自学教程：C++ CGContextDrawImage函数代码示例

DragImageRef scaleDragImage(DragImageRef image, FloatSize scale){    // FIXME: due to the way drag images are done on windows we need     // to preprocess the alpha channel <rdar://problem/5015946>    if (!image)        return 0;    CGContextRef targetContext;    CGContextRef srcContext;    CGImageRef srcImage;    IntSize srcSize = dragImageSize(image);    IntSize dstSize(static_cast<int>(srcSize.width() * scale.width()), static_cast<int>(srcSize.height() * scale.height()));    HBITMAP hbmp = 0;    HWndDC dc(0);    HDC dstDC = CreateCompatibleDC(dc);    if (!dstDC)        goto exit;    hbmp = allocImage(dstDC, dstSize, &targetContext);    if (!hbmp)        goto exit;    srcContext = createCgContextFromBitmap(image);    srcImage = CGBitmapContextCreateImage(srcContext);    CGRect rect;    rect.origin.x = 0;    rect.origin.y = 0;    rect.size = dstSize;    CGContextDrawImage(targetContext, rect, srcImage);    CGImageRelease(srcImage);    CGContextRelease(srcContext);    CGContextRelease(targetContext);    ::DeleteObject(image);    image = 0;exit:    if (!hbmp)        hbmp = image;    if (dstDC)        DeleteDC(dstDC);    return hbmp;}

String ImageBuffer::toDataURL(const String& mimeType, const double* quality, CoordinateSystem) const{    ASSERT(MIMETypeRegistry::isSupportedImageMIMETypeForEncoding(mimeType));    if (context().isAcceleratedContext())        flushContext();    RetainPtr<CFStringRef> uti = utiFromMIMEType(mimeType);    ASSERT(uti);    RefPtr<Uint8ClampedArray> premultipliedData;    RetainPtr<CGImageRef> image;    if (CFEqual(uti.get(), jpegUTI())) {        // JPEGs don't have an alpha channel, so we have to manually composite on top of black.        premultipliedData = getPremultipliedImageData(IntRect(IntPoint(0, 0), logicalSize()));        if (!premultipliedData)            return "data:,";        RetainPtr<CGDataProviderRef> dataProvider;        dataProvider = adoptCF(CGDataProviderCreateWithData(0, premultipliedData->data(), 4 * logicalSize().width() * logicalSize().height(), 0));        if (!dataProvider)            return "data:,";        image = adoptCF(CGImageCreate(logicalSize().width(), logicalSize().height(), 8, 32, 4 * logicalSize().width(),                                    deviceRGBColorSpaceRef(), kCGBitmapByteOrderDefault | kCGImageAlphaNoneSkipLast,                                    dataProvider.get(), 0, false, kCGRenderingIntentDefault));    } else if (m_resolutionScale == 1) {        image = copyNativeImage(CopyBackingStore);        image = createCroppedImageIfNecessary(image.get(), internalSize());    } else {        image = copyNativeImage(DontCopyBackingStore);        RetainPtr<CGContextRef> context = adoptCF(CGBitmapContextCreate(0, logicalSize().width(), logicalSize().height(), 8, 4 * logicalSize().width(), deviceRGBColorSpaceRef(), kCGImageAlphaPremultipliedLast));        CGContextSetBlendMode(context.get(), kCGBlendModeCopy);        CGContextClipToRect(context.get(), CGRectMake(0, 0, logicalSize().width(), logicalSize().height()));        FloatSize imageSizeInUserSpace = scaleSizeToUserSpace(logicalSize(), m_data.backingStoreSize, internalSize());        CGContextDrawImage(context.get(), CGRectMake(0, 0, imageSizeInUserSpace.width(), imageSizeInUserSpace.height()), image.get());        image = adoptCF(CGBitmapContextCreateImage(context.get()));    }    return CGImageToDataURL(image.get(), mimeType, quality);}

void BitmapImage::checkForSolidColor(){    m_checkedForSolidColor = true;    m_isSolidColor = false;    if (frameCount() > 1)        return;    if (!haveFrameAtIndex(0)) {        IntSize size = m_source.frameSizeAtIndex(0, 0);        if (size.width() != 1 || size.height() != 1)            return;        if (!ensureFrameIsCached(0))            return;    }    CGImageRef image = nullptr;    if (m_frames.size())        image = m_frames[0].m_frame;    if (!image)        return;    // Currently we only check for solid color in the important special case of a 1x1 image.    if (CGImageGetWidth(image) == 1 && CGImageGetHeight(image) == 1) {        unsigned char pixel[4]; // RGBA        RetainPtr<CGContextRef> bitmapContext = adoptCF(CGBitmapContextCreate(pixel, 1, 1, 8, sizeof(pixel), deviceRGBColorSpaceRef(),            kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big));        if (!bitmapContext)            return;        GraphicsContext(bitmapContext.get()).setCompositeOperation(CompositeCopy);        CGRect destinationRect = CGRectMake(0, 0, 1, 1);        CGContextDrawImage(bitmapContext.get(), destinationRect, image);        if (!pixel[3])            m_solidColor = Color(0, 0, 0, 0);        else            m_solidColor = Color(pixel[0] * 255 / pixel[3], pixel[1] * 255 / pixel[3], pixel[2] * 255 / pixel[3], pixel[3]);        m_isSolidColor = true;    }}

