos.x, endCircPos.y, Colors.WHITE_FADE);
 
 		// start circle
 		hitCircle.drawCentered(x, y, color);
@@ -201,10 +209,13 @@ public void draw(Graphics g, int trackPosition) {
 
 		// ticks
 		if (ticksT != null) {
-			Image tick = GameImage.SLIDER_TICK.getImage();
+			float tickScale = 0.5f + 0.5f*AnimationEquation.OUT_BACK.calc(decorationsAlpha);
+			Image tick = GameImage.SLIDER_TICK.getImage().getScaledCopy(tickScale);
 			for (int i = 0; i < ticksT.length; i++) {
 				Vec2f c = curve.pointAt(ticksT[i]);
-				tick.drawCentered(c.x, c.y, Colors.WHITE_FADE);
+				Colors.WHITE_FADE.a = decorationsAlpha;
+				tick.drawCentered(c.x , c.y , Colors.WHITE_FADE);
+				Colors.WHITE_FADE.a = alpha;
 			}
 		}
 		if (GameMod.HIDDEN.isActive()) {
@@ -224,24 +235,32 @@ public void draw(Graphics g, int trackPosition) {
 			hitCircleOverlay.drawCentered(x, y, Colors.WHITE_FADE);
 
 		// repeats
-		for (int tcurRepeat = currentRepeats; tcurRepeat <= currentRepeats + 1; tcurRepeat++) {
-			if (hitObject.getRepeatCount() - 1 > tcurRepeat) {
-				Image arrow = GameImage.REVERSEARROW.getImage();
-				if (tcurRepeat != currentRepeats) {
-					if (sliderTime == 0)
-						continue;
-					float t = Math.max(getT(trackPosition, true), 0);
-					arrow.setAlpha((float) (t - Math.floor(t)));
-				} else
-					arrow.setAlpha(1f);
-				if (tcurRepeat % 2 == 0) {
-					// last circle
-					arrow.setRotation(curve.getEndAngle());
-					arrow.drawCentered(endPos.x, endPos.y);
-				} else {
-					// first circle
-					arrow.setRotation(curve.getStartAngle());
-					arrow.drawCentered(x, y);
+		if (curveInterval == 1.0f) {
+			for (int tcurRepeat = currentRepeats; tcurRepeat <= currentRepeats + 1; tcurRepeat++) {
+				if (hitObject.getRepeatCount() - 1 > tcurRepeat) {
+					Image arrow = GameImage.REVERSEARROW.getImage();
+					if (tcurRepeat != currentRepeats) {
+						if (sliderTime == 0) {
+							continue;
+						}
+						float t = Math.max(getT(trackPosition, true), 0);
+						arrow.setAlpha((float) (t - Math.floor(t)));
+					} else {
+						if(Options.isSliderSnaking()){
+							arrow.setAlpha(decorationsAlpha);
+						} else {
+							arrow.setAlpha(1f);
+						}
+					}
+					if (tcurRepeat % 2 == 0) {
+						// last circle
+						arrow.setRotation(curve.getEndAngle());
+						arrow.drawCentered(endPos.x, endPos.y);
+					} else {
+						// first circle
+						arrow.setRotation(curve.getStartAngle());
+						arrow.drawCentered(x, y);
+					}
 				}
 			}
 		}

src/itdelatrisu/opsu/objects/curves/Curve.java

@@ -20,6 +20,7 @@
 
 import itdelatrisu.opsu.GameImage;
 import itdelatrisu.opsu.Options;
+import itdelatrisu.opsu.Utils;
 import itdelatrisu.opsu.beatmap.HitObject;
 import itdelatrisu.opsu.render.CurveRenderState;
 import itdelatrisu.opsu.skins.Skin;
@@ -111,28 +112,31 @@ public static void init(int width, int height, float circleDiameter, Color borde
 	public abstract Vec2f pointAt(float t);
 
 	/**
-	 * Draws the full curve to the graphics context.
+	 * Draws the curve in the range [0, t] (where the full range is [0, 1]) to the graphics context.
 	 * @param color the color filter
+	 * @param t set the curve interval to [0, t]
 	 */
-	public void draw(Color color) {
+	public void draw(Color color, float t) {
 		if (curve == null)
 			return;
 
+		t = Utils.clamp(t, 0.0f, 1.0f);
 		// peppysliders
 		if (Options.getSkin().getSliderStyle() == Skin.STYLE_PEPPYSLIDER || !mmsliderSupported) {
+			int drawUpTo = (int)(curve.length*t);
 			Image hitCircle = GameImage.HITCIRCLE.getImage();
 			Image hitCircleOverlay = GameImage.HITCIRCLE_OVERLAY.getImage();
-			for (int i = 0; i < curve.length; i++)
+			for (int i = 0; i < drawUpTo; i++)
 				hitCircleOverlay.drawCentered(curve[i].x, curve[i].y, Colors.WHITE_FADE);
-			for (int i = 0; i < curve.length; i++)
+			for (int i = 0; i < drawUpTo; i++)
 				hitCircle.drawCentered(curve[i].x, curve[i].y, color);
 		}
 
 		// mmsliders
 		else {
 			if (renderState == null)
-				renderState = new CurveRenderState(hitObject);
-			renderState.draw(color, borderColor, curve);
+				renderState = new CurveRenderState(hitObject,curve);
+			renderState.draw(color, borderColor, t);
 		}
 	}