public static IImageProcessingContext ApplyWatermark(this IImageProcessingContext processingContext, WatermarkConfiguration config)
{
if (config is null)
{
return(processingContext);
}
else if (!string.IsNullOrEmpty(config.SourceFile))
{
return(processingContext.ApplyWatermark(config.SourceFile, config.Opacity));
}
var settings = WatermarkSettings.FromConfig(config);
var size = processingContext.GetCurrentSize();
// Create a new image for the watermark layer.
using var watermark = new Image <Rgba32>(size.Width, size.Height);
var xOffeset = 0;
var yOffeset = 0;
watermark.Mutate(ctx =>
{
// Draw the watermark.
ctx.DrawWatermark(settings);
var angle = 0.0f;
if ((settings.Position == WatermarkPosition.BottomLeft) || (settings.Position == WatermarkPosition.TopRight))
{
angle = 45.0f;
// Calculate the x/y offsets for later when we draw the watermark on top of the source image.
xOffeset = -(int)((Math.Sin(angle) * (size.Width / 2)) / 2);
yOffeset = -(int)((Math.Sin(angle) * (size.Height / 2)) / 2);
}
else if ((settings.Position == WatermarkPosition.BottomRight) || (settings.Position == WatermarkPosition.TopLeft))
{
angle = -45.0f;
// Calculate the x/y offsets for later when we draw the watermark on top of the source image.
xOffeset = (int)((Math.Sin(angle) * (size.Width / 2)) / 2);
yOffeset = (int)((Math.Sin(angle) * (size.Height / 2)) / 2);
}
if (angle != 0)
{
ctx.Rotate(angle);
}
});
// Draw the watermark layer on top of the source image.
processingContext.DrawImage(watermark, new Point(xOffeset, yOffeset), 1);
return(processingContext);
}