cocos2dx 文本 优化

　　不得不说，CCLabelTTF是一个很鸡肋的组件，在2dx for ios库里面，它的底层使用了UIKit包来实现文本显示，但其显示特性较弱，几乎不可扩展。比如实现文字阴影，描边还有另一个更2的问题，当我们采用2dx的多分辨解决方案时，如

CCDirector::sharedDirector()->setContentScaleFactor(2.0); 这时的所有的文字都模糊不清，惨不忍睹。很多人此时会考虑抛弃ios默认字体，该自定义字体库，但几千个字符（包括诸如日文，韩文等）全部整合起来还是很麻烦的

    首先，我们追根溯源，查看2dx源代码，发现CCLabelTTF底层是由CCImage来渲染的，核心代码 

《CCImage.mm》

static bool _initWithString(const char * pText, cocos2d::CCImage::ETextAlign eAlign, const char * pFontName, int nSize, tImageInfo* pInfo)

关于代码细节此处不再详解，大致是用NSString 的draw方法来绘制文字，这里我们仿造来写一个

1.在《CCImage.h》中加入这些方法

//UIImage转CCImage

    bool initWithUIImage(void* uimg);

 /**

获取文字显示大小，注意，只是获取文字的显示区域大小，这个大小是 依据文字fontsize，是否换行等属性来确定，也就是说，调用该方法，文字并未渲染!*/

    static CCSize getImageStringSize(const char *pText,float fontSize, ccColor3B fillColor,ccColor4B shadowColor,bool isShadow,CCSize dimensions,CCTextAlignment hAlignment ,CCVerticalTextAlignment vAlignment);

//渲染文字

    void initWithShadowLabel( const char * pText,float fontSize,ccColor3B fillColor,ccColor4B shadowColor,bool isShadow = true,CCSize dimensions = CCSizeZero,CCTextAlignment h = kCCTextAlignmentLeft,CCVerticalTextAlignment v = kCCVerticalTextAlignmentTop);

 2. 

// UIImage转CCImage

bool CCImage::initWithUIImage(void* uimg)

{

    CGImageRef CGImage = [(UIImage *)uimg CGImage];

    tImageInfo info = {0};

    bool bRet = _initWithImage(CGImage, &info);

    if (bRet)

    {

        m_nHeight = (short)info.height;

        m_nWidth = (short)info.width;

        m_nBitsPerComponent = info.bitsPerComponent;

        m_bHasAlpha = info.hasAlpha;

        m_bPreMulti = info.isPremultipliedAlpha;

        m_pData = info.data;

    }

    return bRet;

}

CCSize CCImage::getImageStringSize(const char *pText,float fontSize, ccColor3B fillColor,ccColor4B shadowColor,bool isShadow,CCSize dimensions,CCTextAlignment hAlignment ,CCVerticalTextAlignment vAlignment)

{

    ETextAlign align;

    //获取文本对齐方式

    if (kCCVerticalTextAlignmentTop == vAlignment)

    {

        align = (kCCTextAlignmentCenter == hAlignment) ? CCImage::kAlignTop

        : (kCCTextAlignmentLeft == hAlignment) ? CCImage::kAlignTopLeft : CCImage::kAlignTopRight;

    }

    elseif (kCCVerticalTextAlignmentCenter == vAlignment)

    {

        align = (kCCTextAlignmentCenter == hAlignment) ? CCImage::kAlignCenter

        : (kCCTextAlignmentLeft == hAlignment) ? CCImage::kAlignLeft : CCImage::kAlignRight;

    }

    elseif (kCCVerticalTextAlignmentBottom == vAlignment)

    {

        align = (kCCTextAlignmentCenter == hAlignment) ? CCImage::kAlignBottom

        : (kCCTextAlignmentLeft == hAlignment) ? CCImage::kAlignBottomLeft : CCImage::kAlignBottomRight;

    }

    else

    {

        CCAssert(false, "Not supported alignment format!");

    }

//此处可以自己修改成其他字体样式，经过比较，我们选择使用系统加粗字体

    UIFont *font = [UIFont boldSystemFontOfSize:fontSize];

    NSString *str = [NSString stringWithUTF8String:pText];

    CGSize dim, constrainSize;

    constrainSize.width = dimensions.width;

    constrainSize.height = dimensions.height;

    // create the font ，这块代码 从引擎拷贝过来

    if (font)

    {

        dim = _calculateStringSize(str, font, &constrainSize);

    }

    // compute start point

    int startH = 0;

    if (constrainSize.height > dim.height)

    {

        // vertical alignment

        unsigned int vAlignment = (align >> 4) & 0x0F;

        if (vAlignment == ALIGN_TOP)

        {

            startH = 0;

