Match APIs

src/ImageSharp/Processing/AffineTransformBuilder.cs

@@ -17,22 +17,13 @@ namespace SixLabors.ImageSharp.Processing
         private readonly List<Func<Size, Matrix3x2>> matrixFactories = new List<Func<Size, Matrix3x2>>();
 
         /// <summary>
-        /// Prepends a centered rotation matrix using the given rotation in radians.
-        /// </summary>
-        /// <param name="radians">The amount of rotation, in radians.</param>
-        /// <param name="centerPoint">The rotation center point</param>
-        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder PrependRotationRadians(float radians, Vector2 centerPoint)
-            => this.PrependMatrix(Matrix3x2.CreateRotation(radians, centerPoint));
-
-        /// <summary>
-        /// Appends a centered rotation matrix using the given rotation in radians.
+        /// Prepends a rotation matrix using the given rotation angle in degrees
+        /// and the image center point as rotation center.
         /// </summary>
-        /// <param name="radians">The amount of rotation, in radians.</param>
-        /// <param name="centerPoint">The rotation center point</param>
+        /// <param name="degrees">The amount of rotation, in degrees.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder AppendRotationRadians(float radians, Vector2 centerPoint)
-            => this.AppendMatrix(Matrix3x2.CreateRotation(radians, centerPoint));
+        public AffineTransformBuilder PrependRotationDegrees(float degrees)
+            => this.PrependRotationRadians(GeometryUtilities.DegreeToRadian(degrees));
 
         /// <summary>
         /// Prepends a rotation matrix using the given rotation angle in radians
@@ -44,31 +35,40 @@ namespace SixLabors.ImageSharp.Processing
             => this.Prepend(size => TransformUtils.CreateRotationMatrixRadians(radians, size));
 
         /// <summary>
-        /// Appends a rotation matrix using the given rotation angle in radians
-        /// and the image center point as rotation center.
+        /// Prepends a centered rotation matrix using the given rotation in radians.
         /// </summary>
         /// <param name="radians">The amount of rotation, in radians.</param>
+        /// <param name="origin">The rotation origin point.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder AppendRotationRadians(float radians)
-            => this.Append(size => TransformUtils.CreateRotationMatrixRadians(radians, size));
+        public AffineTransformBuilder PrependRotationRadians(float radians, Vector2 origin)
+            => this.PrependMatrix(Matrix3x2.CreateRotation(radians, origin));
 
         /// <summary>
-        /// Prepends a rotation matrix using the given rotation angle in degrees
+        /// Appends a rotation matrix using the given rotation angle in degrees
         /// and the image center point as rotation center.
         /// </summary>
         /// <param name="degrees">The amount of rotation, in degrees.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder PrependRotationDegrees(float degrees)
-            => this.PrependRotationRadians(GeometryUtilities.DegreeToRadian(degrees));
+        public AffineTransformBuilder AppendRotationDegrees(float degrees)
+            => this.AppendRotationRadians(GeometryUtilities.DegreeToRadian(degrees));
 
         /// <summary>
-        /// Appends a rotation matrix using the given rotation angle in degrees
+        /// Appends a rotation matrix using the given rotation angle in radians
         /// and the image center point as rotation center.
         /// </summary>
-        /// <param name="degrees">The amount of rotation, in degrees.</param>
+        /// <param name="radians">The amount of rotation, in radians.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder AppendRotationDegrees(float degrees)
-            => this.AppendRotationRadians(GeometryUtilities.DegreeToRadian(degrees));
+        public AffineTransformBuilder AppendRotationRadians(float radians)
+            => this.Append(size => TransformUtils.CreateRotationMatrixRadians(radians, size));
+
+        /// <summary>
+        /// Appends a centered rotation matrix using the given rotation in radians.
+        /// </summary>
+        /// <param name="radians">The amount of rotation, in radians.</param>
+        /// <param name="origin">The rotation origin point.</param>
+        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
+        public AffineTransformBuilder AppendRotationRadians(float radians, Vector2 origin)
+            => this.AppendMatrix(Matrix3x2.CreateRotation(radians, origin));
 
         /// <summary>
         /// Prepends a scale matrix from the given uniform scale.
@@ -79,12 +79,12 @@ namespace SixLabors.ImageSharp.Processing
             => this.PrependMatrix(Matrix3x2.CreateScale(scale));
 
         /// <summary>
-        /// Appends a scale matrix from the given uniform scale.
+        /// Prepends a scale matrix from the given vector scale.
         /// </summary>
-        /// <param name="scale">The uniform scale.</param>
+        /// <param name="scale">The horizontal and vertical scale.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder AppendScale(float scale)
-            => this.AppendMatrix(Matrix3x2.CreateScale(scale));
+        public AffineTransformBuilder PrependScale(SizeF scale)
+            => this.PrependScale((Vector2)scale);
 
         /// <summary>
         /// Prepends a scale matrix from the given vector scale.
@@ -95,28 +95,28 @@ namespace SixLabors.ImageSharp.Processing
             => this.PrependMatrix(Matrix3x2.CreateScale(scales));
 
         /// <summary>
-        /// Appends a scale matrix from the given vector scale.
+        /// Appends a scale matrix from the given uniform scale.
         /// </summary>
-        /// <param name="scales">The horizontal and vertical scale.</param>
+        /// <param name="scale">The uniform scale.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder AppendScale(Vector2 scales)
-            => this.AppendMatrix(Matrix3x2.CreateScale(scales));
+        public AffineTransformBuilder AppendScale(float scale)
+            => this.AppendMatrix(Matrix3x2.CreateScale(scale));
 
