private void drawLine(Point start, Point end, Canvas canvas, Paint paint) {
double d = MathUtils.distance(start.x, start.y, end.x, end.y);
float cosA = (float) ((end.x - start.x) / d);
float sinA = (float) ((end.y - start.y) / d);
float rx = cosA * innerRadius;
float ry = sinA * innerRadius;
canvas.drawLine(rx + start.x, ry + start.y, end.x - rx, end.y - ry, paint);
}
private Point isInRound(float x, float y) {
for (int i = 0; i < mPoints.length; i++) {
for (int j = 0; j < mPoints[i].length; j++)
if (MathUtils.isInRound(mPoints[i][j].x, mPoints[i][j].y, outerRadius, x, y))
return mPoints[i][j];
}
return null;
}
private void drawArrow(Canvas canvas, Paint paint, Point start, Point end, float arrowHeight) {
double d = MathUtils.distance(start.x, start.y, end.x, end.y);
float cosB = (float) ((end.x - start.x) / d);
float sinB = (float) ((end.y - start.y) / d);
float tanC = (float) Math.tan(Math.PI / 4); // 箭头尖锐程度，默认为直角
float h = (float) (d - arrowHeight - outerRadius);
float l = arrowHeight * tanC;
float a = l * cosB;
float b = l * sinB;
float x0 = h * cosB;
float y0 = h * sinB;
float x1 = start.x + (h + arrowHeight) * cosB;
float y1 = start.y + (h + arrowHeight) * sinB;
float x2 = start.x + x0 - b;
float y2 = start.y + y0 + a;
float x3 = start.x + x0 + b;
float y3 = start.y + y0 - a;
Path path = new Path();
path.moveTo(x1, y1);
path.lineTo(x2, y2);
path.lineTo(x3, y3);
path.close();
canvas.drawPath(path, paint);
}