private async Task <(Stream imageStream, string contentType)> GetPngEncodedPreview(
IImageElementValue imageElementValue,
int templateCode,
int width,
int height,
Action <Image <Rgba32> > mutateImage)
{
var cts = new CancellationTokenSource(_requestTimeout);
var rawStream = await GetRawStream(imageElementValue, cts.Token);
EnsureRequestCanBeProcessed(rawStream, cts.Token);
using (var source = Decode(templateCode, rawStream))
{
using (var target = Crop(source, imageElementValue))
{
Resize(target, new Size(width, height));
mutateImage?.Invoke(target);
var pngFormat = ImageFormats.Png;
var targetStream = Encode(target, pngFormat);
return(targetStream, pngFormat.DefaultMimeType);
}
}
}
public async Task <(Stream imageStream, string contentType)> GetPreview(
IImageElementValue imageElementValue,
int templateCode,
int width,
int height)
{
return(await GetPngEncodedPreview(imageElementValue, templateCode, width, height, null));
}
public async Task <(Stream imageStream, string contentType)> GetRoundedPreview(
IImageElementValue imageElementValue,
int templateCode,
int width,
int height)
{
return(await GetPngEncodedPreview(
imageElementValue,
templateCode,
width,
height,
target => ApplyRoundedCorners(target, target.Height * 0.5f)));
}
public static bool TryGetSizeSpecificBitmapImageRawValue(this IImageElementValue imageElementValue, int width, int height, out string rawValue)
{
rawValue = null;
if (imageElementValue is ICompositeBitmapImageElementValue compositeBitmapImageElementValue)
{
var sizeSpecificImage = compositeBitmapImageElementValue.SizeSpecificImages
.SingleOrDefault(x => x.Size.Width == width && x.Size.Height == height);
if (sizeSpecificImage != null)
{
rawValue = sizeSpecificImage.Raw;
return(true);
}
return(false);
}
return(false);
}
public async Task <(Stream imageStream, string contentType)> GetScaledPreview(
IImageElementValue imageElementValue,
int templateCode,
int width,
int height)
{
var cts = new CancellationTokenSource(_requestTimeout);
var rawStream = await GetRawStream(imageElementValue, cts.Token);
await EnsureRequestCanBeProcessed(rawStream, cts.Token);
using (var source = Decode(templateCode, rawStream, out var imageFormat))
{
var anchorPositionMode = EvaluateAnchorPositionMode(imageElementValue);
Resize(source, new Size(width, height), anchorPositionMode);
var targetStream = Encode(source, imageFormat);
return(targetStream, imageFormat.DefaultMimeType);
}
}
private static AnchorPositionMode EvaluateAnchorPositionMode(IImageElementValue imageElementValue)
{
if (!(imageElementValue is IScalableBitmapImageElementValue scalableBitmapImageElementValue))
{
return(AnchorPositionMode.Center);
}
switch (scalableBitmapImageElementValue.Anchor)
{
case Anchor.TopLeft:
return(AnchorPositionMode.TopLeft);
case Anchor.Top:
return(AnchorPositionMode.Top);
case Anchor.TopRight:
return(AnchorPositionMode.TopRight);
case Anchor.Left:
return(AnchorPositionMode.Left);
case Anchor.Middle:
return(AnchorPositionMode.Center);
case Anchor.Right:
return(AnchorPositionMode.Right);
case Anchor.BottomLeft:
return(AnchorPositionMode.BottomLeft);
case Anchor.Bottom:
return(AnchorPositionMode.Bottom);
case Anchor.BottomRight:
return(AnchorPositionMode.BottomRight);
default:
return(AnchorPositionMode.Center);
}
}
private static Image <Rgba32> Crop(Image <Rgba32> image, IImageElementValue elementValue)
