輸入鼠標位置沒有準確捕獲？

Question

我得到鼠標輸入從點A到點B畫一條線到紋理上。我意識到我沒有觸及每個像素，因此將鼠標從左側移動到屏幕的右側，會跳過一些值，導致間隙。當我慢慢移動鼠標時，它會變得更好。

我正在使用鼠標的位置：

var viewPortPosition = Camera.main.ScreenToViewportPoint (Input.mousePosition); 

Answer 1

如果你想畫一條線我您在使用line renderer建議。假設你在Update（）函數中實現了代碼 - 這被稱爲每幀渲染。所以即使你的運動速度很慢，顯然它已經足夠在你畫出的線條上留下空隙了。

下面是從這個link一些代碼，應該可以正常工作對您：

using System.Collections.Generic; 
using UnityEngine; 

[RequireComponent(typeof(LineRenderer))] 
public class LineRendererTest : MonoBehaviour 
{ 
    List<Vector3> linePoints = new List<Vector3>(); 
    LineRenderer lineRenderer; 
    public float startWidth = 1.0f; 
    public float endWidth = 1.0f; 
    public float threshold = 0.001f; 
    Camera thisCamera; 
    int lineCount = 0; 

    Vector3 lastPos = Vector3.one * float.MaxValue; 


    void Awake() 
    { 
     thisCamera = Camera.main; 
     lineRenderer = GetComponent<LineRenderer>(); 
    } 

    void Update() 
    { 
     Vector3 mousePos = Input.mousePosition; 
     mousePos.z = thisCamera.nearClipPlane; 
     Vector3 mouseWorld = thisCamera.ScreenToWorldPoint(mousePos); 

     float dist = Vector3.Distance(lastPos, mouseWorld); 
     if(dist <= threshold) 
      return; 

     lastPos = mouseWorld; 
     if(linePoints == null) 
      linePoints = new List<Vector3>(); 
     linePoints.Add(mouseWorld); 

     UpdateLine(); 
    } 


    void UpdateLine() 
    { 
     lineRenderer.SetWidth(startWidth, endWidth); 
     lineRenderer.SetVertexCount(linePoints.Count); 

     for(int i = lineCount; i < linePoints.Count; i++) 
     { 
      lineRenderer.SetPosition(i, linePoints[i]); 
     } 
     lineCount = linePoints.Count; 
    } 

Answer 2

我已經結束忙什麼做的是運行通過布氏畫線的迄今收集的鼠標位置的功能柵格化線。

來源：

public void line(Vector2 pointA, Vector2 pointB, Texture2D texture) { 
    int x = (int)pointA.x; 
    int y = (int)pointA.y; 

    int x2 = (int)pointB.x; 
    int y2 = (int)pointB.y; 

    int w = x2- x ; 
    int h = y2 - y; 
    int dx1 = 0, dy1 = 0, dx2 = 0, dy2 = 0 ; 
    if (w<0) dx1 = -1 ; else if (w>0) dx1 = 1 ; 
    if (h<0) dy1 = -1 ; else if (h>0) dy1 = 1 ; 
    if (w<0) dx2 = -1 ; else if (w>0) dx2 = 1 ; 
    int longest = Math.Abs(w) ; 
    int shortest = Math.Abs(h) ; 
    if (!(longest>shortest)) { 
     longest = Math.Abs(h) ; 
     shortest = Math.Abs(w) ; 
     if (h<0) dy2 = -1 ; else if (h>0) dy2 = 1 ; 
     dx2 = 0 ;    
    } 
    int numerator = longest >> 1 ; 
    for (int i=0;i<=longest;i++) { 
     texture.SetPixel (x, y, Color.red); 

     numerator += shortest ; 
     if (!(numerator<longest)) { 
      numerator -= longest ; 
      x += dx1 ; 
      y += dy1 ; 
     } else { 
      x += dx2 ; 
      y += dy2 ; 
     } 
    } 
} 

代碼的原始來源，但修改後用於統一C＃：All cases covered Bresenham's line-algorithm