OSStatus GeneratePreviewForURL(void *thisInterface, QLPreviewRequestRef preview, CFURLRef url, CFStringRef contentTypeUTI, CFDictionaryRef options){	CGDataProviderRef dataProvider = CGDataProviderCreateWithURL(url);	if (!dataProvider) return -1;	CFDataRef data = CGDataProviderCopyData(dataProvider);	CGDataProviderRelease(dataProvider);	if (!data) return -1;		int width, height, channels;	unsigned char* rgbadata = SOIL_load_image_from_memory(CFDataGetBytePtr(data), CFDataGetLength(data), &width, &height, &channels, SOIL_LOAD_RGBA);	CFStringRef format=CFStringCreateWithBytes(NULL, CFDataGetBytePtr(data) + 0x54, 4, kCFStringEncodingASCII, false);    CFRelease(data);	if (!rgbadata) return -1;		CGColorSpaceRef rgb = CGColorSpaceCreateDeviceRGB();	CGContextRef context = CGBitmapContextCreate(rgbadata, width, height, 8, width * 4, rgb, kCGImageAlphaPremultipliedLast);	SOIL_free_image_data(rgbadata);	CGColorSpaceRelease(rgb);	if (!context) return -1;	CGImageRef image = CGBitmapContextCreateImage(context);	CGContextRelease(context);	if (!image) return -1;	/* Add basic metadata to title */	CFStringRef name = CFURLCopyLastPathComponent(url);	CFTypeRef keys[1] = {kQLPreviewPropertyDisplayNameKey};	CFTypeRef values[1] = {CFStringCreateWithFormat(NULL, NULL, CFSTR("%@ (%dx%d %@)"), name, width, height, format)}; 	CFDictionaryRef properties = CFDictionaryCreate(NULL, (const void**)keys, (const void**)values, 1, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);	CFRelease(name);	context = QLPreviewRequestCreateContext(preview, CGSizeMake(width, height), true, properties);	CGContextDrawImage(context, CGRectMake(0, 0, width, height), image);	QLPreviewRequestFlushContext(preview, context);		CGContextRelease(context);	CFRelease(format);	CFRelease(properties);		return noErr;}

void BitmapImage::checkForSolidColor(){    m_checkedForSolidColor = true;    if (frameCount() > 1) {        m_isSolidColor = false;        return;    }#if !PLATFORM(IOS)    CGImageRef image = frameAtIndex(0);#else    // Note, checkForSolidColor() may be called from frameAtIndex(). On iOS frameAtIndex() gets passed a scaleHint    // argument which it uses to tell CG to create a scaled down image. Since we don't know the scaleHint here, if    // we call frameAtIndex() again, we would pass it the default scale of 1 and would end up recreating the image.    // So we do a quick check and call frameAtIndex(0) only if we haven't yet created an image.    CGImageRef image = nullptr;    if (m_frames.size())        image = m_frames[0].m_frame;    if (!image)        image = frameAtIndex(0);#endif    // Currently we only check for solid color in the important special case of a 1x1 image.    if (image && CGImageGetWidth(image) == 1 && CGImageGetHeight(image) == 1) {        unsigned char pixel[4]; // RGBA        RetainPtr<CGContextRef> bitmapContext = adoptCF(CGBitmapContextCreate(pixel, 1, 1, 8, sizeof(pixel), deviceRGBColorSpaceRef(),                                                kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big));        if (!bitmapContext)            return;        GraphicsContext(bitmapContext.get()).setCompositeOperation(CompositeCopy);        CGRect destinationRect = CGRectMake(0, 0, 1, 1);        CGContextDrawImage(bitmapContext.get(), destinationRect, image);        if (!pixel[3])            m_solidColor = Color(0, 0, 0, 0);        else            m_solidColor = Color(pixel[0] * 255 / pixel[3], pixel[1] * 255 / pixel[3], pixel[2] * 255 / pixel[3], pixel[3]);        m_isSolidColor = true;    }}

static wxBitmap DoGetAsBitmap(const wxRect *subrect){    CGRect cgbounds = CGDisplayBounds(CGMainDisplayID());    wxRect rect = subrect ? *subrect : wxRect(0, 0, cgbounds.size.width, cgbounds.size.height);    wxBitmap bmp(rect.GetSize().GetWidth(), rect.GetSize().GetHeight(), 32);    CGDisplayCreateImageFunc createImage =        (CGDisplayCreateImageFunc) dlsym(RTLD_NEXT, "CGDisplayCreateImage");    if (createImage == NULL)    {        return bmp;    }    CGRect srcRect = CGRectMake(rect.x, rect.y, rect.width, rect.height);    CGContextRef context = (CGContextRef)bmp.GetHBITMAP();    CGContextSaveGState(context);    CGContextTranslateCTM( context, 0,  cgbounds.size.height );    CGContextScaleCTM( context, 1, -1 );    if ( subrect )        srcRect = CGRectOffset( srcRect, -subrect->x, -subrect->y ) ;    CGImageRef image = NULL;    image = createImage(kCGDirectMainDisplay);    wxASSERT_MSG(image, wxT("wxScreenDC::GetAsBitmap - unable to get screenshot."));    CGContextDrawImage(context, srcRect, image);    CGImageRelease(image);    CGContextRestoreGState(context);    return bmp;}