         /// <summary>
-        /// Prepends a scale matrix from the given vector scale.
+        /// Appends a scale matrix from the given vector scale.
         /// </summary>
-        /// <param name="scale">The horizontal and vertical scale.</param>
+        /// <param name="scales">The horizontal and vertical scale.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder PrependScale(SizeF scale)
-            => this.PrependScale((Vector2)scale);
+        public AffineTransformBuilder AppendScale(SizeF scales)
+            => this.AppendScale((Vector2)scales);
 
         /// <summary>
         /// Appends a scale matrix from the given vector scale.
         /// </summary>
         /// <param name="scales">The horizontal and vertical scale.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder AppendScale(SizeF scales)
-            => this.AppendScale((Vector2)scales);
+        public AffineTransformBuilder AppendScale(Vector2 scales)
+            => this.AppendMatrix(Matrix3x2.CreateScale(scales));
 
         /// <summary>
         /// Prepends a centered skew matrix from the give angles in degrees.
@@ -141,66 +141,58 @@ namespace SixLabors.ImageSharp.Processing
         /// </summary>
         /// <param name="position">The translation position.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder PrependTranslation(Vector2 position)
-            => this.PrependMatrix(Matrix3x2.CreateTranslation(position));
+        public AffineTransformBuilder PrependTranslation(PointF position)
+            => this.PrependTranslation((Vector2)position);
 
         /// <summary>
-        /// Appends a translation matrix from the given vector.
+        /// Prepends a translation matrix from the given vector.
         /// </summary>
         /// <param name="position">The translation position.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder AppendTranslation(Vector2 position)
-            => this.AppendMatrix(Matrix3x2.CreateTranslation(position));
+        public AffineTransformBuilder PrependTranslation(Vector2 position)
+            => this.PrependMatrix(Matrix3x2.CreateTranslation(position));
 
         /// <summary>
-        /// Prepends a translation matrix from the given vector.
+        /// Appends a translation matrix from the given vector.
         /// </summary>
         /// <param name="position">The translation position.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder PrependTranslation(PointF position)
-            => this.PrependTranslation((Vector2)position);
+        public AffineTransformBuilder AppendTranslation(PointF position)
+            => this.AppendTranslation((Vector2)position);
 
         /// <summary>
         /// Appends a translation matrix from the given vector.
         /// </summary>
         /// <param name="position">The translation position.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder AppendTranslation(PointF position)
-            => this.AppendTranslation((Vector2)position);
+        public AffineTransformBuilder AppendTranslation(Vector2 position)
+            => this.AppendMatrix(Matrix3x2.CreateTranslation(position));
 
         /// <summary>
         /// Prepends a raw matrix.
         /// </summary>
         /// <param name="matrix">The matrix to prepend.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder PrependMatrix(Matrix3x2 matrix)
-        {
-            this.matrixFactories.Insert(0, _ => matrix);
-            return this;
-        }
+        public AffineTransformBuilder PrependMatrix(Matrix3x2 matrix) => this.Prepend(_ => matrix);
 
         /// <summary>
         /// Appends a raw matrix.
         /// </summary>
         /// <param name="matrix">The matrix to append.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder AppendMatrix(Matrix3x2 matrix)
-        {
-            this.matrixFactories.Add(_ => matrix);
-            return this;
-        }
+        public AffineTransformBuilder AppendMatrix(Matrix3x2 matrix) => this.Append(_ => matrix);
 
         /// <summary>
         /// Returns the combined matrix for a given source size.
         /// </summary>
-        /// <param name="sourceSize">The source image size</param>
+        /// <param name="sourceSize">The source image size.</param>
         /// <returns>The <see cref="Matrix3x2"/>.</returns>
         public Matrix3x2 BuildMatrix(Size sourceSize) => this.BuildMatrix(new Rectangle(Point.Empty, sourceSize));
 
         /// <summary>
         /// Returns the combined matrix for a given source rectangle.
         /// </summary>
-        /// <param name="sourceRectangle">The rectangle in the source image</param>
+        /// <param name="sourceRectangle">The rectangle in the source image.</param>
         /// <returns>The <see cref="Matrix3x2"/>.</returns>
         public Matrix3x2 BuildMatrix(Rectangle sourceRectangle)
         {

src/ImageSharp/Processing/Processors/Transforms/ProjectiveTransformProcessor.cs

@@ -24,13 +24,13 @@ namespace SixLabors.ImageSharp.Processing.Processors.Transforms
         /// </summary>
         /// <param name="matrix">The transform matrix.</param>
         /// <param name="sampler">The sampler to perform the transform operation.</param>
-        /// <param name="sourceSize">The source image size.</param>
-        public ProjectiveTransformProcessor(Matrix4x4 matrix, IResampler sampler, Size sourceSize)
+        /// <param name="targetDimensions">The target dimensions.</param>
+        public ProjectiveTransformProcessor(Matrix4x4 matrix, IResampler sampler, Size targetDimensions)
         {
             Guard.NotNull(sampler, nameof(sampler));
             this.Sampler = sampler;
             this.TransformMatrix = matrix;
-            this.TargetDimensions = TransformUtils.GetTransformedSize(sourceSize, matrix);
+            this.TargetDimensions = targetDimensions;
         }
 
