CGImageRef YYCGImageCreateAffineTransformCopy()

in iOS/WAStickersThirdParty/YYImageCoder.m [917:979]
54 lines of code
22 McCabe index (conditional complexity)

CGImageRef YYCGImageCreateAffineTransformCopy(CGImageRef imageRef, CGAffineTransform transform, CGSize destSize, CGBitmapInfo destBitmapInfo) {
    if (!imageRef) return NULL;
    size_t srcWidth = CGImageGetWidth(imageRef);
    size_t srcHeight = CGImageGetHeight(imageRef);
    size_t destWidth = round(destSize.width);
    size_t destHeight = round(destSize.height);
    if (srcWidth == 0 || srcHeight == 0 || destWidth == 0 || destHeight == 0) return NULL;
    
    CGDataProviderRef tmpProvider = NULL, destProvider = NULL;
    CGImageRef tmpImage = NULL, destImage = NULL;
    vImage_Buffer src = {0}, tmp = {0}, dest = {0};
    if(!YYCGImageDecodeToBitmapBufferWith32BitFormat(imageRef, &src, kCGImageAlphaFirst | kCGBitmapByteOrderDefault)) return NULL;
    
    size_t destBytesPerRow = YYImageByteAlign(destWidth * 4, 32);
    tmp.data = malloc(destHeight * destBytesPerRow);
    if (!tmp.data) goto fail;
    
    tmp.width = destWidth;
    tmp.height = destHeight;
    tmp.rowBytes = destBytesPerRow;
    vImage_CGAffineTransform vTransform = *((vImage_CGAffineTransform *)&transform);
    uint8_t backColor[4] = {0};
    vImage_Error error = vImageAffineWarpCG_ARGB8888(&src, &tmp, NULL, &vTransform, backColor, kvImageBackgroundColorFill);
    if (error != kvImageNoError) goto fail;
    free(src.data);
    src.data = NULL;
    
    tmpProvider = CGDataProviderCreateWithData(tmp.data, tmp.data, destHeight * destBytesPerRow, YYCGDataProviderReleaseDataCallback);
    if (!tmpProvider) goto fail;
    tmp.data = NULL; // hold by provider
    tmpImage = CGImageCreate(destWidth, destHeight, 8, 32, destBytesPerRow, YYCGColorSpaceGetDeviceRGB(), kCGImageAlphaFirst | kCGBitmapByteOrderDefault, tmpProvider, NULL, false, kCGRenderingIntentDefault);
    if (!tmpImage) goto fail;
    CFRelease(tmpProvider);
    tmpProvider = NULL;
    
    if ((destBitmapInfo & kCGBitmapAlphaInfoMask) == kCGImageAlphaFirst &&
        (destBitmapInfo & kCGBitmapByteOrderMask) != kCGBitmapByteOrder32Little) {
        return tmpImage;
    }
    
    if (!YYCGImageDecodeToBitmapBufferWith32BitFormat(tmpImage, &dest, destBitmapInfo)) goto fail;
    CFRelease(tmpImage);
    tmpImage = NULL;
    
    destProvider = CGDataProviderCreateWithData(dest.data, dest.data, destHeight * destBytesPerRow, YYCGDataProviderReleaseDataCallback);
    if (!destProvider) goto fail;
    dest.data = NULL; // hold by provider
    destImage = CGImageCreate(destWidth, destHeight, 8, 32, destBytesPerRow, YYCGColorSpaceGetDeviceRGB(), destBitmapInfo, destProvider, NULL, false, kCGRenderingIntentDefault);
    if (!destImage) goto fail;
    CFRelease(destProvider);
    destProvider = NULL;
    
    return destImage;
    
fail:
    if (src.data) free(src.data);
    if (tmp.data) free(tmp.data);
    if (dest.data) free(dest.data);
    if (tmpProvider) CFRelease(tmpProvider);
    if (tmpImage) CFRelease(tmpImage);
    if (destProvider) CFRelease(destProvider);
    return NULL;
}