RefPtr<Image> ImageBuffer::copyImage(BackingStoreCopy copyBehavior, ScaleBehavior scaleBehavior) const{    RetainPtr<CGImageRef> image;    if (m_resolutionScale == 1 || scaleBehavior == Unscaled) {        image = copyNativeImage(copyBehavior);        image = createCroppedImageIfNecessary(image.get(), internalSize());    } else {        image = copyNativeImage(DontCopyBackingStore);        RetainPtr<CGContextRef> context = adoptCF(CGBitmapContextCreate(0, logicalSize().width(), logicalSize().height(), 8, 4 * logicalSize().width(), deviceRGBColorSpaceRef(), kCGImageAlphaPremultipliedLast));        CGContextSetBlendMode(context.get(), kCGBlendModeCopy);        CGContextClipToRect(context.get(), FloatRect(FloatPoint::zero(), logicalSize()));        FloatSize imageSizeInUserSpace = scaleSizeToUserSpace(logicalSize(), m_data.backingStoreSize, internalSize());        CGContextDrawImage(context.get(), FloatRect(FloatPoint::zero(), imageSizeInUserSpace), image.get());        image = adoptCF(CGBitmapContextCreateImage(context.get()));    }    if (!image)        return nullptr;    return BitmapImage::create(image.get());}

bool GiCanvasIos::drawImage(CGImageRef image, const Box2d& rectM){    CGContextRef context = m_draw->getContext();    bool ret = false;        if (context && image) {        Point2d ptD = rectM.center() * m_draw->xf().modelToDisplay();        Box2d rect = rectM * m_draw->xf().modelToDisplay();                CGAffineTransform af = CGAffineTransformMake(1, 0, 0, -1, 0, m_draw->height());        af = CGAffineTransformTranslate(af, ptD.x - rect.width() * 0.5f,                                         m_draw->height() - (ptD.y + rect.height() * 0.5f));                CGContextConcatCTM(context, af);        CGContextDrawImage(context, CGRectMake(0, 0, rect.width(), rect.height()), image);        CGContextConcatCTM(context, CGAffineTransformInvert(af));        ret = true;    }        return ret;}

CGImageRef CGimageResize(CGImageRef image, CGSize maxSize){    // calcualte size    CGFloat ratio = MAX(CGImageGetWidth(image)/maxSize.width,CGImageGetHeight(image)/maxSize.height);    size_t width = CGImageGetWidth(image)/ratio;    size_t height = CGImageGetHeight(image)/ratio;    // resize    CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();    CGContextRef context = CGBitmapContextCreate(NULL, width, height,                                                 8, width*4, colorspace, kCGImageAlphaPremultipliedLast);    CGColorSpaceRelease(colorspace);        if(context == NULL) return nil;        // draw image to context (resizing it)    CGContextDrawImage(context, CGRectMake(0, 0, width, height), image);    // extract resulting image from context    CGImageRef imgRef = CGBitmapContextCreateImage(context);    CGContextRelease(context);        return imgRef;}

cv::Mat &osx_cv::toMat(        const CGImageRef &image,        cv::Mat &out,        osx::disp::RGBType destType        ) {    cv::Mat temp;    size_t w = CGImageGetWidth(image), h = CGImageGetHeight(image);    if (CGImageGetBitsPerPixel(image) != 32) {        throw invalid_argument("`image` must be 32 bits per pixel");    }    temp.create(int(h), int(w), CV_8UC4);    CGColorSpaceRef colorSpace = CGImageGetColorSpace(image);    CGContextRef context = CGBitmapContextCreate(            temp.data,            w,            h,            CGImageGetBitsPerComponent(image),            CGImageGetBytesPerRow(image),            colorSpace,            CGImageGetAlphaInfo(image)    );    CGContextDrawImage(            context,            CGRectMake(0, 0, (CGFloat)w, (CGFloat)h),            image            );    _cvtRGBColor(temp, out, CGImageGetAlphaInfo(image), destType);    CGContextRelease(context);    return out;}

