I have tried a lot of different approaches from examples around the web, but I can\'t seem to get this to work. I am trying to make a method that draws a curved line between
I found a solution to my problem myself. Even though there were some great answers, they weren't an exact solution to my particular problem.
Here is what I did:
Here is my code if anyone else should run into the same problem:
public OverlayBuilder drawCurvedArrow(int x1, int y1, int x2, int y2, int curveRadius, int color, int lineWidth) {
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(lineWidth);
paint.setColor(ContextCompat.getColor(context, color));
final Path path = new Path();
int midX = x1 + ((x2 - x1) / 2);
int midY = y1 + ((y2 - y1) / 2);
float xDiff = midX - x1;
float yDiff = midY - y1;
double angle = (Math.atan2(yDiff, xDiff) * (180 / Math.PI)) - 90;
double angleRadians = Math.toRadians(angle);
float pointX = (float) (midX + curveRadius * Math.cos(angleRadians));
float pointY = (float) (midY + curveRadius * Math.sin(angleRadians));
path.moveTo(x1, y1);
path.cubicTo(x1,y1,pointX, pointY, x2, y2);
canvas.drawPath(path, paint);
return this;
}
And here is an example of how the implementation looks like:
Suppose you have two points mPoint1 and mPoint2
int w=canvas.getWidth();
int h=canvas.getHeight();
int w_2= (w / 2);
int h_2= (h / 2);
PointF mPoint1 = new PointF(0, 0); //starts at canvas left top
PointF mPoint2 = new PointF(w_2, h_2);//mid of the canvas
Path drawPath1 =drawCurve(mPoint1, mPoint2);
canvas.drawPath(drawPath1, paint);
Method to draw the line
private Path drawCurve(PointF mPointa, PointF mPointb) {
Path myPath = new Path();
myPath.moveTo(mPointa.x, mPointa.y);
final float x2 = (mPointb.x + mPointa.x) / 3;
final float y2 = (mPointb.y + mPointa.y) / 3;
myPath.quadTo(x2, y2, mPointb.x, mPointb.y);
return myPath;
}
I think you are using wrong method for this purpose, one of the solutions that I can suggest is below
float radius = 20;
final RectF oval = new RectF();
oval.set(point1.x - radius, point1.y - radius, point1.x + radius, point1.y+ radius);
Path myPath = new Path();
myPath.arcTo(oval, startAngle, -(float) sweepAngle, true);
and for calculation of startAngle you will need
int startAngle = (int) (180 / Math.PI * Math.atan2(point.y - point1.y, point.x - point1.x));
for sweepAngle you can find detailed description here.