cocos2d中更改CCSprite的饱和度、色相、亮度等属性

记录一下自己开发学习过程中遇到的问题吧。

本来CCSprite是没有色相、饱和度等属性的，但是CCSprite是通过CCTexture2D绘制的，而CCTexture2D可以通过UIImage创建，所以只要更改UIImage的属性就可以了。下面是大概的步骤：

1、给UIImage增加类别，实现方法：

- (UIImage*) copyImageWithHue:(int)hValue saturation:(int)sValue bright:(int)bValue;
2、创建自己的Sprite类，继承于CCSprite，实现方法：

- (id) initWithFile:(NSString *)filename withHue:(int)h withSaturation:(int)s withBright:(int)b;
3、在需要的地方导入头文件，创建Sprite。
4、具体的代码如下：
1>类别 .m文件

//交换
static inline void SwapRGB(int *a, int *b){
*a+=*b;
*b=*a-*b;
*a-=*b;
}
//范围
static inline void CheckRGB(int *Value)
{
if (*Value < 0) *Value = 0;
else if (*Value > 255) *Value = 255;
}
//赋值
static inline void AssignRGB(int *R, int *G, int *B, int intR, int intG, int intB)
{
*R = intR;
*G = intG;
*B = intB;
}
//设置明亮
static void SetBright(int *R, int *G, int *B, int bValue)
{
int intR = *R;
int intG = *G;
int intB = *B;
if (bValue > 0)
{
intR = intR + (255 - intR) * bValue / 255;
intG = intG + (255 - intG) * bValue / 255;
intB = intB + (255 - intB) * bValue / 255;
}
else if (bValue < 0)
{
intR = intR + intR * bValue / 255;
intG = intG + intG * bValue / 255;
intB = intB + intB * bValue / 255;
}
CheckRGB(&intR);
CheckRGB(&intG);
CheckRGB(&intB);
AssignRGB(R, G, B, intR, intG, intB);
}
//设置色相和饱和度
static void SetHueAndSaturation(int *R, int *G, int *B, int hValue, int sValue)
{
int intR = *R;
int intG = *G;
int intB = *B;

if (intR < intG)
SwapRGB(&intR, &intG);
if (intR < intB)
SwapRGB(&intR, &intB);
if (intB > intG)
SwapRGB(&intB, &intG);

int delta = intR - intB;
if (!delta) return;

int entire = intR + intB;
int H, S, L = entire >> 1;  //右移一位其实就是除以2（很巧妙）
if (L < 128)
S = delta * 255 / entire;
else
S = delta * 255 / (510 - entire);

if (hValue)
{
if (intR == *R)
H = (*G - *B) * 60 / delta;
else if (intR == *G)
H = (*B - *R) * 60 / delta + 120;
else
H = (*R - *G) * 60 / delta + 240;
H += hValue;
if (H < 0) H += 360;
else if (H > 360) H -= 360;
int index = H / 60;
int extra = H % 60;
if (index & 1) extra = 60 - extra;
extra = (extra * 255 + 30) / 60;
intG = extra - (extra - 128) * (255 - S) / 255;
int Lum = L - 128;
if (Lum > 0)
intG += (((255 - intG) * Lum + 64) / 128);
else if (Lum < 0)
intG += (intG * Lum / 128);
CheckRGB(&intG);
switch (index)
{
case 1:
SwapRGB(&intR, &intG);
break;
case 2:
SwapRGB(&intR, &intB);
SwapRGB(&intG, &intB);
break;
case 3:
SwapRGB(&intR, &intB);
break;
case 4:
SwapRGB(&intR, &intG);
SwapRGB(&intG, &intB);
break;
case 5:
SwapRGB(&intG, &intB);
break;
}
}
else
{
intR = *R;
intG = *G;
intB = *B;
}
if (sValue)
{
if (sValue > 0)
{
sValue = sValue + S >= 255? S: 255 - sValue;
sValue = 65025 / sValue - 255;
}
intR += ((intR - L) * sValue / 255);
intG += ((intG - L) * sValue / 255);
intB += ((intB - L) * sValue / 255);
CheckRGB(&intR);
CheckRGB(&intG);
CheckRGB(&intB);
}
AssignRGB(R, G, B, intR, intG, intB);
}

static CGContextRef RequestImagePixelData(CGImageRef inImage)
{
CGContextRef context = NULL;

size_t pixelsWide = CGImageGetWidth(inImage);
size_t pixelsHigh = CGImageGetHeight(inImage);
size_t bitmapBytesPerRow	= (pixelsWide * 4);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