void DrawSubCGImage (CGContextRef ctx, CGImageRef image, CGRect src, CGRect dst){    float	w = (float) CGImageGetWidth(image);    float	h = (float) CGImageGetHeight(image);	CGRect	drawRect = CGRectMake(0.0f, 0.0f, w, h);	if (!CGRectEqualToRect(src, dst))	{		float	sx = CGRectGetWidth(dst)  / CGRectGetWidth(src);		float	sy = CGRectGetHeight(dst) / CGRectGetHeight(src);		float	dx = CGRectGetMinX(dst) - (CGRectGetMinX(src) * sx);		float	dy = CGRectGetMinY(dst) - (CGRectGetMinY(src) * sy);		drawRect = CGRectMake(dx, dy, w * sx, h * sy);	}	CGContextSaveGState(ctx);	CGContextClipToRect(ctx, dst);	CGContextDrawImage(ctx, drawRect, image);	CGContextRestoreGState(ctx);}

bool nglImageCGCodec::Feed(nglIStream* pIStream){  if (!mpCGImage)  {    mpCGImage = ReadInfo(pIStream); ///< shall allocate the buffer  }  if (!mpCGImage)    return false;  mpIStream = pIStream;// Use the generic RGB color space.  CGColorSpaceRef pCGColors = CGColorSpaceCreateDeviceRGB();  if (pCGColors == NULL)  {    NGL_OUT(_T("nglImageCGCodec::Feed Error allocating color space/n"));    return false;  }  nglImageInfo info;  mpImage->GetInfo(info);  NGL_ASSERT(info.mpBuffer);// Create the bitmap context. // The image will be converted to the format specified here by CGBitmapContextCreate.  CGContextRef pCGContext =    CGBitmapContextCreate(info.mpBuffer, info.mWidth, info.mHeight,                          info.mBitDepth/4, info.mBytesPerLine,                          pCGColors, kCGImageAlphaPremultipliedLast);//kCGImageAlphaPremultipliedFirst);  CGColorSpaceRelease(pCGColors);  CGRect rect = { {0,0}, {info.mWidth, info.mHeight} };  CGContextClearRect(pCGContext, rect);  CGContextDrawImage(pCGContext, rect, mpCGImage);  CGContextRelease(pCGContext);  SendData(1.0f);  return (pIStream->GetState()==eStreamWait) || (pIStream->GetState()==eStreamReady);;}

bool SkImageDecoder_CG::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) {    CGImageSourceRef imageSrc = SkStreamToCGImageSource(stream);    if (NULL == imageSrc) {        return false;    }    SkAutoTCallVProc<const void, CFRelease> arsrc(imageSrc);        CGImageRef image = CGImageSourceCreateImageAtIndex(imageSrc, 0, NULL);    if (NULL == image) {        return false;    }    SkAutoTCallVProc<CGImage, CGImageRelease> arimage(image);        const int width = CGImageGetWidth(image);    const int height = CGImageGetHeight(image);    bm->setConfig(SkBitmap::kARGB_8888_Config, width, height);    if (SkImageDecoder::kDecodeBounds_Mode == mode) {        return true;    }        if (!this->allocPixelRef(bm, NULL)) {        return false;    }        bm->lockPixels();    bm->eraseColor(0);    // use the same colorspace, so we don't change the pixels at all    CGColorSpaceRef cs = CGImageGetColorSpace(image);    CGContextRef cg = CGBitmapContextCreate(bm->getPixels(), width, height,                                            8, bm->rowBytes(), cs, BITMAP_INFO);    CGContextDrawImage(cg, CGRectMake(0, 0, width, height), image);    CGContextRelease(cg);    bm->unlockPixels();    return true;}

DragImageRef createDragImageFromImage(Image* img){    HBITMAP hbmp = 0;    HDC dc = GetDC(0);    HDC workingDC = CreateCompatibleDC(dc);    CGContextRef drawContext = 0;    if (!workingDC)        goto exit;    hbmp = allocImage(workingDC, img->size(), &drawContext);    if (!hbmp)        goto exit;    if (!drawContext) {        ::DeleteObject(hbmp);        hbmp = 0;    }    CGImageRef srcImage = img->getCGImageRef();    CGRect rect;    rect.size = img->size();    rect.origin.x = 0;    rect.origin.y = -rect.size.height;    static const CGFloat white [] = {1.0, 1.0, 1.0, 1.0};    CGContextScaleCTM(drawContext, 1, -1);    CGContextSetFillColor(drawContext, white);    CGContextFillRect(drawContext, rect);    CGContextSetBlendMode(drawContext, kCGBlendModeNormal);    CGContextDrawImage(drawContext, rect, srcImage);    CGContextRelease(drawContext);exit:    if (workingDC)        DeleteDC(workingDC);    ReleaseDC(0, dc);    return hbmp;}

cv::Mat CGImageToMat(CGImageRef image) {  CGColorSpaceRef colorSpace = CGImageGetColorSpace(image);  CGFloat cols = CGImageGetWidth(image);  CGFloat rows = CGImageGetHeight(image);  cv::Mat cvMat(rows, cols, CV_8UC4); // 8 bits per component, 4 channels (color channels + alpha)  CGContextRef contextRef = CGBitmapContextCreate(cvMat.data,                 // Pointer to  data						  cols,                       // Width of bitmap						  rows,                       // Height of bitmap						  8,                          // Bits per component						  cvMat.step[0],              // Bytes per row						  colorSpace,                 // Colorspace						  kCGImageAlphaNoneSkipLast |						  kCGBitmapByteOrderDefault); // Bitmap info flags  CGContextDrawImage(contextRef, CGRectMake(0, 0, cols, rows), image);  CGContextRelease(contextRef);  return cvMat;}

