mirror of https://github.com/SixLabors/ImageSharp
James Jackson-South
1 week ago
6 changed files with 226 additions and 12 deletions
@ -0,0 +1,160 @@ |
|||
// Copyright (c) Six Labors.
|
|||
// Licensed under the Six Labors Split License.
|
|||
|
|||
namespace SixLabors.ImageSharp.Formats.Heif; |
|||
|
|||
/// <summary>
|
|||
/// Describes the fractional dimensions and center offsets of a HEIF clean-aperture property.
|
|||
/// </summary>
|
|||
internal readonly struct HeifCleanAperture : IEquatable<HeifCleanAperture> |
|||
{ |
|||
/// <summary>
|
|||
/// Initializes a new instance of the <see cref="HeifCleanAperture"/> struct.
|
|||
/// </summary>
|
|||
/// <param name="widthNumerator">The clean-aperture width numerator.</param>
|
|||
/// <param name="widthDenominator">The clean-aperture width denominator.</param>
|
|||
/// <param name="heightNumerator">The clean-aperture height numerator.</param>
|
|||
/// <param name="heightDenominator">The clean-aperture height denominator.</param>
|
|||
/// <param name="horizontalOffsetNumerator">The horizontal center-offset numerator.</param>
|
|||
/// <param name="horizontalOffsetDenominator">The horizontal center-offset denominator.</param>
|
|||
/// <param name="verticalOffsetNumerator">The vertical center-offset numerator.</param>
|
|||
/// <param name="verticalOffsetDenominator">The vertical center-offset denominator.</param>
|
|||
public HeifCleanAperture( |
|||
int widthNumerator, |
|||
int widthDenominator, |
|||
int heightNumerator, |
|||
int heightDenominator, |
|||
int horizontalOffsetNumerator, |
|||
int horizontalOffsetDenominator, |
|||
int verticalOffsetNumerator, |
|||
int verticalOffsetDenominator) |
|||
{ |
|||
this.WidthNumerator = widthNumerator; |
|||
this.WidthDenominator = widthDenominator; |
|||
this.HeightNumerator = heightNumerator; |
|||
this.HeightDenominator = heightDenominator; |
|||
this.HorizontalOffsetNumerator = horizontalOffsetNumerator; |
|||
this.HorizontalOffsetDenominator = horizontalOffsetDenominator; |
|||
this.VerticalOffsetNumerator = verticalOffsetNumerator; |
|||
this.VerticalOffsetDenominator = verticalOffsetDenominator; |
|||
} |
|||
|
|||
/// <summary>
|
|||
/// Gets the clean-aperture width numerator.
|
|||
/// </summary>
|
|||
public int WidthNumerator { get; } |
|||
|
|||
/// <summary>
|
|||
/// Gets the clean-aperture width denominator.
|
|||
/// </summary>
|
|||
public int WidthDenominator { get; } |
|||
|
|||
/// <summary>
|
|||
/// Gets the clean-aperture height numerator.
|
|||
/// </summary>
|
|||
public int HeightNumerator { get; } |
|||
|
|||
/// <summary>
|
|||
/// Gets the clean-aperture height denominator.
|
|||
/// </summary>
|
|||
public int HeightDenominator { get; } |
|||
|
|||
/// <summary>
|
|||
/// Gets the horizontal center-offset numerator.
|
|||
/// </summary>
|
|||
public int HorizontalOffsetNumerator { get; } |
|||
|
|||
/// <summary>
|
|||
/// Gets the horizontal center-offset denominator.
|
|||
/// </summary>
|
|||
public int HorizontalOffsetDenominator { get; } |
|||
|
|||
/// <summary>
|
|||
/// Gets the vertical center-offset numerator.
|
|||
/// </summary>
|
|||
public int VerticalOffsetNumerator { get; } |
|||
|
|||
/// <summary>
|
|||
/// Gets the vertical center-offset denominator.
|
|||
/// </summary>
|
|||
public int VerticalOffsetDenominator { get; } |
|||
|
|||
/// <summary>
|
|||
/// Converts the clean aperture to an integer crop rectangle within the coded image extent.
