Iphone检测每个手指并绘制线条（使用cocos2d/openGL绘制）

我了解多点触控活动的基本原理

当figer触摸视图/屏幕时，该视图将收到带有一组

UITouch

的

cctouchsbegind

UITouch

将保留位置（

CGPoint

）及其对每个手指的唯一性

如果多个手指同时接触视图，则2

UITouch

将被发送到视图

有时，view会收到带有2个

UITouch

的

cctouchsbegind

，或者

cctouchsbegind

会为每个手指触摸依次调用两次

如果finger1正在移动，视图将接收带有一个

UITouch的
ccTouchesMoved

我的问题是如何分别用手指触摸画线，将1或2个手指放在屏幕上，并为每个手指触摸开始/移动/结束画线

以下代码在只有单触时有效，但对于多触时，由于上述第3点和第4点的原因，无法工作

就这样

---

您可以尝试将触摸位置数组与不同的触摸关联起来（例如NSDictionary，UITouchs作为键，NSArray点作为值）。然后，您可以使用

ccDrawLine

或任何其他方式（如果您使用

draw

方法）绘制这些线。只是不要忘记将这些阵列存储在当前触摸结束的位置

-(void) ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    if ([touches count] > 0) {

        // handle multi touch
        UITouch *touch1 = [[touches allObjects] objectAtIndex:0];
        CGPoint touchLocation1 = [touch1 locationInView: [touch1 view]];
        touchLocation1 = [[CCDirector sharedDirector] convertToGL: touchLocation1];

        Edge *temEdge1 = (Edge*)[temEdges objectAtIndex:0];
        [[temEdge1 end] updateXY:touchLocation1];
        [[temEdge1 start] updateXY:touchLocation1];

        if ([touches count] > 1) {
            UITouch *touch2 = [[touches allObjects] objectAtIndex:1];
            CGPoint touchLocation2 = [touch2 locationInView: [touch2 view]];
            touchLocation2 = [[CCDirector sharedDirector] convertToGL: touchLocation2];

            Edge *temEdge2 = (Edge*)[temEdges objectAtIndex:1];
            [[temEdge2 end] updateXY:touchLocation2];
            [[temEdge2 start] updateXY:touchLocation2];

        }

    }
}

-(void) ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{

    if ([touches count] > 0) {

        // handle multi touch
        UITouch *touch1 = [[touches allObjects] objectAtIndex:0];
        CGPoint touchLocation1 = [touch1 locationInView: [touch1 view]];
        touchLocation1 = [[CCDirector sharedDirector] convertToGL: touchLocation1];

        Edge *temEdge1 = (Edge*)[temEdges objectAtIndex:0];
        [[temEdge1 end] updateXY:touchLocation1];


        if ([touches count] > 1) {
            UITouch *touch2 = [[touches allObjects] objectAtIndex:1];
            CGPoint touchLocation2 = [touch2 locationInView: [touch2 view]];
            touchLocation2 = [[CCDirector sharedDirector] convertToGL: touchLocation2];

            Edge *temEdge2 = (Edge*)[temEdges objectAtIndex:1];
            [[temEdge2 end] updateXY:touchLocation2];
        }

    }

}

-(void) ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    if ([touches count] > 0) {

        // handle multi touch
        UITouch *touch1 = [[touches allObjects] objectAtIndex:0];
        CGPoint touchLocation1 = [touch1 locationInView: [touch1 view]];
        touchLocation1 = [[CCDirector sharedDirector] convertToGL: touchLocation1];

        Edge *temEdge1 = (Edge*)[temEdges objectAtIndex:0];
        [[temEdge1 end] updateXY:touchLocation1];

        if ([touches count] > 1) {

            UITouch *touch2 = [[touches allObjects] objectAtIndex:1];
            CGPoint touchLocation2 = [touch2 locationInView: [touch2 view]];
            touchLocation2 = [[CCDirector sharedDirector] convertToGL: touchLocation2];

            Edge *temEdge2 = (Edge*)[temEdges objectAtIndex:1];
            [[temEdge2 end] updateXY:touchLocation2];
        }
    }

}
-(void)draw
{
    [super draw];
    glLineWidth(5.f);
    ccDrawColor4B(0, 0, 255, 255);
    for (Edge *temEdge in temEdges) {
        CGPoint start = [[temEdge start] toCCP];
        CGPoint end   = [[temEdge end] toCCP];
        ccDrawLine(start , end);
    }

}