{
if (!(elementValue is ICompositeBitmapImageElementValue compositeBitmapImage))
{
return(image);
}
var imageRectangle = image.Bounds();
var cropAreaRectangle = new Rectangle(
compositeBitmapImage.CropArea.Left,
compositeBitmapImage.CropArea.Top,
compositeBitmapImage.CropArea.Width,
compositeBitmapImage.CropArea.Height);
if (!imageRectangle.IntersectsWith(cropAreaRectangle))
{
return(image);
}
if (imageRectangle.Contains(cropAreaRectangle))
{
image.Mutate(ctx => ctx.Crop(cropAreaRectangle));
return(image);
}
Rgba32 backgroundColor;
var leftTopPixel = image[imageRectangle.Left, imageRectangle.Top];
var rightTopPixel = image[imageRectangle.Right - 1, imageRectangle.Top];
var rightBottomPixel = image[imageRectangle.Right - 1, imageRectangle.Bottom - 1];
var leftBottomPixel = image[imageRectangle.Left, imageRectangle.Bottom - 1];
if (ArePixelColorsClose(leftTopPixel, rightBottomPixel) &&
ArePixelColorsClose(rightTopPixel, rightBottomPixel) &&
ArePixelColorsClose(rightBottomPixel, leftBottomPixel) &&
ArePixelColorsClose(leftBottomPixel, leftTopPixel))
{
backgroundColor = leftTopPixel;
}
else
{
var redTop = GetMeanColorValue(image.Width, (intervalCount, index) => GetImagePixelColorOnTop(image, intervalCount, index).R);
var greenTop = GetMeanColorValue(image.Width, (intervalCount, index) => GetImagePixelColorOnTop(image, intervalCount, index).G);
var blueTop = GetMeanColorValue(image.Width, (intervalCount, index) => GetImagePixelColorOnTop(image, intervalCount, index).B);
var redBottom = GetMeanColorValue(image.Width, (intervalCount, index) => GetImagePixelColorOnBottom(image, intervalCount, index).R);
var greenBottom = GetMeanColorValue(image.Width, (intervalCount, index) => GetImagePixelColorOnBottom(image, intervalCount, index).G);
var blueBottom = GetMeanColorValue(image.Width, (intervalCount, index) => GetImagePixelColorOnBottom(image, intervalCount, index).B);
var redLeft = GetMeanColorValue(image.Height, (intervalCount, index) => GetImagePixelColorOnLeft(image, intervalCount, index).R);
var greenLeft = GetMeanColorValue(image.Height, (intervalCount, index) => GetImagePixelColorOnLeft(image, intervalCount, index).G);
var blueLeft = GetMeanColorValue(image.Height, (intervalCount, index) => GetImagePixelColorOnLeft(image, intervalCount, index).B);
var redRight = GetMeanColorValue(image.Height, (intervalCount, index) => GetImagePixelColorOnRight(image, intervalCount, index).R);
var greenRight = GetMeanColorValue(image.Height, (intervalCount, index) => GetImagePixelColorOnRight(image, intervalCount, index).G);
var blueRight = GetMeanColorValue(image.Height, (intervalCount, index) => GetImagePixelColorOnRight(image, intervalCount, index).B);
backgroundColor = new Rgba32(
(byte)((redTop + redBottom + redLeft + redRight) / 4),
(byte)((greenTop + greenBottom + greenLeft + greenRight) / 4),
(byte)((blueTop + blueBottom + blueLeft + blueRight) / 4));
}
var unionRectangle = Rectangle.Union(imageRectangle, cropAreaRectangle);
cropAreaRectangle.Offset(-unionRectangle.X, -unionRectangle.Y);
var extentImage = new Image <Rgba32>(unionRectangle.Width, unionRectangle.Height);
extentImage.Mutate(x => x.BackgroundColor(backgroundColor)
.DrawImage(image, image.Size(), new Point(-unionRectangle.X, -unionRectangle.Y), GraphicsOptions.Default)
.Crop(cropAreaRectangle));
return(extentImage);
}
