我不知道你的目标,可能是完全脱离主题,但为什么不只是使用Quartz 2D?通过CGContextSetBlendMode
覆盖,乘,屏幕和更
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextSetBlendMode(ctx, kCGBlendModeOverlay);
... draw with overlay blending
CGBlendMode
优惠...:
enum CGBlendMode {
/* Available in Mac OS X 10.4 & later. */
kCGBlendModeNormal,
kCGBlendModeMultiply,
kCGBlendModeScreen,
kCGBlendModeOverlay,
kCGBlendModeDarken,
kCGBlendModeLighten,
kCGBlendModeColorDodge,
kCGBlendModeColorBurn,
kCGBlendModeSoftLight,
kCGBlendModeHardLight,
kCGBlendModeDifference,
kCGBlendModeExclusion,
kCGBlendModeHue,
kCGBlendModeSaturation,
kCGBlendModeColor,
kCGBlendModeLuminosity,
/* Available in Mac OS X 10.5 & later. R, S, and D are, respectively,
premultiplied result, source, and destination colors with alpha; Ra,
Sa, and Da are the alpha components of these colors.
The Porter-Duff "source over" mode is called `kCGBlendModeNormal':
R = S + D*(1 - Sa)
Note that the Porter-Duff "XOR" mode is only titularly related to the
classical bitmap XOR operation (which is unsupported by
CoreGraphics). */
kCGBlendModeClear, /* R = 0 */
kCGBlendModeCopy, /* R = S */
kCGBlendModeSourceIn, /* R = S*Da */
kCGBlendModeSourceOut, /* R = S*(1 - Da) */
kCGBlendModeSourceAtop, /* R = S*Da + D*(1 - Sa) */
kCGBlendModeDestinationOver, /* R = S*(1 - Da) + D */
kCGBlendModeDestinationIn, /* R = D*Sa */
kCGBlendModeDestinationOut, /* R = D*(1 - Sa) */
kCGBlendModeDestinationAtop, /* R = S*(1 - Da) + D*Sa */
kCGBlendModeXOR, /* R = S*(1 - Da) + D*(1 - Sa) */
kCGBlendModePlusDarker, /* R = MAX(0, (1 - D) + (1 - S)) */
kCGBlendModePlusLighter /* R = MIN(1, S + D) */
};
typedef enum CGBlendMode CGBlendMode; /* Available in Mac OS X 10.4 & later. */
大。这不是我原来的问题的一部分,但是你知道有哪些UIColor扩展课程可以开箱吗? – samvermette 2011-04-28 21:42:21
不是一个otb实现,但这可能会帮助你:https://github.com/facebook/three20/blob/master/src/Three20Style/Sources/UIColorAdditions.m – 2011-04-28 21:48:32