CFDataRef YYCGImageCreateEncodedWebPData()

in iOS/WAStickersThirdParty/YYImageCoder.m [1237:1301]
57 lines of code
23 McCabe index (conditional complexity)

CFDataRef YYCGImageCreateEncodedWebPData(CGImageRef imageRef, BOOL lossless, CGFloat quality, int compressLevel, YYImagePreset preset) {
    if (!imageRef) return nil;
    size_t width = CGImageGetWidth(imageRef);
    size_t height = CGImageGetHeight(imageRef);
    if (width == 0 || width > WEBP_MAX_DIMENSION) return nil;
    if (height == 0 || height > WEBP_MAX_DIMENSION) return nil;
    
    vImage_Buffer buffer = {0};
    if(!YYCGImageDecodeToBitmapBufferWith32BitFormat(imageRef, &buffer, kCGImageAlphaLast | kCGBitmapByteOrderDefault)) return nil;
    
    WebPConfig config = {0};
    WebPPicture picture = {0};
    WebPMemoryWriter writer = {0};
    CFDataRef webpData = NULL;
    BOOL pictureNeedFree = NO;
    
    quality = quality < 0 ? 0 : quality > 1 ? 1 : quality;
    preset = preset > YYImagePresetText ? YYImagePresetDefault : preset;
    compressLevel = compressLevel < 0 ? 0 : compressLevel > 6 ? 6 : compressLevel;
    if (!WebPConfigPreset(&config, (WebPPreset)preset, quality)) goto fail;
    
    config.quality = round(quality * 100.0);
    config.lossless = lossless;
    config.method = compressLevel;
    switch ((WebPPreset)preset) {
        case WEBP_PRESET_DEFAULT: {
            config.image_hint = WEBP_HINT_DEFAULT;
        } break;
        case WEBP_PRESET_PICTURE: {
            config.image_hint = WEBP_HINT_PICTURE;
        } break;
        case WEBP_PRESET_PHOTO: {
            config.image_hint = WEBP_HINT_PHOTO;
        } break;
        case WEBP_PRESET_DRAWING:
        case WEBP_PRESET_ICON:
        case WEBP_PRESET_TEXT: {
            config.image_hint = WEBP_HINT_GRAPH;
        } break;
    }
    if (!WebPValidateConfig(&config)) goto fail;
    
    if (!WebPPictureInit(&picture)) goto fail;
    pictureNeedFree = YES;
    picture.width = (int)buffer.width;
    picture.height = (int)buffer.height;
    picture.use_argb = lossless;
    if(!WebPPictureImportRGBA(&picture, buffer.data, (int)buffer.rowBytes)) goto fail;
    
    WebPMemoryWriterInit(&writer);
    picture.writer = WebPMemoryWrite;
    picture.custom_ptr = &writer;
    if(!WebPEncode(&config, &picture)) goto fail;
    
    webpData = CFDataCreate(CFAllocatorGetDefault(), writer.mem, writer.size);
    free(writer.mem);
    WebPPictureFree(&picture);
    free(buffer.data);
    return webpData;
    
fail:
    if (buffer.data) free(buffer.data);
    if (pictureNeedFree) WebPPictureFree(&picture);
    return nil;
}