         /// <summary>

src/ImageSharp/Processing/ProjectiveTransformBuilder.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
+using System;
 using System.Collections.Generic;
 using System.Numerics;
 using SixLabors.ImageSharp.Processing.Processors.Transforms;
@@ -13,34 +14,7 @@ namespace SixLabors.ImageSharp.Processing
     /// </summary>
     public class ProjectiveTransformBuilder
     {
-        private readonly List<Matrix4x4> matrices = new List<Matrix4x4>();
-        private Rectangle sourceRectangle;
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="ProjectiveTransformBuilder"/> class.
-        /// </summary>
-        /// <param name="sourceSize">The source image size.</param>
-        public ProjectiveTransformBuilder(Size sourceSize)
-            : this(new Rectangle(Point.Empty, sourceSize))
-        {
-        }
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="ProjectiveTransformBuilder"/> class.
-        /// </summary>
-        /// <param name="sourceRectangle">The source rectangle.</param>
-        public ProjectiveTransformBuilder(Rectangle sourceRectangle)
-        {
-            Guard.MustBeGreaterThan(sourceRectangle.Width, 0, nameof(sourceRectangle));
-            Guard.MustBeGreaterThan(sourceRectangle.Height, 0, nameof(sourceRectangle));
-
-            this.sourceRectangle = sourceRectangle;
-        }
-
-        /// <summary>
-        /// Gets the source image size.
-        /// </summary>
-        internal Size Size => this.sourceRectangle.Size;
+        private readonly List<Func<Size, Matrix4x4>> matrixFactories = new List<Func<Size, Matrix4x4>>();
 
         /// <summary>
         /// Prepends a matrix that performs a tapering projective transform.
@@ -50,7 +24,7 @@ namespace SixLabors.ImageSharp.Processing
         /// <param name="fraction">The amount to taper.</param>
         /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
         public ProjectiveTransformBuilder PrependTaper(TaperSide side, TaperCorner corner, float fraction)
-            => this.PrependMatrix(TransformUtils.CreateTaperMatrix(this.Size, side, corner, fraction));
+            => this.Prepend(size => TransformUtils.CreateTaperMatrix(size, side, corner, fraction));
 
         /// <summary>
         /// Appends a matrix that performs a tapering projective transform.
@@ -60,7 +34,15 @@ namespace SixLabors.ImageSharp.Processing
         /// <param name="fraction">The amount to taper.</param>
         /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
         public ProjectiveTransformBuilder AppendTaper(TaperSide side, TaperCorner corner, float fraction)
-            => this.AppendMatrix(TransformUtils.CreateTaperMatrix(this.Size, side, corner, fraction));
+            => this.Append(size => TransformUtils.CreateTaperMatrix(size, side, corner, fraction));
+
+        /// <summary>
+        /// Prepends a centered rotation matrix using the given rotation in degrees.
+        /// </summary>
+        /// <param name="degrees">The amount of rotation, in degrees.</param>
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
+        public ProjectiveTransformBuilder PrependRotationDegrees(float degrees)
+            => this.PrependRotationRadians(GeometryUtilities.DegreeToRadian(degrees));
 
         /// <summary>
         /// Prepends a centered rotation matrix using the given rotation in radians.
@@ -68,33 +50,32 @@ namespace SixLabors.ImageSharp.Processing
         /// <param name="radians">The amount of rotation, in radians.</param>
         /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
         public ProjectiveTransformBuilder PrependRotationRadians(float radians)
-        {
-            var m = new Matrix4x4(TransformUtils.CreateRotationMatrixRadians(radians, this.Size));
-            return this.PrependMatrix(m);
-        }
+            => this.Prepend(size => new Matrix4x4(TransformUtils.CreateRotationMatrixRadians(radians, size)));
 
         /// <summary>
         /// Appends a centered rotation matrix using the given rotation in radians.
         /// </summary>
         /// <param name="radians">The amount of rotation, in radians.</param>
+        /// <param name="centerPoint">The rotation center.</param>
         /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
-        public ProjectiveTransformBuilder AppendRotationRadians(float radians)
-        {
-            var m = new Matrix4x4(TransformUtils.CreateRotationMatrixRadians(radians, this.Size));
-            return this.AppendMatrix(m);
-        }
+        internal ProjectiveTransformBuilder PrependRotationRadians(float radians, Vector2 centerPoint)
+            => this.PrependMatrix(Matrix4x4.CreateRotationZ(radians, new Vector3(centerPoint, 0)));
+
+        /// <summary>
+        /// Appends a centered rotation matrix using the given rotation in degrees.
+        /// </summary>
+        /// <param name="degrees">The amount of rotation, in degrees.</param>
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
+        public ProjectiveTransformBuilder AppendRotationDegrees(float degrees)
+            => this.AppendRotationRadians(GeometryUtilities.DegreeToRadian(degrees));
 