wxBitmap wxWindowDCImpl::DoGetAsBitmap(const wxRect *subrect) const{    // wxScreenDC is derived from wxWindowDC, so a screen dc will    // call this method when a Blit is performed with it as a source.    if (!m_window)        return wxNullBitmap;    ControlRef handle = (ControlRef) m_window->GetHandle();    if ( !handle )        return wxNullBitmap;    HIRect rect;    CGImageRef image;    CGContextRef context;    HIViewCreateOffscreenImage( handle, 0, &rect, &image);    int width = subrect != NULL ? subrect->width : (int)rect.size.width;    int height = subrect !=  NULL ? subrect->height : (int)rect.size.height ;    wxBitmap bmp = wxBitmap(width, height, 32);    context = (CGContextRef)bmp.GetHBITMAP();    CGContextSaveGState(context);    CGContextTranslateCTM( context, 0,  height );    CGContextScaleCTM( context, 1, -1 );    if ( subrect )        rect = CGRectOffset( rect, -subrect->x, -subrect->y ) ;    CGContextDrawImage( context, rect, image );    CGContextRestoreGState(context);    return bmp;}

CGImageRef CGImageMaskCreateWithImageRef(CGImageRef imageRef) {  size_t maskWidth = CGImageGetWidth(imageRef);  size_t maskHeight = CGImageGetHeight(imageRef);  size_t bytesPerRow = maskWidth;  size_t bufferSize = maskWidth * maskHeight;  CFMutableDataRef dataBuffer = CFDataCreateMutable(kCFAllocatorDefault, 0);  CFDataSetLength(dataBuffer, bufferSize);  CGColorSpaceRef greyColorSpaceRef = CGColorSpaceCreateDeviceGray();  CGContextRef ctx = CGBitmapContextCreate(CFDataGetMutableBytePtr(dataBuffer),                                           maskWidth,                                           maskHeight,                                           8,                                           bytesPerRow,                                           greyColorSpaceRef,                                           kCGImageAlphaNone);  CGContextDrawImage(ctx, CGRectMake(0, 0, maskWidth, maskHeight), imageRef);  CGContextRelease(ctx);  CGDataProviderRef dataProvider = CGDataProviderCreateWithCFData(dataBuffer);  CGImageRef maskImageRef = CGImageMaskCreate(maskWidth,                                              maskHeight,                                              8,                                              8,                                              bytesPerRow,                                              dataProvider,                                              NULL,                                              FALSE);  CGDataProviderRelease(dataProvider);  CGColorSpaceRelease(greyColorSpaceRef);  CFRelease(dataBuffer);  return maskImageRef;}

Screenshot* ScreenShooter::take_screenshot(const CFStringRef format, float compression) {  CGImageRef* images = new CGImageRef[_dsp_count];     /* Grab the images */  for (unsigned int i = 0; i < _dsp_count; i++) {     images[i] = CGDisplayCreateImage(_displays[i]);  }  /* Calculate size of image to produce */  CGSize finalSize = CGSizeMake(_top_right.x - _bottom_left.x, _bottom_left.y - _top_right.y);  /* Round out the bitmap size information */  size_t bytesPerRow = finalSize.width * CGImageGetBitsPerPixel(images[0]) / 8;  /* Create context around bitmap */  CGContextRef context = CGBitmapContextCreate(    NULL, finalSize.width, finalSize.height,    CGImageGetBitsPerComponent(images[0]), bytesPerRow,    CGImageGetColorSpace(images[0]), CGImageGetBitmapInfo(images[0])  );  /* Draw images into the bitmap */  for (unsigned int i = 0; i < _dsp_count; i++)  {      /* Adjust the positions to account for coordinate system shifts         (displays origin is at top left; image origin is at bottom left) */      CGRect adjustedPoint = CGRectMake(_display_bounds[i].origin.x - _bottom_left.x,                                        _bottom_left.y - _display_bounds[i].size.height - _display_bounds[i].origin.y,                                        _display_bounds[i].size.width,                                        _display_bounds[i].size.height);      CGContextDrawImage(context, adjustedPoint, images[i]);  }    delete [] images;  return new Screenshot(context, format, compression);}

