Merge "Fix ArcMotion path creation in some quadrants." into nyc-dev (fdce57b6) · Commits · e / os / android_frameworks_base

core/java/android/transition/ArcMotion.java

+19 −8

Original line number	Diff line number	Diff line
		@@ -15,13 +15,13 @@
		*/
		package android.transition;

		import com.android.internal.R;

		import android.content.Context;
		import android.content.res.TypedArray;
		import android.graphics.Path;
		import android.util.AttributeSet;

		import com.android.internal.R;

		/**
		* A PathMotion that generates a curved path along an arc on an imaginary circle containing
		* the two points. If the horizontal distance between the points is less than the vertical
		@@ -207,7 +207,7 @@ public class ArcMotion extends PathMotion {
		ey = (startY + endY) / 2;
		} else {
		float deltaX = endX - startX;
		float deltaY = startY - endY; // Y is inverted compared to diagram above.
		float deltaY = endY - startY;
		// hypotenuse squared.
		float h2 = deltaX * deltaX + deltaY * deltaY;

		@@ -219,24 +219,35 @@ public class ArcMotion extends PathMotion {
		float midDist2 = h2 * 0.25f;

		float minimumArcDist2 = 0;
		boolean isQuadrant1Or3 = (deltaX * deltaY) > 0;

		if (Math.abs(deltaX) < Math.abs(deltaY)) {
		if ((Math.abs(deltaX) < Math.abs(deltaY))) {
		// Similar triangles bfa and bde mean that (ab/fb = eb/bd)
		// Therefore, eb = ab * bd / fb
		// ab = hypotenuse
		// bd = hypotenuse/2
		// fb = deltaY
		float eDistY = h2 / (2 * deltaY);
		ey = endY + eDistY;
		if (isQuadrant1Or3) {
		ey = startY + eDistY;
		ex = startX;
		} else {
		ey = endY - eDistY;
		ex = endX;
		}

		minimumArcDist2 = midDist2 * mMinimumVerticalTangent
		* mMinimumVerticalTangent;
		} else {
		// Same as above, but flip X & Y
		float eDistX = h2 / (2 * deltaX);
		ex = endX + eDistX;
		if (isQuadrant1Or3) {
		ex = endX - eDistX;
		ey = endY;
		} else {
		ex = startX + eDistX;
		ey = startY;
		}

		minimumArcDist2 = midDist2 * mMinimumHorizontalTangent
		* mMinimumHorizontalTangent;