public ReprojectRowOperation(
Registration registration,
Image <Rgba32> target,
int xOffset,
int yOffset,
RenderOptions options)
{
_registration = registration;
_target = target;
_xOffset = xOffset;
_yOffset = yOffset;
_options = options;
Guard.Against.Null(registration.Image, nameof(registration.Image));
Guard.Against.Null(options.ImageOffset, nameof(options.ImageOffset));
_sourceBuffer = ImageBuffer.ToBuffer(registration.Image);
_imageOffset = options.ImageOffset;
// Normalise longitude range so it doesn't wrap around the map
_longitudeRange = registration.LongitudeRange.UnwrapLongitude();
_latitudeRange = registration.Definition.LatitudeRange;
// Calculate end longitude for blend
var overlap = BlendRatio * (_longitudeRange.End - _longitudeRange.Start);
_blendEndLongitude = _longitudeRange.End + overlap;
}
/// <summary>
/// Crop to a specified latitude range.
/// </summary>
private void Crop(Image <Rgba32> underlay, Range latitudeRange)
{
var yPixelRange = latitudeRange.ToPixelRangeY(underlay.Height);
// Crop underlay to target height
_logger.LogInformation("Cropping underlay to {min} - {max} px height", yPixelRange.Start, yPixelRange.End);
underlay.Mutate(c => c.Crop(new Rectangle(0, yPixelRange.Start, underlay.Width, yPixelRange.Range)));
}
/// <summary>
/// Offsets an equirectangular underlay to start at a specified longitude.
/// </summary>
private void Offset(Image <Rgba32> underlay, Range longitudeRange)
{
var xPixelRange = longitudeRange.ToPixelRangeX(underlay.Width);
var offset = -xPixelRange.Start;
_logger.LogInformation("Offsetting underlay by {pixels} px", offset);
underlay.HorizontalOffset(offset);
}