GLuint load_texure(const char *filename) {	GLuint texid;	// ImageIO loader	CFStringRef path = CFStringCreateWithCString(NULL, filename, kCFStringEncodingUTF8);	CFURLRef url = CFURLCreateWithFileSystemPath(NULL, path, kCFURLPOSIXPathStyle, 0);	CGImageSourceRef imagesource = CGImageSourceCreateWithURL(url, NULL);	CGImageRef image = CGImageSourceCreateImageAtIndex (imagesource, 0, NULL);	size_t width = CGImageGetWidth(image);	size_t height = CGImageGetHeight(image);	CGRect rect = {{0, 0}, {width, height}};	void * data = malloc(width * height * 4);	CGColorSpaceRef space = CGColorSpaceCreateDeviceRGB();	CGContextRef myBitmapContext = CGBitmapContextCreate (data, 							width, height, 8,							width*4, space, 							kCGImageAlphaPremultipliedFirst);	CGContextDrawImage(myBitmapContext, rect, image);	CGContextRelease(myBitmapContext);	CGColorSpaceRelease(space);	CGImageRelease(image);	CFRelease(imagesource);	CFRelease(url);	CFRelease(path);		glGenTextures(1, &texid);	glBindTexture(GL_TEXTURE_2D, texid);	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_BGRA_EXT, GL_UNSIGNED_INT_8_8_8_8_REV, data);	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);	free(data);	return texid;}

bool GiCanvasIos::drawCachedBitmap(float x, float y, bool secondBmp){    int index = secondBmp ? 1 : 0;    CGImageRef image = m_draw->_cacheserr[index] ? NULL : m_draw->_caches[index];    CGContextRef context = m_draw->getContext();    bool ret = false;        if (context && image) {        CGRect rect = CGRectMake(x, y, m_draw->width(), m_draw->height());        CGAffineTransform af = CGAffineTransformMake(1, 0, 0, -1, 0, m_draw->height());                CGContextConcatCTM(context, af);    // 图像是朝上的，上下文坐标系朝下，上下颠倒显示                CGInterpolationQuality oldQuality = CGContextGetInterpolationQuality(context);        CGContextSetInterpolationQuality(context, kCGInterpolationNone);        CGContextDrawImage(context, rect, image);        CGContextSetInterpolationQuality(context, oldQuality);                CGContextConcatCTM(context, CGAffineTransformInvert(af));   // 恢复成坐标系朝下        ret = true;    }        return ret;}

void CAUGuiGraphic::draw( CGContextRef context, UInt32 portHeight, eRect* r, float value ){	// if Image has frames, the frame will be drawn	// otherwise, the plain image will get out		CGRect bounds;        CGContextSaveGState(context);		if ( Frames > 1 )	{     		r->to( &bounds, portHeight );		        CGContextClipToRect(context, bounds);        		SInt32 offset = (SInt32)((float)(Frames-1) * value) * r->h + r->h;				SInt32 height = Frames * r->h;				bounds.size.height = height;				bounds.origin.y += offset-height;		}	else	{		r->to( &bounds, portHeight );	}	if ( Image != NULL )			CGContextDrawImage( context, bounds, Image );    CGContextRestoreGState(context);    }

static CGContextRef createCGContextFromImage(WKImageRef wkImage, FlipGraphicsContextOrNot flip = DontFlipGraphicsContext){    RetainPtr<CGImageRef> image = adoptCF(WKImageCreateCGImage(wkImage));    size_t pixelsWide = CGImageGetWidth(image.get());    size_t pixelsHigh = CGImageGetHeight(image.get());    size_t rowBytes = (4 * pixelsWide + 63) & ~63;    // Creating this bitmap in the device color space should prevent any color conversion when the image of the web view is drawn into it.    RetainPtr<CGColorSpaceRef> colorSpace = adoptCF(CGColorSpaceCreateDeviceRGB());    CGContextRef context = CGBitmapContextCreate(0, pixelsWide, pixelsHigh, 8, rowBytes, colorSpace.get(), kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host);        if (flip == FlipGraphicsContext) {        CGContextSaveGState(context);        CGContextScaleCTM(context, 1, -1);        CGContextTranslateCTM(context, 0, -static_cast<CGFloat>(pixelsHigh));    }        CGContextDrawImage(context, CGRectMake(0, 0, pixelsWide, pixelsHigh), image.get());    if (flip == FlipGraphicsContext)        CGContextRestoreGState(context);    return context;}