         /// <summary>
         /// Appends a centered rotation matrix using the given rotation in radians.
         /// </summary>
         /// <param name="radians">The amount of rotation, in radians.</param>
-        /// <param name="centerPoint">The rotation center.</param>
         /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
-        internal ProjectiveTransformBuilder PrependRotationRadians(float radians, Vector2 centerPoint)
-        {
-            var m = Matrix4x4.CreateRotationZ(radians, new Vector3(centerPoint, 0));
-            return this.PrependMatrix(m);
-        }
+        public ProjectiveTransformBuilder AppendRotationRadians(float radians)
+            => this.Append(size => new Matrix4x4(TransformUtils.CreateRotationMatrixRadians(radians, size)));
 
         /// <summary>
         /// Appends a centered rotation matrix using the given rotation in radians.
@@ -103,80 +84,69 @@ namespace SixLabors.ImageSharp.Processing
         /// <param name="centerPoint">The rotation center.</param>
         /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
         internal ProjectiveTransformBuilder AppendRotationRadians(float radians, Vector2 centerPoint)
-        {
-            var m = Matrix4x4.CreateRotationZ(radians, new Vector3(centerPoint, 0));
-            return this.AppendMatrix(m);
-        }
+            => this.AppendMatrix(Matrix4x4.CreateRotationZ(radians, new Vector3(centerPoint, 0)));
 
         /// <summary>
-        /// Prepends a centered rotation matrix using the given rotation in degrees.
+        /// Prepends a scale matrix from the given uniform scale.
         /// </summary>
-        /// <param name="degrees">The amount of rotation, in degrees.</param>
-        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public ProjectiveTransformBuilder PrependCenteredRotationDegrees(float degrees)
-            => this.PrependRotationRadians(GeometryUtilities.DegreeToRadian(degrees));
+        /// <param name="scale">The uniform scale.</param>
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
+        public ProjectiveTransformBuilder PrependScale(float scale)
+            => this.PrependMatrix(Matrix4x4.CreateScale(scale));
 
         /// <summary>
-        /// Appends a centered rotation matrix using the given rotation in degrees.
+        /// Prepends a scale matrix from the given vector scale.
         /// </summary>
-        /// <param name="degrees">The amount of rotation, in degrees.</param>
-        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public ProjectiveTransformBuilder AppendRotationDegrees(float degrees)
-            => this.AppendRotationRadians(GeometryUtilities.DegreeToRadian(degrees));
+        /// <param name="scale">The horizontal and vertical scale.</param>
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
+        public ProjectiveTransformBuilder PrependScale(SizeF scale)
+            => this.PrependScale((Vector2)scale);
 
         /// <summary>
-        /// Prepends a scale matrix from the given uniform scale.
+        /// Prepends a scale matrix from the given vector scale.
         /// </summary>
-        /// <param name="scale">The uniform scale.</param>
-        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public ProjectiveTransformBuilder PrependScale(float scale)
-            => this.PrependMatrix(Matrix4x4.CreateScale(scale));
+        /// <param name="scales">The horizontal and vertical scale.</param>
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
+        public ProjectiveTransformBuilder PrependScale(Vector2 scales)
+            => this.PrependMatrix(Matrix4x4.CreateScale(new Vector3(scales, 1F)));
 
         /// <summary>
         /// Appends a scale matrix from the given uniform scale.
         /// </summary>
         /// <param name="scale">The uniform scale.</param>
-        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
         public ProjectiveTransformBuilder AppendScale(float scale)
             => this.AppendMatrix(Matrix4x4.CreateScale(scale));
 
         /// <summary>
-        /// Prepends a scale matrix from the given vector scale.
+        /// Appends a scale matrix from the given vector scale.
         /// </summary>
         /// <param name="scales">The horizontal and vertical scale.</param>
-        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public ProjectiveTransformBuilder PrependScale(Vector2 scales)
-            => this.PrependMatrix(Matrix4x4.CreateScale(new Vector3(scales, 1f)));
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
+        public ProjectiveTransformBuilder AppendScale(SizeF scales)
+            => this.AppendScale((Vector2)scales);
 
         /// <summary>
         /// Appends a scale matrix from the given vector scale.
         /// </summary>
         /// <param name="scales">The horizontal and vertical scale.</param>
-        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
         public ProjectiveTransformBuilder AppendScale(Vector2 scales)
-            => this.AppendMatrix(Matrix4x4.CreateScale(new Vector3(scales, 1f)));
-
-        /// <summary>
-        /// Prepends a scale matrix from the given vector scale.
-        /// </summary>
-        /// <param name="scale">The horizontal and vertical scale.</param>
-        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public ProjectiveTransformBuilder PrependScale(SizeF scale)
-            => this.PrependScale((Vector2)scale);
+            => this.AppendMatrix(Matrix4x4.CreateScale(new Vector3(scales, 1F)));
 
         /// <summary>
-        /// Appends a scale matrix from the given vector scale.
+        /// Prepends a translation matrix from the given vector.
         /// </summary>
-        /// <param name="scales">The horizontal and vertical scale.</param>
-        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public ProjectiveTransformBuilder AppendScale(SizeF scales)
-            => this.AppendScale((Vector2)scales);
+        /// <param name="position">The translation position.</param>
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
+        public ProjectiveTransformBuilder PrependTranslation(PointF position)
+            => this.PrependTranslation((Vector2)position);
 
         /// <summary>
         /// Prepends a translation matrix from the given vector.
         /// </summary>
         /// <param name="position">The translation position.</param>
-        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
         public ProjectiveTransformBuilder PrependTranslation(Vector2 position)
             => this.PrependMatrix(Matrix4x4.CreateTranslation(new Vector3(position, 0)));
 
