From fb105aca46852436b9f7a4f8b6bd8062630a0813 Mon Sep 17 00:00:00 2001 From: Lehonti Ramos Date: Wed, 9 Aug 2023 23:19:28 +0200 Subject: [PATCH] Simple refactorings to `LineCurveSeriesEngine` --- .../Editable/Shapes/LineCurveSeriesEngine.cs | 179 +++++++++--------- 1 file changed, 87 insertions(+), 92 deletions(-) diff --git a/Pinta.Tools/Editable/Shapes/LineCurveSeriesEngine.cs b/Pinta.Tools/Editable/Shapes/LineCurveSeriesEngine.cs index 2dcf13c3c..a211b4894 100644 --- a/Pinta.Tools/Editable/Shapes/LineCurveSeriesEngine.cs +++ b/Pinta.Tools/Editable/Shapes/LineCurveSeriesEngine.cs @@ -30,7 +30,7 @@ namespace Pinta.Tools { - public class LineCurveSeriesEngine : ShapeEngine + public sealed class LineCurveSeriesEngine : ShapeEngine { public Arrow Arrow1 = new (), Arrow2 = new (); @@ -71,96 +71,97 @@ public override ShapeEngine Clone () /// public override void GeneratePoints (int brush_width) { + if (ControlPoints.Count < 2) { + GeneratedPoints = new[] { new GeneratedPoint (ControlPoints[0].Position, 0) }; + return; + } + List generatedPoints = new List (); - if (ControlPoints.Count < 2) { - generatedPoints.Add (new GeneratedPoint (ControlPoints[0].Position, 0)); + //Generate tangents for each of the smaller cubic Bezier curves that make up each segment of the resulting curve. + + //The tension calculated for each point is a gradient between the previous + //control point's tension and the following control point's tension. + + //Stores all of the tangent values. + List bezierTangents = new List (); + + int pointCount = ControlPoints.Count - 1; + double pointCountDouble = (double) pointCount; + double tensionForPoint; + + //Calculate the first tangent. + if (Closed) { + bezierTangents.Add (new PointD ( + ControlPoints[0].Tension * (ControlPoints[1].Position.X - ControlPoints[pointCount].Position.X), + ControlPoints[0].Tension * (ControlPoints[1].Position.Y - ControlPoints[pointCount].Position.Y))); + } else { + bezierTangents.Add (new PointD ( + ControlPoints[0].Tension * (ControlPoints[1].Position.X - ControlPoints[0].Position.X), + ControlPoints[0].Tension * (ControlPoints[1].Position.Y - ControlPoints[0].Position.Y))); + } + + //Calculate all of the middle tangents. + for (int i = 1; i < pointCount; ++i) { + tensionForPoint = ControlPoints[i].Tension * (double) i / pointCountDouble; + + bezierTangents.Add (new PointD ( + tensionForPoint * + (ControlPoints[i + 1].Position.X - ControlPoints[i - 1].Position.X), + tensionForPoint * + (ControlPoints[i + 1].Position.Y - ControlPoints[i - 1].Position.Y))); + } + + //Calculate the last tangent. + if (Closed) { + bezierTangents.Add (new PointD ( + ControlPoints[pointCount].Tension * + (ControlPoints[0].Position.X - ControlPoints[pointCount - 1].Position.X), + ControlPoints[pointCount].Tension * + (ControlPoints[0].Position.Y - ControlPoints[pointCount - 1].Position.Y))); } else { - //Generate tangents for each of the smaller cubic Bezier curves that make up each segment of the resulting curve. - - //The tension calculated for each point is a gradient between the previous - //control point's tension and the following control point's tension. - - //Stores all of the tangent values. - List bezierTangents = new List (); - - int pointCount = ControlPoints.Count - 1; - double pointCountDouble = (double) pointCount; - double tensionForPoint; - - //Calculate the first tangent. - if (Closed) { - bezierTangents.Add (new PointD ( - ControlPoints[0].Tension * (ControlPoints[1].Position.X - ControlPoints[pointCount].Position.X), - ControlPoints[0].Tension * (ControlPoints[1].Position.Y - ControlPoints[pointCount].Position.Y))); - } else { - bezierTangents.Add (new PointD ( - ControlPoints[0].Tension * (ControlPoints[1].Position.X - ControlPoints[0].Position.X), - ControlPoints[0].Tension * (ControlPoints[1].Position.Y - ControlPoints[0].Position.Y))); - } - - //Calculate all of the middle tangents. - for (int i = 1; i < pointCount; ++i) { - tensionForPoint = ControlPoints[i].Tension * (double) i / pointCountDouble; - - bezierTangents.Add (new PointD ( - tensionForPoint * - (ControlPoints[i + 1].Position.X - ControlPoints[i - 1].Position.X), - tensionForPoint * - (ControlPoints[i + 1].Position.Y - ControlPoints[i - 1].Position.Y))); - } - - //Calculate the last tangent. - if (Closed) { - bezierTangents.Add (new PointD ( - ControlPoints[pointCount].Tension * - (ControlPoints[0].Position.X - ControlPoints[pointCount - 1].Position.X), - ControlPoints[pointCount].Tension * - (ControlPoints[0].Position.Y - ControlPoints[pointCount - 1].Position.Y))); - } else { - bezierTangents.Add (new PointD ( - ControlPoints[pointCount].Tension * - (ControlPoints[pointCount].Position.X - ControlPoints[pointCount - 1].Position.X), - ControlPoints[pointCount].Tension * - (ControlPoints[pointCount].Position.Y - ControlPoints[pointCount - 1].Position.Y))); - } - - - int iMinusOne; - - //Generate the resulting curve's points with consecutive cubic Bezier curves that - //use the given points as end points and the calculated tangents as control points. - for (int i = 1; i < ControlPoints.Count; ++i) { - iMinusOne = i - 1; - - generatedPoints.AddRange (GenerateCubicBezierCurvePoints ( + bezierTangents.Add (new PointD ( + ControlPoints[pointCount].Tension * + (ControlPoints[pointCount].Position.X - ControlPoints[pointCount - 1].Position.X), + ControlPoints[pointCount].Tension * + (ControlPoints[pointCount].Position.Y - ControlPoints[pointCount - 1].Position.Y))); + } + + + int iMinusOne; + + //Generate the resulting curve's points with consecutive cubic Bezier curves that + //use the given points as end points and the calculated tangents as control points. + for (int i = 1; i < ControlPoints.Count; ++i) { + iMinusOne = i - 1; + + generatedPoints.AddRange (GenerateCubicBezierCurvePoints ( + ControlPoints[iMinusOne].Position, + new PointD ( + ControlPoints[iMinusOne].Position.X + bezierTangents[iMinusOne].X, + ControlPoints[iMinusOne].Position.Y + bezierTangents[iMinusOne].Y), + new PointD ( + ControlPoints[i].Position.X - bezierTangents[i].X, + ControlPoints[i].Position.Y - bezierTangents[i].Y), + ControlPoints[i].Position, + i)); + } + + if (Closed) { + // Close the shape. + + iMinusOne = ControlPoints.Count - 1; + + generatedPoints.AddRange (GenerateCubicBezierCurvePoints ( ControlPoints[iMinusOne].Position, new PointD ( ControlPoints[iMinusOne].Position.X + bezierTangents[iMinusOne].X, ControlPoints[iMinusOne].Position.Y + bezierTangents[iMinusOne].Y), new PointD ( - ControlPoints[i].Position.X - bezierTangents[i].X, - ControlPoints[i].Position.Y - bezierTangents[i].Y), - ControlPoints[i].Position, - i)); - } - - if (Closed) { - // Close the shape. - - iMinusOne = ControlPoints.Count - 1; - - generatedPoints.AddRange (GenerateCubicBezierCurvePoints ( - ControlPoints[iMinusOne].Position, - new PointD ( - ControlPoints[iMinusOne].Position.X + bezierTangents[iMinusOne].X, - ControlPoints[iMinusOne].Position.Y + bezierTangents[iMinusOne].Y), - new PointD ( - ControlPoints[0].Position.X - bezierTangents[0].X, - ControlPoints[0].Position.Y - bezierTangents[0].Y), - ControlPoints[0].Position, - 0)); - } + ControlPoints[0].Position.X - bezierTangents[0].X, + ControlPoints[0].Position.Y - bezierTangents[0].Y), + ControlPoints[0].Position, + 0)); } GeneratedPoints = generatedPoints.ToArray (); @@ -175,11 +176,8 @@ public override void GeneratePoints (int brush_width) /// The second end point that the curve passes through. /// The index of the previous ControlPoint to the generated points. /// The List of generated points. - protected static List GenerateCubicBezierCurvePoints (PointD p0, PointD p1, PointD p2, PointD p3, int cPIndex) + private static IEnumerable GenerateCubicBezierCurvePoints (PointD p0, PointD p1, PointD p2, PointD p3, int cPIndex) { - List resultList = new List (); - - //Note: this must be low enough for mouse clicks to be properly considered on/off the curve at any given point. double tInterval = .025d; @@ -220,14 +218,11 @@ protected static List GenerateCubicBezierCurvePoints (PointD p0, //This is done for both the X and Y given a value t going from 0d to 1d at a very small interval //and given 4 points p0, p1, p2, and p3, where p0 and p3 are end points and p1 and p2 are control points. - resultList.Add (new GeneratedPoint (new PointD ( + yield return new GeneratedPoint (new PointD ( oneMinusTCubed * p0.X + oneMinusTSquaredTimesTTimesThree * p1.X + oneMinusTTimesTSquaredTimesThree * p2.X + tCubed * p3.X, oneMinusTCubed * p0.Y + oneMinusTSquaredTimesTTimesThree * p1.Y + oneMinusTTimesTSquaredTimesThree * p2.Y + tCubed * p3.Y), - cPIndex)); + cPIndex); } - - - return resultList; } } }