    bool GCPVideoRenderer::OnWindowRefresh(FB::RefreshEvent* pEvt)    {        FB::CoreGraphicsDraw* pCgDrawEvt(static_cast<FB::CoreGraphicsDraw*>(pEvt));        CGContextRef pContext = pCgDrawEvt->context;        boost::mutex::scoped_lock winLock(m_winMutex);        const int stride = m_width*4;            const int frameBufferSize = m_height*stride;        static SInt32 osMajorVersion = 0;        static SInt32 osMinorVersion = 0;        static CGInterpolationQuality interpolationMode = kCGInterpolationNone;                if(0 == osMajorVersion || 0 == osMinorVersion)        {            if(noErr != Gestalt(gestaltSystemVersionMajor, &osMajorVersion))            {                osMajorVersion = 10;            }            if(noErr != Gestalt(gestaltSystemVersionMinor, &osMinorVersion))            {                osMinorVersion = 6;            }            if(10 <= osMajorVersion && 7 <= osMinorVersion)            {                interpolationMode = kCGInterpolationDefault;            }        }                if(NULL == pContext || NULL == m_pFrameBuffer.get())        {            return false;        }                int winWidth = pCgDrawEvt->bounds.right - pCgDrawEvt->bounds.left;        int winHeight = pCgDrawEvt->bounds.bottom - pCgDrawEvt->bounds.top;                if(winWidth<=1 || winHeight<=1)            return false;                CGContextSaveGState(pContext);                CGContextSetShouldAntialias(pContext, true);        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();        CGImageRef cgImage = CGImageCreate(m_width, m_height, 8, 32, stride, colorSpace,                                            kCGImageAlphaNoneSkipLast,                                           CGDataProviderCreateWithData(NULL,                                                                        m_pFrameBuffer.get(),                                                                        frameBufferSize,                                                                        NULL),                                           NULL, false, kCGRenderingIntentDefault);        if(NULL == cgImage)        {            CGColorSpaceRelease(colorSpace);            CGContextRestoreGState(pContext);            return false;        }                CGContextSetInterpolationQuality(pContext, interpolationMode);        CGContextTranslateCTM(pContext, 0, winHeight);        CGContextScaleCTM(pContext, 1, -1);        CGContextDrawImage(pContext, CGRectMake(0, 0, winWidth, winHeight), cgImage);                CGImageRelease(cgImage);        CGColorSpaceRelease(colorSpace);        CGContextRestoreGState(pContext);                return true;    }

void x_async_refresh(CGContextRef myContext,CGRect myBoundingBox){	#ifdef ENABLEQD	CEmulatorMac* pEmu = (CEmulatorMac*)CEmulator::theEmulator;	if (!pEmu) return ;#endif    #ifndef DRIVER_IOS	x_vbl_count++;#endif		addFrameRate(0);	CHANGE_BORDER(1,0xFF);		// OG	if (macUsingCoreGraphics)	{		if(r_sim65816.is_emulator_offscreen_available() && g_kimage_offscreen.dev_handle)		{	            /*			void addConsoleWindow(Kimage* _dst);			addConsoleWindow(&g_kimage_offscreen);	*/            			CGContextSaveGState(myContext);			#ifndef DRIVER_IOS		//	CGContextTranslateCTM(myContext,0.0, X_A2_WINDOW_HEIGHT);        	CGContextTranslateCTM(myContext,0.0, myBoundingBox.size.height);    			CGContextScaleCTM(myContext,1.0,-1.0);#endif									CGImageRef myImage = CGBitmapContextCreateImage((CGContextRef)g_kimage_offscreen.dev_handle);                                    			CGContextDrawImage(myContext, myBoundingBox, myImage);// 6	#ifndef VIDEO_SINGLEVLINE			if (r_sim65816.get_video_fx() == VIDEOFX_CRT)			{                				CGContextSetRGBFillColor(myContext,0,0,0,0.5);				for(int h=0;h<g_kimage_offscreen.height;h+=2)				{					CGRect r = CGRectMake(0,h,g_kimage_offscreen.width_act,1);					CGContextFillRect(myContext,r);				}                			}                       #endif            			CGImageRelease(myImage);					CGContextRestoreGState(myContext);#ifndef DRIVER_IOS			if (!messageLine.IsEmpty())			{				CGContextSaveGState(myContext);				CGContextSetTextMatrix(myContext,CGAffineTransformIdentity);				CGContextTranslateCTM(myContext,0.0, X_A2_WINDOW_HEIGHT);				CGContextScaleCTM(myContext,1.0,-1.0);				CGContextSelectFont(myContext, "Courier", 14.0, kCGEncodingMacRoman);				CGContextSetTextDrawingMode(myContext, kCGTextFill);				CGContextSetRGBFillColor (myContext, 1,1, 1, 1);				CGContextSetShouldAntialias(myContext, true);#define SHADOW 4.0                                CGFloat           myColorValues[] = {0.5, 0.5, 0.5, 1.0};                                               CGColorSpaceRef  myColorSpace = CGColorSpaceCreateDeviceRGB ();// 9                 CGColorRef  myColor = CGColorCreate (myColorSpace, myColorValues);				CGContextSetShadowWithColor(myContext, CGSizeMake(SHADOW, -SHADOW), 4,                                            myColor                                            //CGColorCreateGenericGray(0.5,1.0)                                                                );				CGContextShowTextAtPoint(myContext, 20.0, X_A2_WINDOW_HEIGHT-20.0, messageLine.c_str(), messageLine.GetLength());							CGContextRestoreGState(myContext);				messageLineVBL--;				if (messageLineVBL<0)					messageLine.Empty();				else 					x_refresh_video();			}#endif					}		else//.........这里部分代码省略.........

static void drawPatternCallback(void* info, CGContextRef context){    CGImageRef image = (CGImageRef)info;    CGContextDrawImage(context, GraphicsContext(context).roundToDevicePixels(FloatRect(0, 0, CGImageGetWidth(image), CGImageGetHeight(image))), image);}

