您好。如何制作只能在四个方向上移动的操纵杆?谁能给我一些建议?
现在写我正在使用此代码进行操纵杆。如何让这个只允许四个方向?
-(void) trackVelocity:(CGPoint) nodeTouchPoint {
CGPoint ankPt = self.anchorPointInPoints;
// Get the touch point relative to the joystick home (anchor point)
CGPoint relPoint = ccpSub(nodeTouchPoint, ankPt);
// Determine the raw unconstrained velocity vector
CGPoint rawVelocity = CGPointMake(relPoint.x / travelLimit.x,relPoint.y / travelLimit.y);
// If necessary, normalize the velocity vector relative to the travel limits
CGFloat rawVelLen = ccpLength(rawVelocity);
velocity = (rawVelLen <= 1.0) ? rawVelocity : ccpMult(rawVelocity, 1.0f/rawVelLen);
// Calculate the vector in angular coordinates
// ccpToAngle returns counterclockwise positive relative to X-axis.
// We want clockwise positive relative to the Y-axis.
CGFloat angle = 90.0- CC_RADIANS_TO_DEGREES(ccpToAngle(velocity));
if(angle > 180.0) {
angle -= 360.0;
}
// angularVelocity.radius = ccpLength(velocity);
// angularVelocity.heading = angle;
// Update the thumb's position, clamping it within the contentSize of the Joystick
[thumbNode setPosition: ccpAdd(ccpCompMult(velocity, travelLimit), ankPt)];
}
答案 0 :(得分:0)