@@ -184,68 +154,72 @@ namespace SixLabors.ImageSharp.Processing
         /// Appends a translation matrix from the given vector.
         /// </summary>
         /// <param name="position">The translation position.</param>
-        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public ProjectiveTransformBuilder AppendTranslation(Vector2 position)
-            => this.AppendMatrix(Matrix4x4.CreateTranslation(new Vector3(position, 0)));
-
-        /// <summary>
-        /// Prepends a translation matrix from the given vector.
-        /// </summary>
-        /// <param name="position">The translation position.</param>
-        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public ProjectiveTransformBuilder PrependTranslation(PointF position)
-            => this.PrependTranslation((Vector2)position);
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
+        public ProjectiveTransformBuilder AppendTranslation(PointF position)
+            => this.AppendTranslation((Vector2)position);
 
         /// <summary>
         /// Appends a translation matrix from the given vector.
         /// </summary>
         /// <param name="position">The translation position.</param>
-        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public ProjectiveTransformBuilder AppendTranslation(PointF position)
-            => this.AppendTranslation((Vector2)position);
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
+        public ProjectiveTransformBuilder AppendTranslation(Vector2 position)
+            => this.AppendMatrix(Matrix4x4.CreateTranslation(new Vector3(position, 0)));
 
         /// <summary>
         /// Prepends a raw matrix.
         /// </summary>
         /// <param name="matrix">The matrix to prepend.</param>
         /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
-        public ProjectiveTransformBuilder PrependMatrix(Matrix4x4 matrix)
-        {
-            this.matrices.Insert(0, matrix);
-            return this;
-        }
+        public ProjectiveTransformBuilder PrependMatrix(Matrix4x4 matrix) => this.Prepend(_ => matrix);
 
         /// <summary>
         /// Appends a raw matrix.
         /// </summary>
         /// <param name="matrix">The matrix to append.</param>
         /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
-        public ProjectiveTransformBuilder AppendMatrix(Matrix4x4 matrix)
-        {
-            this.matrices.Add(matrix);
-            return this;
-        }
+        public ProjectiveTransformBuilder AppendMatrix(Matrix4x4 matrix) => this.Append(_ => matrix);
+
+        /// <summary>
+        /// Returns the combined matrix for a given source size.
+        /// </summary>
+        /// <param name="sourceSize">The source image size.</param>
+        /// <returns>The <see cref="Matrix4x4"/>.</returns>
+        public Matrix4x4 BuildMatrix(Size sourceSize) => this.BuildMatrix(new Rectangle(Point.Empty, sourceSize));
 
         /// <summary>
-        /// Returns the combined matrix.
+        /// Returns the combined matrix for a given source rectangle.
         /// </summary>
+        /// <param name="sourceRectangle">The rectangle in the source image.</param>
         /// <returns>The <see cref="Matrix4x4"/>.</returns>
-        public Matrix4x4 BuildMatrix()
+        public Matrix4x4 BuildMatrix(Rectangle sourceRectangle)
         {
-            Matrix4x4 matrix = Matrix4x4.Identity;
+            Guard.MustBeGreaterThan(sourceRectangle.Width, 0, nameof(sourceRectangle));
+            Guard.MustBeGreaterThan(sourceRectangle.Height, 0, nameof(sourceRectangle));
 
             // Translate the origin matrix to cater for source rectangle offsets.
-            if (!this.sourceRectangle.Equals(default))
-            {
-                matrix *= Matrix4x4.CreateTranslation(new Vector3(-this.sourceRectangle.Location, 0));
-            }
+            var matrix = Matrix4x4.CreateTranslation(new Vector3(-sourceRectangle.Location, 0));
+
+            Size size = sourceRectangle.Size;
 
-            foreach (Matrix4x4 m in this.matrices)
+            foreach (Func<Size, Matrix4x4> factory in this.matrixFactories)
             {
-                matrix *= m;
+                matrix *= factory(size);
             }
 
             return matrix;
         }
+
+        private ProjectiveTransformBuilder Prepend(Func<Size, Matrix4x4> factory)
+        {
+            this.matrixFactories.Insert(0, factory);
+            return this;
+        }
+
+        private ProjectiveTransformBuilder Append(Func<Size, Matrix4x4> factory)
+        {
+            this.matrixFactories.Add(factory);
+            return this;
+        }
     }
 }

src/ImageSharp/Processing/TransformExtensions.cs

@@ -15,40 +15,32 @@ namespace SixLabors.ImageSharp.Processing
     public static class TransformExtensions
     {
         /// <summary>
-        /// Performs an affine transform of an image using the specified sampling algorithm.
+        /// Performs an affine transform of an image.
         /// </summary>
         /// <typeparam name="TPixel">The pixel format.</typeparam>
-        /// <param name="ctx">The <see cref="IImageProcessingContext{TPixel}"/>.</param>
-        /// <param name="sourceRectangle">The source rectangle</param>
-        /// <param name="transform">The transformation matrix.</param>
-        /// <param name="targetDimensions">The size of the result image.</param>
-        /// <param name="sampler">The <see cref="IResampler"/> to perform the resampling.</param>
+        /// <param name="source">The image to transform.</param>
+        /// <param name="builder">The affine transform builder.</param>
         /// <returns>The <see cref="Image{TPixel}"/></returns>
         public static IImageProcessingContext<TPixel> Transform<TPixel>(
-            this IImageProcessingContext<TPixel> ctx,
-            Rectangle sourceRectangle,
-            Matrix3x2 transform,
-            Size targetDimensions,
-            IResampler sampler)
+            this IImageProcessingContext<TPixel> source,
+            AffineTransformBuilder builder)
             where TPixel : struct, IPixel<TPixel>
-        {
-            return ctx.ApplyProcessor(
-                new AffineTransformProcessor<TPixel>(transform, sampler, targetDimensions),
-                sourceRectangle);
-        }
+            => Transform(source, builder, KnownResamplers.Bicubic);
 