//.........这里部分代码省略.........//            color_space = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);            color_space = CGColorSpaceCreateDeviceRGB();//            bitmap_info = kCGImageAlphaNone;#if __BIG_ENDIAN__            bitmap_info = kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Big; /* XRGB Big Endian */#else            bitmap_info = kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Little; /* XRGB Little Endian */#endif            break;        }        //        // Tatsuhiro Nishioka        // 16 bpp grayscale (8 bit white and 8 bit alpha) causes invalid argument combination        // in CGBitmapContextCreate.        // I guess it is safer to handle 16 bit grayscale image as 32-bit RGBA image.        // It works at least on FlightGear        //        case 16:        case 32:        case 48:        case 64:        {            internal_format = GL_RGBA8;            pixel_format = GL_BGRA_EXT;            data_type = GL_UNSIGNED_INT_8_8_8_8_REV;            bytes_per_row = the_width*4;//            color_space = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);            color_space = CGColorSpaceCreateDeviceRGB();//            bitmap_info = kCGImageAlphaPremultipliedFirst;#if __BIG_ENDIAN__            bitmap_info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Big; /* XRGB Big Endian */#else            bitmap_info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little; /* XRGB Little Endian */#endif            break;        }        default:        {            // OSG_WARN << "Unknown file type in " << fileName.c_str() << " with " << origDepth << std::endl;            return NULL;            break;        }    }        // Sets up a context to be drawn to with image_data as the area to be drawn to    CGContextRef bitmap_context = CGBitmapContextCreate(        image_data,        the_width,        the_height,        bits_per_component,        bytes_per_row,        color_space,        bitmap_info    );        CGContextTranslateCTM(bitmap_context, 0, the_height);    CGContextScaleCTM(bitmap_context, 1.0, -1.0);    // Draws the image into the context's image_data    CGContextDrawImage(bitmap_context, the_rect, image_ref);    CGContextRelease(bitmap_context);        if (!image_data)        return NULL;    // alpha is premultiplied with rgba, undo it        vImage_Buffer vb;    vb.data = image_data;    vb.height = the_height;    vb.width = the_width;    vb.rowBytes = the_width * 4;    vImageUnpremultiplyData_RGBA8888(&vb, &vb, 0);        // changing it to GL_UNSIGNED_BYTE seems working, but I'm not sure if this is a right way.    //    data_type = GL_UNSIGNED_BYTE;    osg::Image* osg_image = new osg::Image;    osg_image->setImage(        the_width,        the_height,        1,        internal_format,        pixel_format,        data_type,        (unsigned char*)image_data,        osg::Image::USE_MALLOC_FREE // Assumption: osg_image takes ownership of image_data and will free    );    return osg_image;}

//.........这里部分代码省略.........      width  = (float)height / (float)aspect;    }    CLog::Log(LOGDEBUG, "Texture manager texture clamp:new texture size: %i x %i", width, height);  }  // use RGBA to skip swizzling  Allocate(width, height, XB_FMT_RGBA8);  m_orientation = rotate;      CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();  // hw convert jmpeg to RGBA  CGContextRef context = CGBitmapContextCreate(m_pixels,    width, height, 8, GetPitch(), colorSpace,    kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);  CGColorSpaceRelease(colorSpace);  // Flip so that it isn't upside-down  //CGContextTranslateCTM(context, 0, height);  //CGContextScaleCTM(context, 1.0f, -1.0f);  #if MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_5    CGContextClearRect(context, CGRectMake(0, 0, width, height));  #else    #if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5    // (just a way of checking whether we're running in 10.5 or later)    if (CGContextDrawLinearGradient == 0)      CGContextClearRect(context, CGRectMake(0, 0, width, height));    else    #endif      CGContextSetBlendMode(context, kCGBlendModeCopy);  #endif  //CGContextSetBlendMode(context, kCGBlendModeCopy);  CGContextDrawImage(context, CGRectMake(0, 0, width, height), image);  CGContextRelease(context);  CGImageRelease(image);  CFRelease(cfdata);  delete [] imageBuff;#else  DllImageLib dll;  if (!dll.Load())    return false;  ImageInfo image;  memset(&image, 0, sizeof(image));  unsigned int width = maxWidth ? std::min(maxWidth, g_Windowing.GetMaxTextureSize()) : g_Windowing.GetMaxTextureSize();  unsigned int height = maxHeight ? std::min(maxHeight, g_Windowing.GetMaxTextureSize()) : g_Windowing.GetMaxTextureSize();  if(!dll.LoadImage(texturePath.c_str(), width, height, &image))  {    CLog::Log(LOGERROR, "Texture manager unable to load file: %s", texturePath.c_str());    return false;  }  m_hasAlpha = NULL != image.alpha;  Allocate(image.width, image.height, XB_FMT_A8R8G8B8);  if (autoRotate && image.exifInfo.Orientation)    m_orientation = image.exifInfo.Orientation - 1;  if (originalWidth)    *originalWidth = image.originalwidth;  if (originalHeight)    *originalHeight = image.originalheight;  unsigned int dstPitch = GetPitch();