施加到相对球尺寸的力

Question

在我的代码中，我有一个开始下落的球，每次你点击它时它都会应用下面的代码。这在 iPhone 上完美运行，但我也在为 iPad 开发。现在在 iPad 上，球显然必须更大，我也希望将相同的效果应用于这些球。我试着做数学来得到球大小的相对力，我知道我做的数学是正确的，但必须有一个更简单的方法来完成这个。任何帮助将不胜感激！

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
/* Called when a touch begins */

UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInNode:self];
SKNode *node = [self nodeAtPoint:location];

// if ball is tapped apply impulse
if ([node.name isEqualToString:@"ball"]) {
    node.physicsBody.velocity = CGVectorMake(0, 15);
    [node.physicsBody applyImpulse:
     CGVectorMake(0, 50)];

    [GameState sharedInstance].easyScore += 1;
    [_lblEasyScore setText:[NSString stringWithFormat:@"%d", [GameState sharedInstance].easyScore]];

    NSLog(@"ball pressed");
}
}

Answer 1

//Create private CGVector variable.
CGVector ballApplyImpulse;

//In your start method.(initWithSize, didMoveToView etc)
if ( UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad )//iPad Detected
{
    ballApplyImpulse = CGVectorMake(0, 100);//I haven't tested values. You can test yourself for true values.
}
else//iPhone Detected
{
    ballApplyImpulse = CGVectorMake(0, 50);
}

//In your on touch method
if ([node.name isEqualToString:@"ball"]) {
    node.physicsBody.velocity = CGVectorMake(0, 15);
    [node.physicsBody applyImpulse:ballApplyImpulse;

    [GameState sharedInstance].easyScore += 1;
    [_lblEasyScore setText:[NSString stringWithFormat:@"%d", [GameState sharedInstance].easyScore]];

    NSLog(@"ball pressed");
}
}