         /// <summary>
-        /// Performs an affine transform of an image.
+        /// Performs an affine transform of an image using the specified sampling algorithm.
         /// </summary>
         /// <typeparam name="TPixel">The pixel format.</typeparam>
-        /// <param name="source">The image to transform.</param>
+        /// <param name="ctx">The <see cref="IImageProcessingContext{TPixel}"/>.</param>
         /// <param name="builder">The affine transform builder.</param>
+        /// <param name="sampler">The <see cref="IResampler"/> to perform the resampling.</param>
         /// <returns>The <see cref="Image{TPixel}"/></returns>
         public static IImageProcessingContext<TPixel> Transform<TPixel>(
-            this IImageProcessingContext<TPixel> source,
-            AffineTransformBuilder builder)
+            this IImageProcessingContext<TPixel> ctx,
+            AffineTransformBuilder builder,
+            IResampler sampler)
             where TPixel : struct, IPixel<TPixel>
-            => Transform(source, builder, KnownResamplers.Bicubic);
+            => ctx.Transform(new Rectangle(Point.Empty, ctx.GetCurrentSize()), builder, sampler);
 
         /// <summary>
         /// Performs an affine transform of an image using the specified sampling algorithm.
@@ -76,16 +68,22 @@ namespace SixLabors.ImageSharp.Processing
         /// </summary>
         /// <typeparam name="TPixel">The pixel format.</typeparam>
         /// <param name="ctx">The <see cref="IImageProcessingContext{TPixel}"/>.</param>
-        /// <param name="builder">The affine transform builder.</param>
+        /// <param name="sourceRectangle">The source rectangle</param>
+        /// <param name="transform">The transformation matrix.</param>
+        /// <param name="targetDimensions">The size of the result image.</param>
         /// <param name="sampler">The <see cref="IResampler"/> to perform the resampling.</param>
         /// <returns>The <see cref="Image{TPixel}"/></returns>
         public static IImageProcessingContext<TPixel> Transform<TPixel>(
             this IImageProcessingContext<TPixel> ctx,
-            AffineTransformBuilder builder,
+            Rectangle sourceRectangle,
+            Matrix3x2 transform,
+            Size targetDimensions,
             IResampler sampler)
             where TPixel : struct, IPixel<TPixel>
         {
-            return ctx.Transform(new Rectangle(Point.Empty, ctx.GetCurrentSize()), builder, sampler);
+            return ctx.ApplyProcessor(
+                new AffineTransformProcessor<TPixel>(transform, sampler, targetDimensions),
+                sourceRectangle);
         }
 
         /// <summary>
@@ -105,15 +103,59 @@ namespace SixLabors.ImageSharp.Processing
         /// Performs a projective transform of an image using the specified sampling algorithm.
         /// </summary>
         /// <typeparam name="TPixel">The pixel format.</typeparam>
-        /// <param name="source">The image to transform.</param>
+        /// <param name="ctx">The <see cref="IImageProcessingContext{TPixel}"/>.</param>
         /// <param name="builder">The projective transform builder.</param>
         /// <param name="sampler">The <see cref="IResampler"/> to perform the resampling.</param>
         /// <returns>The <see cref="Image{TPixel}"/></returns>
         public static IImageProcessingContext<TPixel> Transform<TPixel>(
-            this IImageProcessingContext<TPixel> source,
+            this IImageProcessingContext<TPixel> ctx,
+            ProjectiveTransformBuilder builder,
+            IResampler sampler)
+            where TPixel : struct, IPixel<TPixel>
+            => ctx.Transform(new Rectangle(Point.Empty, ctx.GetCurrentSize()), builder, sampler);
+
+        /// <summary>
+        /// Performs a projective transform of an image using the specified sampling algorithm.
+        /// </summary>
+        /// <typeparam name="TPixel">The pixel format.</typeparam>
+        /// <param name="ctx">The <see cref="IImageProcessingContext{TPixel}"/>.</param>
+        /// <param name="sourceRectangle">The source rectangle</param>
+        /// <param name="builder">The projective transform builder.</param>
+        /// <param name="sampler">The <see cref="IResampler"/> to perform the resampling.</param>
+        /// <returns>The <see cref="Image{TPixel}"/></returns>
+        public static IImageProcessingContext<TPixel> Transform<TPixel>(
+            this IImageProcessingContext<TPixel> ctx,
+            Rectangle sourceRectangle,
             ProjectiveTransformBuilder builder,
             IResampler sampler)
             where TPixel : struct, IPixel<TPixel>
-            => source.ApplyProcessor(new ProjectiveTransformProcessor<TPixel>(builder.BuildMatrix(), sampler, builder.Size));
+        {
+            Matrix4x4 transform = builder.BuildMatrix(sourceRectangle);
+            Size targetDimensions = TransformUtils.GetTransformedSize(sourceRectangle.Size, transform);
+            return ctx.Transform(sourceRectangle, transform, targetDimensions, sampler);
+        }
+
+        /// <summary>
+        /// Performs a projective transform of an image using the specified sampling algorithm.
+        /// </summary>
+        /// <typeparam name="TPixel">The pixel format.</typeparam>
+        /// <param name="ctx">The <see cref="IImageProcessingContext{TPixel}"/>.</param>
+        /// <param name="sourceRectangle">The source rectangle</param>
+        /// <param name="transform">The transformation matrix.</param>
+        /// <param name="targetDimensions">The size of the result image.</param>
+        /// <param name="sampler">The <see cref="IResampler"/> to perform the resampling.</param>
+        /// <returns>The <see cref="Image{TPixel}"/></returns>
+        public static IImageProcessingContext<TPixel> Transform<TPixel>(
+            this IImageProcessingContext<TPixel> ctx,
+            Rectangle sourceRectangle,
+            Matrix4x4 transform,
+            Size targetDimensions,
+            IResampler sampler)
+            where TPixel : struct, IPixel<TPixel>
+        {
+            return ctx.ApplyProcessor(
+                new ProjectiveTransformProcessor<TPixel>(transform, sampler, targetDimensions),
+                sourceRectangle);
+        }
     }
 }