        }

        else if (vAlignment == ALIGN_CENTER)

        {

            startH = (constrainSize.height - dim.height) / 2;

        }

        else

        {

            startH = constrainSize.height - dim.height;

        }

    }

    return CCSizeMake(dim.width, dim.height - startH);

}

 

void CCImage::initWithShadowLabel(const char *pText,float fontSize, ccColor3B fillColor,ccColor4B shadowColor,bool isShadow,CCSize dimensions,CCTextAlignment hAlignment ,CCVerticalTextAlignment vAlignment)

{

    do {    

        CGFloat scaleFactor = CCDirector::sharedDirector()->getContentScaleFactor();

        //获取文本对齐方式

        ETextAlign align;

        if (kCCVerticalTextAlignmentTop == vAlignment)

        {

            align = (kCCTextAlignmentCenter == hAlignment) ? CCImage::kAlignTop

            : (kCCTextAlignmentLeft == hAlignment) ? CCImage::kAlignTopLeft : CCImage::kAlignTopRight;

        }

        elseif (kCCVerticalTextAlignmentCenter == vAlignment)

        {

            align = (kCCTextAlignmentCenter == hAlignment) ? CCImage::kAlignCenter

            : (kCCTextAlignmentLeft == hAlignment) ? CCImage::kAlignLeft : CCImage::kAlignRight;

        }

        elseif (kCCVerticalTextAlignmentBottom == vAlignment)

        {

            align = (kCCTextAlignmentCenter == hAlignment) ? CCImage::kAlignBottom

            : (kCCTextAlignmentLeft == hAlignment) ? CCImage::kAlignBottomLeft : CCImage::kAlignBottomRight;

        }

        else

        {

            break;

        }

        UIFont *font = [UIFont boldSystemFontOfSize:fontSize];

        NSString *str = [NSString stringWithUTF8String:pText];

        CC_BREAK_IF(!font);

        CGSize dim, constrainSize;

        constrainSize.width = dimensions.width;

        constrainSize.height = dimensions.height;

        

        // create the font

 

        dim = _calculateStringSize(str, font, &constrainSize);

        

        // compute start point

        int startH = 0;

        if (constrainSize.height > dim.height)

        {

            // vertical alignment

            unsigned int vAlignment = (align >> 4) & 0x0F;

            if (vAlignment == ALIGN_TOP)

            {

                startH = 0;

            }

            else if (vAlignment == ALIGN_CENTER)

            {

                startH = (constrainSize.height - dim.height) / 2;

            }

            else

            {

                startH = constrainSize.height - dim.height;

            }

        }

        // adjust text rect

        if (constrainSize.width > 0 && constrainSize.width > dim.width)

        {

            dim.width = constrainSize.width;

        }

        if (constrainSize.height > 0 && constrainSize.height > dim.height)

        {

            dim.height = constrainSize.height;

        }

        

        CGSize size;

        size.width = dim.width * scaleFactor;

        size.height = dim.height * scaleFactor;

        

        UIGraphicsBeginImageContextWithOptions(size,false,scaleFactor);

        

        CGContextRef context = UIGraphicsGetCurrentContext();

        CC_BREAK_IF(!context);

 

        //    CGContextSetLineWidth(context, 2);

        ccColor4F fillColor4f = ccc4FFromccc3B(fillColor);

　　　//设置文本颜色

        CGContextSetRGBFillColor(context, fillColor4f.r, fillColor4f.g, fillColor4f.b, fillColor4f.a);

        // 这个地方 绘制文本阴影

        ccColor4F sColor4F =ccc4FFromccc4B(shadowColor);

        float sColor[4] = {sColor4F.r, sColor4F.g, sColor4F.b, sColor4F.a};

        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

        CGColorRef color = CGColorCreate(colorSpace,sColor);

　　　　　　　　
        CGColorSpaceRelease(colorSpace);

        if (isShadow)

        {

　　　　//设置文字阴影

            CGContextSetShadowWithColor(context, CGSizeMake(1.0, 1.0), 0.0, color);

        }

        // draw in context

        CGContextScaleCTM(context, scaleFactor, scaleFactor);
　　　　　CGColorRelease(color);

　　　//绘制换行文本

        [str drawInRect:CGRectMake(0, startH, dim.width, dim.height) withFont:font lineBreakMode:(UILineBreakMode)UILineBreakModeWordWrapalignment:align];

        //    [str drawAtPoint:CGPointMake(0.0, 0.0) withFont:font]; // 画单行文本

        UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

        UIGraphicsEndImageContext();

        this->initWithUIImage(image);        

    }

    while (0);

}

剩下的就是把CCImage转成CCtexture2D，然后交给CCSprite显示