|
|||
/// </summary>
|
|||
/// <param name="imageExtent">The coded image dimensions.</param>
|
|||
/// <returns>The clean-aperture crop rectangle.</returns>
|
|||
/// <exception cref="InvalidImageContentException">
|
|||
/// The clean-aperture fractions do not describe an integer rectangle inside the coded image extent.
|
|||
/// </exception>
|
|||
public Rectangle ToRectangle(Size imageExtent) |
|||
{ |
|||
if (this.WidthNumerator <= 0 || this.HeightNumerator <= 0 || |
|||
this.WidthDenominator <= 0 || this.HeightDenominator <= 0 || |
|||
this.HorizontalOffsetDenominator <= 0 || this.VerticalOffsetDenominator <= 0) |
|||
{ |
|||
throw new InvalidImageContentException("The clean aperture dimensions and denominators must be positive."); |
|||
} |
|||
|
|||
if ((this.WidthNumerator % this.WidthDenominator) != 0 || |
|||
(this.HeightNumerator % this.HeightDenominator) != 0) |
|||
{ |
|||
throw new InvalidImageContentException("The clean aperture dimensions must resolve to integer pixels."); |
|||
} |
|||
|
|||
int width = this.WidthNumerator / this.WidthDenominator; |
|||
int height = this.HeightNumerator / this.HeightDenominator; |
|||
|
|||
// Express each top-left coordinate over twice the offset denominator. This is the exact
|
|||
// center-plus-offset-minus-half-size equation without floating-point rounding.
|
|||
long xNumerator = ((long)(imageExtent.Width - width) * this.HorizontalOffsetDenominator) + |
|||
(2L * this.HorizontalOffsetNumerator); |
|||
long xDenominator = 2L * this.HorizontalOffsetDenominator; |
|||
long yNumerator = ((long)(imageExtent.Height - height) * this.VerticalOffsetDenominator) + |
|||
(2L * this.VerticalOffsetNumerator); |
|||
long yDenominator = 2L * this.VerticalOffsetDenominator; |
|||
|
|||
if ((xNumerator % xDenominator) != 0 || (yNumerator % yDenominator) != 0) |
|||
{ |
|||
throw new InvalidImageContentException("The clean aperture offsets must resolve to integer pixels."); |
|||
} |
|||
|
|||
long x = xNumerator / xDenominator; |
|||
long y = yNumerator / yDenominator; |
|||
if (x < 0 || y < 0 || x + width > imageExtent.Width || y + height > imageExtent.Height) |
|||
{ |
|||
throw new InvalidImageContentException("The clean aperture lies outside the coded image extent."); |
|||
} |
|||
|
|||
return new Rectangle((int)x, (int)y, width, height); |
|||
} |
|||
|
|||
/// <inheritdoc/>
|
|||
public bool Equals(HeifCleanAperture other) |
|||
=> this.WidthNumerator == other.WidthNumerator && |
|||
this.WidthDenominator == other.WidthDenominator && |
|||
this.HeightNumerator == other.HeightNumerator && |
|||
this.HeightDenominator == other.HeightDenominator && |
|||
this.HorizontalOffsetNumerator == other.HorizontalOffsetNumerator && |
|||
this.HorizontalOffsetDenominator == other.HorizontalOffsetDenominator && |
|||
this.VerticalOffsetNumerator == other.VerticalOffsetNumerator && |
|||
this.VerticalOffsetDenominator == other.VerticalOffsetDenominator; |
|||
|
|||
/// <inheritdoc/>
|
|||
public override bool Equals(object? obj) => obj is HeifCleanAperture other && this.Equals(other); |
|||
|
|||
/// <inheritdoc/>
|
|||
public override int GetHashCode() |
|||
{ |
|||
HashCode hashCode = default; |
|||
hashCode.Add(this.WidthNumerator); |
|||
hashCode.Add(this.WidthDenominator); |
|||
hashCode.Add(this.HeightNumerator); |
|||
hashCode.Add(this.HeightDenominator); |
|||
hashCode.Add(this.HorizontalOffsetNumerator); |
|||
hashCode.Add(this.HorizontalOffsetDenominator); |
|||
hashCode.Add(this.VerticalOffsetNumerator); |
|||
hashCode.Add(this.VerticalOffsetDenominator); |
|||
return hashCode.ToHashCode(); |
|||
} |
|||
} |
|||
Loading…
Reference in new issue