//size_t bitmapByteCount	= (bitmapBytesPerRow * pixelsHigh);
//bitmapData = malloc( bitmapByteCount );
void *bitmapData = calloc( pixelsWide*pixelsHigh,4);
if (bitmapData == NULL)
{
fprintf (stderr, "Memory not allocated!");
CGColorSpaceRelease( colorSpace );
return NULL;
}

context = CGBitmapContextCreate (bitmapData, pixelsWide, pixelsHigh, 8, bitmapBytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast);

CGRect rect = {{0,0},{pixelsWide, pixelsHigh}};
CGContextDrawImage(context, rect, inImage);

CGColorSpaceRelease( colorSpace );
return context;
}

- (UIImage*) copyImageWithHue:(int)hValue saturation:(int)sValue bright:(int)bValue{
if (hValue==0&&sValue==0&&bValue==0) {
UIImage *my_Image=nil;
if ([UIImage respondsToSelector:@selector(imageWithCGImage:scale:orientation:)]) {
my_Image=[UIImage imageWithCGImage:[self CGImage] scale:self.scale orientation:self.imageOrientation];
}else {
my_Image = [UIImage imageWithCGImage:[self CGImage]];
}
return my_Image;
}

sValue = sValue * 255 / 100;
bValue = bValue * 255 / 100;

CGImageRef inImageRef = [self CGImage];
CGContextRef cgctx = RequestImagePixelData(inImageRef);
if (cgctx==NULL) {
fprintf (stderr, "Create PixelData error!");
return nil;
}
NSUInteger w = CGBitmapContextGetWidth(cgctx);
NSUInteger h = CGBitmapContextGetHeight(cgctx);
unsigned char *imgPixel = CGBitmapContextGetData(cgctx);

int pixOff = 0;  //每一个像素结束

for(NSUInteger y = 0;y< h;y++){
for (NSUInteger x = 0; x<w; x++){
//int alpha = (unsigned char)imgPixel[pixOff];
int red = (unsigned char)imgPixel[pixOff];
int green = (unsigned char)imgPixel[pixOff+1];
int blue = (unsigned char)imgPixel[pixOff+2];

if ((red|green|blue)!=0) {
//根据条件的不同，对图片的处理顺序不一样
if (sValue > 0 && bValue)
SetBright(&red, &green, &blue, bValue);

SetHueAndSaturation(&red, &green, &blue, hValue, sValue);

if (bValue && sValue <= 0)
SetBright(&red, &green, &blue, bValue);
}

imgPixel[pixOff] = red;
imgPixel[pixOff+1] = green;
imgPixel[pixOff+2] = blue;

pixOff += 4;
}
}

CGImageRef imageRef = CGBitmapContextCreateImage(cgctx);

UIImage *my_Image=nil;
if ([UIImage respondsToSelector:@selector(imageWithCGImage:scale:orientation:)]) {
my_Image=[UIImage imageWithCGImage:imageRef scale:self.scale orientation:self.imageOrientation];
}else {
my_Image = [UIImage imageWithCGImage:imageRef];
}

CFRelease(imageRef);
CGContextRelease(cgctx);
free(imgPixel);
return my_Image;
}

2>自定义Sprite .m文件

- (id) initWithFile:(NSString *)filename withHue:(int)h withSaturation:(int)s withBright:(int)b
{
if (self = [super init])
{
UIImage* image = [UIImage imageNamed:filename];
UIImage* newimage = [image copyImageWithHue:h saturation:s bright:b];
self = (YSGOrderCCSprite *)[self convertImageToSprite:newimage];
}

return self;
}

- (CCSprite *) convertImageToSprite:(UIImage *)image
{
CGImageRef imageref = image.CGImage;

CCTexture2D* texture = [[CCTexture2D alloc] initWithCGImage:imageref resolutionType:kCCResolutioniPhoneRetinaDisplay];
CCSprite* sprite = [CCSprite spriteWithTexture:texture];
[texture release];
return sprite;
}