tests/ImageSharp.Tests/Processing/Transforms/AffineTransformBuilderTests.cs

@@ -1,28 +1,31 @@
 // Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
-using System;
 using System.Numerics;
 using SixLabors.ImageSharp.Processing;
-using SixLabors.ImageSharp.Processing.Processors.Transforms;
 using SixLabors.Primitives;
-using Xunit;
 
 namespace SixLabors.ImageSharp.Tests.Processing.Transforms
 {
     public class AffineTransformBuilderTests : TransformBuilderTestBase<AffineTransformBuilder>
     {
         protected override void AppendTranslation(AffineTransformBuilder builder, PointF translate) => builder.AppendTranslation(translate);
+
         protected override void AppendScale(AffineTransformBuilder builder, SizeF scale) => builder.AppendScale(scale);
+
         protected override void AppendRotationRadians(AffineTransformBuilder builder, float radians) => builder.AppendRotationRadians(radians);
+
         protected override void AppendRotationRadians(AffineTransformBuilder builder, float radians, Vector2 center) =>
             builder.AppendRotationRadians(radians, center);
 
         protected override void PrependTranslation(AffineTransformBuilder builder, PointF translate) => builder.PrependTranslation(translate);
+
         protected override void PrependScale(AffineTransformBuilder builder, SizeF scale) => builder.PrependScale(scale);
+
         protected override void PrependRotationRadians(AffineTransformBuilder builder, float radians) => builder.PrependRotationRadians(radians);
-        protected override void PrependRotationRadians(AffineTransformBuilder builder, float radians, Vector2 center) =>
-            builder.PrependRotationRadians(radians, center);
+
+        protected override void PrependRotationRadians(AffineTransformBuilder builder, float radians, Vector2 origin) =>
+            builder.PrependRotationRadians(radians, origin);
 
         protected override AffineTransformBuilder CreateBuilder(Rectangle rectangle) => new AffineTransformBuilder();
 
@@ -35,4 +38,4 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
             return Vector2.Transform(sourcePoint, matrix);
         }
     }
-}
+}

tests/ImageSharp.Tests/Processing/Transforms/ProjectiveTransformBuilderTests.cs

@@ -1,60 +1,40 @@
 // Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
-using System;
 using System.Numerics;
 using SixLabors.ImageSharp.Processing;
 using SixLabors.Primitives;
-using Xunit;
 
 namespace SixLabors.ImageSharp.Tests.Processing.Transforms
 {
     public class ProjectiveTransformBuilderTests : TransformBuilderTestBase<ProjectiveTransformBuilder>
     {
-        [Fact]
-        public void ConstructorAssignsProperties()
-        {
-            var s = new Size(1, 1);
-            var builder = new ProjectiveTransformBuilder(new Rectangle(Point.Empty, s));
-            Assert.Equal(s, builder.Size);
-        }
-
-        [Fact]
-        public void ConstructorThrowsInvalid()
-        {
-            Assert.Throws<ArgumentOutOfRangeException>(() =>
-            {
-                var s = new Size(0, 1);
-                var builder = new ProjectiveTransformBuilder(new Rectangle(Point.Empty, s));
-            });
-
-            Assert.Throws<ArgumentOutOfRangeException>(() =>
-            {
-                var s = new Size(1, 0);
-                var builder = new ProjectiveTransformBuilder(new Rectangle(Point.Empty, s));
-            });
-        }
-
-        protected override ProjectiveTransformBuilder CreateBuilder(Rectangle rectangle) => new ProjectiveTransformBuilder(rectangle);
+        protected override ProjectiveTransformBuilder CreateBuilder(Rectangle rectangle) => new ProjectiveTransformBuilder();
 
         protected override void AppendTranslation(ProjectiveTransformBuilder builder, PointF translate) => builder.AppendTranslation(translate);
+
         protected override void AppendScale(ProjectiveTransformBuilder builder, SizeF scale) => builder.AppendScale(scale);
+
         protected override void AppendRotationRadians(ProjectiveTransformBuilder builder, float radians) => builder.AppendRotationRadians(radians);
+
         protected override void AppendRotationRadians(ProjectiveTransformBuilder builder, float radians, Vector2 center) =>
             builder.AppendRotationRadians(radians, center);
 
