unity image 画线
public class Drawing : MonoBehaviour, IPointerDownHandler, IDragHandler
{
public Image m_Image; //画线的Image
protected Vector2 rectA; //起点
protected Vector2 rectB; //终点
protected float offsetX = Screen.width / 2;
protected float offsetY = Screen.height / 2;
protected RectTransform line;
public void OnPointerDown(PointerEventData eventData)
{
Debug.LogWarning($"x:{eventData.position.x},y:{eventData.position.y}");
Debug.LogWarning($"x:{Screen.width},y:{Screen.height}");
Vector2 startPoint = new Vector2(
eventData.position.x - offsetX,
eventData.position.y - offsetY
);
rectA = startPoint;
if (line == null)
{
var image = Instantiate(m_Image);
image.transform.SetParent(m_Image.transform.parent);
line = image.GetComponent<RectTransform>();
}
}
public void OnDrag(PointerEventData eventData)
{
Vector2 endPoint = new Vector2(
eventData.position.x - offsetX,
eventData.position.y - offsetY
);
rectB = endPoint;
DrawLine(line, rectA, rectB);
}
void DrawLine(RectTransform rect, Vector2 a, Vector2 b)
{
float distance = Vector2.Distance(a, b); // distance
float angle = Vector2.SignedAngle(a - b, Vector2.left); // angle
rect.anchoredPosition = (a + b) / 2;
rect.sizeDelta = new Vector2(distance, 10);
rect.transform.localRotation = Quaternion.AngleAxis(-angle, Vector3.forward);
}
}