From 3b6ebc7b9977e0b2f8afa3a1e3bacd03260cc3b1 Mon Sep 17 00:00:00 2001
From: That_One_Nerd <dev@that-one-nerd.net>
Date: Tue, 2 Apr 2024 09:53:42 -0400
Subject: [PATCH] Some quick parametrics. See how fast it is to homebrew this?
 I know I haven't completed a bunch of stuff but I'll get to it soon.

---
 Base/Graphables/ParametricEquation.cs | 63 +++++++++++++++++++++++++++
 Testing/Program.cs                    |  3 +-
 2 files changed, 65 insertions(+), 1 deletion(-)
 create mode 100644 Base/Graphables/ParametricEquation.cs

diff --git a/Base/Graphables/ParametricEquation.cs b/Base/Graphables/ParametricEquation.cs
new file mode 100644
index 0000000..0d92743
--- /dev/null
+++ b/Base/Graphables/ParametricEquation.cs
@@ -0,0 +1,63 @@
+using Graphing.Abstract;
+using Graphing.Forms;
+using Graphing.Parts;
+using System;
+using System.Collections.Generic;
+
+namespace Graphing.Graphables;
+
+public class ParametricEquation : Graphable, ITranslatableXY
+{
+    private static int equationNum;
+
+    public double OffsetX { get; set; }
+    public double OffsetY { get; set; }
+
+    public double InitialT { get; set; }
+    public double FinalT { get; set; }
+
+    protected readonly ParametricDelegate equX, equY;
+
+    public ParametricEquation(double initialT, double finalT,
+                              ParametricDelegate equX, ParametricDelegate equY)
+    {
+        equationNum++;
+        Name = $"Parametric Equation {equationNum}";
+
+        InitialT = initialT;
+        FinalT = finalT;
+
+        this.equX = equX;
+        this.equY = equY;
+    }
+
+    public override Graphable ShallowCopy() => new ParametricEquation(InitialT, FinalT, equX, equY);
+
+    public override IEnumerable<IGraphPart> GetItemsToRender(in GraphForm graph)
+    {
+        const int step = 10;
+
+        double epsilon = Math.Abs(graph.ScreenSpaceToGraphSpace(new Int2(0, 0)).x
+                                - graph.ScreenSpaceToGraphSpace(new Int2(step / 2, 0)).x) / 5;
+        epsilon *= graph.DpiFloat / 192;
+
+        List<IGraphPart> lines = [];
+
+        Float2 previousPoint = GetPointAt(InitialT);
+        for (double t = InitialT; t <= FinalT; t += epsilon)
+        {
+            Float2 currentPoint = GetPointAt(t);
+            lines.Add(new GraphLine(previousPoint, currentPoint));
+            previousPoint = currentPoint;
+        }
+
+        return lines;
+    }
+
+    public Float2 GetPointAt(double t)
+    {
+        return new(equX(t) + OffsetX, equY(t) + OffsetY);
+    }
+}
+
+public delegate double ParametricDelegate(double t);
diff --git a/Testing/Program.cs b/Testing/Program.cs
index 2e256f7..333cacb 100644
--- a/Testing/Program.cs
+++ b/Testing/Program.cs
@@ -19,7 +19,8 @@ internal static class Program
         Equation equA = new(Math.Sin),
                  equB = new(Math.Cos);
         EquationDifference diff = new(2, equA, equB);
-        graph.Graph(equA, equB, diff);
+        ParametricEquation equC = new(0, 4, t => t * t - 1, t => Math.Sqrt(t) + t + 1);
+        graph.Graph(equA, equB, diff, equC);
 
         Application.Run(graph);
     }