objective-c - 排序颜色(Objective-C)

Question

我正在做这样的事情:

- (NSArray*)colors {
    float divisor = .3333;
    NSMutableArray *retVal = [NSMutableArray array];
    for (float one=0; one <= 1.0f; one += divisor) {
        for (float two = 0; two <= 1.0f; two += divisor) {
            for (float three = 0; three <= 1.0f; three += divisor) {
                UIColor *color = [UIColor colorWithRed:one green:two blue:three alpha:.5];
                // also bad
                // UIColor *color = [UIColor colorWithHue:one saturation:two brightness:three alpha:.5];
                [retVal addObject:color];
            }
        }
    }
    return retVal;
}

而且，正如我所怀疑的那样，颜色(在眼睛看来)非常困惑。红不带红，紫不带紫等。

是否没有简单的方法来创建一个包含不同颜色的列表，并根据“看起来是蓝色”等人类标准很好地分组？

Answer 1

这很有效。你有很多重复的颜色，这无济于事。见下文:

NSArray *sorted = [[dict allValues] sortedArrayUsingComparator:^NSComparisonResult(UIColor* obj1, UIColor* obj2) {
    float hue, saturation, brightness, alpha;
    [obj1 getHue:&hue saturation:&saturation brightness:&brightness alpha:&alpha];
    float hue2, saturation2, brightness2, alpha2;
    [obj2 getHue:&hue2 saturation:&saturation2 brightness:&brightness2 alpha:&alpha2];
    if (hue < hue2)
        return NSOrderedAscending;
    else if (hue > hue2)
        return NSOrderedDescending;

    if (saturation < saturation2)
        return NSOrderedAscending;
    else if (saturation > saturation2)
        return NSOrderedDescending;

    if (brightness < brightness2)
        return NSOrderedAscending;
    else if (brightness > brightness2)
        return NSOrderedDescending;

    return NSOrderedSame;
}];

您可以在 iOS 4.x 中像这样访问组件 (HSBA):

    CGFloat *components = (CGFloat *)CGColorGetComponents([color CGColor]);
    float hue = components[0];
    float saturation = components[1]; // etc. etc.

为了避免重复颜色:您可以将元素放在 NSMutableDictionary 中，以诸如它们的色调-饱和度-亮度(每个四舍五入到最接近的 .10)之类的东西为键...然后您得到来自 THAT 的数组，然后排序。