@ -3,10 +3,9 @@
// Licensed under the Apache License, Version 2.0.
// </copyright>
using System.Numerics ;
namespace ImageProcessorCore.Samplers
{
using System.Numerics ;
using System.Threading.Tasks ;
/// <summary>
@ -15,12 +14,20 @@ namespace ImageProcessorCore.Samplers
public class Rotate : ImageSampler
{
/// <summary>
/// The angle of rotation.
/// The image used for storing the first pass pixels.
/// </summary>
private Image firstPass ;
/// <summary>
/// The angle of rotation in degrees.
/// </summary>
private float angle ;
/// <inheritdoc/>
public override int Parallelism { get ; set ; } = 1 ;
/// <summary>
/// Gets or sets the angle of rotation.
/// Gets or sets the angle of rotation in degrees .
/// </summary>
public float Angle
{
@ -50,47 +57,84 @@ namespace ImageProcessorCore.Samplers
/// </summary>
public Point Center { get ; set ; }
/// <summary>
/// Gets or sets a value indicating whether to expand the canvas to fit the rotated image.
/// </summary>
public bool Expand { get ; set ; }
/// <inheritdoc/>
protected override void Apply ( ImageBase target , ImageBase source , Rectangle targetRectangle , Rectangle sourceRectangle , int startY , int endY )
protected override void On Apply( ImageBase source , ImageBase target , Rectangle targetRectangle , Rectangle sourceRectangle )
{
int targetY = targetRectangle . Y ;
int targetBottom = targetRectangle . Bottom ;
int startX = targetRectangle . X ;
int endX = targetRectangle . Right ;
float negativeAngle = - this . angle ;
Point centre = this . Center = = Point . Empty ? Rectangle . Center ( sourceRectangle ) : this . Center ;
// If we are expanding we need to pad the bounds of the source rectangle.
// We can use the resizer in nearest neighbor mode to do this fairly quickly.
if ( this . Expand )
{
// First find out how the target rectangle should be.
Rectangle rectangle = ImageMaths . GetBoundingRotatedRectangle ( source . Width , source . Height , - this . angle ) ;
ResizeOptions options = new ResizeOptions
{
Size = new Size ( rectangle . Width , rectangle . Height ) ,
Mode = ResizeMode . BoxPad ,
Sampler = new NearestNeighborResampler ( )
} ;
// Scaling factors
float widthFactor = source . Width / ( float ) target . Width ;
float heightFactor = source . Height / ( float ) target . Height ;
// Get the padded bounds and resize the image.
Rectangle bounds = ResizeHelper . CalculateTargetLocationAndBounds ( source , options ) ;
this . firstPass = new Image ( rectangle . Width , rectangle . Height ) ;
target . SetPixels ( rectangle . Width , rectangle . Height , new float [ rectangle . Width * rectangle . Height * 4 ] ) ;
new Resize ( new NearestNeighborResampler ( ) ) . Apply ( this . firstPass , source , rectangle . Width , rectangle . Height , bounds , sourceRectangle ) ;
}
else
{
// Just clone the pixels across.
this . firstPass = new Image ( source . Width , source . Height ) ;
this . firstPass . ClonePixels ( source . Width , source . Height , source . Pixels ) ;
}
}
Matrix3x2 rotation = Point . CreateRotatation ( centre , negativeAngle ) ;
/// <inheritdoc/>
protected override void Apply ( ImageBase target , ImageBase source , Rectangle targetRectangle , Rectangle sourceRectangle , int startY , int endY )
{
int targetY = this . firstPass . Bounds . Y ;
int targetHeight = this . firstPass . Height ;
int startX = this . firstPass . Bounds . X ;
int endX = this . firstPass . Bounds . Right ;
float negativeAngle = - this . angle ;
Point centre = this . Center = = Point . Empty ? Rectangle . Center ( this . firstPass . Bounds ) : this . Center ;
Matrix3x2 rotation = Point . CreateRotatation ( centre , negativeAngle ) ;
// Since we are not working in parallel we use full height and width of the first pass image.
Parallel . For (
startY ,
endY ,
0 ,
targetHeight ,
y = >
{
if ( y > = targetY & & y < targetBottom )
// Y coordinates of source points
int originY = y - targetY ;
for ( int x = startX ; x < endX ; x + + )
{
// Y coordinates of source points
int originY = ( int ) ( ( y - targetY ) * heightFactor ) ;
// X coordinates of source points
int originX = x - startX ;
for ( int x = startX ; x < endX ; x + + )
// Rotate at the centre point
Point rotated = Point . Rotate ( new Point ( originX , originY ) , rotation ) ;
if ( this . firstPass . Bounds . Contains ( rotated . X , rotated . Y ) )
{
// X coordinates of source points
int originX = ( int ) ( ( x - startX ) * widthFactor ) ;
// Rotate at the centre point
Point rotated = Point . Rotate ( new Point ( originX , originY ) , rotation ) ;
if ( sourceRectangle . Contains ( rotated . X , rotated . Y ) )
{
target [ x , y ] = source [ rotated . X , rotated . Y ] ;
}
target [ x , y ] = this . firstPass [ rotated . X , rotated . Y ] ;
}
this . OnRowProcessed ( ) ;
}
this . OnRowProcessed ( ) ;
} ) ;
}
/// <inheritdoc/>
protected override void AfterApply ( ImageBase source , ImageBase target , Rectangle targetRectangle , Rectangle sourceRectangle )
{
// Cleanup.
this . firstPass . Dispose ( ) ;
}
}
}
James Jackson-South
10 years ago