         protected override void PrependTranslation(ProjectiveTransformBuilder builder, PointF translate) => builder.PrependTranslation(translate);
+
         protected override void PrependScale(ProjectiveTransformBuilder builder, SizeF scale) => builder.PrependScale(scale);
+
         protected override void PrependRotationRadians(ProjectiveTransformBuilder builder, float radians) => builder.PrependRotationRadians(radians);
-        protected override void PrependRotationRadians(ProjectiveTransformBuilder builder, float radians, Vector2 center) =>
-            builder.PrependRotationRadians(radians, center);
+
+        protected override void PrependRotationRadians(ProjectiveTransformBuilder builder, float radians, Vector2 origin) =>
+            builder.PrependRotationRadians(radians, origin);
 
         protected override Vector2 Execute(
             ProjectiveTransformBuilder builder,
             Rectangle rectangle,
             Vector2 sourcePoint)
         {
-            Matrix4x4 matrix = builder.BuildMatrix();
+            Matrix4x4 matrix = builder.BuildMatrix(rectangle);
             return Vector2.Transform(sourcePoint, matrix);
         }
     }

tests/ImageSharp.Tests/Processing/Transforms/ProjectiveTransformTests.cs

@@ -70,7 +70,7 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
             IResampler sampler = GetResampler(resamplerName);
             using (Image<TPixel> image = provider.GetImage())
             {
-                ProjectiveTransformBuilder builder = new ProjectiveTransformBuilder(image.Size())
+                ProjectiveTransformBuilder builder = new ProjectiveTransformBuilder()
                     .AppendTaper(TaperSide.Right, TaperCorner.Both, .5F);
 
                 image.Mutate(i => i.Transform(builder, sampler));
@@ -87,7 +87,7 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
         {
             using (Image<TPixel> image = provider.GetImage())
             {
-                ProjectiveTransformBuilder builder = new ProjectiveTransformBuilder(image.Size())
+                ProjectiveTransformBuilder builder = new ProjectiveTransformBuilder()
                     .AppendTaper(taperSide, taperCorner, .5F);
 
                 image.Mutate(i => i.Transform(builder));
@@ -113,7 +113,7 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
                 Matrix4x4 matrix = Matrix4x4.Identity;
                 matrix.M13 = 0.01F;
 
-                ProjectiveTransformBuilder builder = new ProjectiveTransformBuilder(image.Size())
+                ProjectiveTransformBuilder builder = new ProjectiveTransformBuilder()
                 .AppendMatrix(matrix);
 
                 image.Mutate(i => i.Transform(builder));

tests/ImageSharp.Tests/Processing/Transforms/TransformBuilderTestBase.cs

@@ -18,7 +18,6 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
             new TheoryData<Vector2, Vector2, Vector2, Vector2>
                 {
                     // scale, translate, source, expectedDest
-
                     { Vector2.One, Vector2.Zero, Vector2.Zero, Vector2.Zero },
                     { Vector2.One, Vector2.Zero, new Vector2(10, 20), new Vector2(10, 20) },
                     { Vector2.One, new Vector2(3, 1), new Vector2(10, 20), new Vector2(13, 21) },
@@ -44,7 +43,6 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
             new TheoryData<Vector2, Vector2, Vector2, Vector2>
                 {
                     // translate, scale, source, expectedDest
-
                     { Vector2.Zero, Vector2.One, Vector2.Zero, Vector2.Zero },
                     { Vector2.Zero, Vector2.One, new Vector2(10, 20), new Vector2(10, 20) },
                     { new Vector2(3, 1), new Vector2(2, 0.5f), new Vector2(10, 20), new Vector2(26, 10.5f) },
@@ -183,14 +181,20 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
         protected abstract TBuilder CreateBuilder(Rectangle rectangle);
 
         protected abstract void AppendTranslation(TBuilder builder, PointF translate);
+
         protected abstract void AppendScale(TBuilder builder, SizeF scale);
+
         protected abstract void AppendRotationRadians(TBuilder builder, float radians);
+
         protected abstract void AppendRotationRadians(TBuilder builder, float radians, Vector2 center);
 
         protected abstract void PrependTranslation(TBuilder builder, PointF translate);
+
         protected abstract void PrependScale(TBuilder builder, SizeF scale);
+
         protected abstract void PrependRotationRadians(TBuilder builder, float radians);
-        protected abstract void PrependRotationRadians(TBuilder b1, float v, Vector2 vector2);
+
+        protected abstract void PrependRotationRadians(TBuilder builder, float radians, Vector2 origin);
 
         protected virtual void AppendRotationDegrees(TBuilder builder, float degrees) =>
             this.AppendRotationRadians(builder, GeometryUtilities.DegreeToRadian(degrees));
@@ -199,7 +203,5 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
             this.AppendRotationRadians(builder, GeometryUtilities.DegreeToRadian(degrees), center);
 
         protected abstract Vector2 Execute(TBuilder builder, Rectangle rectangle, Vector2 sourcePoint);
-
-        private static float Sqrt(float a) => (float)Math.Sqrt(a);
     }
 }