Android中使用Bezier曲线
import android.graphics.Point;
/**
*
* @author http://blog.csdn.net/arui319
*
*/
public class Bezier {
private static final float AP = 0.5f;
private Point[] bPoints;
/**
* Creates a new Bezier curve.
*
* @param points
*/
public Bezier(Point[] points) {
int n = points.length;
if (n < 3) {
// Cannot create bezier with less than 3 points
return;
}
bPoints = new Point[2 * (n - 2)];
double paX, paY;
double pbX = points[0].x;
double pbY = points[0].y;
double pcX = points[1].x;
double pcY = points[1].y;
for (int i = 0; i < n - 2; i++) {
paX = pbX;
paY = pbY;
pbX = pcX;
pbY = pcY;
pcX = points[i + 2].x;
pcY = points[i + 2].y;
double abX = pbX - paX;
double abY = pbY - paY;
double acX = pcX - paX;
double acY = pcY - paY;
double lac = Math.sqrt(acX * acX + acY * acY);
acX = acX / lac;
acY = acY / lac;
double proj = abX * acX + abY * acY;
proj = proj < 0 ? -proj : proj;
double apX = proj * acX;
double apY = proj * acY;
double p1X = pbX - AP * apX;
double p1Y = pbY - AP * apY;
bPoints[2 * i] = new Point((int) p1X, (int) p1Y);
acX = -acX;
acY = -acY;
double cbX = pbX - pcX;
double cbY = pbY - pcY;
proj = cbX * acX + cbY * acY;
proj = proj < 0 ? -proj : proj;
apX = proj * acX;
apY = proj * acY;
double p2X = pbX - AP * apX;
double p2Y = pbY - AP * apY;
bPoints[2 * i + 1] = new Point((int) p2X, (int) p2Y);
}
}
/**
* Returns the calculated bezier points.
*
* @return the calculated bezier points
*/
public Point[] getPoints() {
return bPoints;
}
/**
* Returns the number of bezier points.
*
* @return number of bezier points
*/
public int getPointCount() {
return bPoints.length;
}
/**
* Returns the bezier points at position i.
*
* @param i
* @return the bezier point at position i
*/
public Point getPoint(int i) {
return bPoints[i];
}
}
补充：移动开发 , Android ,
