private SKData GetImageData(string imagePath, ResizeParams resizeParams, DateTime lastWriteTimeUtc)
{
// check cache and return if cached
long cacheKey;
unchecked
{
cacheKey = imagePath.GetHashCode() + lastWriteTimeUtc.ToBinary() + resizeParams.ToString().GetHashCode();
}
SKData imageData;
byte[] imageBytes;
bool isCached = _memoryCache.TryGetValue <byte[]>(cacheKey, out imageBytes);
if (isCached)
{
_logger.LogInformation("Serving from cache");
return(SKData.CreateCopy(imageBytes));
}
SKEncodedOrigin origin; // this represents the EXIF orientation
var bitmap = LoadBitmap(File.OpenRead(imagePath), out origin); // always load as 32bit (to overcome issues with indexed color)
if (resizeParams.w == 0)
{
resizeParams.w = bitmap.Width;
}
if (resizeParams.h == 0)
{
resizeParams.h = bitmap.Height;
}
// if autorotate = true, and origin isn't correct for the rotation, rotate it
if (resizeParams.autorotate && origin != SKEncodedOrigin.TopLeft)
{
bitmap = RotateAndFlip.RotateAndFlipImage(bitmap, origin);
}
// if either w or h is 0, set it based on ratio of original image
if (resizeParams.h == 0)
{
resizeParams.h = (int)Math.Round(bitmap.Height * (float)resizeParams.w / bitmap.Width);
}
else if (resizeParams.w == 0)
{
resizeParams.w = (int)Math.Round(bitmap.Width * (float)resizeParams.h / bitmap.Height);
}
// if we need to crop, crop the original before resizing
if (resizeParams.mode == "crop")
{
bitmap = Crop.CropImage(bitmap, resizeParams);
}
// store padded height and width
var paddedHeight = resizeParams.h;
var paddedWidth = resizeParams.w;
// if we need to pad, or max, set the height or width according to ratio
if (resizeParams.mode == "pad" || resizeParams.mode == "max")
{
var bitmapRatio = (float)bitmap.Width / bitmap.Height;
var resizeRatio = (float)resizeParams.w / resizeParams.h;
if (bitmapRatio > resizeRatio) // original is more "landscape"
{
resizeParams.h = (int)Math.Round(bitmap.Height * ((float)resizeParams.w / bitmap.Width));
}
else
{
resizeParams.w = (int)Math.Round(bitmap.Width * ((float)resizeParams.h / bitmap.Height));
}
}
// resize
var resizedImageInfo = new SKImageInfo(resizeParams.w, resizeParams.h, SKImageInfo.PlatformColorType, bitmap.AlphaType);
var resizedBitmap = bitmap.Resize(resizedImageInfo, SKFilterQuality.High);
// optionally pad
if (resizeParams.mode == "pad")
{
resizedBitmap = Padding.PaddingImage(resizedBitmap, paddedWidth, paddedHeight, resizeParams.format != "png");
}
// watermarkText
if (resizeParams.wmtext != 0)
{
if (watermarkText != null)
{
resizedBitmap = Watermark.WatermarkText(resizedBitmap, resizeParams, watermarkText);
}
}
// watermarkImage
if (resizeParams.wmimage != 0)
{
if (watermarkImage != null)
{
resizedBitmap = Watermark.WatermarkImage(resizedBitmap, resizeParams, watermarkImage);
}
}
// encode
var resizedImage = SKImage.FromBitmap(resizedBitmap);
var encodeFormat = resizeParams.format == "png" ? SKEncodedImageFormat.Png : SKEncodedImageFormat.Jpeg;
imageData = resizedImage.Encode(encodeFormat, resizeParams.quality);
// cache the result
_memoryCache.Set <byte[]>(cacheKey, imageData.ToArray());
// cleanup
resizedImage.Dispose();
bitmap.Dispose();
resizedBitmap.Dispose();
return(imageData);
}
