如何在多点触控序列中有效地处理UITouches [英] How to effectively process UITouches in a multitouch sequence

问题描述

我在写作时正在使用多点触控，所以基本上我正在做的是，我正在用手支持写作，因为通常，它是用户写的，我按照这个链接如何忽略多点触控序列中的某些UITouch积分

I am working with multitouch while writing, So basically what I am doing is, I am writing with hand support, because typically, its how user writes, I followed this link How to ignore certain UITouch Points in multitouch sequence

单手触摸时一切正常，但是当我用手触摸屏幕时，它们是一些问题，即多个UItouches
以下是我的代码

Everything is working fine with single touch, but their is some problem when I write with my hand touching the screen i.e multiple UItouches Below is my code

在触摸开始时，我经历了所有触摸，我发现触摸的y位置最高，下面​​是我的代码

In touches began, I go through all touches and I find the touch with highest y position, below is my code

以下是我的代码

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch* topmostTouch = self.trackingTouch;
    for (UITouch *touch in touches)
    {
        ctr = 0;

        touchStartPoint1 = [touch locationInView:self];


        if(!topmostTouch || [topmostTouch locationInView:self].y > touchStartPoint1.y)
        {
            topmostTouch = touch;
            pts[0] = touchStartPoint1;
        }
    }   

    self.trackingTouch = topmostTouch;
}

在移动的触摸中，我只会使用self.trackingTouch，我找到了触摸开始

In touches moved., I will only take self.trackingTouch, which I found in touches Began

我的动态下面的移动代码

My touches Moved code below

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{ 
    if(self.trackingTouch== nil)
    {
        return;
    }

    CGPoint p = [self.trackingTouch locationInView:self];
    ctr++;
    pts[ctr] = p;

    if (ctr == 4)
    {
        pts[3] = midPoint(pts[2], pts[4]);

        self.currentPath = [[DrawingPath alloc] init];

        [self.currentPath setPathColor:self.lineColor];
        self.currentPath.pathWidth = [NSString stringWithFormat:@"%f",self.lineWidth];


        [self.currentPath.path moveToPoint:pts[0]];
        [self.currentPath.path addCurveToPoint:pts[3] controlPoint1:pts[1] controlPoint2:pts[2]];

        [self setNeedsDisplay];


        pts[0] = pts[3];
        pts[1] = pts[4];
        ctr = 1;
    }
}

以下是您的参考图像触摸和多点触控

For your reference here is the image of writing with single touch and multitouch respectively

你可以看到，当我用单点触摸书写时，我的书写很流畅，曲线很流畅，但是当我用手休息写字时，我的曲线变得锯齿状，正如你在第二张图片。

You can see that, when I write with single touch, my writing is smooth, the curves are smooth, but when I write with hand resting, I curves get jagged, as you can see in the second image.

所以朋友们，请帮帮我

推荐答案

我终于解决了我的问题，

I finally solved my issue,

这是代码

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch* topmostTouch = self.trackingTouch;
    for (UITouch *touch in touches)
    {


        touchStartPoint1 = [touch locationInView:self];


        if(!topmostTouch || [topmostTouch locationInView:self].y > touchStartPoint1.y)
        {
            ctr = 0;
            topmostTouch = touch;
            pts[0] = touchStartPoint1;
        }
    }   

    self.trackingTouch = topmostTouch;
}

问题非常简单，只需在支票内设置ctr = 0，像这样......

The problem was very simple, just set ctr = 0 , inside the check, like this..

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